论文标题
Ultra Strong Mg II吸收器的寄主星系z $ \ sim $ 0.5
Host Galaxies of Ultra Strong Mg II absorbers at z $\sim$ 0.5
论文作者
论文摘要
从109个候选超强Mg II的样本中（USMGII；具有Mg II吸收的静止宽度，$ W_ {2796}> 3.0 $ angstrom系统在z = 0.4-0.6处，我们确认27，并确认27并鉴定基于20个系统的宿主星系，基于我们的盐构度观察或从SDSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSRACATION进行。测得的冲击参数，[O II]光度，恒星形成速率，B波段光度和恒星质量在范围内$ 7.3 \ le d [KPC] \ le79 $，$ 0.2 \ le l _ {[o ii]} [o ii]} [10^{41} {41} sfr [m_ \ odot yr^{ - 1}] \ le 33.51 $，$ 0.15l_b^*\ le l_b \ le1.63l_b^*$和$ 10.21 \ le log [m _*/m_*/m_ \ odot] \ le11.62 $。发现的影响参数比$ w_ {2796} $ vs d的MG II吸收器的一般人群的关系大。在给定的D中，与典型的MG II吸收剂相比，USMGII宿主星系更加发光和巨大。但是，测得的SFR略低于$ z \ sim0.5 $的同一m $ _ \ star $的主序列星系。我们报告了$ l _ {[O ii]} $和W $ _ {2796} $的$ L _ {[O II]} $之间的相关性，该$ MG II吸收剂的人口主要由弱Mg II吸收剂的宿主星系驱动，而Mg II吸收剂的宿主星系往往低$ L _ {[O II]} $和大型影响参数。我们发现至少$ \ sim $ 33％的USMGII主机星系（限制幅度为$ m_r <23.6 $）是孤立的，在这些情况下，大型但不是Starburst Galaxies中的大量阳极流量（输入/流出），大的$ w_ {2796} $可能源自气流（输入/流出）。我们还发现，在至少$ \ sim $ 17％的情况下，Galaxy交互可能导致较大的速度宽度。
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.
