J/A+A/574/A4ivo://CDS.VizieR/J/A+A/574/A4doi:10.26093/cds/vizier.35740004CDSVardoulaki E.Charmandaris V.Murphy E.J.Diaz-Santos T.Armus L.,Evans A.Mazzarella J.M.Privon G.C.Stierwalt S.Barcos-Munoz L.2018-05-30T07:02:39Z2015-01-15T09:29:02ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frgalaxiesinfrared-sourcesradio-galaxiesradio-continuum-emissionLuminous Infrared Galaxies (LIRGs) are systems enshrouded in dust, which absorbs most of their optical/UV emission and radiates it again in the mid- and far-infrared. Radio observations are largely unaffected by dust obscuration, enabling us to study the central regions of LIRGs in an unbiased manner. The main goal of this project is to examine how the radio properties of local LIRGs relate to their infrared spectral characteristics. Here we present an analysis of the radio continuum properties of a subset of the Great Observatories All-sky LIRG Survey (GOALS), which consists of 202 nearby systems (z<0.088). Our radio sample consists of 35 systems, containing 46 individual galaxies, that were observed at both 1.49 and 8.44GHz with the VLA with a resolution of about 1-arcsec (FWHM). The aim of the project is to use the radio imagery to probe the central kpc of these LIRGs in search of Active Galactic Nuclei (AGN). We used the archival data at 1.49 and 8.44GHz to create radio-spectral-index maps using the standard relation between flux density S{nu} and frequency {nu}, S{nu}~{nu}^-{alpha}^, where {alpha} is the radio spectral index. By studying the spatial variations in {alpha}, we classified the objects as radio-AGN, radio-SB, and AGN/SB (a mixture). We identified the presence of an active nucleus using the radio morphology, deviations from the radio/infrared correlation, and spatially resolved spectral index maps, and then correlated this to the usual mid-infrared ([NeV]/[NeII] and [OIV]/[NeII] line ratios and equivalent width of the 6.2um PAH feature) and optical (BPT diagram) AGN diagnostics. We find that 21 out of the 46 objects in our sample (~45%) are radio-AGN, 9 out of the 46 (~20%) are classified as starbursts (SB) based on the radio analysis, and 16 (~35%) are AGN/SB. After comparing to other AGN diagnostics we find 3 objects out of the 46 (~7%) that are identified as AGN based on the radio analysis, but are not classified as such based on the mid-infrared and optical AGN diagnostics presented in this study.2015A&A...574A...4Vhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/574/A4CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/574/A4https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/574/A4http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/574/A4https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/574/A4https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/574/A4http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/574/A4GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/574/A4/table1 (Radio and Infrared data for the 35 LIRG systems of our sample)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/574/A4/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/574/A4/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/574/A4/table1?GETtext/xml+votable180.050000true2.777083-12.1072220.005555555555555556Associated datahttps://cdsarc.cds.unistra.fr/assocdata/?obs_collection=J/A+A/574/A46/231 295 650 4993 5116 5523 5816 6098 7552 8673 8997 9770 9895 10081 10144 10465 11029 11101 11206 11908 16755 17075 17183 17506 18406 20061 20208 21016 26028 26298 27537 28188 28393 36188 446719.87284372295006e-25 5.5924024392990166e-24https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/574/A4?format=asciiInfraredRadiodefaultJ/A+A/574/A4/table1Radio and Infrared data for the 35 LIRG systems of our sampleSimbadNameSimbad column added by the CDSmeta.idcharSeq[1/46] Sequential number used in Fig.5 of papermeta.recordintprimaryNameName of the galaxy. Systems are marked with the relative position to each other (e.g. N, S, E, W)meta.id;meta.maincharRAJ2000Right ascension (J2000) (1)pos.eq.ra;meta.mainDEJ2000Declination (J2000) (1)pos.eq.dec;meta.mainim1Download the 1.49GHz imagemeta.ref.urlcharim8Download the 8.44GHz imagemeta.ref.urlcharS1.49[4/304] Integrated flux density at 1.49GHz (2)mJyphot.flux.density;em.radio.750-1500MHzfloate_S1.49[0.04/1.9] rms uncertainty on S1.49GHzmJystat.errorfloatS8.44[0.5/267] Integrated flux density at 8.44GHz (2)mJyphot.flux.density;em.radio.6-12GHzfloate_S8.44[0.002/0.5] rms uncertainty on S8.44GHzmJystat.errorfloatalpha[-0.06/2.6] Radio spectral index {alpha} calculated between 1.49 and 8.44GHz (S_{nu}_{prop.to}{nu}^-{alpha}^)spect.index;em.radio.6-12GHzfloate_alpharms uncertainty on alphastat.error;pos.eq.rafloatlogL1.4Radio luminosity at 1.49GHz (3)log(W.Hz**-1)phys.luminosity;em.radio.750-1500MHzfloatlogLIR? Total infrared luminosity calculated from 14 to 1000m (see Diaz-Santos et al., 2010ApJ...723..993D, Cat. J/ApJ/723/993)log(solLum)phys.luminosity;em.IRfloatnullableqIR[2.2/3.5]? qIR parameter (4)phot.flux;arith.ratiofloatnullableIR8[4.9/103]? Ratio of total IR luminosity to the luminosity at 8um (see Elbaz et al., 2011A&A...533A.119E, Cat. J/A+A/533/A119)phys.luminosity;arith.ratiofloatnullablen_IR8[t] t for total measurement for the system (5)meta.notecharSt1.49Radio structure at 1.49GHz (6)phot.flux.density;em.radio.750-1500MHzcharSt8.44Radio structure at 8.44GHz (6)phot.flux.density;em.radio.6-12GHzcharONameAlternative namemeta.idcharVLA1.49Name of file with 512x512 VLA image at 1.49GHz (scale=0.4arcsec/pix), in subdirectory imagesmeta.id;instr.scalecharVLA8.44Name of file with 128x128 VLA image at 8.44GHz (scale= 0.05arcsec/pix), in subdirectory imagesmeta.id;instr.scalechar