On I Line Emission in the Quasar PG 1116+215

By observing the near-infrared spectrum of the quasar PG 1116+215 at z = 0.176 and combining with the HST/FOS spectrum, we obtained the relative strengths of three permitted O I lines (λ1304, λ8446, and λ11287) in a quasar for the first time. The photon flux ratios of the O I lines of the quasar were compared with those previously measured in a Seyfert 1 and six narrow-line Seyfert 1s. No significant differences were found in the O I line flux ratios between the quasar and the other Seyferts, suggesting that the gas density in the O I and Fe II line-emitting regions in the quasar is of the same order as those in low-luminosity AGNs. It was also found that the line width of O I λ11287 is significantly narrower than that of Lyα, which is consistent with O I and Fe II emission occurring in the partly ionized regions at the outermost portion of the broad-line region where velocities are small.


ISO deep far-infrared survey in the ``Lockman Hole''. III. Catalogs and source counts at 90 & 170 μm

We present the catalogs and source counts for the C90 (reference wavelength of 90 μm) and C160 (170 μm) bands, which were extracted from our analysis of an ISO deep far-infrared survey conducted as part of the Japan/UH ISO cosmology project. The total survey area is ?0.9 deg2 in two fields within the Lockman Hole. The analysis consists of source extraction using the IRAF DAOPHOT package and simulations carried out by adding artificial sources to the maps to estimate the detection rate, the flux bias, the positional accuracy, and the noise. The flux calibration was performed using the Sb galaxy UGC 06009 - the photometric error was estimated to be ?50% at C90 and ?65% at C160. The total noise estimated from the simulation is dominated by the confusion noise due to the high source density. The confusion noise is ?20 mJy at C90 and ?35 mJy at C160, which is much larger than the instrumental noise which is at the level of a few mJy or less. The catalogs were constructed by selecting 223 C90 sources and 72 C160 sources with a Signal to Noise Ratio (SNR) of three or greater. The distribution of the observed associations between C90 and C160 sources indicates that the 1 ς positional errors are ?20 arcsec and ?35 arcsec at C90 and C160, respectively. The corrections for the detection rate and the flux bias are significant for sources fainter than 200 mJy at C90 and 250 mJy at C160. Most of the sources detected both at C90 and C160 have a F(C160)/F(C90) color redder than the Sb galaxy UGC 06009. Such a red color could result from reddening due to the flux bias or a K-correction brightening due to the effect of redshift. Red sources brighter than 200 mJy at C160 may be very luminous galaxies like Arp 220 at moderate redshift. The source counts are derived by applying the corrections for the detection rate and flux bias. The resultant counts are quite consistent with the constraints derived from the fluctuation analysis performed in Paper II. The C160 counts are also consistent with the results from the FIRBACK project. Our C90 survey, which is 2-3 times deeper than those previously published, reveals an upturn in the count slope at around 200 mJy. While recent models give a reasonable fit to the C160 counts, none of them are successful in accounting for the upturn in the C90 counts. If the upturn is caused by ultraluminous IR galaxies, their redshifts would need to be at z ? 0.5, implying a major event in galaxy evolution at moderate redshift. Based on observations with ISO, an ESA project with instruments funded by ESA member states (especially the PI countries: France, Germany, The Netherlands, and the UK) and with the participation of ISAS and NASA.


Radio and FIR Sources in the Lockman Hole ISOPHOT Survey Field

To investigate the nature and the evolution of optically faint, luminous infrared starburst galaxies, a deep survey of two 44'×44' fields in the Lockman Hole region was conducted using ISOPHOT camera on ISO at 95 and 175 mu m (Kawara et al. 1998). We present the preliminary results from our multi-wavelength investigations of the identified sources in the Lockman Hole ROSAT/XMM deep field (de Ruiter et al. 1997, Hasinger et al. 2001). One or more radio sources are found at the source position in more than 80% of cases, and spectroscopic redshifts of about 50% of the sources have been obtained so far.

Revista Mexicana de Astronomia y Astrofisica Conference Series


SDSSp J104433.04?012502.2 at z=5.74 is Gravitationally Magnified by an Intervening Galaxy

During the course of our optical deep survey program on Lα emitters at z ? 5.7 in the sky area surrounding the quasar SDSSp J104433.04 012502.2 at z = 5.74, we found that a faint galaxy with mB(AB) ? 25 is located at 1."9 southwest of the quasar. Its broad-band color properties from B to z' suggest that the galaxy is located at a redshift of z ? 1.5 2.5. This is consistent with no strong emission line in our optical spectroscopy. Since the counter-image of the quasar cannot be seen in our deep optical images, the magnification factor seems not to be very high. Our modest estimate is that this quasar is gravitationally magnified by a factor of 2.

Publications of the Astronomical Society of Japan


A New High-Redshift Lyα Emitter: Possible Superwind Galaxy at z=5.69

During the course of our deep optical imaging survey for Lyα emitters at z~5.7 in the field around the z=5.74 quasar SDSSp J104433.04-012502.2, we found a candidate strong emission line source. Follow-up optical spectroscopy shows that the emission-line profile of this object is asymmetric, showing excess red wing emission. These properties are consistent with an identification of Lyα emission at a redshift of z=5.687+/-0.002. The observed broad line width (?vFWHM~=340 km s-1) and excess red wing emission also suggest that this object hosts a galactic superwind. Based on data collected at the Subaru Telescope, which is operated by the National Astronomical Observatory of Japan, and at the W. M. Keck Observatory.


ISO continuum observations of quasars at z=1-4. I. Spectral energy distributions of quasars from the UV to far-infrared

Eight luminous quasars with -30 < MB < -27 at z = 1.4-3.7 have been observed in the mid- and far-infrared using ISO. All the quasars have been detected in the mid-infrared bands of ISOCAM, while no far-infrared detections have been made with ISOPHOT. SEDs (Spectral Energy Distributions) from the UV to far-infrared have been obtained while supplementing ISO observations with photometry in the optical and near-infrared made from the ground within 17 months. The SEDs are compared with the MED (Mean spectral Energy Distributions) of low-redshift quasars with -27 < MB < -22. It is shown that our far-infrared observations were limited by confusion noise due to crowded sources. The observations reported here were made with ISO, an ESA project with instruments funded by ESA member states (especially the PI countries: France, Germany, The Netherlands, and the UK) and with the participation of ISAS and NASA, and with the facilities at the Cerro Tololo Inter-american Observatory (CTIO), NOAO, which is operated by AURA, Inc., under contract with NSF, at the Kiso Observatory, which is operated by Institute of Astronomy, the University of Tokyo, and at the Okayama Astrophysical Observatory, the National Astronomical Observatory of Japan.


Identification of ISOPHOT Deep Field Sources


ISO Continuum Observations of Quasars at z=1-4

Eight luminous quasars with -30 < MB < -27 at z = 1.4 - 3.7 have been observed in the mid- and far-infrared with ISO. To obtain SEDs (Spectral observed in the mid- and far-infrared with ISO. To obtain spectral energy distributions (SEDs) from the UV to far-infrared, additional optical and near-infrared observations were made from the ground. The observed SEDs are compared with the mean-SED of low-redshift quasars with less luminosity (-27 < MB < -22) given by Elvis et al. (1994). There is no evidence of excess in the mid- and far- infrared in our quasar sample.

Institute of Space and Astronautical Science Report


GREX-PLUS: Galaxy Reionization EXplorer and PLanetary Universe Spectrometer


SPICA Mid-infrared Instrument Calibration plan

宇宙航空研究開発機構研究開発報告

宇宙航空研究開発機構研究開発報告


SPICA Mid-infrared Instrument (SMI): The latest design and specifications

SMI (SPICA Mid-infrared Instrument) is one of the three focal-plane science instruments for SPICA. SMI is the Japanese-led instrument proposed and managed by a university consortium. SMI covers the wavelength range from 10 to 36 μm with four separate channels: the low-resolution (R = 60 - 160) spectroscopy function for 17 - 36 μm, the broad-band (R = 5) imaging function at 34 μm, the mid-resolution (R = 1400 - 2600) spectroscopy function for 18 - 36 μm, and the high-resolution (R = 29000) spectroscopy function for 10 - 18 μm. In this presentation, we will show the latest design and specifications of SMI as a result of feasibility studies.


