Possible evolution of the circum-galactic medium around QSOs with QSO age and cosmic time revealed by Ly?α haloes
Possible evolution of the circum-galactic medium around QSOs with QSO age and cosmic time revealed by Ly?α haloes
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Lyα 晕揭示了 QSO 周围环绕银河系介质的可能演化以及 QSO 年龄和宇宙时间
DOI：
10.1093/mnras/stz1707
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发表时间：
2019
影响因子：
4.8
通讯作者：
Miyazaki Satoshi
中科院分区：
文献类型：
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作者：
Momose Rieko;Goto Tomotsugu;Utsumi Yousuke;Hashimoto Tetsuya;Chiang Chia-Ying;Kim Seong-Jin;Kashikawa Nobunari;Shimasaku Kazuhiro;Miyazaki Satoshi
我们首先给出了Ly α晕在类恒星天体CFHQ J232908−030158 atz=6.42附近的新的斯巴鲁窄带观测结果，该晕在z>；5(llyα=9.8x×1043erg Vengerg−1，直径在37 pkpc内)是最明亮和扩展的晕。然后，将这些测量结果与文献中的现有数据相结合，我们发现类星体的Ly α晕有两种不同的演化。第一个可能是随着类星体年龄的短期演化，这在四个类星体中可以看到。发现Ly α晕的尺度与类星体的红外光度成反相关关系，其中J2329−0301‘S晕是最亮、最大的晕。它表明，当宿主星系尘埃较少时，电离光子更容易逃逸到银河系周围区域。我们还发现红外光度与黑洞质量(MBH)呈正相关。作为类星体年龄的指示器，我们提出了一个假设，即大的Ly α晕主要存在于类星体活动的年轻阶段，原因是有少量的尘埃。第二个是在∼2-5上观察到的宇宙时间演化。我们发现表面亮度向低红移方向增加的增长速度与暗物质晕的增长速度相似，暗物质晕在z=2时演化到MDH=1012-1013M⊙。Ly α晕的范围也随着暗物质晕的维里半径的增加而以速率标度增加。这些增长与类星体周围的环星系介质在质量和大小上与托管DHS保持同步的情况是一致的。
We first present new Subaru narrow-band observations of the Ly α halo around the quasi-stellar object (QSO) CFHQ J232908−030158 atz= 6.42, which appears the most luminous and extended halo atz> 5 (LLyα= 9.8 × 1043erg s−1within 37 pkpc diameter). Then, combining these measurements with available data in the literature, we find two different evolutions of QSOs’ Ly α haloes. First is a possible short-term evolution with QSO age seen in fourz> 6 QSOs. We find the anticorrelation between the Ly α halo scales with QSOs’ infrared (IR) luminosity, with J2329−0301’s halo being the brightest and largest. It indicates that ionizing photons escape more easily out to circum-galactic regions when host galaxies are less dusty. We also find a positive correlation between IR luminosity and black hole mass (MBH). GivenMBHas an indicator of QSO age, we propose a hypothesis that a large Ly α halo mainly exists around QSOs in the young phase of their activity due to a small amount of dust. The second is an evolution with cosmic time seen overz∼ 2–5. We find the increase of surface brightness towards lower redshift with a similar growth rate to that of dark matter haloes (DHs) that evolve toMDH= 1012–1013M⊙atz= 2. The extent of Ly α haloes is also found to increase at a rate scaling with the virial radius of growing DHs,. These increases are consistent with a scenario that the circum-galactic medium around QSOs evolves in mass and size keeping pace with hosting DHs.