J. M. Dickey, N. McClure-Griffiths, S. J. Gibson, J. F. Gomez, H. Imai, P. Jones, S. Stanimirovic, J. Th. van Loon, A. Walsh, A. Alberdi, G. Anglada, L. Uscanga… 展开作者
J. M. Dickey, N. McClure-Griffiths, S. J. Gibson, J. F. Gomez, H. Imai, P. Jones, S. Stanimirovic, J. Th. van Loon, A. Walsh, A. Alberdi, G. Anglada, L. Uscanga, H. Arce, M. Bailey, A. Begum, B. Wakker, N. Ben Bekhti, P. Kalberla, B. Winkel, K. Bekki, B. -Q. For, L. Staveley-Smith, T. Westmeier, M. Burton, M. Cunningham, J. Dawson, S. Ellingsen, P. Diamond, J. A. Green, A. S. Hill, B. Koribalski, D. McConnell, J. Rathborne, M. Voronkov, K. A. Douglas, J. English, H. A. Ford, T. Foster, Y. Gomez, A. Green, J. Bland-Hawthorn, S. Gulyaev, M. Hoare, G. Joncas, J-H. Kang, C. R. Kerton, B-C. Koo, D. Leahy, N. Lo, F. J. Lockman, V. Migenes, J. Nakashima, Y. Zhang, D. Nidever, J. E. G. Peek, D. Tafoya, W. Tian, D. Wu
备注：
45 pages, 8 figures, Pub. Astron. Soc. Australia (in press)
A survey of the Milky Way disk and the Magellanic System at the wavelengths of the 21-cm atomic hydrogen (HI) line and three 18-cm lines of the OH molecule will be carried out with the Australian Square Kilometre Array Pathfinder telescope. The survey will study the distribution of HI emission and absorption with unprecedented angular and velocity resolution, as well as molecular line thermal emission, absorption, and maser lines. The area to be covered includes the Galactic plane (|b|< 10deg) at all declinations south of delta = +40deg, spanning longitudes 167deg through 360deg to 79deg at b=0deg, plus the entire area of the Magellanic Stream and Clouds, a total of 13,020 square degrees. The brightness temperature sensitivity will be very good, typically sigma_T ~ 1 K at resolution 30arcsec and 1 km/s. The survey has a wide spectrum of scientific goals, from studies of galaxy evolution to star formation, with particular contributions to understanding stellar wind kinematics, the thermal phases of the interstellar medium, the interaction between gas in the disk and halo, and the dynamical and thermal states of gas at various positions along the Magellanic Stream.
We present the most sensitive and detailed view of the neutral hydrogen (HI) emission associated with the Small Magellanic Cloud (SMC), through the combination of data from the Australian Square Kilometre Array Pathfinder (ASKAP) and Parkes (Murriyang), as part of the Galactic Australian Square Kilometre Array Pathfinder (GASKAP) pilot survey. These GASKAP-HI pilot observations, for the first time, reveal HI in the SMC on similar physical scales as other important tracers of the interstellar medium, such as molecular gas and dust. The resultant image cube possesses an rms noise level of 1.1 K …
Using the Australian Square Kilometre Array Pathfinder to measure 21-cm absorption spectra toward continuum background sources, we study the cool phase of the neutral atomic gas in the far outer disk, and in the inner Galaxy near the end of the Galactic bar at longitude 340 degrees. In the inner Galaxy the cool atomic gas has a smaller scale height than in the solar neighborhood, similar to the molecular gas and the superthin stellar population in the bar. In the outer Galaxy the cool atomic gas is mixed with the warm, neutral medium, with the cool fraction staying roughly constant with Galact…
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 ove…
High-spatial-resolution HI observations have led to the realisation that the nearby (within few hundreds of parsecs) Galactic atomic filamentary structures are aligned with the ambient magnetic field. Enabled by the high quality data from the Australian Square Kilometre Array Pathfinder (ASKAP) radio telescope for the Galactic ASKAP HI (GASKAP-HI) survey, we investigate the potential magnetic alignment of the $\gtrsim 10\,{\rm pc}$-scale HI filaments in the Small Magellanic Cloud (SMC). Using the Rolling Hough Transform (RHT) technique that automatically identifies filamentary structures, comb…
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）
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）
A sample of short-lived Galactic radio transients from ASKAP VAST
University of North Carolina at Chapel Hill（北卡罗来纳大学教堂山分校）；University of Wisconsin-Milwaukee（威斯康星大学密尔沃基分校）；Curtin University（科廷大学）；California Institute of Technology（加州理工学院）；Carnegie Institution for Science（卡内基科学研究所）；University of Sydney（悉尼大学）
The Rapid ASKAP Continuum Survey (RACS) is the first large sky survey using the Australian Square Kilometre Array Pathfinder (ASKAP), covering the sky south of +41$^\circ$ declination. With ASKAP's large, instantaneous field of view, $\sim 31$ deg$^2$, RACS observed the entire sky at a central frequency of 887.5 MHz using 903 individual pointings with 15 minute observations. This has resulted in the deepest radio survey of the full Southern sky to date at these frequencies. In this paper, we present the first Stokes I catalogue derived from the RACS survey. This catalogue was assembled from 79…
