Probing radio source environments via HI and OH absorption

Abstract

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 absorption system was detected against the radio galaxy 3C258, while five previously known HI absorption systems, and one galaxy detected in emission, were studied with improved frequency resolution and/or sensitivity. Our sample included 17 GPS and CSS objects, 4 of which exhibit HI absorption. This detection rate of ~25% compares with a value of ~40% by Vermeulen et al. for similar sources. We detected neither OH emission nor absorption towards any of the sources that were observed at Arecibo, and estimate a limit on the abundance ratio of N(HI)/N(OH)>4x10^6 for 3C258. We have combined our results with those from other available HI searches to compile a heterogeneous sample of 96 radio sources consisting of 27 GPS, 35 CSS, 13 flat spectrum and 21 large sources. The HI absorption detection rate is highest (~45%) for the GPS sources and least for the large sources. We find HI column density to be anticorrelated with source size, as reported earlier by Pihlström et al. The HI column density shows no significant dependence on either redshift or luminosity, which are themselves strongly correlated. These results suggest that the environments of radio sources on GPS/CSS scales are similar at different redshifts. Further, in accordance with the unification scheme, the GPS/CSS galaxies have an HI detection rate of ~40% which is significantly higher than the detection rate (~20%) towards the GPS/CSS quasars. Also, the principal (strongest) absorption component detected towards GPS sources appears blue-shifted in ~65% of the cases, in agreement with the growing evidence for jet-cloud interactions.

Abridged abstract, 22 pages, 21 figures, moderately revised, accepted for publication in MNRAS

References in corpus (42)

• First Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Determination of Cosmological Parameters
• Black Holes in Galaxy Mergers: Evolution of Quasars
• NICMOS Imaging of Infrared-Luminous Galaxies
• The VLBA Calibrator Survey - VCS1
• Fast neutral outflows in powerful radio galaxies: a major source of feedback in massive galaxies
• VLBI Observations of a Complete Sample of Radio Galaxies. 10 Years Later
• CAIRNS: The Cluster And Infall Region Nearby Survey I. Redshifts and Mass Profiles
• HST imaging of CFRS and LDSS galaxies - I: Morphological Properties
• The Deep X-ray Radio Blazar Survey (DXRBS). I. Methods and First Results
• The Third VLBA Calibrator Survey
• Observations of HI Absorbing Gas in Compact Radio Sources at Cosmological Redshifts
• A Search for OH Megamasers at z > 0.1. III. The Complete Survey
• HI absorption in radio galaxies: effect of orientation or interstellar medium?
• Redshifted Neutral Hydrogen 21cm Absorption toward Red Quasars
• Sub-Milliarcsecond Imaging of Quasars and Active Galactic Nuclei. II. Additional Sources
• The Presence and Distribution of HI Absorbing Gas in Sub-galactic Sized Radio Sources
• HST observations of nearby radio-loud early-type galaxies
• Highly extinguished emission line outflows in the young radio source PKS 1345+12
• Obscuration of the Parsec Scale Jets in the Compact Symmetric Object 1946+708
• Kinematic Age Estimates for 4 Compact Symmetric Objects from the Pearson-Readhead Survey
• 4C +12.50: A Superluminal Precessing Jet in the Recent Merger System IRAS 13451+1232
• Accurate Redshifts and Classifications for 110 Radio-Loud AGNs
• Compact steep-spectrum sources from the S4 sample
• VLBA observations of GHz-Peaked-Spectrum radio sources at 15 GHz
• An asymmetric relativistic model for classical double radio sources
• Bi-Directional Relativistic Jets of the Radio Galaxy 1946+708: Constraints on the Hubble Constant
• Associated absorption in radio quasars. I. C IV absorption and the growth of radio sources
• HST/STIS low dispersion spectroscopy of three Compact Steep Spectrum sources Evidence for jet-cloud interaction
• A sample of southern Compact Steep Spectrum radio sources: The VLBI observations
• A Parkes half-Jansky sample of GPS galaxies
• The unfriendly ISM in the radio galaxy 4C12.50 (PKS 1345+12)
• Molecular gas at intermediate redshifts
• EVN observations of candidate Compact Symmetric Objects
• Unification scheme and the distribution of neutral gas in compact radio sources
• Redshifts and Neutral Hydrogen Observations of Compact Symmetric Objects in the COINS Sample
• Molecular Gas in the Powerful Radio Galaxies 3C~31 and 3C~264: Major or Minor Mergers?
• Polarization asymmetry in CSS sources: evidence of AGN fuel?
• VLBI Observations of a Complete Sample of Radio Galaxies V. 3C346 and 4C31.04: two Unusual CSS Sources
• 3C459: A highly asymmetric radio galaxy with a starburst
• Outflowing material in the CSS quasar 3C48: evidence of jet-cloud interaction?
• CSSs in a sample of B2 radio sources of intermediate strength
• The radio counter-jet of the QSO 3C~48