Transmittance measurement of low/high-resistivity of CdZnTe at cryogenic temperature for material selection of the immersion grating of SPICA SMI

We measured the transmittance of low-resistivity (∼ 10^2 Ωcm) and high-resistivity (> 10^10 Ωcm) CdZnTe, which are candidates for Immersion grating (IG) in 10-18μm wavelength, at cryogenic temperature. IG is a compact diffraction grating and we are developing a cryogenically operated 10--18μm IG for SMI/HR (SPICA Mid-Infrared Instrument / High-Resolution spectrometer) of SPICA (SPace Infrared telescope for Cosmology and Astrophysics) We performed two experiments: transmittance measurement with a convergent light Fourier transform spectrometer, and with a collimated lamp beam system. Our result shows that the low-resistivity CdZnTe has large absorption (> 0.5 cm^{-1} ) and the high-resistivity CdZnTe has low absorption (< 0.1 cm^{-1} ) at 8.5K at 10--18 μm. The high-resistivity CdZnTe is promising as an IG material although higher precision measurement is needed to determine whether it meets the absorption coefficient requirement (< 0.01 cm^{-1}) at cryogenic temperature.


PAHs and star formation in ELAIS N1 as seen by AKARI

We have examined the relationship between star formation and polycyclic aromatic hydrocarbons (PAHs) by fitting the spectral energy distributions (SED) of AKARI selected galaxies. PAHs are excited by the ultraviolet (UV) photons of young stars and can trace star formation in galaxies, but they are disassociated by the strong UV radiation in starbursts. AKARI covered the mid-infrared, where the PAHs emit their radiation, with a high density of photometric bands. These observations allow us to estimate the star formation rate and the PAH mass fraction of the dust in galaxies. In the future the James Webb Space Telescope (JWST) will also make measurements in this wavelength range. This research can therefore be considered as a pathfinder to similar studies that will come later from JWST observations.

Uncovering Early Galaxy Evolution in the ALMA and JWST Era


SPICA mid-infrared instrument (SMI): conceptual design and feasibility studies

SMI (SPICA Mid-infrared Instrument) is one of the two focal-plane science instruments for SPICA. SMI is the Japanese led instrument proposed and managed by a nation-wide university consortium in Japan and planned to be developed in collaboration with Taiwan and the US. SMI covers the wavelength range from 12 to 36 μm with 4 separate channels: the low-resolution (R = 50-120) spectroscopy function for 17-36 μm, the broad-band (R = 5) imaging function at 34 μm, the mid-resolution (R = 1300-2300) spectroscopy function for 18-36 μm, and the high-resolution (R = 28000) spectroscopy function for 12-18 μm. In this paper, we show the results of our conceptual design and feasibility studies of SMI.

Space Telescopes and Instrumentation 2018: Optical, Infrared, and Millimeter Wave


Processing of hydrocarbon dust in star-forming galaxies revealed with AKARI

Hydrocarbon dust is one of the dominant components of interstellar dust, which mainly consists of polycyclic aromatic hydrocarbons and aliphatic hydrocarbons. While hydrocarbon dust is thought to be processed in interstellar radiation fields or shocks, detailed processing mechanisms are not completely understood yet. Therefore, we study the infrared spectral properties of hydrocarbon dust for 138 pure star-forming galaxies at redshift z less than 0.3. Using near-infrared spectra (2.5-5 micrometers) obtained with AKARI/IRC, we derived the luminosities of the aromatic hydrocarbon feature at 3.3 micrometers(L(sub aromatic)) and the aliphatic hydrocarbon feature at 3.4-3.6 micrometers (L(sub aliphatic)). We also derived the total infrared luminosity (L(sub IR)), the total PAH luminosity (L(sub PAH)) and the radiation field strength by modeling the spectral energy distributions of the sample galaxies with AKARI, IRAS, and WISE photometry data. We find that L(sub aliphatic)/L(sub IR) decreases with L(sub IR), like L(sub PAH)/L(sub IR) shown in previous studies. Moreover, we find that L(sub aliphatic)/L(sub aromatic) decreases with L(sub IR), indicating that aliphatic hydrocarbons are more highly processed than aromatic hydrocarbons. In this paper, we discuss possible processing mechanisms of interstellar hydrocarbon dust in galaxies with higher L(sub IR).

The Cosmic Wheel and the Legacy of the AKARI Archive: From Galaxies and Stars to Planets and Life


AKARI MIR slitless spectroscopic survey of galaxies at z less than 0.5

We aim to study star-forming galaxies by using a blind spectroscopic survey at mid-infrared (MIR) wavelengths to understand evolution of their star formation rate (SFR) and specific SFR (SFR per stellar mass) up to z in the order of 0.5, by paying particular attention to their Polycyclic Aromatic Hydrocarbon (PAH) properties. We conducted a low- resolution (R approximately equal to 50) slitless spectroscopic survey at 5-13 micrometers of 9 micrometers flux-selected sources (approximately greater than 0.3 mJy) around the North Ecliptic Pole with the Infrared Camera (IRC) onboard AKARI. We identified 48 PAH galaxies with PAH 6.2, 7.7, and 8.6 micrometers features at z approximately less than 0.5. The rest-frame optical-MIR spectral energy distributions (SEDs) based on CFHT and AKARI/IRC imaging are produced and analyzed in conjunction with the PAH spectroscopy. The rest-frame SEDs of all PAH galaxies have a universal shape with stellar and 7.7 micrometers (PAH) bumps, except that the PAH enhancement (luminosity ratio of the 7.7 micrometers PAH feature over the 3.5 micrometers stellar bump) significantly varies as a function of the PAH luminosities. We identified a PAH-enhanced population at z approximately less than 0.35, whose SEDs and luminosities are typical of luminous infrared galaxies. They show particularly larger PAH enhancement at high luminosity, implying that they are vigorous star-forming galaxies with elevated specific SFR. Our composite starburst model that combines a young and dusty starburst with a very old population can successfully reproduce most SED characteristics.


Free-form reflective optics for mid-infrared camera and spectrometer on board SPICA

SPICA (Space Infrared Telescope for Cosmology and Astrophysics) is an astronomical mission optimized for mid-and far-infrared astronomy with a cryogenically cooled 3-m class telescope, envisioned for launch in early 2020s. Mid-infrared Camera and Spectrometer (MCS) is a focal plane instrument for SPICA with imaging and spectroscopic observing capabilities in the mid-infrared wavelength range of 5-38μm. MCS consists of two relay optical modules and following four scientific optical modules of WFC (Wide Field Camera; 5'x 5' field of view, f/11.7 and f/4.2 cameras), LRS (Low Resolution Spectrometer; 2'.5 long slits, prism dispersers, f/5.0 and f/1.7 cameras, spectral resolving power R ? 50-100), MRS (Mid Resolution Spectrometer; echelles, integral field units by image slicer, f/3.3 and f/1.9 cameras, R ? 1100-3000) and HRS (High Resolution Spectrometer; immersed echelles, f/6.0 and f/3.6 cameras, R ? 20000-30000). Here, we present optical design and expected optical performance of MCS. Most parts of MCS optics adopt off-axis reflective system for covering the wide wavelength range of 5-38μm without chromatic aberration and minimizing problems due to changes in shapes and refractive indices of materials from room temperature to cryogenic temperature. In order to achieve the high specification requirements of wide field of view, small F-number and large spectral resolving power with compact size, we employed the paraxial and aberration analysis of off-axial optical systems (Araki 2005 [1]) which is a design method using free-form surfaces for compact reflective optics such as head mount displays. As a result, we have successfully designed compact reflective optics for MCS with as-built performance of diffraction-limited image resolution.

Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series


MAXI and AKARI investigation of nearby active galactic nuclei

7 years of MAXI: monitoring X-ray Transients


Sensitivity estimates for the SPICA Mid-Infrared Instrument (SMI)

We present the latest results of the sensitivity estimate for spectrometers of the SPICA Mid-Infrared Instrument (SMI). SMI has three spectroscopic channels; low resolution spectrometer (LRS), medium resolution spectrometer (MRS) and high resolution spectrometer (HRS). Taking account of the results of optical design of each spectrometer and the latest information of the expected performance of detector arrays, the continuum sensitivity for a point source, the continuum sensitivity for an extended source, the line sensitivity for a point source, the line sensitivity for an extended source, and the saturation limit are calculated for LRS, MRS and HRS and are provided in this paper.

Space Telescopes and Instrumentation 2016: Optical, Infrared, and Millimeter Wave


A strong clustering of FIR-selected galaxies in the AKARI All-Sky Survey

Various previous galaxy surveys have revealed that different types of galaxies show different spatial distributions. By comparing their clustering strengths, we can investigate the relationship between the environments where galaxies reside and the properties of galaxies. This provides us vital information on when, where, and how galaxies are formed. In this study, we focus on FIR-selected galaxies from AKARI All- Sky Survey, which are considered to be dusty star-forming galaxies. We measure their power spectrum and compare our final result with previous studies using different galaxy samples detected at other wavelengths. It is found that there is the very clear wavelength dependence of the clustering strength.

Proceedings of the International Astronomical Union

No.S309 (Galaxies in 3D across the Universe)


Unveiling Energy Contribution of Buried AGN in Infrared Galaxies

Suzaku-MAXI 2014: Expanding the Frontiers of the X-ray Universe


A cryogenic dichroic mirror for separating visible light from wideband infrared

We present the design, fabrication and test results for a dichroic mirror, which was primarily developed for the SPICA Coronagraph Instrument (SCI), but is potentially useful for various types of astronomical instrument. The dichroic mirror is designed to reflect near- and mid-infrared but to transmit visible light. Two designs, one with 3 layers and one with 5 layers on BK7 glass substrates, are presented. The 3-layer design, consisting of Ag and ZnS, is simpler, and the 5-layer design, consisting of Ag and TiO2 is expected to have better performance. Tape tests, evaluation of the surface figure, and measurements of the reflectivity and transmittance were carried out at ambient temperature in air. The reflectivity obtained from measurements made on mirrors with 5 layers were < 80 % for wavelengths, λ, from 1.2 to 22 μm and < 90 % for λ from 1.8 to 20 μm. The transmittance obtained from measurements made on mirrors with 5 layers were < 70 % for λ between 0.4 and 0.8 μm. Optical ghosting is estimated to be smaller than 10-4 at λ < 1.5 μm. A protective coating for preventing corrosion was applied and its influence on the reflectivity and transmittance evaluated. A study examining the trade-offs imposed by various configurations for obtaining a telescope pointing correction signal was also undertaken.

Space Telescopes and Instrumentation 2014: Optical, Infrared, and Millimeter Wave


A 2.5-5 μm spectroscopic study of hard X-ray selected AGNs with AKARI

We explore the relationships between the 3.3 μm polycyclic aromatic hydrocarbon (PAH) feature and active galactic nucleus (AGN) properties of a sample of 54 hard X-ray selected bright AGNs, including both Seyfert 1 and Seyfert 2 type objects, using the InfraRed Camera (IRC) on board the infrared astronomical satellite AKARI. The sample is selected from the 9-month Swift/BAT survey in the 14-195 keV band and all of them have measured X-ray spectra at E <~ 10 keV. These X-ray spectra provide measurements of the neutral hydrogen column density (N H) towards the AGNs. We use the 3.3 μm PAH luminosity (L 3.3μm) as a proxy for star formation activity and hard X-ray luminosity (L 14-195keV) as an indicator of the AGN activity. We searched for possible difference of star-formation activity between type 1 (un-absorbed) and type 2 (absorbed) AGNs. Our regression analysis of log L 14-195keV versus log L 3.3μm shows a positive correlation and the slope seems steeper for type 1/unobscured AGNs than that of type 2/obscured AGNs. The same trend has been found for the log (L 14-195keV/M BH) versus log (L 3.3μm/MBH) correlation. Our analysis show that the circum-nuclear star-formation is more enhanced in type 2/absorbed AGNs than type 1/un-absorbed AGNs for low X-ray luminosity/low Eddington ratio AGNs.


An inverse-polished mirror for wavefront correction of space-based telescopes

In this report we describe our development of a prototype inverse- polished mirror for the passive correction of the static and predictable wavefront errors (WFE) of space-based telescopes, in particular, especially for infrared coronagraphs. An artificial WFE pattern with a root mean square (rms) value of 350 nm was numerically generated to facilitate the design of the prototype mirror. The surface of the mirror is approximately flat, is 50.0 mm in diameter and 15.0 mm thick at the edge. The designed WFE pattern was constructed on the mirror surface by micro-polishing. Both the figure and roughness of the mirror surface were evaluated. The rms value of the measured surface figure was reduced to 135 nm after subtraction of the designed surface figure. The benefit of subtraction to mid-infrared coronagraph performance was simulated, which showed the contrast was improved by a factor of ~100 close to the core (closer than 10 λ/D where λ and D are the wavelength and telescope aperture diameter, respectively) of the coronagraphic image of a point source. An analysis of the power spectrum density shows that the lower frequencies in the WFE are well reproduced on the mirror, while the higher frequencies remain due to the limitations imposed on the controllable spatial resolution by the fabrication process. In this study, inverse-polished mirrors combined with deformable mirrors and their application to ground-based telescopes are also discussed. To fully explore the potential of the inverse-polished mirror, a systematic allocation of the error budget is essential taking into account not only the fabrication accuracy of the mirror but also an evaluation of the telescope and other factors with non-predictable uncertainties.

Advances in Optical and Mechanical Technologies for Telescopes and Instrumentation


Luminosity and redshift dependence of covering factor of dust torus viewed with AKARI and WISE

We present the relation between (i) the covering factor (CF) of AGN and mid-infrared (MIR) luminosity and (ii) CF and redshift (0 < z < 0.3) from the 12 and 22 μm luminosity functions (LFs) we made from the Wide-field Infrared Survey Explorer (WISE). Combining the WISE catalog with the Sloan Digital Sky Survey (SDSS) spectroscopic catalog, we selected ?300,000 galaxies at 12 μm and ?30,000 galaxies at 22 μm. We then extracted ?10,000 AGNs at 12 μm and ?5,000 AGNs at 22 μm from them according to the optical emission lines and catalog classification in the SDSS. We found that (i) CF clearly decreases with MIR luminosity, which supports the implications from 18 μm LFs obtained by the Japanese infrared satellite, AKARI, and (ii) CF also seems to decrease with redshift. The latter correlation may result from the close correlation between redshift and luminosity in our magnitude-limited sample, rather than any true cosmic evolution.


Mid-infrared and hard X-ray luminosity correlation of a complete sample of local AGNs

We present the mid-infrared (MIR) properties of a complete sample of local active galactic nuclei (AGNs) detected in the Swift/BAT all-sky hard X-ray (14-195 keV) survey, based on the cross matches with the AKARI, IRAS, and WISE infrared all-sky survey catalogs. Out of 135 non- blazar AGNs in the Swift/BAT 9-month catalog, we unambiguously identify the MIR photometric data of 128 sources. We find a good luminosity correlation between the hard X-ray and MIR band over three orders of magnitude (42 ? log LHX ? 45). This suggests that MIR emission is suitable for estimating the AGN intrinsic power. Both X- ray unabsorbed and absorbed AGNs follow the same correlation, implying isotropic infrared emission, as expected in clumpy dust tori rather than homogeneous ones. We also find 9 μm excess sign in the averaged infrared spectral energy distribution of a population of deeply buried ("new type") AGNs. This excess signal could originate from polycyclic aromatic hydrocarbon emission feature, suggesting that their host galaxies have strong starburst activities.


