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相关论文: VLBA Observations of HI in the Archetype Compact S…

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We report the results of our observations of HI absorption towards the central region of the rejuvenated radio galaxy 4C29.30 (J0840+2949) with the Giant Metrewave Radio Telescope (GMRT). The radio source has diffuse, extended emission with…

宇宙学与河外天体物理 · 物理学 2015-05-14 Yogesh Chandola , D. J. Saikia , Neeraj Gupta

We present the results of a mini-survey for associated HI 21-cm absorption at z < 0.42 with the Giant Metrewave Radio Telescope. Our targets are radio galaxies, selected on the basis that the 1216 Angstrom luminosities are below 10^23 W/Hz,…

宇宙学与河外天体物理 · 物理学 2015-05-27 S. J. Curran , M. T. Whiting , J. K. Webb , R. Athreya

To search for low-redshift damped Lyman-alpha (DLA) and sub-DLA quasar absorbers, we have conducted a 21cm absorption survey of radio-loud quasars at small impact parameters to foreground galaxies selected from the Sloan Digital Sky Survey…

宇宙学与河外天体物理 · 物理学 2014-11-20 Sanchayeeta Borthakur , Todd M. Tripp , Min S. Yun , Emmanuel Momjian , Joseph D. Meiring , David V. Bowen , Donald G. York

We present sensitive, high-resolution 21-cm VLBA+VLA observations of the radio jet and nuclear HI absorption in NGC 4151. The 25-mas (1.6-pc) resolution continuum image reveals a highly collimated radio jet, underlying the discrete…

天体物理学 · 物理学 2007-05-23 C. G. Mundell , J. M. Wrobel , A. Pedlar , J. F. Gallimore

We report on WSRT observations of HI and OH absorption at z=0.885 towards the radio lens PKS 1830-21, mm wave transitions of several molecular species have already been observed at this redshift. At mm wavelengths the source structure is…

天体物理学 · 物理学 2011-05-23 Jayaram N. Chengalur , A. G. de Bruyn , D. Narasimha

We present multifrequency radio continuum as well as HI observations of the superwind galaxy NGC1482, with both the GMRT and the VLA. This galaxy has a remarkable hourglass-shaped optical emission line outflow as well as bi-polar soft X-ray…

天体物理学 · 物理学 2009-11-10 Ananda Hota , D. J. Saikia

We present results from a search for the HI 21-cm line in absorption towards 16 bright radio sources with the 6-antenna commissioning array of the Australian Square Kilometre Array Pathfinder (ASKAP). Our targets were selected from the 2-Jy…

We present the results of HI and OH absorption measurements towards a sample of radio sources using the Arecibo 305-m telescope and the GMRT. In total, 27 radio sources were searched for associated 21-cm HI absorption. One totally new HI…

天体物理学 · 物理学 2009-11-11 Neeraj Gupta , C. J. Salter , D. J. Saikia , T. Ghosh , S. Jeyakumar

We present an HI 21cm absorption study of a sample of 26 radio-loud active galactic nuclei (AGN) at $0.25 < z < 0.4$ carried out with the Karl G. Jansky Very Large Array. Our aim was to study the rate of incidence of HI in various classes…

星系天体物理 · 物理学 2021-10-20 Suma Murthy , Raffaella Morganti , Tom Oosterloo , Filippo M. Maccagni

We report the detection of HI absorption towards the inner double of the double-double radio galaxy (DDRG) J1247+6723 with the Giant Metrewave Radio Telescope (GMRT). The inner double is a Giga-hertz peaked spectrum (GPS) source with a…

天体物理学 · 物理学 2008-11-26 D. J. Saikia , Neeraj Gupta , C. Konar

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…

天体物理学 · 物理学 2009-11-06 K. S. Dwarakanath , F. N. Owen

In this paper we further explore the implications that this has for the currently popular consensus that it is the orientation of the circumnuclear obscuring torus which determines whether absorption is present along our sight-line. The…

宇宙学与河外天体物理 · 物理学 2010-03-04 S. J. Curran , M. T. Whiting

The Westerbork Synthesis Radio Telescope finds a weak 21cm line emission feature at the coordinates (RA-Dec-velocity) of the sub-Damped Lyman-alpha absorber observed at z_abs=0.00632 in the spectrum of PG1216+069. The emission feature,…

天体物理学 · 物理学 2009-11-11 F. H. Briggs , D. G. Barnes

We present new, high angular resolution (~0.22") MERLIN observations of neutral hydrogen (HI) absorption and 21-cm radio continuum emission across the central ~900 parsecs of the ultraluminous infrared galaxy, Arp220. Spatially resolved HI…

天体物理学 · 物理学 2009-11-06 C. G. Mundell , P Ferruit , A Pedlar

We report on new aspects of the star-forming region S235AB revealed through high-resolution observations at radio and mid-infrared wavelengths. Using the Very Large Array, we carried out sensitive observations of S235AB in the cm continuum…

天体物理学 · 物理学 2009-11-11 Marcello Felli , Fabrizio Massi , Massimo Robberto , Riccardo Cesaroni

The goal of this work is a detailed study of the nearby, low power radio galaxy B2 1144+35B. For this purpose, we performed new Very Long Baseline Array (VLBA) and Very Large Array (VLA) observations. This source has several properties…

天体物理学 · 物理学 2009-11-13 G. Giovannini , M. Giroletti , G. B. Taylor

The dark cloud Lynds 723 (L723) is a low-mass star-forming region where one of the few known cases of a quadrupolar CO outflow has been reported. Two recent works have found that the radio continuum source VLA 2, towards the centre of the…

星系天体物理 · 物理学 2015-05-19 R. Lopez , J. A. Acosta-Pulido , G. Gomez , R. Estalella , C. Carrasco-Gonzalez

We show an archival 1.4-GHz Very Large Array (VLA) image of the core-dominated triple (CDT) radio source J1628+3906, along with a recent high-resolution 5-GHz Very Long Baseline Interferometry (VLBI) image of its core. This core is resolved…

天体物理学 · 物理学 2009-04-14 D. Cseh , A. Fuhl , S. Frey

WSRT observations have provided a first inventory of the incidence of HI 21 cm line absorption associated with AGN at redshifts up to z=1.0. There is a large range in line depths, from tau=0.44 to tau less than 0.001, and a substantial…

天体物理学 · 物理学 2007-05-23 R. C. Vermeulen

Supermassive binary black holes (BBHs) on sub-parsec scales are prime targets for gravitational wave experiments. They also provide insights on close binary evolution and hierarchical structure formation. Sub-parsec BBHs cannot be spatially…

高能天体物理现象 · 物理学 2017-11-08 K. P. Mooley , J. M. Wrobel , M. M. Anderson , G. Hallinan