An extended cold gas absorber in a central cluster galaxy.
An extended cold gas absorber in a central cluster galaxy.
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中央星团星系中的延伸冷气体吸收器。
DOI：
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
A. Edge
中科院分区：
文献类型：
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作者：
Russell J. Smith;A. Edge
我们偶然地从档案积分场光谱学中发现了一个延伸的冷气体结构，它投射在z=0.045星系团中最亮的星系团Abell3716附近。气体是通过狭窄的Na-D线吸收揭示出来的，在卡介苗的恒星光的映衬下可以看到，这可以追溯到∼25kpc，宽度为2-4kpc。气体被抵消到比卡介苗更高的速度(∼100 KM S−1)，表明它是流入而不是流出；固有线宽为∼80 KM S−1(FWHM)。从该结构中探测到了很弱的H- α线发射，从光学成像中发现了一种微弱的尘埃吸收特征，但没有发现与之对应的恒星。我们讨论了对吸收体的一些可能的解释：作为一个投射的低表面亮度星系，作为从流入的星系团中剥离出来的一股气体流，或者作为一个已经退役的冷核星云灯丝。
We present the serendipitous discovery of an extended cold gas structure projected close to the brightest cluster galaxy (BCG) of the z = 0.045 cluster Abell 3716, from archival integral field spectroscopy. The gas is revealed through narrow Na D line absorption, seen against the stellar light of the BCG, which can be traced for ∼25 kpc, with a width of 2–4 kpc. The gas is offset to higher velocity than the BCG (by ∼100 km s−1), showing that it is infalling rather than outflowing; the intrinsic linewidth is ∼80 km s−1 (FWHM). Very weak H α line emission is detected from the structure, and a weak dust absorption feature is suggested from optical imaging, but no stellar counterpart has been identified. We discuss some possible interpretations for the absorber: as a projected low-surface-brightness galaxy, as a stream of gas that was stripped from an infalling cluster galaxy or as a ‘retired’ cool-core nebula filament.