New constraints on the cosmic optical background

We present the new constraints on the cosmic optical background (COB) obtained from an analysis of the Pioneer 10/11 Imaging Photopolarimeter (IPP) data. After careful examination of the data quality, the usable measurements free from the zodiacal light are integrated into sky maps at the blue (~0.44 μm) and red (~0.64 μm) bands. Accurate starlight subtraction is achieved by referring to all-sky star catalogs and a Galactic stellar population model down to 32.0 mag. We find that the residual light is separated into two components: one component shows a clear correlation with thermal 100 μm brightness, while another betrays a constant level in the lowest 100 μm brightness region. Presence of the second component is significant after all the uncertainties and possible residual light in the Galaxy are taken into account, thus it most likely has the extragalactic origin (i.e., the COB). The derived COB brightness is 7.9 +/- 4.0 and 7.7 +/- 5.8 nW m-2 sr-1 at the blue and red band, respectively. Based on the comparison with the integrated brightness of galaxies, we conclude that the bulk of the COB is comprised of normal galaxies which have already been resolved by the current deepest observations.


SPICA coronagraph instrument: characterization of atmospheres and physical parameters of giant planets by direct imaging and spectroscopy

We present the current status of the development of the SPICA Coronagraph Instrument (SCI). SPICA is a next-generation 3-meter class infrared telescope, which will be launched in 2022. SCI is high-contrast imaging, spectroscopic instrument mainly for direct detection and spectroscopy of extra-solar planets in the near-to-mid infrared wavelengths to characterize their atmospheres, physical parameters and evolutionary scenarios. SCI is now under the international review process. In this paper, we present a science case of SCI. The main targets of SCI, not only for direct imaging but also for spectroscopy, are young to matured giant planets. We will also show that some of known exoplanets by ground-based direct detection are good targets for SCI, and a number of direct detection planets that are suitable for SCI will be significantly increased in the next decade. Second, a general design of SCI and a key technology including a new high-throughput binary mask coronagraph, will be presented. Furthermore, we will show that SCI is potentially capable of achieving 10-6 contrast by a PSF subtraction method, even with a telescope pointing error. This contrast enhancement will be important to characterize low-mass and cool planets.

Space Telescopes and Instrumentation 2012: Optical, Infrared, and Millimeter Wave


Mid-infrared camera and spectrometer on board SPICA

SPICA (Space Infrared Telescope for Cosmology and Astrophysics) is an astronomical mission optimized for mid- and far-infrared astronomy, envisioned for launch in early 2020s. The core wavelength coverage of this mission is 5 to 200 micron. Mid-infrared Camera and Spectrometer (MCS) will provide imaging and spectroscopic observing capabilities in the mid-infrared region with 4 modules. WFC (Wide Field Camera) has two 5 arcminutes square field of view and covers the wavelength range from 5 to 38 micron. MRS (Mid Resolution Spectrometer) has integral field units by image slicer and covers the wavelength range from 12.2 to 37.5 micron simultaneously using dichroic filter and two sets of spectrometers. HRS (High Resolution Spectrometer) covers the wavelength range from 12 to 18 micron with resolving power 20000 to 30000, and it has optional short wavelength channel which covers from 4 to 8 micron with resolving power 30000. LRS (Low Resolution Spectrometer) adopts prism disperser and covers the wavelength range from 5 to 38 micron with resolving power 50 to 100. Here, we present detailed specifications of MCS, optical design, and estimated performance on orbit.


Summary of observations of the infrared camera (IRC) onboard AKARI

AKARI, the Japanese satellite mission dedicated to infrared astronomy was launched in 2006 February and exhausted its liquid helium in 2007 August. During the cold mission phase, the Infrared Camera (IRC) onboard carried out an all-sky survey at 9 and 18?m with better spatial resolution and higher sensitivity than IRAS. Both bands also have slightly shorter wavelength coverage than IRAS 12 and 25&#956m bands and thus provide different information on the infrared sky. All-sky image data of the IRC are now in the final processing and will be released to the public within a year. After the exhaustion of the cryogen, the telescope and focal plane instruments of AKARI had still been kept at sufficiently low temperatures owing to the onboard cryocooler. Near-infrared (NIR) imaging and spectroscopic observations with the IRC had continued until 2011 May, when the spacecraft had a serious problem in the power supply system that forced us to terminate the observation. The IRC carried out nearly 20000 pointing observations in total despite of its near-earth orbit. About a half of them were performed after the exhaustion of the cryogen in the spectroscopic modes, which provided high-sensitivity NIR spectra from 2 to 5?m without disturbance of the terrestrial atmosphere. During the warm mission phase, the temperature of the instrument gradually increased and changed the array operation conditions. We present a summary of AKARI/IRC observations, including the all-sky mid-infrared diffuse data as well as the data taken in the warm mission phase.


WISH, Wide-field Imaging Surveyor for High-redshiftt, is a space mission concept to conduct very deep and widefield surveys at near infrared wavelength at 1-5μm to study the properties of galaxies at very high redshift beyond the epoch of cosmic reionization. The concept has been developed and studied since 2008 to be proposed for future JAXA/ISAS mission. WISH has a 1.5m-diameter primary mirror and a wide-field imager covering 850 arcmin2. The pixel scale is 0.155 arcsec for 18μm pitch, which properly samples the diffraction-limited image at 1.5μm. The main program is Ultra Deep Survey (UDS) covering 100 deg2 down to 28AB mag at least in five broad bands. We expect to detect <104 galaxies at z=8-9, 103-104 galaxies at z=11-12, and 50-100 galaxies at z<14, many of which can be feasible targets for deep spectroscopy with Extremely Large Telescopes. With recurrent deep observations, detection and light curve monitoring for type-Ia SNe in rest-frame infrared wavelength is also conducted, which is another main science goal of the mission. During the in-orbit 5 years observations, we expect to detect and monitor <2000 type-Ia SNe up to z~2. WISH also conducts Ultra Wide Survey, covering 1000deg2 down to 24-25AB mag as well as Extreme Survey, covering a limited number of fields of view down to 29-30AB mag. We here report the progress of the WISH project including the basic telescope and satellite design as well as the results of the test for a proto- model of the flip-type filter exchanger which works robustly near 100K.


The Mid-Infrared luminosity function of galaxies using the AKARI mid-infrared All-Sky Survey Catalogue

We present the first determination of the 18 μm luminosity function (LF) of galaxies at 0.006 < z < 0.7 (the average redshift is ~ 0.04) using the AKARI mid-infrared All-Sky Survey catalogue. We have selected a 18 μm flux-limited sample of 243 galaxies from the catalogue in the SDSS spectroscopic region. We then classified the sample into four types; Seyfert 1 galaxies (including QSOs), Seyfert 2 galaxies, LINERs and Star-Forming galaxies using mainly [OIII]/Hβ vs. [NII]/Hα line ratios obtained from the SDSS. As a result of constructing Seyfert 1 and Seyfert 2 LFs, we found the following results; (i) the number density ratio of Seyfert 2s to Seyfert 1s is 3.98 +/- 0.41 obtained from Sy1 and Sy2 LFs; this value is larger than the results obtained from optical LFs. (ii) the fraction of Sy2s in the entire AGNs may be anti- correlated with 18 μm luminosity. These results suggest that the torus structure probably depends on the mid-infrared luminosity of AGNs and most of the AGNs in the local Universe are obscured by dust.

The Spectral Energy Distribution of Galaxies - SED 2011


Far Infrared Luminosity Function of Local Galaxies in the AKARI Deep Field South

We present the first far-infrared luminosity function in the AKARI Deep Field South, a premier deep field of the AKARI Space Telescope, using spectroscopic redshifts obtained with AAOmega. To date, we have found spectroscopic redshifts for 389 galaxies in this field and have measured the local (z<0.25) 90 μm luminosity function using about one-third of these redshifts. The results are in reasonable agreement with recent theoretical predictions.


