From a sample of 109 candidate Ultra-Strong Mg II (USMgII; having rest equivalent width of Mg II absorption, $W_{2796}>3.0$ Angstrom) systems at z=0.4-0.6, we confirm 27 and identify host galaxies of 20 systems based on associated nebular line emission from our SALT observations or from SDSS fiber spectra. The measured impact parameter, [O II] luminosity, star formation rate, B-band luminosity and stellar mass are in the ranges $7.3\le D[kpc]\le79$, $0.2\le L_{[O II]}[ 10^{41}~erg s^{-1}]$ $\le 4.5$, $2.59\le SFR[M_\odot yr^{-1} ]\le 33.51$, $0.15L_B^*\le L_B\le1.63L_B^*$ and $10.21\le log[M_*/M_\odot]\le11.62$ respectively. The impact parameters found are larger than that predicted by the $W_{2796}$ vs D relationship of the general population of Mg II absorbers. At a given D, USMgII host galaxies are more luminous and massive compared to typical Mg II absorbers. However, the measured SFRs are slightly lower than that of main-sequence galaxies with the same M$_\star$ at $z\sim0.5$. We report a correlation between $L_{[O II]}$ and W$_{2796}$ for the full population of Mg II absorbers, driven mainly by the host galaxies of weak Mg II absorbers that tend to have low $L_{[O II]}$ and large impact parameters. We find at least $\sim$33% of the USMgII host galaxies (with a limiting magnitude of $m_r<23.6$) are isolated and the large $W_{2796}$ in these cases may originate from gas flows (infall/outflow) in single halos of massive but not starburst galaxies. We also find galaxy interactions could be responsible for large velocity widths in at least $\sim$17% cases.
Mapping the z>=5 SiIV Column Density Distribution onto the Galaxy Stellar Mass Function Using the Cumulative Absorption Cross Section
New Mexico State University(新墨西哥州立大学);Cosmic Dawn Center (DAWN), Niels Bohr Institute, University of Copenhagen / DTU-Space, Technical University of Denmark(哥本哈根大学尼尔斯·玻尔研究所宇宙黎明中心(DAWN)/丹麦技术大学DTU空间);Vanderbilt University(范德堡大学);Space Telescope Science Institute(太空望远镜科学研究所)
Exploring galaxy dark matter halos across redshifts with strong quasar absorbers
类星体的视线相交干预星系盘或环银河系的环境在随机的碰撞参量和潜在的井深。已知吸收线速度宽度($Δv_{90}$)与宿主星系的恒星质量成比例,与类星体视线的投影距离成反比。它对恒星质量的依赖性可以通过与宿主星系的发射线宽度$σ_{em}$归一化来消除,因此可以直接比较具有$Δv_{90}$值范围的吸收体。利用一个在0.2 < z < 3.2的DLA系统的样本,我们发现,速度比$Δv_{90}/σ_{em}$与主机的投影距离减小。我们比较的数据与预期的视线速度分散来自不同的暗物质晕质量分布,并发现模型与陡峭的径向暗物质配置文件提供了一个更好的拟合的意见,虽然散射仍然很大。从星系流出的气体可能会导致散射增加,或者暗物质晕模型的尺度半径可能不代表星系。通过计算维里速度,我们证明了属于大质量星系晕(M $_{halo} \approx 10^{12}$ M $_{\odot}$)的富含金属的DLAs大部分仍然受引力束缚在晕上。
A dense, metal-rich absorber driven by a heavily dust-obscured galaxy: The direct evidence of CGM enrichment at $z\sim7$
