SALVAGE II：活动星系核宿主星系中心2千秒差距内无系统性分子气体耗竭
SALVAGE II: no systematic molecular gas depletion in the central 2 kpc of AGN hosts
- University of Victoria（维多利亚大学）
- ESA, European Space Astronomy Centre (ESAC)（欧洲航天局欧洲空间天文中心）
- Institut de Radioastronomie Millimétrique (IRAM)（毫米波射电天文学研究所）
- Herzberg Astronomy and Astrophysics Research Centre, National Research Council of Canada（加拿大国家研究委员会赫茨伯格天体物理学研究中心）
- Centro de Astrobiología (CAB), CSIC-INTA（西班牙国家航空航天技术研究所与高等科学研究中心联合天体生物学中心）
- Observatorio Astronómico Nacional (OAN-IGN)-Observatorio de Madrid（马德里国家天文台）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
本研究利用SALVAGE数据，发现低红移AGN宿主星系中心2 kpc内无系统性分子气体耗竭，仅两类光学AGN有初步耗竭信号，为AGN反馈的气体移除尺度设定上限。
AI中文摘要：
在宇宙学模拟中，活动星系核（AGN）反馈被认为是通过加热和/或移除分子气体来关闭星系级恒星形成所必需的。然而，在低红移处，几乎没有系统性大尺度气体耗竭的证据。近期一些观测发现AGN宿主星系中存在分子气体耗竭，但仅限于星系中心区域。在本工作中，我们使用SDSS-ALMA遗产价值档案气体探索（SALVAGE）数据集，该数据集提供了星系内部（r < 0.5-2 kpc）和外部区域的分子气体及恒星质量测量。利用来自光学发射线、中红外颜色和X射线光度的AGN诊断，我们在z < 0.07处识别出70个AGN，并通过一系列指标与非AGN对照样本比较其中心分子气体储库。与低红移AGN宿主星系的整体研究一致，我们发现，与匹配的非AGN相比，AGN中心区域具有相同的分子气体分数和增强的分子气体面密度。我们首次探索了通过不同选择标准识别的AGN的中心气体储库，发现两类光学AGN显示出中心分子气体耗竭的初步1.5σ和1.8σ信号。然而，具有中心气体耗竭的AGN并未占据参数空间（如AGN光度）中的任何特定区域，从而无法为耗竭提供物理解释。如果AGN负责大尺度气体移除，SALVAGE AGN中缺乏系统性气体耗竭为气体移除的物理尺度设定了上限，同时AGN仍保持可观测。
英文摘要：
In cosmological simulations, active galactic nuclei (AGN) feedback is found to be necessary for the shutdown of galaxy-wide star-formation by heating and/or removing molecular gas. However, at low-redshift, there is little evidence of systematic large-scale gas depletion. Some recent observations have found molecular gas depletion in AGN hosts, but limited to the central regions of galaxies. In this work, we use the SDSS-ALMA Legacy-Value Archival Gas Exploration (SALVAGE) dataset, which provides molecular gas and stellar mass measurements from the inner (r < 0.5-2 kpc) and outer region of the galaxy. Using AGN diagnostics from optical emission lines, mid-IR colour, and X-ray luminosity, we identify 70 AGN at z < 0.07 and inspect their central molecular gas reservoirs with a suite of metrics compared to non-AGN controls. In agreement with global studies of low-z AGN hosts, we find that, compared to matched non-AGN, the central regions of AGN have equal molecular gas fractions and enhanced molecular gas surface densities. For the first time, we explore the central gas reservoirs of AGN identified with different selection criteria and find two optical AGN classes that show a tentative 1.5$σ$ and 1.8$σ$ signal of central molecular gas depletion. However, the AGN with central gas depletion do not occupy any specific region of the parameter space, such as AGN luminosity, that can provide a physical explanation for the depletion. If AGN are responsible for large-scale gas removal, the lack of systematic gas depletion in SALVAGE AGN sets an upper limit on the physical scale of the gas removal while the AGN remains observable.