Cosmic Optical Background: the view from Pioneer 10/11

We present the new constraints on the cosmic optical background (COB) obtained from an analysis of the Pioneer 10/11 Imaging Photopolarimeter (IPP) data. After careful examination of data quality, the usable measurements free from the zodiacal light are integrated into sky maps at the blue (~0.44 μm) and red (~0.64 μm) bands. Accurate starlight subtraction is achieved by referring to all-sky star catalogs and a Galactic stellar population synthesis model down to 32.0 mag. We find that the residual light is separated into two components: one component shows a clear correlation with thermal 100 μm brightness, while another betrays a constant level in the lowest 100 μm brightness region. Presence of the second component is significant after all the uncertainties and possible residual light in the Galaxy are taken into account, thus it most likely has the extragalactic origin (i.e., the COB). The derived COB brightness is (1.8 +/- 0.9) × 10-9 and (1.2 +/- 0.9) × 10-9 erg s-1 cm-2 sr-1 ?-1 at the blue and red band, respectively, or 7.9 +/- 4.0 and 7.7 +/- 5.8 nW m-2 sr-1. Based on a comparison with the integrated brightness of galaxies, we conclude that the bulk of the COB is comprised of normal galaxies which have already been resolved by the current deepest observations. There seems to be little room for contributions of other populations including ``first stars'' at these wavelengths. On the other hand, the first component of the IPP residual light represents the diffuse Galactic light (DGL)--scattered starlight by the interstellar dust. We derive the mean DGL-to-100 μm brightness ratios of 2.1 × 10-3 and 4.6 × 10-3 at the two bands, which are roughly consistent with the previous observations toward denser dust regions. Extended red emission in the diffuse interstellar medium is also confirmed.


Luminosity dependent covering factor of the dust torus around AGN viewed with AKARI and WISE


A 2.5-5 micron Spectroscopic Study of Hard X-ray Selected AGNs using AKARI InfraRed Camera

Proceedings of Nuclei of Seyfert galaxies and QSOs - Central engine & conditions of star formation (Seyfert 2012). 6-8 November


Search for Active Galactic Nuclei using AKARI Mid-infrared All-Sky Survey

Many observations have found evidence of the presence of a large number of heavily obscured active galactic nuclei (AGNs). These AGNs contribute to the local black hole mass density, and are potentially important contributors to the growth of supermassive black holes throughout the history of the universe. However, the nature of this population, even in the local universe, is only poorly understood, because of the strong selection bias against finding them at optical wavelengths. Mid-infrared AGN searches can overcome this obstacle by penetrating through dust extinction to identify most of the AGN population, including Type 2 Seyferts and buried AGNs. Using AKARI Mid-infrared All-Sky Survey and the follow-up observations, we are performing AGN search as well as the study of AGN natures. We will present our discovery of two obscured AGNs that do not show any AGN features in other bands. In addition, we will present new mid-infrared luminosity functions of AGNs.

The Starburst-AGN Connection under the Multiwavelength Limelight


Development of AKARI Reduction Tools for IRC Slow-Scan

We are developing the AKARI reduction tools for the IRC slow-scan. To create an image, we need position information provided from the satellite telemetry. However, the typical accuracy of the position is as large as ?10". Here, we developed a software called self-pointing reconstruction, which is the most important part of the tools. Using this method, the position accuracy reaches as good as ?1".

Astronomical Data Analysis Software and Systems XIX


AKARI, the Japanese infrared satellite launched at February 2006, have a primary mirror of 70cm diameter cooled with the combination of liquid helium and mechanical coolers. It had unique capabilities of near- infrared spectroscopy in the wavelength between 2um and 5um, all-sky survey in the mid- and far-infrared as well as broadband filters consecutively covering the near-, mid- and far-infrared wavelengths. Using the point source catalog in the AKARI Mid-infrared All-Sky Survey, we are searching for Active Galactic Nuclei (AGNs), not only normal AGNs but also dusty AGNs, in the local Universe. AKARI provides remarkable improvement in sensitivity and spatial resolution upon the previous all- sky survey with IRAS. We are performing the follow-up observations of mid-infrared sources showing red-color in the near- and mid-infrared bands with the AKARI near-infrared spectroscopy and the ground-based optical spectroscopy. During the follow-up observations, we have started to detect hidden AGNs located in galaxies that were previously unrecognized to contain an AGN at other wavelengths.

The First Year of MAXI: Monitoring Variable X-ray Sources


The optical spectrum classifications of mid-infrared excess sources found by the AKARI All-SKy Survey

We present optical spectrum classifications of mid-infrared excess sources found by the AKARI All-Sky Survey. AKARI is the first infrared astronomical satellite in Japan launched in 2006. AKARI's main purpose is mid-infrared (9 and 18 micron) All-Sky survey as well as far-infrared (65, 90, 140 and 160 micron) All-Sky Survey. The spatial resolutions and sensitivities are one-order better than those of Infrared Astronomical Satellite IRAS which performed previous All-Sky Survey. As a result, AKARI can detect much fainter objects in much higher pointing accuracy. We are searching for Active Galactic Nuclei (AGNs) using AKARI mid- infrared All-Sky Survey catalog. One of the advantages of the mid- infrared searches is that we can directly detect infrared radiation from the dust torus which surrounds the central engine. About 2000 AGN candidates are selected by comparing their 9um fluxes with Ks-band photometry of Two Micron All-Sky Survey. Then, we obtained 130 spectra from our optical spectroscopic observations at Kitt Peak National Observatory and Lick Observatory and the archived data in the Sloan Digital Sky Survey (SDSS). We have classified these spectra into several types (type I AGNs, type II AGNs, Star-Forming galaxies etc) by these optical emission line ratios.


AKARI, the Japanese satellite mission dedicated for infrared astronomy launched in 2006 February, exhausted its 180 litter liquid helium (LHe) in 2007 August. After the LHe exhaustion, the telescope and focal plane of AKARI have still been kept less than 50K by the onboard cryocooler and near-infrared (NIR) observations with the Infrared Camera (IRC) are continuing. The data reduction software optimized for the warm mission enables us to carry out efficient and sensitive observations in the NIR despite the increase of hot pixels. In particular, the NIR spectroscopic capability of the IRC provides a unique opportunity to obtain spectra in 2.5-5μm with a high sensitivity, which will not be able to be carried out with any other facilities until JWST. An overview of the AKARI warm mission is given together with the performance and some observational results taken during the warm mission.

Space Telescopes and Instrumentation 2010: Optical, Infrared, and Millimeter Wave


WISH: wide-field imaging surveyor at high redshift

WISH is a new space science mission concept whose primary goal is to study the first galaxies in the early universe. We will launch a 1.5m telescope equipped with 1000 arcmin2 wide-field NIR camera by late 2010's in order to conduct unique ultra-deep and wide-area sky surveys at 1-5 micron. The primary science goal of WISH mission is pushing the high-redshift frontier beyond the epoch of reionization by utilizing its unique imaging capability and the dedicated survey strategy. We expect to detect ~104 galaxies at z=8-9, ~3-6x103 galaxies at z=11-12, and ~50-100 galaxies at z=14-17 within about 5 years of the planned mission life time. It is worth mentioning that a large fraction of these objects may be bright enough for the spectroscopic observations with the extremely large telescopes. By adopting the optimized strategy for the recurrent observations to reach the depth, we also use the surveys to detect transient objects. Type Ia Supernova cosmology is thus another important primary goal of WISH. A unique optical layout has been developed to achieve the diffraction- limited imaging at 1-5micron over the required large area. Cooling the mirror and telescope to ~100K is needed to achieve the zodiacal light limited imaging and WISH will achieve the required temperature by passive cooling in the stable thermal environment at the orbit near Sun- Earth L2. We are conducting the conceptual studies and development for the important components of WISH including the exchange mechanism for the wide-field filters as well as the primary mirror fixation.


