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Related papers: The 21-SPONGE HI Absorption Survey I: Techniques a…

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We present an analysis of morphological, kinematic and spectral asymmetries in observations of atomic neutral hydrogen (HI) gas from the Local Volume HI Survey (LVHIS), the VLA Imaging of Virgo in Atomic Gas (VIVA) survey and the Hydrogen…

Astrophysics of Galaxies · Physics 2020-03-11 T. N. Reynolds , T. Westmeier , L. Staveley-Smith , G. Chauhan , C. D. P. Lagos

We report a uGMRT detection of HI 21-cm absorption associated with the radio source 8C 0604+728, at $z = 3.52965$. The source is at the highest redshift at which associated HI 21-cm absorption has been discovered to date, surpassing earlier…

Astrophysics of Galaxies · Physics 2020-11-20 J. N. H. S. Aditya , Regina Jorgenson , Vishal Joshi , Veeresh Singh , Tao An , Yogesh Chandola

In this paper we present the results of the statistical analysis of high-latitude HI turbulence in the Milky Way. We have observed HI in the 21 cm line, obtained with the Arecibo L-Band Feed Array (ALFA) receiver at the Arecibo radio…

Astrophysics · Physics 2014-10-13 A. Chepurnov , A. Lazarian , S. Stanimirovic , C. Heiles , J. E. G. Peek

Absorption lines at high redshift in front of quasars are rare in the mm domain. Only five associated and five intervening systems have been reported in the literature. These bring very useful information complementary to emission lines,…

Astrophysics of Galaxies · Physics 2023-12-19 Francoise Combes , Neeraj Gupta

Hypercompact HII regions (HC) are regions of ionized gas associated with the early stages of high-mass star formation. With the aim of better understanding their characteristics, we studied five candidate HC HII regions. Here, we present…

Astrophysics of Galaxies · Physics 2026-05-12 I. T. Rodríguez-Esnard , S. Kurtz , J. D. Pandian , J. Franco , A. Sánchez-Monge , M. A. Trinidad , V. Migenes

We use the 21 cm emission line data from the DINGO-VLA project to study the atomic hydrogen gas H\,{\textsc i} of the Universe at redshifts $z<0.1$. Results are obtained using a stacking analysis, combining the H\,{\textsc i} signals from…

We use observations made with the Giant Metrewave Radio Telescope (GMRT) to probe the neutral hydrogen (HI) gas content of field galaxies in the VIMOS VLT Deep Survey (VVDS) 14h field at $z \approx 0.32$. Because the HI emission from…

We aim at analysing systematically the distribution and physical properties of neutral and mildly ionised gas in the Milky Way halo, based on a large absorption-selected data set. Multi-wavelength studies were performed combining optical…

Astrophysics of Galaxies · Physics 2015-06-04 N. Ben Bekhti , B. Winkel , P. Richter , J. Kerp , U. Klein , M. T. Murphy

In the Halo21 absorption modeling challenge we generated synthetic absorption spectra of the circumgalactic medium (CGM), and attempted to estimate the metallicity, temperature, and density (Z, T, and nH) of the underlying gas using…

We present global VLBI observations of the ~8100 km s$^{-1}$ HI absorption feature detected toward the strong radio nucleus 3C 84 of NGC 1275 in the Perseus cluster (${V_{\rm sys}\sim}$5200 km s$^{-1}$). The observations were obtained using…

Astrophysics · Physics 2009-11-07 E. Momjian , J. D. Romney , T. H. Troland

We model the distribution of neutral hydrogen (HI) in the post-reionization era and investigate its detectability in 21 cm intensity mapping with the future SKA radio telescope. We rely on high resolution hydrodynamical N-body simulations.…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-19 Francisco Villaescusa-Navarro , Matteo Viel , Kanan K. Datta , T. Roy Choudhury

In a poster presentation for IAU Symposium 392: "Neutral hydrogen in and around galaxies in the SKA era", we gave an overview of the HI-MaNGA project which is working to obtain complementary information about the cold gas (neutral hydrogen…

Astrophysics of Galaxies · Physics 2025-02-14 Karen Masters , David Stark

We present new sub-arcsecond-resolution Karl G. Jansky Very Large Array (VLA) imaging at 10 GHz of 155 ultra-luminous ($L_{\rm bol}\sim10^{11.7-14.2} L_\odot$) and heavily obscured quasars with redshifts $z \sim0.4-3$. The sample was…

The formation of hypercompact (HC) HII regions is an important stage in massive star formation. Spectral line and continuum observations can explore its dynamic conditions. We present high angular resolution observations carried out with…

Astrophysics of Galaxies · Physics 2014-09-29 Chuan-Peng Zhang , Jun-Jie Wang , Jin-Long Xu , Friedrich Wyrowski , Karl M. Menten

The 21cm forest -- HI absorption features in the spectra of high-redshift radio sources -- can potentially provide a unique probe of the largely neutral intergalactic medium (IGM) during the epoch of reionization. We present simulations of…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Katherine J. Mack , J. Stuart B. Wyithe

We present a complete catalogue of 27 O VI absorbers at low redshift (0.12 < z < 0.5) from a blind survey of 16 QSO echelle spectra in the HST/STIS data archive. These absorbers are identified based only upon matching line profiles and the…

Astrophysics · Physics 2009-11-13 Christopher Thom , Hsiao-Wen Chen

We conducted a HI 21cm absorption study of a sample of 147 nearby (z < 0.1) low-power radio sources with $10\,\mathrm{mJy} < S_{1.4\,\mathrm{GHz}} < 30\,\mathrm{mJy}$ and $\log(P_{1.4\,\mathrm{GHz}}/\mathrm{W\,Hz^{-1}}) = 20.5-23.7$, using…

Astrophysics of Galaxies · Physics 2026-03-06 Yang Su , Qingzheng Yu , Taotao Fang , Junfeng Wang , Jianfeng Wu , Bo Zhang

We present 33 GHz imaging for 112 pointings towards galaxy nuclei and extranuclear star-forming regions at $\approx$2" resolution using the Karl G. Jansky Very Large Array (VLA) as part of the Star Formation in Radio Survey. A comparison…

Astrophysics of Galaxies · Physics 2018-02-14 E. J. Murphy , D. Dong , E. Momjian , S. Linden , R. C. Kennicutt, , D. S. Meier , E. Schinnerer , J. L. Turner

We present an automated routine to search for HI self-absorption features within the Southern Galactic Plane Survey (SGPS). The data were taken with the Australia Telescope Compact Array (ATCA) and the Parkes Radio Telescope and encompass 3…

Astrophysics · Physics 2009-11-10 D. W. Kavars , J. M. Dickey , N. M. McClure-Griffiths , B. M. Gaensler , A. J. Green

We present the results of a neutral hydrogen survey of the Bootes void carried out with the VLA in D-array. The survey covers $\sim 1100$ Mpc$^{3}$, about 1\% of the volume of the void as defined by Kirshner \etal 1987. We observed 24…

Astrophysics · Physics 2009-10-28 A. Szomoru , J. H. van Gorkom , M. D. Gregg