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Related papers: HI and OH Absorption toward NGC6240

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We present and discuss European VLBI Network UHF band spectral line observations, made to localise the redshifted 21cm HI absorption known to occur in the subgalactic sized compact steep spectrum galaxies 3C 49 and 3C 268.3. We have…

Astrophysics · Physics 2009-11-11 A. Labiano , R. C. Vermeulen , P. D. Barthel , C. P. O'Dea , J. F. Gallimore , S. Baum , W. de Vries

The study of the optical continuum of radio galaxies shows that about 30% have a young stellar population component. Among them are the most far-IR bright radio galaxies. A further indication of the relatively gas rich environment of these…

We present Giant Metrewave Radio Telescope (GMRT) observations of OH absorption in B3~1504+377 ($z \sim 0.673$) and PKS 1413+135 ($z \sim 0.247$). OH has now been detected in absorption towards four intermediate redshift systems, viz. the…

Astrophysics · Physics 2009-11-07 Nissim Kanekar , Jayaram N Chengalur

Using a combination of observations involving the VLA, MERLIN and global VLBI networks we have made a detailed study of the radio continuum and the neutral hydrogen (HI) kinematics and distribution within the central kiloparsec of the radio…

Astrophysics · Physics 2009-11-10 R. J. Beswick , A. B. Peck , G. B. Taylor , G. Giovannini

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…

Astrophysics of Galaxies · Physics 2021-10-20 Suma Murthy , Raffaella Morganti , Tom Oosterloo , Filippo M. Maccagni

Recent studies have shown that both 21cm HI absorption and soft X-ray absorption serve as excellent tracers of the dense and dusty gas near the active nucleus of young radio galaxies, offering new insight into the physical nature of the…

Astrophysics of Galaxies · Physics 2022-01-05 Emily F. Kerrison , Vanessa A. Moss , Elaine M. Sadler , James R. Allison

Recent targeted studies of associated HI absorption in radio galaxies are starting to map out the location, and potential cosmological evolution, of the cold gas in the host galaxies of Active Galactic Nuclei (AGN). The observed 21 cm…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 J. R. Allison , E. M. Sadler , S. J. Curran , S. N. Reeves

We report the detection of 21-cm HI absorption towards the core of the Fanaroff-Riley II radio galaxy 3C452 (J2245+3941). The absorption profile is well resolved into three components; the strongest and narrowest component being coincident…

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

We study the properties of HI gas in the outer regions (~2r_25) of a spiral galaxy, UGC 00439 (z = 0.01769), using HI 21-cm absorption towards different components of an extended background radio source, J0041$-$0043 (z = 1.679). The radio…

Astrophysics of Galaxies · Physics 2016-01-20 Rajeshwari Dutta , Neeraj Gupta , Raghunathan Srianand , John O'Meara

We study the structure and kinematics of the OH-streamer and the +80 km/s cloud and their interactions with the circumnuclear disk (CND) and with other molecular clouds in the vicinity of the Galactic centre (GC), and we map OH absorption…

Astrophysics of Galaxies · Physics 2015-11-04 Roland Karlsson , Aage Sandqvist , Kambiz Fathi , Sergio Martín

We present the first results of a study aimed to detect large HI structures in radio galaxies. In two of the three cases presented (Coma A and B2 0648+27), the detection of a large amount of HI distributed over several tens of kpc suggests…

Astrophysics · Physics 2009-11-07 R. Morganti , T. Oosterloo , C. Tadhunter , B. Emonts

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

Hydrogen column densities inferred from X-ray absorption are typically 5 - 30 times larger than the neutral atomic hydrogen column densities derived from 21cm HI absorption toward radio-loud active galactic nuclei. Some part of the…

Astrophysics of Galaxies · Physics 2021-02-24 Harvey Liszt

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…

The BL Lac PKS 1413+135 was observed by the Large Survey Project "MeerKAT Absorption Line Survey" (MALS) in the L-band, at 1139 MHz and 1293-1379 MHz, targeting the HI and OH lines in absorption at z = 0.24671. The radio continuum is…

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…

Astrophysics · Physics 2007-05-23 R. C. Vermeulen

We present MERLIN and Hubble Space Telescope (HST) observations of the central region of the nearby radio galaxy 3C305 and use them to study the gas and dust in this object. The MERLIN observations are of neutral hydrogen (HI) absorption…

Astrophysics · Physics 2009-11-07 N. Jackson , R. Beswick , A. Pedlar , G. H. Cole , W. B. Sparks , J. P. Leahy , D. J. Axon

We present the Green Bank Telescope absorption survey of cold atomic hydrogen ($\lesssim 300$K) in the inner halo of low-redshift galaxies. The survey aims to characterize the cold gas distribution and to address where condensation - the…

Astrophysics of Galaxies · Physics 2016-10-05 Sanchayeeta Borthakur

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,…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 S. J. Curran , M. T. Whiting , J. K. Webb , R. Athreya

We present new observations, performed with the Australia Telescope Compact Array, of the HI absorption in the central regions of Centaurus A. For the first time, absorption is detected against the radio core at velocities blueshifted with…

Astrophysics · Physics 2009-11-13 R. Morganti , T. Oosterloo , C. Struve , L. Saripalli