The AKARI Extragalactic Large Area Survey Towards the North Ecliptic Pole

Large area surveys in the infrared wavelengths have revealed a significant evolution of the star formation activity of the universe in the past. Extragalactic surveys we have conduced with AKARI towards the north ecliptic pole (NEP) are unique, in terms of a comprehensive wavelength coverage from 2 to 24 μm using all 9 photometric bands of the IRC. This includes new wavelength windows for extragalactic surveys, such as 18 μm. We demonstrate that this IRC all-band photometry is capable of tracing a steep rise in the flux at the blue side of the polycyclic aromatic hydrocarbon (PAH) 6.2 μm emission feature of infrared luminous galaxies at z<1. Starburst-dominated ULIRGs are identified using IRC all-band photometry. The PAH-to-total IR luminosity ratio of these starburst ULIRGs is systematically higher than that of local ULIRGs. The nature of ULIRGs could be different from local ones even at z~1.


The Japanese infrared satellite AKARI has unique capabilities for near- infrared spectroscopy and an all-sky survey in the mid- and far- infrared. We present the recent results on active galactic nuclei that use the unique capabilities of AKARI.

Co-Evolution of Central Black Holes and Galaxies


AKARI Near and Mid-Infrared Spectroscopy of APM 08279+5255 at z=3.91

We present rest-frame optical/near-infrared spectra of the gravitationally lensed quasar APM 08279+5255 at z=3.91 that has been taken using the Infrared Camera (IRC) onboard the AKARI infrared satellite. The observed continuum consists of two components; a power- law component dominating optical wavelengths which is the direct light from the central source and thermal emission dominating near-infrared wavelengths which is attributed to the emission from hot dust in the circumnuclear region. The thermal emission well represents optically thick emission by hot dust at T ? 1300 K with &tau2μm > 2. Thus, our observations directly detected the optically thick region of hot dust in APM 08279+5255. HI recombination lines of Hα(0.656 μm), Paα(1.875 μm), and Paβ(1.282 μm) are clearly detected at 3.2, 6.3, and 9.3 μm. Simulations with the photoionization models suggest that APM 08279+5255 has BLR(Broad Line Region) clouds characterized by log nH ? 12 - 14 for the gas density, log U ? -2 - -6 for the ionization parameter, and E(B-V)? 0.3 - 0.6 for the broad line region. Thus, optically thick emission of hot dust support an idea on non- spherical distribution of dust near the central source, consistent with the Active Galactic Nuclei model with the dust torus.

AKARI, a Light to Illuminate the Misty Universe


Galactic and Extragalactic Sources in the North Ecliptic Pole: Wide Field Survey

The North Ecliptic Pole (NEP) Wide Survey was carried out for about one year starting from May 2006 with 9 passbands from 2.5 to 24 μm and the areal coverage of about 5.8 sq. degrees centered on NEP. We present the initial results of the data analysis of all passbands except for the 24 μm. The survey depth reaches to around 22 magnitude (AB) at the near infrared (NIR) bands, and ? 18.5 magnitude at the mid infrared (MIR) bands such as 15 and 18 μm. We matched our infrared sources with the optical sources detected in CFHT imaging survey of about 2 sq. degree area that lies inside the NEP-Wide survey region in order to characterize the nature of infrared sources. The stars are identified by the stellarity parameter of CFHT's r'-band image data given by SExtractor. The fraction of the stars among the infrared sources are found to dependent sensitively on the brightness as well as the wavelength. For example, the majority of bright sources in 9 and 11 μm are stars while stellar fraction decreases toward fainter sources. The stellar fraction at longer 15 and 18 μm bands remains to be less than 10% regardless of the brightness. Most of the non-stellar objects detected in mid-infrared are found to be star forming disk galaxies, with smaller fraction of early type galaxies and AGNs.


Extremely Red Mid-infrared Selected Objects in the AKARI NEP Deep Field: Dust Obscured Type-1 AGN?

We describe observational characteristics of three Extremely Red MIR- bright Objects (ERMOs, satisfying R - [15] ? 6.5 AB mag) found in the AKARI North Ecliptic Pole (NEP) deep field at z=1.5-2.2, showing broad Mg II emission (?5000 km sec-1) while their broad-band spectral energy distributions (SEDs) at optical and mid-infrared are power-law, similar to that of the type-2 AGN. Since their SEDs cannot be explained solely by any AGN dust torus templates, we propose that the stellar population co-exists with the AGN dust torus. The interstellar dust clouds associated with the stellar population may be responsible for the extinction of the broad-line regions.


On the Removal of Point and Extended Sources from NIR Image Data of the AKARI's NEP Monitor Field

The imaging data resulting from deep sky observations contain the diffuse component coming from the foreground medium and from unresolved faint objects. AKARI has made very deep imaging observations of a `Monitor Field' near the North Ecliptic Pole (NEP) to check the stability of the instruments. We have created diffuse maps from this data by removing the contributions from known point and extended sources, by applying a 2ς clipping method to remove the bright resolved objects. However, we find excess signals around the rims of the clipped regions that are believed to be due to contributions by the outer parts of the point spread function (PSF), which could then be further removed by careful modeling of the PSF. We have further modeled the extended objects using high resolution near infrared images taken by large aperture ground based telescopes. From this technique, we have generated NIR images of extended sources by convolving a high resolution IR image with the NIR PSF of AKARI, and obtained diffuse images which can be used to study the foreground and background emission.


SPICA Deep Cosmological Survey: From AKARI to SPICA

On the basis of the results of the AKARI far-infrared deep surveys, we propose a multi-wavelength far-infrared deep cosmological survey with SAFARI on SPICA. We have carried out a far-infrared deep cosmological survey with AKARI, and successfully obtained the galaxy counts and new limits on the absolute brightness of the cosmic far-infrared background. These results provide strong constraints on evolutionary scenarios, and suggest the necessity for a new model to explain galaxy evolution. Thanks to the excellent sensitivity and spatial resolution of SPICA/SAFARI, we will be able to resolve the cosmic infrared background into individual objects with 3 times or more higher spatial resolution than that of AKARI, and will also be able to conduct infrared photometry and spectroscopy on those objects. The far-infrared deep survey with SPICA/SAFARI will be an ideal opportunity to reveal the origin of the cosmic far-infrared background residual brightness and fluctuations. These observation will allow us to reveal the star formation history in the early Universe without the uncertainty of dust attenuation, which is essential if we are to understand the process of galaxy formation.

The Next-Generation Infrared Space Mission: SPICA


AKARI All-sky Survey observations were carried out in the mid- to far- infrared spectral region with six photometric bands during the cryogenic mission phase of AKARI from May 8, 2006 to August 26, 2007. This paper reports the mid-infrared part of the AKARI all-sky survey. It was carried out with two mid-infrared broad bands centered at 9 and 18 μm. More than 90 percent of entire sky was observed by both bands during this period. The 5ς sensitivities for point sources are about 50 and 120 mJy, respectively. The spatial resolution is better than 10'' at both bands. The AKARI mid-infrared survey achieved a deeper sensitivity and a finer spatial resolution than the previous IRAS survey, the AKARI mid- infrared survey has the sensitivity to detect a debris disk of β Pic at a distance of 100 pc and several new debris disk candidates have already been discovered at 18 μm in a preliminary study, separately discussed by Fujiwara et al. (in this volume). More debris disk candidates are expected to be found in further investigations, which will make a significant impact on the statistical study of debris disks.


The AKARI Cosmological Surveys: Initial Results and New Capabilities

Using AKARI, the first Japanese satellite dedicated to infrared astronomy, we conducted multi-band large-area surveys around the ecliptic poles. The north ecliptic pole (NEP) is the best region for AKARI which has a sun-synchronous orbit that allows it conduct legacy surveys with all AKARI bands, i.e. nine bands in 2 -- 24 μm and 4 bands in 65 -- 160 μm. We prove that this survey, which has such unprecedented infrared wavelength coverage, is certainly unique and useful to search out new galaxy populations such as "PAH-luminous" galaxies.

