Environmental impacts on molecular gas in protocluster galaxies at z~2
Environmental impacts on molecular gas in protocluster galaxies at z~2
复制标题
z~2 处原星系团中分子气体的环境影响
DOI：
10.1093/pasj/psz005
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发表时间：
2019
影响因子：
2.3
通讯作者：
Umehata Hideki
中科院分区：
文献类型：
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作者：
Tadaki Ken-ichi;Kodama Tadayuki;Hayashi Masao;Shimakawa Rhythm;Koyama Yusei;Lee Minju;Tanaka Ichi;Hatsukade Bunyo;Iono Daisuke;Kohno Kotaro;Matsuda Yuichi;Suzuki Tomoko L;Tamura Yoichi;Toshikawa Jun;Umehata Hideki
我们给出了阿尔马CO（3-2）对射电星系周围三个原星系团中66个Hα选择星系的观测结果：PKS 1138−262（= 2.16），USS 1558−003（= 2.53）和4C 23.56（= 2.49）。指向区域的密度比场环境中星系的平均表面数密度高100倍。我们在16个恒星形成星系中探测到CO发射线，其中包括6个先前发表的星系，以测量分子气体质量。在10.5 < log（M星/M星）< 11.0的恒星质量范围内，原团星系的气体质量分数和气体耗尽时间尺度都比场星系的尺度关系大。另一方面，log（Mstar/M）> 11.0的更大质量星系中的分子气体量与标度关系相当或更小。我们的研究结果表明，环境对气体性质的影响是质量相关的：在高密度环境中，通过宇宙细丝的气体吸积在质量较小的星系中加速，而在质量最大的系统中则被抑制。
We present the results from ALMA CO(3–2) observations of 66 Hα-selected galaxies in three protoclusters around radio galaxies: PKS 1138−262 (= 2.16), USS 1558−003 (= 2.53), and 4C 23.56 (= 2.49). The pointing areas have an overdensity of ∼100 compared to the mean surface number density of galaxies in field environments. We detect the CO emission line in 16 star-forming galaxies, including six previously published galaxies, to measure the molecular gas mass. In the stellar mass range of 10.5 < log (Mstar/M⊙) < 11.0, the protocluster galaxies have larger gas mass fractions and longer gas depletion timescales compared to the scaling relations established for field galaxies. On the other hand, the amounts of molecular gas in more massive galaxies with log (Mstar/M⊙) > 11.0 are comparable in mass to the scaling relation, or smaller. Our results suggest that the environmental effects on gas properties are mass dependent: in high-density environments, gas accretion through cosmic filaments is accelerated in less massive galaxies, while this is suppressed in the most massive system.