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Related papers: Parsec-scale HI absorption structure in a low-reds…

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We present the results of Giant Metrewave Radio Telescope (GMRT) observations to detect H{\sc i} in absorption towards the cores of a sample of radio galaxies. From observations of a sample of 16 sources, we detect H{\sc i} in absorption…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Yogesh Chandola , Neeraj Gupta , D. J. Saikia

We present sensitive, high resolution Very Long Baseline Array (VLBA) observations of the central 0.3 arcsec of PKS 2322-123 at 1.3 and 5 GHz. These observations reveal straight and symmetric jets emerging from both sides of an inverted…

Astrophysics · Physics 2009-10-31 G. B. Taylor , C. P. O'Dea , A. B. Peck , A. M. Koekemoer

We present Giant Metrewave Radio Telescope and Very Large Array observations of HI 21-cm absorption in ten z<=0.2 galaxy mergers that host strong radio sources. Seven of these mergers show strong absorption [with N(HI) ~10^{21-22} cm^{-2},…

Astrophysics of Galaxies · Physics 2018-08-01 Rajeshwari Dutta , Raghunathan Srianand , Neeraj Gupta

We present a study, done with the Australian LBA, of HI absorption for two compact radio galaxies (PKS 1549-79 and PKS 1814-63). In both the radio galaxies, the HI appears to give us information about the environment in which the radio…

Astrophysics · Physics 2007-05-23 R. Morganti , T. A. Oosterloo , C. N. Tadhunter , K. A. Wills , A. Tzioumis , J. Reynolds

We present an HST Cosmic Origins Spectrograph (COS) spectrum of the QSO SDSS J095109.12+330745.8 ($z_{em} = 0.645$) whose sightline passes through the SMC-like dwarf galaxy UGC 5282 ($M_B = -16.0$, $cz = 1577$ km s$^{-1}$ ), 1.2 kpc in…

Astrophysics of Galaxies · Physics 2020-04-29 David V. Bowen , Todd M. Tripp , Edward B. Jenkins , Max Pettini , Doron Chelouche , Renyue Cen , Donald G. York

We present a detailed analysis of a H2-bearing metal-rich sub-damped Lyman-alpha system at zabs = 0.10115 towards the radio-loud quasar J0441-4313, at a projected separation of ~7.6 kpc from a star-forming galaxy. The H2, C I and Na I…

Astrophysics of Galaxies · Physics 2015-06-23 R. Dutta , R. Srianand , S. Muzahid , N. Gupta , E. Momjian , J. Charlton

Galaxy disks are shown to contain a significant population of atomic clouds of 100pc linear size which are self-opaque in the 21cm transition. These objects have HI column densities as high as 10^23 and contribute to a global opacity…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Robert Braun

We study the absorption along lines of sight toward high-z radio sources caused by the 21 cm transition of neutral hydrogen in the intergalactic medium (IGM) before reionization. Using semi-analytic methods, we compute the number density of…

Astrophysics · Physics 2009-11-07 Steven Furlanetto , Abraham Loeb

WSRT observations have been used to investigate the presence of neutral hydrogen in extremely young radio galaxies. These objects were selected from a sample of High-Frequency Peakers (HFPs). We detect 2 of the 6 observed galaxies…

Astrophysics · Physics 2009-11-11 M. Orienti , R. Morganti , D. Dallacasa

We examine the consistency of HI properties with the unification scheme for radio galaxies and quasars, and any correlation with the symmetry parameters for a sample of CSS and GPS sources. In our sample, 15 out of 23 galaxies exhibit 21-cm…

Astrophysics · Physics 2009-11-11 Neeraj Gupta , D. J. Saikia

Neutral atomic hydrogen and molecular gas in the host galaxies of radio active galactic nuclei (AGN) can be traced using H I 21-cm and OH-1667 MHz absorption lines to understand the fueling and feedback processes. We present the results of…

Astrophysics of Galaxies · Physics 2024-07-01 Yogesh Chandola , D. J. Saikia , Yin-Zhe Ma , Zheng Zheng , Chao-Wei Tsai , Di Li , Denis Tramonte , Hengxing Pan

The star-forming reservoir in the distant Universe can be detected through HI 21-cm absorption arising from either cool gas associated with a radio source or from within a galaxy intervening the sight-line to the continuum source. In order…

Astrophysics of Galaxies · Physics 2016-08-23 S. J. Curran , S. W. Duchesne , A. Divoli , J. R. Allison

Using the recently completed Giant Meterwave Radio Telescope, we have detected the HI 21 cm-line absorption from the peculiar galaxy C153 in the galaxy cluster Abell 2125. The HI absorption is at a redshift of 0.2533, with a peak optical…

Astrophysics · Physics 2009-11-06 K. S. Dwarakanath , F. N. Owen

One of the most important problems in the study of AGN is understanding the detailed geometry, physics, and evolution of the central engines and their environments. The leading models involve an accretion disk and torus around a central…

Astrophysics · Physics 2007-05-23 A. B. Peck , G. B. Taylor

During the past decade or so, measurements of Galactic HI absorption using VLBI against extra-galactic sources, as well as multi-epoch observatios in pulsar directions, have detected small-scale transverse variations corresponding to tens…

Astrophysics · Physics 2008-11-26 Avinash A. Deshpande

We present VLT-UVES echelle spectra of the Lyman alpha emission and absorption in five radio galaxies at redshifts z=2.55-4.1. Together with data from our pilot study, we have a sample of 7 such systems with radio source sizes ~ 1-90 kpc…

Astrophysics · Physics 2009-11-10 R. J. Wilman , M. J. Jarvis , H. J. A. Rottgering , L. Binette

This is a paper on young jet material in a frustratingly complex environment. NGC 1052 has a compact, flat- or GHz-peaked-spectrum radio nucleus consisting of bi-symmetric jets, oriented close to the plane of the sky. Many features on both…

We present WSRT observations of the neutral hydrogen in the nearby radio galaxy B2 0648+27. In emission, we detect a very large amount of HI (M_HI = 1.1 x 10^10 M_sun) that is distributed in a very extended disk, or ring-like structure, of…

We present and discuss two catalogues of UV-selected (NUV $< 22.8$ mag) galaxies that lie within a 200 deg$^2$ area of sky covered by the ASKAP FLASH survey and have an impact parameter of less than 20 arcsec to a FLASH radio continuum…

Astrophysics of Galaxies · Physics 2024-11-15 Sophie L. Eden , Elaine M. Sadler , Kevin A. Pimbblet , Elizabeth K. Mahony , Hyein Yoon

We present Giant Metrewave Radio Telescope (GMRT) observations of redshifted 21-cm absorption from the $z=0.437$ metal line absorption system towards PKS 1243-072. HI absorption is clearly detected; the absorption profile has a velocity…

Astrophysics · Physics 2009-11-07 Nissim Kanekar , Ramana M. Athreya , Jayaram N. Chengalur