Panoramic Views of Galaxy Formation and Evolution


We present the North Ecliptic Pole (NEP) Surveys with Infrared Camera (IRC) onboard the AKARI infrared satellite. Two NEP surveys were designed: NEP-Deep was deep and NEP-Wide was wide, but shallow. One of the unique characteristics of IRC is nine broad-band filters which cover the continuous wavelength from 2 to 26 μm and all IRC filters were used for both surveys. We also present the status of multi-wavelength follow- up.


Mid-infrared all-sky survey with AKARI/IRC

AKARI is the first Japanese astronomical infrared satellite mission orbiting around the Earth in a sun-synchronous polar orbit at the altitude of 700 km. One of the major observation programs of the AKARI is an all-sky survey in the mid- to far-infrared spectral regions with 6 photometric bands. The mid-infrared part of the AKARI All-Sky Survey was carried out with the Infrared Camera (IRC) at the 9 and 18 ??m bands with the sensitivity of about 50 and 120 mJy (5ς per scan), respectively. The spatial resolution is about 9.4" at both bands. AKARI mid-infrared (MIR) all-sky survey substantially improves the MIR dataset of the IRAS survey of two decades ago and provides a significant database for studies of various fields of astronomy ranging from star- formation and debris disk systems to cosmology. This paper describes the current status of the data reduction and the characteristics of the AKARI MIR all-sky survey data.

Space Telescopes and Instrumentation 2008: Optical, Infrared, and Millimeter


Data reduction techniques for slit and slit-less spectroscopy of diffuse emission with the Infrared Camera onboard AKARI

Infrared Camera (IRC) onboard AKARI satellite has carried out more than 4000 pointed observations during the phases 1 and 2, a significant amount of which were performed in the spectroscopic mode. In this paper, we investigate the properties of the spectroscopic data taken with MIR-S channel and propose a new data reduction procedure for slit-less spectroscopy of sources embedded in complicated diffuse background structures. The relative strengths of the 0th to 1st order light as well as the efficiency profiles of the 2nd order light are examined for various objects taken with MIR-S dispersers. The boundary shapes of the aperture mask are determined by using the spectroscopic data of uniform zodiacal emission. Based on these results, if the appropriate template spectra of zodiacal light emission and the diffuse background emission are prepared and the geometries of the diffuse structures are obtained by the imaging data, we can reproduce the slit-less spectroscopic patterns made by a uniform zodiacal emission and the diffuse background emission by a convolution of those template profiles. This technique enables us to obtain the spectra of infrared sources in highly complicated diffuse background and/or foreground structures, such as in the Galactic plane and in nearby galaxies.


The Infrared Camera (IRC) for AKARI: in-flight imaging performance and the post cryogen mission

The Infrared Camera (IRC) is one of two focal-plane instruments on the AKARI satellite. It is designed for wide-field deep imaging and low- resolution spectroscopy in the near- to mid-infrared (1.8-26.5 micron) in the pointed observation mode of AKARI. The IRC is also operated in the survey mode to make an All-Sky Survey at 9 and 18 microns. The IRC is composed of three channels. The NIR channel (1.8-5.5 micron) employs a 512x412 InSb photodiode array, whereas both the MIR-S (4.6-13.4 micron) and MIR-L (12.6-26.5 micron) channels use 256x256 Si:As impurity band conduction (IBC) arrays. Each of the three channels has a field- ofview of approximately 10x10 arcmin., and they are operated simultaneously. The NIR and MIR-S channels share the same field-of-view by virtue of a beam splitter. The MIR-L observes the sky about 25 arcmin. away from the NIR/MIR-S field-of-view. The in-flight performance of the IRC has been confirmed to be in agreement with the pre-flight expectation. More than 4000 pointed observations dedicated for the IRC are successfully completed, and more than 90% of the sky are covered by the all-sky survey before the exhaustion of the Akari's cryogen. The focal-plane instruments are currently cooled by the mechanical cooler and only the NIR channel is still working properly. Brief introduction, in-flight performance and scientific highlights from the IRC cool mission, together with the result of performance test in the warm mission, are presented.


The Slit-Less Spectroscopic Survey of Galaxies (SPICY) with the InfraRed Camera (IRC) Onboard AKARI (ASTRO-F) Satellite

AKARI (formerly ASTRO-F) is a new space telescope for NIR-MIR-FIR observations. The InfraRed Camera (IRC) onboard, covering NIR-MIR, has a capability of low-resolution (R=λ/?λ=20-50) slit-less spectroscopy, and one can simultaneously obtain spectral information of all objects within the camera's large FOV (10× 10 arcmin^2) over wide wavelength range (2-26μm). To exploit this unique capability, we will perform a deep NIR- MIR spectroscopic survey, the `S'pectrosco`PIC' surve`Y' of galaxies (the `SPICY' mission program), down to ? 1 mJy around 15-24μm, to study galaxy evolution at z? 0.5-1.0.

Infrared Diagnostics of Galaxy Evolution


Serendipitous Spectroscopic Detection of Faint Galaxies at MIR with the IRC Onboard the AKARI During Its In-orbit PV Period

The AKARI (formally ASTRO-F) is a space telescope for near-mid-far infrared observations launched on February 2006. One of the two focal- plane instruments, the InfraRed Camera (IRC), is composed of three individual wide-field cameras to cover near-mid infrared wavelength, and each camera is equipped with a selectable filter wheel mounting two transmitting dispersers (grisms and prism) for spectroscopy. With this instrument, slit-less spectroscopy can be performed, i.e., one can simultaneously obtain spectral information of all objects within the camera's field of view (about 10x10 arcmin2) over wide wavelength range (2-26μm), without any a priori source information. With these unique capabilities, we expect to obtain excellent sample of galaxies for studying their evolution. Specifically, we may be able to investigate I) What contributes to the excess found in mid-infrared source count studies with ISO/ Spitzer surveys? How does the luminosity function evolve with redshift? II) How do the spectral features (PAH, etc.) evolve with redshift? How do PAH, mid-infrared, and far-infrared luminosities correlate with each other? We have performed some IRC spectroscopic observations during its in-orbit performance verification period, and in this paper we show examples of IRC spectra of faint galaxies obtained during this period. Although we have taken only a very small number of frames for initial flux and wavelength calibrations, etc., we have serendipitously detected some faint galaxies that are as faint as a few - several mJy in flux. In spite of their faintness, they can be easily recognized by their prominent spectroscopic features (e.g., PAH emission lines), and we can investigate their basic properties, such as redshift and types of activity, by directly analyzing their spectra. We believe that initial success of searching faint galaxies spectroscopically at mid-infrared clearly indicates the power of mid-infrared slit-less spectroscopy as a tool of studying galaxy evolution.


AKARI in Orbit-Scientific Potential for Understanding Galaxy Evolution

The AKARI (formerly known as ASTRO-F) mission is the first Japanese satellite dedicated for large area surveys in the infrared. AKARI was launched successfully on February 22nd 2006 (JST) from JAXA's Uchinoura Space Centre, Japan. AKARI is now orbiting around the Earth in a Sun- synchronous polar orbit at the altitude of 700km. The 68.5cm aperture telescope and scientific instruments are cooled to 6K by liquid Helium and mechanical coolers. The expected liquid Helium holding time is about one year after the successful aperture lid-opening on 2006 April 13th (JST). AKARI will perform the most advanced all-sky survey in 6 mid- to far-infrared wavebands since the preceding IRAS mission over 2 decades ago. Deep imaging and spectroscopic surveys with pointed observations are also on-going in 13 wavelength bands from 2-160micron. AKARI is a perfect complement to Spitzer in respect of its wide sky area and wavelength coverage. In this poster we present the unique characteristics of AKARI and its scientific potential for understanding of galaxy evolution. Not only the All-Sky Survey but also the deep pointing surveys near the ecliptic poles over ?15 square degrees will be particularly well suited to construct the luminosity functions of the infrared galaxies, to evaluate their clustering nature, and also to discover rare, exotic objects at various redshifts out to z ? 3. AKARI is also capable of detecting and measuring the spectrum and the fluctuations of the cosmic infrared background. We have confirmed that the in-orbit sensitivity and spatial resolution of the all-sky survey and the pointing surveys are sufficient to obtain the scientific goals listed above.


