Star-Gas Surface Density Correlations in Twelve Nearby Molecular Clouds I: Data Collection and Star-Sampled Analysis
Riwaj Pokhrel, Robert A. Gutermuth, Sarah K. Betti, Stella S. R. Offner, Philip C. Myers, S. Thomas Megeath, Alyssa D. Sokol, Babar Ali, Lori Allen, Tom S. Alle… 展开作者
Riwaj Pokhrel, Robert A. Gutermuth, Sarah K. Betti, Stella S. R. Offner, Philip C. Myers, S. Thomas Megeath, Alyssa D. Sokol, Babar Ali, Lori Allen, Tom S. Allen, Michael M. Dunham, William J. Fischer, Thomas Henning, Mark Heyer, Joseph L. Hora, Judith L. Pipher, John J. Tobin, Scott J. Wolk
We explore the relation between the stellar mass surface density and the mass surface density of molecular hydrogen gas in twelve nearby molecular clouds that are located at $<$1.5 kpc distance. The sample clouds span an order of magnitude range in mass, size, and star formation rates. We use thermal dust emission from $Herschel$ maps to probe the gas surface density and the young stellar objects from the most recent $Spitzer$ Extended Solar Neighborhood Archive (SESNA) catalog to probe the stellar surface density. Using a star-sampled nearest neighbor technique to probe the star-gas surface density correlations at the scale of a few parsecs, we find that the stellar mass surface density varies as a power-law of the gas mass surface density, with a power-law index of $\sim$2 in all the clouds. The consistent power-law index implies that star formation efficiency is directly correlated with gas column density, and no gas column density threshold for star formation is observed. We compare the observed correlations with the predictions from an analytical model of thermal fragmentation, and with the synthetic observations of a recent hydrodynamic simulation of a turbulent star-forming molecular cloud. We find that the observed correlations are consistent for some clouds with the thermal fragmentation model and can be reproduced using the hydrodynamic simulations.
ALMA FACTS III. High-Resolution CO(2-1)/CO(1-0) Maps of Twelve Nearby Galaxies
Stony Brook University（石溪大学）；Institute of Astronomy, Graduate School of Science, The University of Tokyo（东京大学理学研究科天文学研究所）；National Astronomical Observatory of Japan（日本国立天文台）；Joint ALMA Observatory（ALMA联合观测站）；Division of Liberal Arts, Kogakuin University（工学院大学教养学部）；Research Center for Physics and Mathematics, Osaka Electro-Communication University（大阪电通大学理数研究中心）
APEX and NOEMA observations of H$_{2}$S in nearby luminous galaxies and the ULIRG Mrk~231 -- Is there a relation between dense gas properties and molecular outflows?
Formation of star clusters and enrichment by massive stars in simulations of low-metallicity galaxies with a fully sampled initial stellar mass function
Survey of Ionized Gas of the Galaxy, Made with the Arecibo telescope (SIGGMA): Inner Galaxy Data Release
