Evidence of wind signatures in the gas velocity profiles of Red Geysers
Namrata Roy, Kevin Bundy, Rebecca Nevin, Francesco Belfiore, Renbin Yan, Stephanie Campbell, Rogemar A. Riffel, Rogerio Riffel, Matthew Bershady, Kyle Westfall,… 展开作者
Namrata Roy, Kevin Bundy, Rebecca Nevin, Francesco Belfiore, Renbin Yan, Stephanie Campbell, Rogemar A. Riffel, Rogerio Riffel, Matthew Bershady, Kyle Westfall, Niv Drory, Kai Zhang
Spatially resolved spectroscopy from SDSS-IV MaNGA survey has revealed a class of quiescent, relatively common early-type galaxies, termed "red geysers", that possibly host large scale active galactic nuclei driven winds. Given their potential importance in maintaining low level of star formation at late times, additional evidence confirming that winds are responsible for the red geyser phenomenon is critical. In this work, we present follow-up observations with the Echellette Spectrograph and Imager (ESI) at the Keck telescope of two red geysers (z$<$0.1) using multiple long slit positions to sample different regions of each galaxy. Our ESI data with a spectral resolution (R) $\sim$ 8000 improves upon MaNGA's resolution by a factor of four, allowing us to resolve the ionized gas velocity profiles along the putative wind cone with an instrumental resolution of $\rm σ= 16~km~s^{-1}$. The line profiles of H$α$ and [NII]$\rm λ6584$ show asymmetric shapes that depend systematically on location $-$ extended blue wings on the red-shifted side of the galaxy and red wings on the opposite side. We construct a simple wind model and show that our results are consistent with geometric projections through an outflowing conical wind oriented at an angle towards the line of sight. An alternative hypothesis that assigns the asymmetric pattern to "beam-smearing" of a rotating, ionized gas disk does a poor job matching the line asymmetry profiles. While our study features just two sources, it lends further support to the notion that red geysers are the result of galaxy-scale winds.
Galactic Rain: Cool Gas Inflows in Red Geyser Galaxies and Their Connection to AGN Activity and Interactions
University of California, Santa Cruz（加州大学圣克鲁兹分校）；Arizona State University（亚利桑那州立大学）；Johns Hopkins University（约翰斯·霍普金斯大学）；University of California Observatories（加州大学天文台）；San Diego State University（圣地亚哥州立大学）；University of California, San Diego（加州大学圣地亚哥分校）
Mechanical feedback from stellar winds with an application to galaxy formation at high redshift
我们计算不同的恒星演化轨迹，以量化的能量，质量和金属产生的大规模主序星和主序星后风。我们的目的是调查的影响的二进制系统和金属度依赖的初始旋转速度分布的反馈恒星风。我们发现显着的变化相比，常用的非旋转，单星的情况。最大的差异是明显的低金属，其中机械能预算大幅增加。以建立最大的（即忽略近拱星环境中的耗散）风对星系形成早期阶段的影响，我们用我们新的反馈估计来模拟红移为3的亚$L_*$星系的形成和演化（由质量为$1.8\times 10^{11}$ M $_\odot$的暗物质晕托管），并将结果与仅考虑超新星（SN）反馈的模拟结果进行比较。考虑到恒星风持续不断的能量注入，恒星的总质量、金属含量、恒星形成速率的突然性以及流出的气体质量都会降低。然而，我们的数值实验表明，旋转和双星风的增强机械反馈对最相关的星系性质的影响有限，相比非旋转的单星情况。最终，我们研究了风中夹带的金属和SNe喷射的金属之间的相对丰度，发现它在模拟星系及其周围的晕中几乎保持不变。
