论文标题
哈勃太空望远镜捕获UGC〜12591：在非常庞大且快速旋转的杂种星系中的凸起/圆盘特性，恒星形成和“失踪的Baryons”人口普查
Hubble Space Telescope Captures UGC~12591: Bulge/Disc Properties, Star Formation and `Missing Baryons' Census in a Very Massive and Fast Spinning Hybrid Galaxy
论文作者
论文摘要
我们提出了附近的大规模，高度旋转的杂种Galaxy UGC〜12591的哈勃太空望远镜（HST）观察结果，以及在紫外线对FIR带中的观察结果。 V，I和H频段中的HST数据用于解散结构组件。表面光度法显示了凸起的主导地位，H频段B/D比为$ 69 \％$。光谱能分布（SED）拟合显示出极低的全球恒星形成速率（SFR）为$ \ rm \ sim0.1-0.2 m_ \ odot yr^{ - 1} $，对于银河系的巨大巨大$ \ rm 1.6 \ rm 1.6 \ rm 1.6 \ times10^{11} m_ \ odot的高度，与一定的高度相关的高度均高于A的巨大恒星质量。 $ 3-5 \％$。至少在过去的$ \ rm 10^{8} $年中，银河系一直处于无菌状态，“红色和死亡”星系。 UGC〜12591拥有一个超级质量的黑洞（SMBH），为6.18 \ rm 6.18 \ times 10^{8} m_ \ odot $，目前可能是静止的，即，我们都不会看到大型（$ \ rm> 1 kpc $）无线电销量，也不是SMB的贡献，也不是对中等范围的高级助手的范围。我们获得了所有可观察到的重子的详细人口普查，总质量为$ \ rm 6.46 \ times10^{11} m_ \ odot $在病毒半径内，相当于$ \ sim $$ 85 \％$的Baryonic缺陷相对于宇宙的含义。这些重子中只有一小部分位于温暖/热的X射线X射线光环中，而大多数仍然无法观察到。我们讨论了各种天体物理场景，以解释其异常特性。我们的工作是理解如此庞大，孤立星系的组装历史的重要一步。
We present Hubble Space Telescope (HST) observations of the nearby, massive, highly rotating hybrid galaxy UGC~12591, along with observations in UV to FIR bands. HST data in V, I, and H bands is used to disentangle the structural components. Surface photometry shows a dominance of the bulge over the disc with H-band B/D ratio of $69\%$. The spectral energy distribution (SED) fitting reveals an extremely low global star formation rate (SFR) of $\rm\sim0.1-0.2 M_\odot yr^{-1}$, exceptionally low for the galaxy's huge stellar mass of $\rm 1.6\times10^{11}M_\odot$, implying a strong quenching of its SFR with star formation efficiency of $3-5\%$. For at least the past $\rm 10^{8}$ years, the galaxy has remained in a quiescent state as a sterile, `red and dead' galaxy. UGC~12591 hosts a supermassive black hole (SMBH) of $\rm 6.18\times 10^{8} M_\odot$ which is possibly quiescent at present, i.e. neither we see large ($\rm>1 kpc$) radio jets nor is the SMBH contributing significantly to the mid-IR SED, ruling out strong radiative feedback of AGN. We obtained a detailed census of all observable baryons with a total mass of $\rm 6.46\times10^{11} M_\odot$ within the virial radius, amounting to a baryonic deficiency of $\sim$$85\%$ relative to the cosmological mean. Only a small fraction of these baryons resides in a warm/hot circum-galactic X-ray halo, while the majority are still unobservable. We discussed various astrophysical scenarios to explain its unusual properties. Our work is a major step forward in understanding the assembly history of such extremely massive, isolated galaxies.