Cited by in corpus (95)

• EMU: Evolutionary Map of the Universe
• Fast outflows in compact radio sources: evidence for AGN-induced feedback in the early stages of radio source evolution
• Compact steep-spectrum and peaked-spectrum radio sources
• On the Evolution of and High-Energy Emission from GHz-Peaked-Spectrum Sources
• The HI absorption "Zoo"
• The interstellar and circumnuclear medium of active nuclei traced by HI 21-cm absorption
• Kinematics and physical conditions of HI in nearby radio sources. The last survey of the old Westerbork Synthesis Radio Telescope
• X-ray Properties of the GigaHertz-Peaked and Compact Steep Spectrum Sources
• VLBI observations of 10 CSO candidates: expansion velocities of hot spots
• Discovery of HI gas in a young radio galaxy at $z=0.44$ using the Australian Square Kilometre Array Pathfinder
• A survey for redshifted molecular and atomic absorption lines - II. Associated HI, OH and millimetre lines in the z >~ 3 Parkes quarter-Jansky flat-spectrum sample
• The X-ray view of Giga-Hertz Peaked Spectrum Radio Galaxies
• Radio properties of Compact Steep Spectrum and GHz-Peaked Spectrum radio sources
• Detection of a High Brightness Temperature Radio Core in the AGN-Driven Molecular Outflow Candidate NGC 1266
• The BINGO Project I: Baryon Acoustic Oscillations from Integrated Neutral Gas Observations
• Search for cold gas in z>2 damped Lyman-alpha systems: 21-cm and H_2 absorption
• X-ray Emitting GHz-Peaked Spectrum Galaxies: Testing a Dynamical-Radiative Model with Broad-Band Spectra
• HI absorption towards nearby compact radio sources
• A complete sample of 21-cm absorbers at z~1.3: Giant Metrewave Radio Telescope Survey Using MgII Systems
• A search for 21 cm HI absorption in AT20G compact radio galaxies
• What triggers a radio AGN? The intriguing case of PKSB 1718-649
• Detection of 21-cm, H2 and Deuterium absorption at z>3 along the line-of-sight to J1337+3152
• Search for cold gas in strong MgII absorbers at 0.5<z<1.5: nature and evolution of 21-cm absorbers
• HI 21-cm absorption and unified schemes of active galactic nuclei
• A Giant Metrewave Radio Telescope search for associated H{\sc i} 21\,cm absorption in GHz-peaked-spectrum sources
• On the HI column density - radio source size anti-correlation in compact radio sources
• Radio spectra and polarisation properties of a bright sample of Radio-Loud Broad Absorption Line Quasars
• Probing the gas content of radio galaxies through HI absorption stacking
• Redshifted HI and OH absorption in radio galaxies and quasars
• Complete ionisation of the neutral gas: why there are so few detections of 21-cm hydrogen in high redshift radio galaxies and quasars
• Associated 21-cm absorption towards the cores of radio galaxies
• A Giant Metrewave Radio Telescope search for associated HI 21cm absorption in high-redshift flat-spectrum sources
• The First Large Absorption Survey in HI (FLASH): I. Science Goals and Survey Design
• A Search for Intrinsic HI 21 cm and OH 18 cm Absorption Toward Compact Radio Sources
• A Giant Metrewave Radio Telescope survey for associated HI 21-cm absorption in the Caltech-Jodrell Flat-spectrum sample
• Blind HI and OH absorption line search: first results with MALS and uGMRT processed using ARTIP
• Correlation between X-ray and radio absorption in compact radio galaxies
• The last breath of the young gigahertz-peaked spectrum radio source PKS 1518+047
• A comparative study of intervening and associated HI 21-cm absorption profiles in redshifted galaxies
• Prevalence of neutral gas in centres of merging galaxies
• Connecting X-ray absorption and 21cm neutral hydrogen absorption in obscured radio AGN
• A correlation between the HI 21-cm absorption strength and impact parameter in external galaxies
• MIGHTEE-HI: The first MeerKAT HI mass function from an untargeted interferometric survey
• HI gas in rejuvenated radio galaxies: GMRT observations of the DDRG J1247+6723
• Prevalence of neutral gas in centres of merging galaxies-II: nuclear HI and multi-wavelength properties
• Circumnuclear and infalling HI gas in a merging galaxy pair at z=0.123
