论文标题
Flash Pilot调查：与0.42 <z <1.00相关的21厘米HI吸收相关的检测
FLASH Pilot Survey: Detections of associated 21 cm HI absorption in GAMA galaxies at 0.42 < z <1.00
论文作者
论文摘要
我们介绍了在红移0.42 <z <z <z <1.00的21厘米HI吸收的结果中，来自三个星系和大众组装（GAMA）调查场的无线电大路。这些观察结果是在HI（Flash）中进行ASKAP首次大吸收调查的试点调查的一部分。从高于10 MJY的855.5 MHz峰值密度的326个无线电源的样品中，我们检测到两个相关的HI吸收系统，在SDSS J090331+010847中，Z = 0.522和SDSS J113622+004852在z = 0.563时。这两个星系都是巨大的（恒星质量> 10 $^{11} $ m $ _ {sun} $），并且具有发光红星系的光谱特征，尽管SED拟合意味着SDSS J113622+004852包含SFR 〜69 m $ $ $ $ _ $ _ $ _ y y y-y的SFRING sTARBURST，其中包含STARBURST的STARBURST。 HI吸收线具有很高的光学深度，SDSS J090331+010847的$τ_{Pk} $为1.77 $ \ pm $ 0.16（迄今为止发现的任何Z> 0.1相关系统的最高值）和SDSS J113622+0001的0.14 $ \ pm $ 0.01 $ \ pm $ 0.01。在我们的askap观测值探测的红移范围内，相关的HI吸收线的检测率（$τ_{pk} $> 0.1和至少3 $σ$ nightance）为2.9（+9.7 -2.6）。尽管当前的样本很小，但该速率与其他研究中发现的趋势是一致的，该研究的检测率较低，在较高的红移下，相关的21 cm HI吸收系统的检测率较低。我们还以0.67 <z <1.34搜索OH吸收线，但是在搜索的145个无线电源中未进行检测。
We present the results of a search for associated 21 cm HI absorption at redshift 0.42 < z < 1.00 in radio-loud galaxies from three Galaxy And Mass Assembly (GAMA) survey fields. These observations were carried out as part of a pilot survey for the ASKAP First Large Absorption Survey in HI (FLASH). From a sample of 326 radio sources with 855.5 MHz peak flux density above 10 mJy we detected two associated HI absorption systems, in SDSS J090331+010847 at z= 0.522 and SDSS J113622+004852 at z= 0.563. Both galaxies are massive (stellar mass > 10$^{11}$ M$_{sun}$) and have optical spectra characteristic of luminous red galaxies,though SED fitting implies that SDSS J113622+004852 contains a dust-obscured starburst with SFR ~ 69 M$_{sun}$ yr$^{-1}$. The HI absorption lines have a high optical depth, with $τ_{pk}$ of 1.77 $\pm$ 0.16 for SDSS J090331+010847 (the highest value for any z > 0.1 associated system found to date) and 0.14 $\pm$ 0.01 for SDSS J113622+004852. In the redshift range probed by our ASKAP observations, the detection rate for associated HI absorption lines (with $τ_{pk}$ > 0.1 and at least 3$σ$ significance) is 2.9 (+9.7 -2.6) percent. Although the current sample is small, this rate is consistent with a trend seen in other studies for a lower detection rate of associated 21 cm HI absorption systems at higher redshift. We also searched for OH absorption lines at 0.67 < z < 1.34, but no detection was made in the 145 radio sources searched.
