THE FOSSIL NUCLEAR OUTFLOW in the CENTRAL 30 pc of the GALACTIC CENTER

Please use this identifier to cite or link to this item: https://ir.lib.ncu.edu.tw/handle/987654321/102056

Title:	THE FOSSIL NUCLEAR OUTFLOW in the CENTRAL 30 pc of the GALACTIC CENTER
Authors:	黃崇源;Hsieh, Pei-Ying;Ho, Paul T. P.;Hwang, Chorng-Yuan;Shimajiri, Yoshito;Matsushita, Satoki;Koch, Patrick M.;Iono, Daisuke
Contributors:	理學院天文研究所
Keywords:	Astrophysics;Bubbles;Clouds;Explosions;Galactic disk;Galaxy: center;Galaxy: structure;ISM: molecules;Molecular clouds;Molecular gases;radio lines: ISM;techniques: image processing;Time;Velocity gradient
Date:	2016-11-01
Issue Date:	2026-04-21 14:58:35 (UTC+8)
Publisher:	IOP Publishing Ltd.;Philadelphia: The American Astronomical Society
Abstract:	摘要： ABSTRACT We report a new 1 pc (30″) resolution CS( ) line map of the central 30 pc of the Galactic center (GC), made with the Nobeyama 45 m telescope. We revisit our previous study of an extraplanar feature called the polar arc (PA), which is a molecular cloud located above SgrA, with a velocity gradient perpendicular to the galactic plane. We find that the PA can be traced back to the galactic disk. This provides clues to the launching point of the PA, roughly 6 × 106 years ago. Implications of the dynamical timescale of the PA might be related to the Galactic center lobe at parsec scale. Our results suggest that, in the central 30 pc of the GC, the feedback from past explosions could alter the orbital path of molecular gas down to the central tenth of a parsec. In the follow-up work of our new CS( ) map, we also find that, near systemic velocity, the molecular gas shows an extraplanar hourglass-shaped feature (HG-feature) with a size of ∼13 pc. The latitude-velocity diagrams show that the eastern edge of the HG-feature is associated with an expanding bubble B1, ∼7 pc away from SgrA. The dynamical timescale of this bubble is ∼3 × 105 years. This bubble is interacting with the 50 km s−1 cloud. Part of the molecular gas from the 50 km s−1 cloud was swept away by the bubble to . The western edge of the HG-feature seems to be molecular gas entrained from the 20 km s−1 cloud toward the north of the galactic disk. Our results suggest a fossil explosion in the central 30 pc of the GC, a few 105 years ago. 其他題名： APJ 其他題名： Astrophys. J 出版者： Philadelphia: The American Astronomical Society 出版日期： 2016-11-01 出處： The Astrophysical Journal, 2016-11, Vol.831 (1), p.72- 資源來源： Institute of Physics Journals 版權： 2016. The American Astronomical Society. All rights reserved. 版權： Copyright IOP Publishing Nov 01, 2016 識別號： ISSN: 0004-637X 識別號： ISSN: 1538-4357 識別號： EISSN: 1538-4357 識別號： DOI: 10.3847/0004-637X/831/1/72
Appears in Collections:	[Graduate Institute of Astronomy] journal & Dissertation

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