GASS 3505：HI过剩被动星系的原型
GASS 3505: the prototype of HI-excess, passive galaxies
摘要：
我们提出了我们的多波长分析的原型\HI -过剩星系，GASS 3505，选择的基础上有一个大的气体含量（$M_{\rm HI} = 10^{9.9}$ \msun）相比，它的小相关的恒星形成活动（$\sim$ 0.1 \msun \ yr $^{-1}$）在银河阿雷西博SDSS调查（GASS）。甚大阵列（VLA）观测表明，GASS 3505中的\HI \分布在一个规则旋转的扩展（$\sim$ 50 kpc半径）气体环中。在SDSS的光学影像中，GASS 3505看起来像是一个以膨胀为主的星系，然而深层光学影像显示在中央膨胀周围有低表面亮度（$\gtrsim25$ mag arcsec $^{-2}$）的恒星辐射。吸积的直接证据是以扩展的（$\sim$ 60 kpc）恒星流的形式检测到的，表明GASS 3505在不久的过去经历了一次小合并。我们调查的可能性，\HI \环在GASS 3505吸积在这样的合并事件使用N体和光滑粒子流体动力学（SPH）模拟。再现一般性质的最佳模型（即，气体分布和运动学，恒星形态）的星系涉及合并之间的中央隆起和气体丰富（$M_{\star}$ = 10 $^9$ \msun \ and $M_{\rm HI}$ / $M_{\star}$ = 10）盘星系。然而，观察到的和模拟的性质的小差异可能表明，其他来源的气体必须参与气藏的建设。这项工作是朝着更大的计划迈出的第一步，该计划旨在研究驱动附近星系气体标度关系中大散射的物理机制。
英文摘要：
We present our multiwavelength analysis of a prototype \HI-excess galaxy, GASS 3505, selected based on having a large gas content ($M_{\rm HI} = 10^{9.9}$ \msun) compared to its little associated star formation activity ($\sim$0.1 \msun\ yr$^{-1}$) in the GALEX Arecibo SDSS Survey (GASS). Very Large Array (VLA) observations show that the \HI\ in GASS 3505 is distributed in a regularly rotating, extended ($\sim$50 kpc radius) gas ring. In the SDSS optical image GASS 3505 appears as a bulge-dominated galaxy, however deep optical imaging reveals low surface brightness ($\gtrsim25$ mag arcsec$^{-2}$) stellar emission around the central bulge. Direct evidence for accretion is detected in form of an extended ($\sim$60 kpc) stellar stream, showing that GASS 3505 has experienced a minor merger in the recent past. We investigate the possibility that the \HI\ ring in GASS 3505 was accreted in such a merger event using N-body and smoothed particle hydrodynamic (SPH) simulations. The best model that reproduces the general properties (i.e., gas distribution and kinematics, stellar morphology) of the galaxy involves a merger between the central bulge and a gas-rich ($M_{\star}$ = 10$^9$ \msun\ and $M_{\rm HI}$/$M_{\star}$ = 10) disk galaxy. However, small discrepancies in the observed and modeled properties could suggest that other sources of gas have to be involved in the build-up of the gas reservoir. This work is the first step toward a larger program to investigate the physical mechanisms that drive the large scatter in the gas scaling relations of nearby galaxies.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
