The location of the broad H i absorption in 3C 305: clear evidence for a jet-accelerated neutral outflow

Morganti, Raffaella; Oosterloo, Thomas; Tadhunter, C. N.; Moorsel, G. van; Emonts, Bjorn

doi:10.1051/0004-6361:20053175

Cited by 104 publications

(152 citation statements)

References 28 publications

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“…However, as well as occuring in outflowing gas (e.g. Vermeulen et al 2003;Morganti et al 2003Morganti et al , 2005aMorganti et al ,b, 2007Allison et al 2016), the bulk of the absorption is believed to occur in the large-scale galactic disk, rather than the sub-pc torus 13 , which is expected to have a random orientation to the radio jets (Curran & Whiting 2010 and references therein).…”

Section: Discussionmentioning

confidence: 99%

Atomic and molecular absorption in redshifted radio sources

Curran

Whiting

Allison

et al. 2017

Monthly Notices of the Royal Astronomical Society

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We report on a survey for associated H I 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 luminosity (L UV ∼ 10 23 W Hz −1 ), which is hypothesised to ionise all of the neutral gas in the host galaxy, we do not obtain any detections in the six sources searched. Analysing these in context of the previous surveys, in addition to the anti-correlation with the ultra-violet luminosity (ionising photon rate), we find a correlation between the strength of the absorption and the blue -near-infrared colour, as well as the radio-band turnover frequency. We believe that these are due to the photo-ionisation of the neutral gas, an obscured sight-line being more conducive to the presence of cold gas and the compact radio emission being better intercepted by the absorbing gas, maximising the flux coverage, respectively. Regarding the photo-ionisation, the compilation of the previous surveys increases the significance of the critical ionising photon rate, above which all of the gas in the host galaxy is hypothesised to be ionised (Q H I ≈ 3 × 10 56 sec −1 ), to > 5σ. This reaffirms that this is an ubiquitous effect, which has profound implications for the detection of neutral gas in these objects with the Square Kilometre Array.

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Section: Discussionmentioning

confidence: 99%

Atomic and molecular absorption in redshifted radio sources

Curran

Whiting

Allison

et al. 2017

Monthly Notices of the Royal Astronomical Society

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“…These outflow rates are estimated from the gas column density, the outflow velocity, and the radius within which the flow originates (see, e.g., Heckman 2002, for a review). In some cases, such as 3C 305 (Morganti et al 2005a), IC 5063 (Oosterloo et al 2000;Morganti et al 2007), and 3C 293 Emonts et al 2005), this radius is estimated from high-resolution radio and optical observations, where the outflow is spatially resolved against the radio continuum, and cospatial with regions where the radio emission in the propagating radio jet is enhanced. For the other sources, the radii are more uncertain.…”

Section: The Sample Of H I-outflow Radio Galaxiesmentioning

confidence: 99%

Strong Molecular Hydrogen Emission and Kinematics of the Multiphase Gas in Radio Galaxies With Fast Jet-Driven Outflows

Guillard

Ogle

Emonts

et al. 2012

ApJ

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115

157

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Observations of ionized and neutral gas outflows in radio galaxies (RGs) suggest that active galactic nucleus (AGN) radio jet feedback has a galaxy-scale impact on the host interstellar medium, but it is still unclear how the molecular gas is affected. Thus, it is crucial to determine the physical conditions of the molecular gas in powerful RGs to understand how radio sources may regulate the star formation in their host galaxies. We present deep Spitzer Infrared Spectrograph (IRS) high-resolution spectroscopy of eight nearby RGs that show fast H i outflows. Strikingly, all of these H i-outflow RGs have bright H 2 mid-IR lines that cannot be accounted for by UV or X-ray heating. This strongly suggests that the radio jet, which drives the H i outflow, is also responsible for the shock excitation of the warm H 2 gas. In addition, the warm H 2 gas does not share the kinematics of the ionized/neutral gas. 4C 12.50, 3C 459, and PKS 1549-79. This shows that, contrary to the H i gas, the H 2 gas is inefficiently coupled to the AGN jet-driven outflow of ionized gas. While the dissipation of a small fraction (<10%) of the jet kinetic power can explain the turbulent heating of the molecular gas, our data show that the bulk of the warm molecular gas is not expelled from these galaxies.

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“…In most cases, interferometric HI data for these sources exist in the literature. For further studies of galaxies with associated HI absorption, see van Gorkom et al (1989), Pihlstr€ om (2001), Taylor et al (2002), and Morganti et al (2005).…”

Section: Appendixmentioning

confidence: 99%

Overview on Spectral Line Source Finding and Visualisation

Koribalski¹

2012

Publ. – Astron. Soc. Aust

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Here I will outline successes and challenges for finding spectral line sources in large data cubes that are dominated by noise. This is a 3D challenge as the sources we wish to catalog are spread over several spatial pixels and spectral channels. While 2D searches can be applied, e.g. channel by channel, optimal searches take into account the 3-dimensional nature of the sources. In this overview I will focus on HI 21-cm spectral line source detection in extragalactic surveys, in particular HIPASS, the HI Parkes All-Sky Survey and WALLABY, the ASKAP HI All-Sky Survey. I use the original HIPASS data to highlight the diversity of spectral signatures of galaxies and gaseous clouds, both in emission and absorption. Among others, I report the discovery of a 680 km s À1 wide HI absorption trough in the megamaser galaxy NGC 5793. Issues such as source confusion and baseline ripples, typically encountered in single-dish HI surveys, are much reduced in interferometric HI surveys. Several large HI emission and absorption surveys are planned for the Australian Square Kilometre Array Pathfinder (ASKAP): here we focus on WALLABY, the 21-cm survey of the sky (d , þ308; z , 0.26) which will take about one year of observing time with ASKAP. Novel phased array feeds ('radio cameras') will provide 30 deg 2 instantaneous field-of-view. WALLABY is expected to detect more than 500 000 galaxies, unveil their large-scale structures and cosmological parameters, detect their extended, low-surface-brightness disks as well as gas streams and filaments between galaxies. It is a precursor for future HI surveys with SKA Phase I and II, exploring galaxy formation and evolution. The compilation of highly reliable and complete source catalogs will require sophisticated source-finding algorithms as well as accurate source parametrisation.

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The location of the broad H i absorption in 3C 305: clear evidence for a jet-accelerated neutral outflow

Cited by 104 publications

References 28 publications

Atomic and molecular absorption in redshifted radio sources

Atomic and molecular absorption in redshifted radio sources

Strong Molecular Hydrogen Emission and Kinematics of the Multiphase Gas in Radio Galaxies With Fast Jet-Driven Outflows

Overview on Spectral Line Source Finding and Visualisation

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