Interacting and merging galaxies from  the second Byurakan survey

Huchtmeier, W. K.; Петросян, А. Р.; Krishna, Gopal; McLean, B.; Kunth, D.

doi:10.1051/0004-6361:200810734

Cited by 11 publications

(11 citation statements)

References 44 publications

(48 reference statements)

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“…pairs) in xGASS had a factor of two higher f gas than isolated central galaxies of the same stellar mass. Other surveys that have reported elevated H i gas fractions in mergers include Casasola et al (2004), Huchtmeier et al (2008) and Jaskot et al (2015). Conversely, based on a sample of dwarf galaxy pairs, Stierwalt et al (2015) found H i gas fractions consistent with their control sample.…”

Section: Comparison With Previous Resultsmentioning

confidence: 97%

Enhanced atomic gas fractions in recently merged galaxies: quenching is not a result of post-merger gas exhaustion

Ellison

Catinella

Cortese

2018

Monthly Notices of the Royal Astronomical Society

101

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We present a detailed assessment of the global atomic hydrogen gas fraction ( f gas =log[M HI /M ]) in a sample of post-merger galaxies identified in the Sloan Digital Sky Survey (SDSS). Archival H i measurements of 47 targets are combined with new Arecibo observations of a further 51 galaxies. The stellar mass range of the post-merger sample, our observing strategy, detection thresholds and data analysis procedures replicate those of the extended GALEX Arecibo SDSS Survey (xGASS) which can therefore be used as a control sample. Our principal results are: 1) The post-merger sample shows a ∼ 50 per cent higher H i detection fraction compared with xGASS; 2) Accounting for non-detections, the median atomic gas fraction of the post-merger sample is larger than the control sample by 0.3 -0.6 dex; 3) The median atomic gas fraction enhancement (∆ f gas ), computed on a galaxy-by-galaxy basis at fixed stellar mass, is 0.51 dex. Our results demonstrate that recently merged galaxies are typically a factor of ∼ 3 more H i rich than control galaxies of the same M . If the control sample is additionally matched in star formation rate, the median H i excess is reduced to ∆ f gas = 0.2 dex, showing that the enhanced atomic gas fractions in post-mergers are not purely a reflection of changes in star formation activity. We conclude that merger-induced starbursts and outflows do not lead to prompt quenching via exhaustion/expulsion of the galactic gas reservoirs. Instead, we propose that if star formation ceases after a merger, it is more likely due to an enhanced turbulence which renders the galaxy unable to effectively form new stars.

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Section: Comparison With Previous Resultsmentioning

confidence: 97%

Enhanced atomic gas fractions in recently merged galaxies: quenching is not a result of post-merger gas exhaustion

Ellison

Catinella

Cortese

2018

Monthly Notices of the Royal Astronomical Society

101

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“…High molecular gas fractions may follow from the increased central surface densities that precede starbursts in mergers. Indeed, several previous observational studies have measured increased gas fractions in either atomic or molecular gas (Braine & Combes 1993;Bettoni et al 2001;Huchtmeier et al 2008;Stark et al 2013;Goncalves et al 2014).…”

Section: Introductionmentioning

confidence: 99%

“…Despite well documented SFR enhancements in this same sample (Scudder et al 2012;Patton et al 2013), Fertig et al (2015) do not detect any decline in the HI gas fraction of close pairs. Indeed, in an earlier study based on a small sample of confusion-free HI measurements, Huchtmeier et al (2008) suggested that mergers may be relatively HI-rich. Casasola et al (2004) present a similar study, but with over 1000 galaxies drawn from all interaction stages, from well separated pairs to coalesced remnants.…”

Section: Introductionmentioning

confidence: 99%

The neutral gas content of post-merger galaxies

Ellison

Fertig

Rosenberg

et al. 2015

Monthly Notices of the Royal Astronomical Society

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Measurements of the neutral hydrogen gas content of a sample of 93 post-merger galaxies are presented, from a combination of matches to the ALFALFA.40 data release and new Arecibo observations. By imposing completeness thresholds identical to that of the ALFALFA survey, and by compiling a mass-, redshift-and environment-matched control sample from the public ALFALFA.40 data release, we calculate gas fraction offsets (∆f gas ) for the post-mergers, relative to the control sample. We find that the post-mergers have HI gas fractions that are consistent with undisturbed galaxies. However, due to the relative gas richness of the ALFALFA.40 sample, from which we draw our control sample, our measurements of gas fraction enhancements are likely to be conservative lower limits. Combined with comparable gas fraction measurements by Fertig et al. in a sample of galaxy pairs, who also determine gas fraction offsets consistent with zero, we conclude that there is no evidence for significant neutral gas consumption throughout the merger sequence. From a suite of 75 binary merger simulations we confirm that star formation is expected to decrease the post-merger gas fraction by only 0.06 dex, even several Gyr after the merger. Moreover, in addition to the lack of evidence for gas consumption from gas fraction offsets, the observed HI detection fraction in the complete sample of post-mergers is twice as high as the controls, which suggests that the post-merger gas fractions may actually be enhanced. We demonstrate that a gas fraction enhancement in post-mergers, relative to a stellar mass-matched control sample, would indeed be the natural result of merging randomly drawn pairs from a parent population which exhibits a declining gas fraction with increasing stellar mass.

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“…Galaxy 1200 (PGC035568) has very blue g − r 0 and is in catalogues of both emission line galaxies/UV excess galaxies (Markarian & Stepanian 1983) and BCDs (Thuan et al 1999), and is Huchtmeier et al (2008). It is another extremely metal-poor galaxy (Morales-Luis et al 2011).…”

Section: Galaxy 1200; Sdssj11320262+5722366mentioning

confidence: 99%

X-ray sources in dwarf galaxies in the Virgo cluster and the nearby field

Papadopoulou

Phillipps

Young

2016

Mon. Not. R. Astron. Soc.

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The extent to which dwarf galaxies represent essentially scaled down versions of giant galaxies is an important question with regards the formation and evolution of the galaxy population as a whole. Here, we address the specific question of whether dwarf galaxies behave like smaller versions of giants in terms of their X-ray properties. We discuss two samples of around 100 objects each, dwarfs in the Virgo cluster and dwarfs in a large Northern hemisphere area. We find nine dwarfs in each sample with Chandra detections. For the Virgo sample, these are in dwarf elliptical (or dwarf lenticular) galaxies and we assume that these are (mostly) low-mass X-ray binaries (LMXB) [some may be nuclear sources]. We find a detection rate entirely consistent with scaling down from massive ellipticals, viz. about one bright (i.e. L X > 10 38 erg s −1 ) LMXB per 5 × 10 9 M of stars. For the field sample, we find one (known) Seyfert nucleus, in a galaxy which appears to be the lowest mass dwarf with a confirmed X-ray emitting nucleus. The other detections are in star-forming dwarf irregular or blue compact dwarf galaxies and are presumably high-mass X-ray binaries (HMXB). This time, we find a very similar detection rate to that in large late-type galaxies if we scale down by star formation rate, roughly one HMXB for a rate of 0.3 M per year. Nevertheless, there does seem to be one clear difference, in that the dwarf late-type galaxies with X-ray sources appear strongly biased to very low metallicity systems.

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Interacting and merging galaxies from the second Byurakan survey

Cited by 11 publications

References 44 publications

Enhanced atomic gas fractions in recently merged galaxies: quenching is not a result of post-merger gas exhaustion

Enhanced atomic gas fractions in recently merged galaxies: quenching is not a result of post-merger gas exhaustion

The neutral gas content of post-merger galaxies

X-ray sources in dwarf galaxies in the Virgo cluster and the nearby field

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