UCI主導の天文学者が、ジェームス・ウェッブ宇宙望遠鏡のデータをいち早く利用可能に(UCI-led astronomers capitalize on early access to James Webb Space Telescope data)


銀河系外核のコヒーレントなイメージの形成に、最新機器が貢献 Advanced instruments aid in development of coherent picture of extragalactic nucleus

2022-11-14 カリフォルニア大学校アーバイン校(UCI)

研究チームは、JWSTの超高感度中間赤外線検出装置を用いて、近傍の銀河NGC 7469を調べた結果を、論文で発表している。超巨大ブラックホールが支配する活動銀河核と、それを取り巻く星形成銀河領域との相互作用について、これまでで最も詳細な解析が行われた。
NGC 7469は、超巨大ブラックホールと星形成領域のリングを持つ活動的な中心部を持つセイファート銀河で、全銀河の約10パーセントを占めるこの系の詳しいダイナミクスを何十年にもわたって研究してきましたが、中心部に多く存在する塵がそれを阻んできた。JWSTは、研究者たちに、ダストのベールの向こうにあるものにアクセスする機会を与えてくれた。


GOALS-JWST:NGC 7469 の円周核ガスダイナミクスの中間赤外線による解像 GOALS-JWST: Resolving the Circumnuclear Gas Dynamics in NGC 7469 in the Mid-infrared

Vivian U, Thomas Lai, Marina Bianchin, Raymond P. Remigio, Lee Armus, Kirsten L. Larson, Tanio Díaz-Santos, Aaron Evans, Sabrina Stierwalt, David R. Law, Matthew A. Malkan, Sean Linden, Yiqing Song, Paul P. van der Werf, Tianmu Gao, George C. Privon, Anne M. Medling, Loreto Barcos-Muñoz, Christopher C. Hayward, Hanae Inami, Jeff Rich, Susanne Aalto, Philip Appleton, Thomas Bohn, Torsten Böker, Michael J. I. Brown, Vassilis Charmandaris, Luke Finnerty, Justin Howell, Kazushi Iwasawa, Francisca Kemper, Jason Marshall, Joseph M. Mazzarella, Jed McKinney, Francisco Muller-Sanchez, Eric J. Murphy, David Sanders, and Jason Surace
The Astrophysical Journal Letters  Published: 2022 November 14


The nearby, luminous infrared galaxy NGC 7469 hosts a Seyfert nucleus with a circumnuclear star-forming ring and is thus the ideal local laboratory for investigating the starburst–AGN (active galactic nucleus) connection in detail. We present integral-field observations of the central 1.3 kpc region in NGC 7469 obtained with the JWST Mid-InfraRed Instrument. Molecular and ionized gas distributions and kinematics at a resolution of ∼100 pc over the 4.9–7.6 μm region are examined to study the gas dynamics influenced by the central AGN. The low-ionization [Fe ii] λ5.34 μm and [Ar ii] λ6.99 μm lines are bright on the nucleus and in the starburst ring, as opposed to H2 S(5) λ6.91 μm, which is strongly peaked at the center and surrounding ISM. The high-ionization [Mg v] line is resolved and shows a broad, blueshifted component associated with the outflow. It has a nearly face-on geometry that is strongly peaked on the nucleus, where it reaches a maximum velocity of −650 km s−1, and extends about 400 pc to the east. Regions of enhanced velocity dispersion in H2 and [Fe ii] ∼ 180 pc from the AGN that also show high L(H2)/L(PAH) and L([Fe ii])/L(Pfα) ratios to the W and N of the nucleus pinpoint regions where the ionized outflow is depositing energy, via shocks, into the dense interstellar medium between the nucleus and the starburst ring. These resolved mid-infrared observations of the nuclear gas dynamics demonstrate the power of JWST and its high-sensitivity integral-field spectroscopic capability to resolve feedback processes around supermassive black holes in the dusty cores of nearby luminous infrared galaxies.