• Deep Chandra X-ray Imaging of a Nearby Radio Galaxy 4C+29.30: X-ray/Radio Connection
• Multi-Frequency Optical-Depth Maps and the Case for Free-Free Absorption in Two Compact Symmetric Radio Sources: the CSO candidate J1324+4048 and the CSO J0029+3457
• The parsec-scale HI outflows in powerful radio galaxies
• Invisible Active Galactic Nuclei. II Radio Morphologies & Five New HI 21 cm Absorption Line Detections
• Giant Metrewave Radio Telescope detection of associated HI 21cm absorption at $z=1.2230$ towards TXS1954+513
• Ionisation of the atomic gas in redshifted radio sources
• Detecting cold gas at intermediate redshifts: GMRT survey using Mg II systems
• A survey for HI in the distant Universe: the detection of associated 21-cm absorption at z=1.28
• Large-scale HI in nearby radio galaxies (II): the nature of classical low-power radio sources
• VLBA Observations of HI in the Archetype Compact Symmetric Object B2352+495
• Polarimetry of Compact Symmetric Objects
• An ASKAP survey for HI absorption towards dust-obscured quasars
• The HI absorption zoo: JVLA extension to $z\sim 0.4$
• HI gas in the rejuvenated radio galaxy 4C29.30
• Atomic and Molecular Absorption in Redshifted Radio Sources
• The Discovery of Host Galaxy HI Absorption in CTA 21
• A search for HI and OH absorption in z > 3 CO emitters
• Evolution of cold gas at 2<z<5: a blind search for HI and OH absorption lines towards mid-infrared color selected radio-loud AGNs
• Strongly lensed neutral hydrogen emission: detection predictions with current and future radio interferometers
• Toward a direct measurement of the cosmic acceleration: the first preparation with FAST
• The Expanded Giant Metrewave Radio Telescope
• HI absorption towards low luminosity radio-loud AGNs of different accretion modes and WISE colours
• Tracing the neutral gas environments of young radio AGN with ASKAP
• The mid-infrared properties and gas content of active galaxies over large look-back times
• Parsec-scale HI absorption structure in a low-redshift galaxy seen against a Compact Symmetric Object
• H I absorption towards radio Active Galactic Nuclei of different accretion modes
• Discovery of CO absorption at z=0.05 in G0248+430
• FLASH Pilot Survey: Detections of associated 21 cm HI absorption in GAMA galaxies at 0.42 < z <1.00
• Further Observational Evidence for a Critical Ionising Luminosity in Active Galaxies
• Broad, weak 21 cm absorption in an early type galaxy: spectral-line finding and parametrization for future surveys
• "Invisible AGN" I: Sample Selection and Optical/Near-IR Spectral Energy Distributions
• uGMRT search for cold gas at z~1-1.4 towards red quasars
• X-ray Emission of the $\gamma$-ray Loud Young Radio Galaxy NGC 3894
• Intervening or associated? Machine learning classification of redshifted H I 21-cm absorption
• Probing galaxy evolution through HI 21-cm emission and absorption: current status and prospects with the Square Kilometre Array
• Redshift evolution of the HI detection rate in radio-loud active galactic nuclei
• uGMRT HI 21-cm absorption observations of two extremely inverted spectrum sources
• N_H - N_HI correlation in Gigahertz-peaked-spectrum galaxies
• A relation between circumnuclear HI, dust, and optical cores in low-power radio galaxies
• The FAST HI 21-cm absorption blind survey. II. -- Statistic Exploration for Associated and Intervening systems
• HI absorption associated with Norma's brightest cluster galaxy
• HI 21-cm absorption in radio-loud AGN with double-peaked [OIII] emission
• Serendipitous Detection of HI Absorption Sets the True Redshift of 4C +15.05 to $z=0.833$
• FASHI: An untargeted survey of the 21 cm HI absorption galaxies with FAST
• From galaxy-scale fueling to nuclear-scale feedback: the merger-state of radio galaxies 3C293, 3C305 & 4C12.50
• A first quantification of the effects of absorption for HI Intensity Mapping experiments
• Cold gas and the disruptive effect of a young radio jet
• Analysis of the Absorption Line Profile at 21 cm for the Hydrogen Atom in Interstellar Medium
• N(HI) and jet power/emission in AGNs