We present an analysis of a new 120 deg$^{2}$ radio continuum image of the Large Magellanic Cloud (LMC) at 888 MHz with a bandwidth of 288 MHz and beam size of $13\rlap{.}^{\prime\prime}9\times12\rlap{.}^{\prime\prime}1$, from the Australian Square Kilometre Array Pathfinder (ASKAP) processed as part of the Evolutionary Map of the Universe (EMU) survey. The median Root Mean Squared noise is 58 $μ$Jy beam$^{-1}$. We present a catalogue of 54,612 sources, divided over a GOLD list (30,866 sources) complete down to 0.5 mJy uniformly across the field, a SILVER list (22,080 sources) reaching down to…
Obscuration of quasars by accreted gas and dust, or dusty intervening galaxies, can cause active galactic nuclei (AGN) to be missed in optically-selected surveys. Radio observations can overcome this dust bias. In particular, radio surveys searching for HI absorption inform us on how the AGN can impact on the cold neutral gas medium within the host galaxy, or the population of intervening galaxies through the observed line of sight gas kinematics. We present the results of a HI absorption line survey at $0.4 < z < 1$ towards 34 obscured quasars with the Australian SKA Pathfinder (ASKAP) commis…
I can see your halo: Constraining the Milky Way halo DM with FRB population studies
International Centre for Radio Astronomy Research, Curtin University（国际射电天文中心，科廷大学）；Department of Astronomy and Astrophysics, University of California, Santa Cruz（天体物理学系，加州大学圣克鲁兹分校）；Institute for Astronomy, University of Edinburgh, Royal Observatory（天文研究所，爱丁堡大学，皇家天文台）
We present observations of a region of the Galactic plane taken during the Early Science Program of the Australian Square Kilometre Array Pathfinder (ASKAP). In this context, we observed the SCORPIO field at 912 MHz with an uncompleted array consisting of 15 commissioned antennas. The resulting map covers a square region of ~40 deg^2, centred on (l, b)=(343.5°, 0.75°), with a synthesized beam of 24"x21" and a background rms noise of 150-200 μJy/beam, increasing to 500-600 μJy/beam close to the Galactic plane. A total of 3963 radio sources were detected and characterized in the field using the …
An improved view of cosmic-ray transport and the galactic outflow in NGC 253
Yunnan University（云南大学）；SKA Observatory（平方公里阵列望远镜观测站）；CSIRO Space and Astronomy（CSIRO空间与天文学部）；South-Western Institute for Astronomy Research, Yunnan University（云南大学西南天文研究所）；Purple Mountain Observatory, Chinese Academy of Sciences（中国科学院紫金山天文台）；National Astronomical Observatories, Chinese Academy of Sciences（中国科学院国家天文台）；Institute for Frontiers in Astronomy and Astrophysics, Beijing Normal University（北京师范大学前沿天文与天体物理研究所）；School of Astronomy and Space Science, University of Chinese Academy of Sciences（中国科学院大学天文与空间科学学院）；International Centre for Radio Astronomy Research, University of Western Australia（西澳大利亚大学国际射电天文研究中心）；Research School of Astronomy and Astrophysics, Australian National University（澳大利亚国立大学天文与天体物理研究学院）
The Australian SKA Pathfinder (ASKAP) telescope has started to localize Fast Radio Bursts (FRBs) to arcsecond accuracy from the detection of a single pulse, allowing their host galaxies to be reliably identified. We discuss the global properties of the host galaxies of the first four FRBs localized by ASKAP, which lie in the redshift range $0.11<z<0.48$. All four are massive galaxies (log( $M_{*}/ M_{\odot}$) $\sim 9.4 -10.4$) with modest star-formation rates of up to $2M_{\odot}$yr$^{-1}$ -- very different to the host galaxy of the first repeating FRB 121102, which is a dwarf galaxy with a hi…
This study uses HI image data from the WALLABY pilot survey with the ASKAP telescope, covering the Hydra cluster out to 2.5$r_{200}$. We present the projected phase-space distribution of HI-detected galaxies in Hydra, and identify that nearly two thirds of the galaxies within $1.25r_{200}$ may be in the early stages of ram pressure stripping. More than half of these may be only weakly stripped, with the ratio of strippable HI (i.e., where the galactic restoring force is lower than the ram pressure in the disk) mass fraction (over total HI mass) distributed uniformly below 90%. Consequently, th…
We describe the scientific goals and survey design of the First Large Absorption Survey in HI (FLASH), a wide field survey for 21-cm line absorption in neutral atomic hydrogen (HI) at intermediate cosmological redshifts. FLASH will be carried out with the Australian Square Kilometre Array Pathfinder (ASKAP) radio telescope and is planned to cover the sky south of $δ\approx +40$deg at frequencies between 711.5 and 999.5MHz. At redshifts between $z = 0.4$ and $1.0$ (look back times of 4 - 8Gyr), the HI content of the Universe has been poorly explored due to the difficulty of carrying out radio s…
From NVSS to RACS: Identifying truly Compact Galactic and Extragalactic sources with Steep Spectra
Indian Institute of Science Education and Research – Pune（印度科学教育研究所浦那分校）；National Centre for Radio Astrophysics (NCRA – TIFR)（国家射电天体物理学中心（NCRA-TIFR））；International Centre for Radio Astronomy Research, Curtin University（科廷大学国际射电天文研究中心）