AKARI (formerly called ASTRO-F) is the first Japanese astronomical infrared satellite and it is now in a sun-synchronous polar orbit at the altitude of 700 km. One of the major programs of AKARI observations is an all-sky survey in the mid- to far-infrared spectral region with 6 photometric bands. AKARI has a 685mm telescope, which is cooled down to about 6K by superfluid liquid helium and mechanical coolers. The expected liquid helium holding time is longer than one year. The AKARI mid-infrared (MIR) survey is being carried out with the 9 and 18 mu m bands and the 5sigma sensitivities are estimated to be better than 80 and 130 mJy, respectively. The spatial resolution is better than 10 arcseconds at both bands. The sensitivity and spatial resolution of the MIR survey have been verified in orbit. The AKARI MIR survey will achieve a deeper sensitivity and a finer spatial resolution by about an order of magnitude than the previous survey of the 12 and 25 mu m with IRAS. It will provide a unique and significant database for studies of various fields of astronomy, ranging from star-formation and debris disk systems to cosmology. The first AKARI point source catalogue is planned to be released to the public 2 years after the completion of the survey. This paper reports the flight performance and the current status of the AKARI MIR survey.

Memorie della Societa Astronomica Italiana


Molecular Cloud Core MCLD 123.5+24.9 in Polaris Cirrus


Simultaneous seeing measurements at Atacama

Institute of Astronomy, University of Tokyo is now planning to build a 6.5-m optical-infrared telescope in Atacama, Chile. This project is called "Univ. Tokyo Atacama Observatory (TAO)", and the site evaluation is now under way. As a part of this evaluation process, we started an investigation to compare the astronomical seeing at Atacama with that at Mauna Kea. Here, we report preliminary results of seeing measurements at several sites in Atacama, carried out on October 2003. In order to separate the temporal and site-to-site variation of the seeing, we used two sets of Differential Image Motion Monitors (DIMMs), each of which has two pairs of 7.4 cm sub-apertures with 20.5 cm separation. Three sites were investigated; the point near the TAO weather station (4,950m), the summit of Cello Chico (5,150m) and the point at 5,430m altitude on Cello Toco. Simultaneous measurements were carried out for three half nights out of four half nights measurements. Although the amount of our data is very limited, the results suggest following: 1) Seeing becomes better and more stable as time passing to midnight (eg. From 0."7 to 0."4 at V-band). 2) Higher altitude sites show better seeing than lower altitude sites.


Optical Identification of the ISOPHOTFIR Sources

We present the optical follow up observations of the ISOPHOTFIR sources found in our 175 micron deep survey in the Lockman Hole using ISOPHOT on board ISO (Kawara et al. 1998, AA, 328, L9). Optical and NIR observations were made using ESI and NIRSPEC on the Keck II, IRCS on the Subaru, the 8k mosaic CCD camera on the UH88, and VLA. We have identified optical counterparts of 35 ISOPHOT FIR sources with redshift between 0.03 and 1.6. We discuss their observational properties.

Studies of Galaxies in the Young Universe with New Generation Telescope


Fe+ Emission in PG1626+554: Model Predictions and HST/FOS Observations

Recently, the number of observational efforts to measure the Fe II /Mg II emission ratios in QSOs has increased, due to their potential to give a clue to understanding of host galaxies and star formation in quasars. In our first attempt to translate these observational measurements into abundances, we use numerical simulations of Fe II ion and spectra of quasar, PG 1626+554, obtained with the HST/FOS. The Fe II emission contributes to the Mg II doublet which complicates measurement of Fe II(UV)/Mg II emission ratio. We discuss the observational errors in UV and optical parts of PG 1626+554 spectra that affect Fe II flux measurements. Then we demonstrate how to use Fe II (UV) band, Fe II (optical) band and Mg II (UV) doublet fluxes to derive the iron abundance. We utilize the most sophisticated Fe II ion model (830 levels) to obtain the best fit with observations. As a result of these calculations we estimate iron abundance, hydrogen density and photoionizing flux in quasar environment. Although the result suggests that the iron has solar abundance in the PG 1626+554, more accurate observations are needed to confirm this conclusion. This work was initiated while EV visit at NAOJ/IoA-UT as a NAOJ COE visiting professor. EV research and travel to AAS is supported by the National Science Foundation (NSF 0206150) program. We acknowledge the set of HST/FOS observations.

American Astronomical Society Meeting Abstracts


SDSSp J104433.04-012502.2 at z=5.74 is Gravitationally Magnified by an Intervening Galaxy

During the course of our optical deep survey program on Lyα emitters at z ? 5.7 in the sky area surrounding the quasar SDSSp J104433.04-012502.2 at z=5.74, we have found that a faint galaxy with mB(AB) ? 25 is located at 1.9 arcsec southwest of the quasar. Its broad band color properties from B to z' suggest that the galaxy is located at a redshift of z ? 1.5 -- 2.5. This is consistent with no strong emission line in our optical spectroscopy. Since the counter image of the quasar cannot be seen in our deep optical images, the magnification factor seems not so high. Our modest estimate is that this quasar is gravitationally magnified by a factor of 2.

8th Asian-Pacific Regional Meeting, Volume II


Spectroscopic investigation of ISO far-infrared sources


Obtaining FeII/MgII flux ratios in Low-Redshift QSOs

A delay of ~ 1.5 Gyr in Fe enrichment, relative to Mg ((alpha) element), might provide a chronometer for measuring the age of quasars and then constraining the age of the Universe. We are carrying out a project to do spectroscopy of many quasars from low-redshift to high-redshift in order to obtain the relation of the FeII/MgII flux ratio versus redshift. Combining this relation with the models of chemical evolution of galaxies, we would be able to know:(1)whether or not Fe is overabundant in broad-line gas of low-redshift quasars, (2)how quasar host galaxies formed, (3)the epoch of host galaxy formation, (4)the age of quasars, and eventually (5)the age of the Universe. As part of this project, we propose to do optical spectroscopy of 20 low- redshift quasars by using the GoldCam Spectrometer on KPNO-2.1m telescope. These optical spectra will be combined FOS UV spectra to extract broad FeII emission feature in the UV.


Radio Study of the Lockman Hole ISOPHOT Survey Sources

One of the most exciting discoveries made by the Infrared Space Observatory (ISO) was the detection of a substantial excess in the number density of faint far-infrared (95 μm & 175 μm) sources, suggesting strong cosmological evolution in the population of luminous infrared galaxies. The number density of 175μm sources derived from two deep fields (each 44' × 44') in the Lockman Hole region is >?10 times larger than predicted from no-evolution models. Several lines of reasoning suggest that the majority of the faint ISOPHOT sources may be at modest redshift (z<?1), and the ISOPHOT sources appear to bridge the gap between the starburst galaxies in the local universe and z>=2 obscured starbursts detected by the SCUBA surveys. We have carried out deep, high-resolution 1.4 GHz observations of the ISOPHOT survey fields using the VLA as part of a multi-wavelength follow-up study. In concert with deep optical and near-infrared (B, V, R, I, K) imaging, individual ISOPHOT sources are identified using high-resolution radio continuum images. Spectroscopic observations to determine the redshift and the nature of the powering sources are currently underway. Combined with ongoing SCUBA observations, photometric redshifts may be obtained even for sources that are heavily obscured. We are also investigating the nature of a radio selected galaxy sample using the same multi-wavelength database.


Spectroscopic Investigation of the ISO far-infrared sources


ISO Continuum Observations of Quasars at z =1-4

Mid- and Far-Infrared Astronomy and Future Space Missions