用阿雷西博望远镜（SIGGMA）进行的银河系电离气体巡天（Survey of Ionized Gas of the Galaxy）提供了一个来自阿雷西博可见的银河平面部分的射电复合线（RRL）发射的完整采样视图。观测使用阿雷西博L波段馈源阵列（ALFA），其半高宽光束尺寸为3.4弧分。从H163 $α$到H174 $α$的12个氢RRL位于从1225 MHz到1525 MHz的瞬时带通内。我们在这里提供立方体的平均（“堆叠”）RRL发射的内星系区域$32 \le \ell \le 70$度，$|b|\le1.5$度，与角分辨率为6角分。在5.1 km/s速度分辨率下的叠加RRL rms为$\sim0.65$ mJy波束$^{-1}$，使其成为现存最灵敏的大规模全采样RRL调查。我们使用SIGGMA数据编目319 RRL检测在244个已知的HII区域的方向，和108个新的检测在79 HII区域候选人的方向。我们确定了11个碳RRL排放区域，所有这些区域在空间上都与已知的HII区域相一致。我们检测到的RRL发射的32超新星遗迹（SNRs）在调查区域中发现的14个方向。这种RRL发射通常具有与SNR相同的形态。RRL速度给出的运动学距离与文献中发现的一致，表明RRL可能提供一个额外的工具来约束距离SNR。最后，我们分析了两个明亮的恒星形成复合体：W 49和W51。我们讨论了在SNR W …
Targeted search for eccentric supermassive binary black holes in OJ 287 and nearby galaxy clusters with PPTA DR3
Institute for Frontier in Astronomy and Astrophysics & Faculty of Arts and Sciences, Beijing Normal University（北京师范大学前沿天文与天体物理研究所及文理学院）；School of Physics and Astronomy, Beijing Normal University（北京师范大学物理与天文学院）；Max Planck Institute for Gravitational Physics (Albert Einstein Institute)（马克斯·普朗克引力物理研究所（爱因斯坦研究所））；Leibniz Universität Hannover（汉诺威莱布尼茨大学）；School of Physics and Astronomy, Monash University（蒙纳士大学物理与天文学院）；ARC Centre for Excellence for Gravitational Wave Discovery (OzGrav)（ARC引力波发现卓越中心（OzGrav））；Australia Telescope National Facility, CSIRO, Space & Astronomy（澳大利亚望远镜国家设施，CSIRO空间与天文部）；School of Physics, University of Melbourne（墨尔本大学物理学院）；Center for Gravitation, Cosmology and Astrophysics, Department of Physics, University of Wisconsin–Milwaukee（威斯康星大学密尔沃基分校物理系引力、宇宙学与天体物理中心）
SIGGMA: A Survey of Ionized Gas in the Galaxy, Made with the Arecibo Telescope
阿雷西博望远镜（SIGGMA）进行的银河系电离气体巡天（Survey of Ionized Gas in the Galaxy）使用阿雷西博L波段馈源阵列（ALFA）对银河系平面（30 < l < 75和-2 < b < 2; 175 < l < 207和-2 < b < 1）进行了全面采样，并在射电复合线（RRL）中进行了观测。经处理的数据集以2度（沿l）x4度（沿b）x151（通道数）的数据立方体的形式制作，存档并公布。151个通道的速度范围为600 km/s，速度分辨率从最低频率通道到最高频率通道分别为4.2 km/s到5.1 km/s，RRL图的分辨率为3.4 arcmin，线通量密度灵敏度为0.5 mJy，研究碳RRL的光解离区（PDR）的物理，并研究扩展低密度介质（ELDM）的起源。12条Hnα谱线位于ALFA的300 MHz带通范围内;它们被重新采样到一个共同的速度分辨率，以将信噪比（SN）提高3倍或更多，并保持谱线宽度。SIGGMA将进行迄今为止最敏感的完全抽样RRL调查。在这里，我们详细讨论了观测和数据处理技术。对HII区复合体S255/S257的测试观测发现了SN>10的Hnα和Cnα线。
Resolved Dust-Gas-Metallicity relations in nearby spiral galaxies
INAF – Istituto di Radioastronomia（意大利国家天体物理研究所射电天文台）；Dipartimento di Fisica e Astronomia, Alma Mater Studiorum Università di Bologna（博洛尼亚大学物理与天文系）；INAF – Osservatorio di Astrofisica e Scienza dello Spazio di Bologna（意大利国家天体物理研究所博洛尼亚天体物理与空间科学观测站）；Instituto de Radioastronomía y Astrofísica, UNAM（墨西哥国立自治大学射电天文与天体物理研究所）；Departamento de Física de la Tierra y Astrofísica, Fac. de C.C. Físicas, Universidad Complutense de Madrid（马德里康普顿斯大学物理学院地球与天体物理学系）；Instituto de Física de Partículas y del Cosmos, IPARCOS, Fac. C.C. Físicas, Universidad Complutense de Madrid（马德里康普顿斯大学物理学院粒子与宇宙物理研究所IPARCOS）；INAF – Osservatorio Astrofisico di Arcetri（意大利国家天体物理研究所阿切特里天文台）
