Molecular outflows in the most luminous ULIRGs

One of Herschel.s most important legacies will be the detection and<br>systematic study of largescale molecular outflows. Galaxy outflows<br>are a key ingredient in galaxy evolution: they regulate the growth of<br>galaxies reducing the amount of molecular gas available for star<br>formation, contribute to establish the observed correlation between<br>the black hole mass of a galaxy and the stellar velocity dispersion<br>of its bulge, and play a critical role in the morphological<br>transformation of gasrich mergers into ellipticals. Before the<br>launch of Herschel, our knowledge of the properties of galactic<br>outflows was mostly limited to the study of the ionized and neutral<br>atomic gas. Little was known about the amount of molecular gas<br>involved in the outflows, its velocity structure and spatial<br>distribution. Herschel revolutionized this field. Since 2009 our group<br>has discovered powerful molecular outflows in the majority of the<br>ultraluminous infrared galaxies (ULIRG) studied. These outflows can<br>be easily identified in the form of strong blueshifted absorption and<br>redshifted emission PCygni profiles in the OH 119, 79 and<br>65micron lines. The outflows in some of these galaxies have<br>maximum velocities &amp;amp;amp;gt;1000km/s, mass outflow rates several times<br>larger than the SFR in the galaxy, and molecular gas depletion<br>times &amp;amp;amp;lt;10Myr. Objects with higher AGN luminosity appear to have<br>higher terminal outflow velocities and shorter gas depletion<br>timescales, which indicates that the molecular outflows in these<br>systems might be mostly driven by the AGN. Here we propose to<br>complement current Herschel molecular outflow studies observing<br>a sample of 10 ULIRGs selected among the most IR luminous<br>objects in the local Universe. We will use the redshifted<br>OH 119micron doublet for this purpose. These observations will<br>extend to higher SFR and AGN lum [tru [truncated!, Please see actual data for full text]

赫歇尔望远镜最为重要的遗产之一，便是其对大规模分子喷流的探测与系统性研究。星系喷流是星系演化过程中的关键因素：它们调控着星系的生长，减少了可用于恒星形成的分子气体量，有助于建立观测到的星系黑洞质量与其球状星团恒星速度弥散之间的相关性，并在将富含气体的并合星系转化为椭圆星系的过程中扮演着至关重要的角色。在赫歇尔望远镜发射之前，我们对星系喷流特性的认识主要局限于对电离和中性原子气体的研究。关于参与喷流的分子气体量、其速度结构和空间分布的信息知之甚少。赫歇尔望远镜彻底改变了这一领域。自2009年以来，我们小组在所研究的绝大多数超亮红外星系（ULIRG）中发现了强大的分子喷流。这些喷流可以通过OH 119、79和65微米线的强蓝移吸收和红移发射PCygni谱线轻松识别。其中一些星系的喷流最大速度超过1000公里/秒，质量喷流率是星系恒星形成率数倍之大，分子气体耗竭时间小于10百万年。具有更高活动伽马射线源（AGN）亮度对象似乎具有更高的终端喷流速度和更短的气体耗竭时间尺度，这表明这些系统中的分子喷流可能主要是由AGN驱动的。在此，我们提出通过观测本地宇宙中最亮红外物体中选取的10个ULIRG样本，来补充当前赫歇尔分子喷流研究。我们将利用红移的OH 119微米双线进行此观测。这些观测将扩展至更高的恒星形成率和AGN亮度... [文本截断，请参阅实际数据以获取全文]