Curriculum Vitaes
Profile Information
- Affiliation
- Assistant Professor, Institute of Space and Astronautical Science, Department of Space Astronomy and Astrophysics, Japan Aerospace Exploration Agency
- Degree
- 博士(理学)(Mar, 2002, 東京大学理学系研究科物理学専攻)
- J-GLOBAL ID
- 202001017082346100
- researchmap Member ID
- R000012159
Research Interests
8Research Areas
2Research History
11-
Apr, 2024 - Present
-
Apr, 2018 - Mar, 2019
-
Apr, 2017 - Mar, 2018
-
Apr, 2016 - Mar, 2017
Education
2-
Apr, 1999 - Mar, 2002
-
Apr, 1997 - Mar, 1999
Awards
2Major Papers
119-
The Astrophysical Journal, Aug 1, 2023 Peer-reviewedLead author
-
Monthly Notices of the Royal Astronomical Society, 512(4) 5995-6006, Mar 25, 2022 Peer-reviewed
-
The Astrophysical Journal, 899(1) 17-17, Aug 7, 2020 Peer-reviewedLead author
-
The Astrophysical Journal, 850(2) 193-193, Dec 1, 2017 Peer-reviewedLead author
-
PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 68(6), Dec, 2016
Misc.
57-
日本惑星科学会秋季講演会予稿集(Web), 2024, 2024
-
VizieR On-line Data Catalog, Oct, 2023
-
Space Telescopes and Instrumentation 2020: Optical, Infrared, and Millimeter Wave, Dec 13, 2020
-
Space Telescopes and Instrumentation 2018: Optical, Infrared, and Millimeter Wave, Jul 12, 2018
-
Space Telescopes and Instrumentation 2018: Ultraviolet to Gamma Ray, 10699, Jul 6, 2018
-
Space Telescopes and Instrumentation 2018: Ultraviolet to Gamma Ray, Jul 6, 2018
-
宇宙航空研究開発機構特別資料 = JAXA Special Publication: The Cosmic Wheel and the Legacy of the AKARI archive: from galaxies and stars to planets and life, (17) 217-220, Mar 9, 2018第4回「あかり」国際会議 (2017年10月17-20日. 東京大学), 文京区, 東京形態: カラー図版あり資料番号: AA1730026036レポート番号: JAXA-SP-17-009E The 4th AKARI International Conference: The Cosmic Wheel and the Legacy of the AKARI archive: from galaxies and stars to planets and life (October 17-20, 2017. The University of Tokyo), Bunkyo-ku, Tokyo, JapanWe analyzed the 4.67 micrometers CO ro-vibrational absorption band in nearby ten active galactic nuclei (AGNs) observed with AKARI and Spitzer by fitting a plane-parallel local thermal equilibrium gas model. We found that the CO gas is warm (200-500 K) with a large column density (N(sub H) less than in the order of 10(exp 23) cm-2). Such a large column of warm gas is not achievable with UV heating or shock heating in starbursts. The most convincing heating source is X-ray photons emitted from the nuclei, which can produce warm gas of N(sub H) in the order of 10(exp 24) cm-2. This indicates that the region probed by the CO absorption is in the vicinity of the nuclei. The hydrogen column density estimated from the CO band is smaller than that inferred from X-ray observations. The observed deep absorption implies that the gas is close to the continuum source. We suggest that the probed region is outside the X-ray emitting region and just in front of the dust sublimation layer, which can be designated as the inner rim of the obscuring material around the AGNs.Physical characteristics: Original contains color illustrations
-
宇宙航空研究開発機構特別資料 = JAXA Special Publication: Proceedings of the SPICA Science Conference from Exoplanets to Distant Galaxies: SPICA's New Window on the Cool Universe, (17) 117-119, Mar 9, 2018形態: カラー図版あり資料番号: AA1730027026レポート番号: JAXA-SP-17-010E SPICA Science Conference from Exoplanets to Distant Galaxies: SPICA's New Window on the Cool Universe (June 18-21, 2013. Ito Hall, the University of Tokyo), Bunkyou-ku, Tokyo, JapanWe carried out systematic observations of the HI recombination line Bra (4.05 μm) in nearby (z less than 0.3) ultraluminous infrared galaxies (ULIRGs), using AKARI near-infrared 2.5-5.0 μm spectroscopy. We derived star formation rates (SFRs) from the Bra line, whose observed flux is predicted to be the highest among HI recombination lines in conditions with large dust extinction (visual extinction Av greater than 15 mag) expected in ULIRGs. Using the 3.3 μm polycyclic aromatic hydrocarbon emission in addition to the Bra line as an indicator of the SFR, we estimated the contribution of the star formation to the total infrared luminosity in 51 ULIRGs. The contribution was on average 28 plus or minus4 0/o in ULIRGs optically classified as H II, while 14 plus or minus2 0/o in ULIRGs optically classified as LINER or Seyfert. This result indicates that the star formation is significantly active in H II ULIRGs and other energy source, i.e. active galactic nuclei, is needed in LINER ULIRGs.Physical characteristics: Original contains color illustrations
-
