GASKAP-HI Pilot Survey Science III: An unbiased view of cold gas in the Small Magellanic Cloud
James Dempsey, N. M. McClure-Griffiths, Claire Murray, John M. Dickey, Nickolas M. Pingel, Katherine Jameson, Helga Dénes, Jacco Th. van Loon, D. Leahy, Min-You… 展开作者
James Dempsey, N. M. McClure-Griffiths, Claire Murray, John M. Dickey, Nickolas M. Pingel, Katherine Jameson, Helga Dénes, Jacco Th. van Loon, D. Leahy, Min-Young Lee, S. Stanimirović, Shari Breen, Frances Buckland-Willis, Steven J. Gibson, Hiroshi Imai, Callum Lynn, C. D. Tremblay
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Accepted for publication in PASA, 19 pages, 17 figures, 5 tables
We present the first unbiased survey of neutral hydrogen (HI) absorption in the Small Magellanic Cloud (SMC). The survey utilises pilot HI observations with the Australian Square Kilometre Array Pathfinder (ASKAP) telescope as part of the Galactic ASKAP HI (GASKAP-HI) project whose dataset has been processed with the GASKAP-HI absorption pipeline, also described here. This dataset provides absorption spectra towards 229 continuum sources, a 275% increase in the number of continuum sources previously published in the SMC region, as well as an improvement in the quality of absorption spectra over previous surveys of the SMC. Our unbiased view, combined with the closely matched beam size between emission and absorption, reveals a lower cold gas faction (11%) than the 2019 ATCA survey of the SMC and is more representative of the SMC as a whole. We also find that the optical depth varies greatly between the SMC's bar and wing regions. In the bar we find that the optical depth is generally low (correction factor to the optically thin column density assumption of $\mathcal{R}_{\rm HI} \sim 1.04$) but increases linearly with column density. In the wing however, there is a wide scatter in optical depth despite a tighter range of column densities.
HI filaments as potential compass needles? Comparing the magnetic field structure of the Small Magellanic Cloud to the orientation of GASKAP-HI filaments
The GASKAP-HI Survey towards the Magellanic Clouds: Cold Atomic Gas Survival and Evolution in the Large Magellanic Cloud
University of Wisconsin–Madison（威斯康星大学麦迪逊分校）；Research School of Astronomy & Astrophysics, The Australian National University（澳大利亚国立大学天文与天体物理研究学院）；Lennard-Jones Laboratories, Keele University（基尔大学伦纳德-琼斯实验室）；Max-Planck-Institut für Radioastronomie（马克斯·普朗克射电天文研究所）；Department of Astronomy, Indiana University（印第安纳大学天文学系）
A Detailed GASKAP-HI View of Shells and Loops in the Magellanic Bridge
Laboratoire de Physique de l’École Normale Supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Université Paris Cité, Observatoire de Paris（巴黎高等师范学院物理实验室，巴黎文理研究大学，法国国家科学研究中心，索邦大学，巴黎西岱大学，巴黎天文台）；SKA Observatory, Jodrell Bank（平方公里阵列射电望远镜天文台，乔德雷尔银行）；School of Mathematical and Physical Sciences and Astrophysics and Space Technologies Research Centre, Macquarie University（麦考瑞大学数理科学与天体物理及太空技术研究学院）；College of Sciences and Engineering, Universidad San Francisco de Quito（基多圣弗朗西斯科科技大学科学与工程学院）；School of Natural Sciences, University of Tasmania（塔斯马尼亚大学自然科学学院）；Department of Physics and Astronomy, Western Kentucky University（肯塔基西部大学物理与天文系）
Revealing the cold skeleton of the Magellanic Clouds and the Magellanic Bridge with ASKAP
The Australian National University（澳大利亚国立大学）；CSIRO Information Management and Technology（CSIRO信息与技术部）；Laboratoire de Physique de l’École Normale Supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Université Paris Cité（巴黎高等师范学院物理实验室，ENS，巴黎文理研究大学，法国国家科学研究中心，索邦大学，巴黎西岱大学）；LUX, Observatoire de Paris, Université PSL, Sorbonne Université（卢克斯天文台，巴黎天文台，巴黎文理研究大学，索邦大学）；Stanford University（斯坦福大学）；Kavli Institute for Particle Astrophysics & Cosmology（卡弗里粒子天体物理学与宇宙学研究所）；University of Tasmania（塔斯马尼亚大学）；Korea Astronomy and Space Science Institute（韩国天文学与空间科学研究院）；Johns Hopkins University（约翰斯·霍普金斯大学）；Space Telescope Science Institute（太空望远镜科学研究所）
HST astrometry in the 30 Doradus region: II. Runaway stars from new proper motions in the Large Magellanic Cloud
我们提出了一个目录的相对自行368,787恒星在30剑鱼座地区的大麦云（LMC），基于专门的两个历元的调查与哈勃太空望远镜（HST）和补充自行从我们的试点档案研究。我们证明，一个相对较短的3年的历元差是足以达到$\sim$ 0.1 mas yr $^{-1}$的精度水平或更好。一些恒星的相对自行超过了3 σ误差阈值，代表了银河系居民和17颗潜在的LMC失控恒星的混合物。基于183 VFTS OB-星的最佳自行，我们得出结论，他们没有一个移动速度超过$\sim$ 0.3 mas yr $^{-1}$在每个坐标-相当于$\sim$ 70 km s $^{-1}$。在剩下的351颗自行精度较低的VFTS恒星中，只有一颗候选OB逃逸星可以被识别。我们排除任何OB星在我们的样本中移动的切向速度超过$\sim$ 120公里秒$^{-1}$。这项研究最重要的结果是发现了10颗质量范围很广的恒星，它们似乎是从大质量星团R136的切平面上从$35^{\prime\prime}$到$407^{\prime\prime}$的角距离上被弹射出来的，相当于8-98 pc。这些失控的切向速度似乎与视星等相关，表明可能依赖于恒星质量。
