The MeerKAT Fornax Survey: I. Survey description and first evidence of ram pressure in the Fornax galaxy cluster
The MeerKAT Fornax Survey: I. Survey description and first evidence of ram pressure in the Fornax galaxy cluster
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MeerKAT Fornax 巡天：I. 巡天描述和 Fornax 星系团中冲压压力的第一个证据
DOI：
10.1051/0004-6361/202346071
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发表时间：
2023
影响因子：
6.5
通讯作者：
Dettmar, R. J.
中科院分区：
文献类型：
--
作者：
Serra, P.;Maccagni, F. M.;Kleiner, D.;Molnár, D.;Ramatsoku, M.;Loni, A.;Loi, F.;de Blok, W. J.;Bryan, G. L.;Dettmar, R. J.
MeerKAT天炉巡天使用MeerKAT望远镜绘制了附近天炉星系团中原子中性氢气（H I）的分布和运动学。12度的测量足迹覆盖了星团的中心区域，一直延伸到~ 2rvird，向西南延伸到~ 2rvird，包括NGC 1316星系群。H I柱密度灵敏度（3σ / 25 km s−1）的范围从5 × 1019cm−2at（分辨率为~ 10″）（距离天炉座20 Mpc时为~ 1 kpc）到~ 1018cm−2at ~ 1 ' (~ 6 kpc)，最低分辨率为~ 100″（~ 10 kpc）时略低于此水平。H I的质量灵敏度（3σ大于50 km s−1）为6 × 105M⊙。H I速度分辨率为1.4 km s−1。在本文中，我们描述了调查设计和H I数据处理，并提出了六个星系的样本，它们具有长，单侧，无恒星的H I尾巴（其中只有一个以前已知），在星团内径向定向，并且具有可测量的内部速度梯度。我们认为，H I尾部的联合性质代表了冲压压力塑造了H I在天文学家星团中的分布的第一个明确证据。所有宿主星系的扰动光学形态支持了这样的观点，即尾巴由H I组成，它最初是被潮汐力从星系的恒星体中拉出来的。然后，Ram压力能够进一步取代弱束缚的H I，并给出尾部当前的方向、长度和速度梯度。
The MeerKAT Fornax Survey maps the distribution and kinematics of atomic neutral hydrogen gas (H I) in the nearby Fornax galaxy cluster using the MeerKAT telescope. The 12 deg2survey footprint covers the central region of the cluster out to ∼Rvirand stretches south-west out to ∼2Rvirto include the NGC 1316 galaxy group. The H I column density sensitivity (3σover 25 km s−1) ranges from 5 × 1019cm−2at a resolution of ∼10″ (∼1 kpc at the 20 Mpc distance of Fornax) down to ∼1018cm−2at ∼1′ (∼6 kpc), and slightly below this level at the lowest resolution of ∼100″ (∼10 kpc). The H I mass sensitivity (3σover 50 km s−1) is 6 × 105M⊙. The H I velocity resolution is 1.4 km s−1. In this paper, we describe the survey design and H I data processing, and we present a sample of six galaxies with long, one-sided, starless H I tails (only one of which was previously known) radially oriented within the cluster and with measurable internal velocity gradients. We argue that the joint properties of the H I tails represent the first unambiguous evidence of ram pressure shaping the distribution of H I in the Fornax cluster. The disturbed optical morphology of all host galaxies supports the idea that the tails consist of H I that was initially pulled out of the galaxies’ stellar body by tidal forces. Ram pressure was then able to further displace the weakly bound H I and give the tails their current direction, length, and velocity gradient.