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Westerbork Radio Synthesis Telescope observations of the redshifted 21cm line absorber against the z_em = 0.871 double lobed quasar 3C196 show that the intervening absorber is an L approximately equal L* spiral galaxy (3C196-G1) and that…

Astrophysics · Physics 2009-11-06 F. H. Briggs , A. G. de Bruyn , R. C. Vermeulen

We present milliarcsecond (mas) angular resolution observations of the gravitationally lensed radio source MG J0751+2716 (at z=3.2) obtained with global Very Long Baseline Interferometry (VLBI) at 1.65 GHz. The background object is highly…

Astrophysics of Galaxies · Physics 2018-07-17 C. Spingola , J. P. McKean , M. W. Auger , C. D. Fassnacht , L. V. E. Koopmans , D. J. Lagattuta , S. Vegetti

Existing studies of the atomic hydrogen gas content in distant galaxies, through the absorption of the 21-cm line, often infer that the total column density is anti-correlated with the linear extent of the background radio source. We…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 S. J. Curran , J. R. Allison , M. Glowacki , M. T. Whiting , E. M. Sadler

We present a search for associated HI 21 cm absorption in a sample of 29 radio-loud active galactic nuclei (AGNs) at $0.7 < z < 1$, carried out with the upgraded Giant Metrewave Radio Telescope. We detect HI 21 cm absorption against none of…

Astrophysics of Galaxies · Physics 2022-03-30 Suma Murthy , Raffaella Morganti , Nissim Kanekar , Tom Oosterloo

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

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,…

Astrophysics · Physics 2009-11-11 F. H. Briggs , D. G. Barnes

We have used the Very Long Baseline Array (VLBA) and the Very Large Array (VLA) to image Galactic neutral hydrogen in absorption towards four compact extragalactic radio sources with 10 milliarcsecond resolution. Previous VLBA data by…

Astrophysics · Physics 2015-06-24 M. D. Faison , W. M. Goss

We have selected a sample of 80 candidates for obscured radio-loud active galactic nuclei and presented their basic optical/near-infrared (NIR) properties in Paper 1. In this paper, we present both high-resolution radio continuum images for…

Astrophysics of Galaxies · Physics 2016-03-16 Ting Yan , John T. Stocke , Jeremy Darling , Emmanuel Momjian , Soniya Sharma , Nissim Kanekar

We explore the possibility of detecting HI 21cm absorption by the neutral intergalactic medium (IGM) toward very high redshift radio sources. The epoch considered is between the time when the first ionizing sources form and when the bulk of…

Astrophysics · Physics 2016-08-30 C. Carilli , N. Y. Gnedin , F. Owen

We report on a survey for associated HI 21-cm and OH 18-cm absorption with the Giant Metrewave Radio Telescope at redshifts z = 0.2-0.4. Although the low redshift selection ensures that our targets are below the critical ultra-violet…

Astrophysics of Galaxies · Physics 2017-03-29 S. J. Curran , M. T. Whiting , J. R. Allison , A. Tanna E. M. Sadler , R. Athreya

We present the results of a large search for intrinsic HI 21 cm and OH 18 cm absorption in 145 compact radio sources in the redshift range 0.02< z <3.8 with the Green Bank Telescope. We re-detect HI 21 cm absorption toward six known…

Astrophysics of Galaxies · Physics 2019-11-27 Kathryn Grasha , Jeremy Darling , Alberto Bolatto , Adam K. Leroy , John T. Stocke

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

Using archival data from the HI Parkes All Sky Survey (HIPASS) we have searched for 21 cm line absorption in 204 nearby radio and star-forming galaxies with continuum flux densities greater than $S_{1.4} \approx 250$ mJy within the redshift…

Astrophysics of Galaxies · Physics 2015-06-18 J. R. Allison , E. M. Sadler , A. M. Meekin

European VLBI Network spectral imaging of the "compact double" radio source 2050+364 in the UHF band at 1049 MHz has resolved the HI absorbing region, and has shown a faint continuum component to the North (N), in addition to the well-known…

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

We present the early science results from a blind search of the extragalactic HI 21-cm absorption lines at z $\leqslant$ 0.09 with the drift-scan observation of the Five-hundred-meter Aperture Spherical radio Telescope (FAST). We carried…

We report the detection of HI 21-cm absorption in a member of the rare and recently discovered class of compact radio sources, 'Extremely Inverted Spectrum Extragalactic Radio Sources (EISERS)'. EISERS conceivably form a special sub-class…

Astrophysics of Galaxies · Physics 2020-11-25 Mukul Mhaskey , Surajit Paul , Neeraj Gupta , Dipanjan Mukherjee , Gopal-Krishna

We report the detection of 21-cm absorption from foreground galaxies towards quasars, specifically z_gal = 0.3120 towards SDSS J084957.97+510829.0 (z_qso = 0.584; Pair-I) and z_gal = 0.3714 towards SDSS J144304.53+021419.3 (z_qso = 1.82;…

Astrophysics of Galaxies · Physics 2015-06-16 N. Gupta , R. Srianand , P. Noterdaeme , P. Petitjean , S. Muzahid

We present MeerKAT observations searching for HI absorption in a sample of 17 powerful ($L_{\rm 1.4GHz}> 10^{27}$ W Hz$^{-1}$) radio sources at intermediate redshifts ($0.25<z<0.7$). The sample is well characterised at radio and optical…

Astrophysics of Galaxies · Physics 2026-02-11 Raffaella Morganti , Tom Oosterloo , Clive Tadhunter , Suma Murthy

We present results from a search for 21 cm associated HI absorption in a sample of 29 radio sources selected from the Australia Telescope 20 GHz survey. Observations were conducted using the Australia Telescope Compact Array Broadband…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 J. R. Allison , S. J. Curran , B. H. C. Emonts , K. Gareb , E. K. Mahony , S. Reeves , E. M. Sadler , A. Tanna , M. T. Whiting , M. A. Zwaan

New radio continuum (8 GHz and 1.4 GHz) and HI 21 cm line observations of the Seyfert 2 galaxy IC 5063 (PKS 2048-572) were obtained with the Australia Telescope Compact Array (ATCA). The 8 GHz image reveals a linear triple structure (~4'',…

Astrophysics · Physics 2009-10-30 R. Morganti , T. Oosterloo , Z. Tsvetanov