宇宙物理学研究系

山田 亨

ヤマダ トオル  (TORU YAMADA)

基本情報

所属
国立研究開発法人宇宙航空研究開発機構 宇宙科学研究所 教授
東北大学大学院 理学研究科 (名誉教授)
学位
京都大学博士(理学)(1994年3月 京都大学)

J-GLOBAL ID
202001002640673973
researchmap会員ID
R000014747

学歴

 2

論文

 313
  • Ken Mawatari, Akio K. Inoue, Toru Yamada, Tomoki Hayashino, J. Xavier Prochaska, Khee-Gan Lee, Nicolas Tejos, Nobunari Kashikawa, Takuya Otsuka, Satoshi Yamanaka, David J. Schlegel, Yuichi Matsuda, Joseph F. Hennawi, Ikuru Iwata, Hideki Umehata, Shiro Mukae, Masami Ouchi, Yuma Sugahara, Yoichi Tamura
    The Astronomical Journal 2023年5月1日  
  • Akio K. Inoue, Hidehiro Kaneda, Toru Yamada, Yuichi Harikane, Daisuke Ishihara, Tadayuki Kodama, Yutaka Komiyama, Takashi Moriya, Kentaro Motohara, Hideko Nomura, Masami Ouchi, Shinki Oyabu, Toyoaki Suzuki, Takehiko Wada, Issei Yamamura
    Space Telescopes and Instrumentation 2022: Optical, Infrared, and Millimeter Wave 2022年8月27日  
  • Mariko Kubo, Hideki Umehata, Yuichi Matsuda, Masaru Kajisawa, Charles C. Steidel, Toru Yamada, Ichi Tanaka, Bunyo Hatsukade, Yoichi Tamura, Kouichiro Nakanishi, Kotaro Kohno, Kianhong Lee, Keiichi Matsuda, Yiping Ao, Tohru Nagao, Min S. Yun
    The Astrophysical Journal 935(2) 89-89 2022年8月1日  
    Abstract We report the detection of an ionized gas outflow from an X-ray active galactic nucleus hosted in a massive quiescent galaxy in a protocluster at z = 3.09 (J221737.29+001823.4). It is a type-2 QSO with broad (W80 > 1000 km s−1) and strong ($\mathrm{log}({L}_{[\mathrm{OIII}]}$/erg s−1) ≈ 43.4) [O iii]λλ 4959,5007 emission lines detected by slit spectroscopy in three-position angles using Multi-Object Infra-Red Camera and Spectrograph (MOIRCS) on the Subaru telescope and the Multi-Object Spectrometer For Infra-Red Exploration (MOSFIRE) on the Keck-I telescope. In the all slit directions, [O iii] emission is extended to ∼15 physical kpc and indicates a powerful outflow spreading over the host galaxy. The inferred ionized gas mass outflow rate is 22 ± 3 M yr−1. Although it is a radio source, according to the line diagnostics using Hβ, [O ii], and [O iii], photoionization by the central QSO is likely the dominant ionization mechanism rather than shocks caused by radio jets. On the other hand, the spectral energy distribution of the host galaxy is well characterized as a quiescent galaxy that has shut down star formation several hundred Myr ago. Our results suggest a scenario that QSOs are powered after the shutdown of the star formation and help complete the quenching of massive quiescent galaxies at high redshift.
  • Naoki Yonekura, Masaru Kajisawa, Erika Hamaguchi, Ken Mawatari, Toru Yamada
    The Astrophysical Journal 930 102 2022年5月  査読有り
  • Yuxing Zhong, Akio K. Inoue, Satoshi Yamanaka, Toru Yamada
    The Astrophysical Journal 925(2) 157-157 2022年2月1日  
    <title>Abstract</title> Morphological studies are crucial to investigate the connections between active galactic nucleus (AGN) activities and the evolution of galaxies. Substantial studies have found that radiative-mode AGNs primarily reside in disk galaxies, questioning the merger-driven mechanism of AGN activities. In this study, through Sérsic profile fitting and nonparametric morphological parameter measurements, we investigated the morphology of host galaxies of 485 optical variability-selected low-luminosity AGNs at <italic>z</italic> ≲ 4.26 in the COSMOS field. We analyzed high-resolution images of the Hubble Space Telescope to measure these morphological parameters. We only successfully measured the morphological parameters for 76 objects and most AGN hosts (∼70%) were visually compact point-like sources. We examined the obtained morphological information as a function of redshift and compared them with literature data. We found that these AGN host galaxies showed no clear morphological preference. However, the merger rate increased with higher host star formation rate and AGN luminosity. Interestingly, we found ongoing star formation consistent with the typical star-forming populations in both elliptical and spiral galaxies, while these two types of galaxies were more symmetric than normal star-forming galaxies. These results suggest that optical variability-selected AGNs have higher probabilities to reside in elliptical galaxies than infrared-selected AGNs, whose host galaxies have a strong disk dominance, and support recent findings that the AGN feedback can enhance star-forming activities in host galaxies.

MISC

 29

所属学協会

 1

共同研究・競争的資金等の研究課題

 17