宇宙航空研究開発機構特別資料 = JAXA Special Publication: The Cosmic Wheel and the Legacy of the AKARI archive: from galaxies and stars to planets and life, (17) 379-382, Mar 9, 2018第4回「あかり」国際会議 (2017年10月17-20日. 東京大学), 文京区, 東京形態: カラー図版あり資料番号: AA1730026077レポート番号: JAXA-SP-17-009E The 4th AKARI International Conference: The Cosmic Wheel and the Legacy of the AKARI archive: from galaxies and stars to planets and life (October 17-20, 2017. The University of Tokyo), Bunkyo-ku, Tokyo, JapanWe made systematic observations of the HI Br alpha (4.05 micrometers) and Br beta (2.63 micrometers) lines in 52 nearby (z less than 0.3) ULIRGs with AKARI. Our observations show that ULIRGs have a tendency to indicate higher Br beta/Br alpha line ratios than those observed in Galactic HII regions, and three galaxies in the observed sample show the anomaly of the Br beta/Br alpha line ratios (in the order of 1.0), which are significantly higher than that of case B (0.565). The high Br beta/Br alpha line ratios cannot be explained by the combination of the dust extinction and the case B, since dust extinction reduces the ratio. We simulate HII regions in the ULIRGs with the Cloudy code, and show that the high Br beta/Br alpha line ratios can be explained with the combination of the optically thick Br alpha line and the optically thin Br beta line. To achieve the column density large enough to make the Br alpha line optically thick, the gas density is required as high as n in the order of 10(exp 8) cm(exp -3). Hence our results suggest that star-formation activity in ULIRGs occurs preferentially in high-density clouds.Physical characteristics: Original contains color illustrations
-
(17) 325-327, Mar 9, 2018The 4th AKARI International Conference: The Cosmic Wheel and the Legacy of the AKARI archive: from galaxies and stars to planets and life (October 17-20, 2017. The University of Tokyo), Bunkyo-ku, Tokyo, JapanWe observed near-infrared (NIR) absorption bands in 48 ultraluminous infrared galaxies (ULIRGs) to study physical conditions in star-forming regions. We focus on two absorption features in this study: the H2O ice absorption at 3.0 micrometers, which traces dark clouds (A(sub V) greater than a few mag), and the aliphatic carbon absorption at 3.4 micrometers, which traces diffuse clouds (A(sub V) less than 1 mag). Spectral analysis shows that optical depths of H2O ice and aliphatic carbon in most of the ULIRGs are similar to those in diffuse clouds in the Galaxy when normalized by silicate optical depth, and ULIRGs do NOT consist of dark clouds. This suggests that the star-forming regions in ULIRGs have more intense radiation field than typical dark clouds in the Galaxy. We also examined the profile of H2O ice for objects showing relatively deep absorption. The observed profiles of H2O ice in ULIRGs sometimes show a sign of saturated absorption, while the continuum emission is not completely absorbed by the feature. This suggests that the dark clouds, where H2O ice resides, do not cover the background sources entirely. These results imply that the dark clouds are sparsely distributed in ULIRGs.Physical characteristics: Original contains color illustrations
-
Astrophysical Journal, 753(2), Jul 10, 2012
-
PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 63(2) 397-405, Apr, 2011
-
SPACE TELESCOPES AND INSTRUMENTATION 2010: ULTRAVIOLET TO GAMMA RAY, 7732 77320Z-77320Z-18, 2010
-
ASTROPHYSICAL JOURNAL, 706(1) 454-463, Nov, 2009
-
PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 61 S327-S335, Jan, 2009
-
PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 61 S377-S386, Jan, 2009
-
PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 60 S317-S331, Feb, 2008
-
Publications of the Astronomical Society of Japan, 59(1) S257-S267, Jan 31, 2007
-
PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 59 S53-S76, Jan, 2007
-
ASTROPHYSICAL JOURNAL, 645(1) 256-263, Jul, 2006
-
PROCEEDINGS OF THE X-RAY UNIVERSE 2005, VOLS 1 AND 2, 604 569-+, 2006
-
Space Telescopes and Instrumentation II: Ultraviolet to Gamma Ray, Pts 1 and 2, 6266(No.) U2663-U2663, 2006
Presentations
24Research Projects
4-
Grants-in-Aid for Scientific Research, Japan Society for the Promotion of Science, Apr, 2023 - Mar, 2026
-
Grants-in-Aid for Scientific Research, Japan Society for the Promotion of Science, Apr, 2021 - Mar, 2025
-
Grants-in-Aid for Scientific Research, Japan Society for the Promotion of Science, 2010 - 2012
-
Grants-in-Aid for Scientific Research, Japan Society for the Promotion of Science, 2008 - 2011