University of Toronto(多伦多大学);Dunlap Institute for Astronomy and Astrophysics(邓普天文学与天体物理研究所);University of Copenhagen(哥本哈根大学);Niels Bohr Institute(尼尔斯·玻尔研究所);Steward Observatory, University of Arizona(亚利桑那大学斯图尔德天文台);MIT Kavli Institute for Astrophysics and Space Research(麻省理工学院卡弗里天体物理学与空间研究学院);Massachusetts Institute of Technology(麻省理工学院)
Ultra-strong MgII absorbers trace both inflowing and outflowing gas: insights from dual down-the-barrel and quasar sightlines
Swinburne University of Technology(斯威本科技大学);ARC Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D)(ARC三维全天空天体物理学卓越中心);The University of Oklahoma(俄克拉荷马大学);San Diego State University(圣地亚哥州立大学)
Ultra-thick warm absorbers: Enlarging the parameter space of AGN ionised outflows
INAF Osservatorio Astronomico di Roma(意大利国家天体物理研究所罗马天文台);Space Science Data Center, Agenzia Spaziale Italiana(意大利航天局空间数据中心);Center for Astrophysics | Harvard & Smithsonian(哈佛与史密森尼天体物理中心);INAF – Osservatorio Astrofisico di Arcetri(意大利国家天体物理研究所阿切尔菲天文台);ASI -Agenzia Spaziale Italiana(意大利航天局);Dipartimento di Fisica, Università degli Studi di Roma Tor Vergata(罗马托维塔大学物理系);INAF - Istituto di Astrofisica e Planetologia Spaziali(意大利国家天体物理研究所天体物理学与行星科学研究所);NASA Goddard Space Flight Center(美国宇航局戈达德太空飞行中心)
Multiphase quasar-driven outflows in PG 1114+445. I. Entrained ultra-fast outflows
近几十年的大量证据表明,超大质量黑洞(SMBH)的流出流在星系演化中起着重要作用,在许多Seyfert星系和类星体的光谱中,经常发现大尺度流出流(WA)和快盘风(UFO),它们之间存在着相关性。最近探测到的低电离和低柱密度外流,但具有与UFO相当的高速度,挑战了这种最初可能的相关性。对活动星系核中UFO的观测表明,它们的能量可能足以对星际介质(ISM)产生影响。然而,内部高电离外流和ISM之间的相互作用的观测证据仍然缺失。我们在这里提出的光谱分析的12 XMM牛顿/EPIC档案观测的类星体PG 1114+445,旨在研究复杂的流出性质的吸收体。我们的分析揭示了三个吸收结构的存在。我们发现一个WA与速度$v\sim530$ km s $^{-1}$,电离$\logξ/\text{erg cm s}^{-1}\sim0.35,$和柱密度$\log N_\text{H}/\text{cm}^{-2}\sim22$,和一个UFO与$v_\text{out}\sim0.145c$,$\logξ/\text{erg cm s}^{-1}\sim4$,和$\log N_\text{H}/\text{cm}^{-2}\sim23$。我们还发现了一个额外的吸收剂在软X射线($E<2$千电子伏)与速度相当的UFO($v_\text{out}\sim0.120c$),但电离($\logξ/\text{e…
Warm Absorbers in X-rays (WAX), a comprehensive high resolution grating spectral study of a sample of Seyfert Galaxies: II. Warm Absorber dynamics and feedback to galaxies
本文是利用XMM-牛顿卫星(WAX-I)的高分辨率光栅光谱数据对X射线中的暖吸收体(WA)进行广泛研究的继续。在这里,我们讨论的全球动力学特性,以及能量的WA组件中检测到的WAX样品。由WAX样品中的电离参数$ξ$和柱密度$N_H$的线性回归斜率估计的WA密度分布($n\propto r^{-α}$)的斜率为$α=1.236\pm 0.034$。我们发现,WA云可能起源于从环面(环面风)的内边缘的光电离蒸发的结果。它们也可以起源于更快的吸积盘流出物,即超快流出物(UFO)撞击星际介质或环面所产生的激波的冷却前沿。WA的加速机制是复杂的,无论是辐射驱动的风或MHD驱动的风的情况下,可以单独描述的外流加速。然而,我们发现,辐射力在加速WA通过软X射线吸收线,也与尘埃不透明度发挥了重要作用。由于WA的距离和体积填充因子估计的不确定性很大,我们得出结论,WA的动力学光度$\dot{E}_k$有时可能大到足以产生显着的反馈到宿主星系。我们发现,最低的电离状态进行最大的质量流出,和源具有较高的Fe M UTA吸收($15-17\rm Å$)有更多的质量流出率。