J/A+A/627/A107ivo://CDS.VizieR/J/A+A/627/A107doi:10.26093/cds/vizier.36270107CDSLisenfeld U.Xu C.K.Gao Y.Domingue D.L.Cao C.Yun M.S.Zuo P.2023-05-05T10:03:38Z2019-07-09T09:14:18ZCDS support team

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

cds-question@unistra.frgalaxiesinfrared-sourcesinterstellar-mediumco-line-emissionWe present CO observations of 78 spiral galaxies in local merger pairs. These galaxies represent a subsample of a Ks-band-selected sample consisting of 88 close major-merger pairs (HKPAIRs), 44 spiral-spiral (S+S) pairs, and 44 spiral-elliptical (S+E) pairs, with separation <20h^-1^kpc and mass ratio <2.5. For all objects, the star formation rate (SFR) and dust mass were derived from Herschel PACS and SPIRE data, and the atomic gas mass, MHI, from the Green Bank Telescope HI observations. The complete data set allows us to study the relation between gas (atomic and molecular) mass, dust mass, and SFR in merger galaxies. We derive the molecular gas fraction (M_H2_/M*), molecular-to-atomic gas mass ratio (M_H2_/M_HI_), gas-to-dust mass ratio and SFE (=SFR/M_H2_) and study their dependences on pair type (S+S compared to S+E), stellar mass, and the presence of morphological interaction signs. We find an overall moderate enhancement (~2x) in both molecular gas fraction (M_H2_/M*) and molecular-to-atomic gas ratio (M_H2_/M_HI_) for star-forming galaxies in major-merger pairs compared to non-interacting comparison samples, whereas no enhancement was found for the SFE nor for the total gas mass fraction ((MHI+MH2)/M^Cstar). When divided into S+S and S+E, low mass and high mass, and with and without interaction signs, there is a small difference in SFE, a moderate difference in M_H2_/M*, and a strong difference in M_H2_/M_HI_ between subsamples. For the molecular-to-atomic gas ratio M_H2_/M_HI_, the difference between S+S and S+E subsamples is 0.55+/-0.18dex and between pairs with and without interaction signs is 0.65+/-0.16dex. Together, our results suggest that (1) star formation enhancement in close major-merger pairs occurs mainly in S+S pairs after the first close encounter (indicated by interaction signs)^Mbecause the HI gas is compressed into star-forming molecular gas by the tidal torque; and (2) this effect is much weakened in the S+E pairs.2019A&A...627A.107Lhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/627/A107CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/627/A107https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/627/A107http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/627/A107https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/627/A107https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/627/A107http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/627/A107GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/627/A107/table12 (Results of CO(1-0) and CO(2-1) observations (table 1) and molecular gas mass (table 2))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/627/A107/table12?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/627/A107/table12?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/627/A107/table12?GETtext/xml+votable180.050000true5.10750.82638890.005555555555555556Cone search capability for table J/A+A/627/A107/listco10 (List of CO(1-0) spectra)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/627/A107/listco10?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/627/A107/listco10?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/627/A107/listco10?GETtext/xml+votable180.050000true144.4342.7608190.005555555555555556Cone search capability for table J/A+A/627/A107/listco21 (List of CO(2-1) spectra)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/627/A107/listco21?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/627/A107/listco21?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/627/A107/listco21?GETtext/xml+votable180.050000true144.4342.7608190.0055555555555555566/4718 4742 5040 5515 5719 5816 5930 6057 6459 6464 7187 7223 7344 8210 8373 8573 9344 9402 9471 9828 9859 9883 9946 10514 10518 10574 10652 10739 10847 10915 10948 11049 11264 11463 11876 11908 17812 18003 18098 23197 25841 25992 26064 26987 27339 27394 27466 27525 27652 27769 28599 30044https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/627/A107?format=asciiInfraredRadiodefaultJ/A+A/627/A107/table12Results of CO(1-0) and CO(2-1) observations (table 1) and molecular gas mass (table 2)SimbadNameSimbad column added by the CDSmeta.idcharnullablel_ICO21Upper limit flag on ICO(2-1)meta.code.errorcharICO21? Velocity integrated intensity of the CO(2-1) spectrumK.km/sspect.dopplerVeloc.radiofloatnullablee_ICO21? Error of the velocity integrated intensity of the CO(2-1) spectrumK.km/sstat.errorfloatnullablen_ICO21[*] Note on ICO21 (1)meta.notechardVCO21? Zero-level line width of the CO(2-1) spectrumkm/sspect.line.widthintnullableDistDistanceMpcpos.distancefloatl_logMmol0Upper limit flag on logMmol0meta.code.errorcharlogMmol0Decimal logarithm of the molecular gas mass extrapolated to the entire disklog(solMass)phys.massfloatfaperAperture correction factor (ratio between the molecular gas mass in the central pointing and the extrapolated value)instr.paramfloat_RAPosition from name (right ascension part)degpos.eq.ra;meta.main_DEPosition from name (declination part)degpos.eq.dec;meta.mainrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintGalaxyName of the galaxy (JHHMMSSss+DDMMSSs)meta.id;meta.maincharGroupName of the pair (JHHMM+DDMM)meta.id.parentcharrmsCO10Root-mean-square noise of the CO(1-0) spectrummKstat.snr;instr.det.noisefloatl_ICO10Upper limit flag on ICO10meta.code.errorcharICO10Velocity integrated intensity of the CO(1-0) spectrumK.km/sspect.dopplerVeloc.radiofloate_ICO10? Error of the velocity integrated intensity of the CO(1-0) spectrumK.km/sstat.errorfloatnullablen_ICO10[*] Note on ICO10 (1)meta.notechardVCO10? Zero-level line width of the CO(1-0) spectrumkm/sspect.line.widthintnullablermsCO21? Root-mean-square noise of the CO(2-1) spectrummKstat.snr;instr.det.noisefloatnullableJ/A+A/627/A107/listco10List of CO(1-0) spectrarecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintspShow the spectrummeta.ref.urlcharLineObserved linemeta.id;spect.linecharNameGalaxy pair name (JHHMM+DDMM)meta.id;meta.maincharn_Name[AB] Multiplicity index on Namemeta.notecharf_Name[*] Flag on Namemeta.codecharRAJ2000Right ascension (J2000)degpos.eq.ra;meta.mainDEJ2000Declination (J2000)degpos.eq.dec;meta.mainRestFreqRest frequencyHzem.freqdoubleImgFreqImage frequencyHzem.freqdoubleVelVelocitym/sphys.velocdoublen_VelVelocity reference (RADI-HEL or RADI-LSR)meta.notecharDVelVelocity resolutionm/sphys.veloc;spect.resolutiondoubleObs.DateObservation datetime.epoch;obsnullableJ/A+A/627/A107/listco21List of CO(2-1) spectraf_Name[*] Flag on Namemeta.codecharspShow the spectrummeta.ref.urlcharLineObserved linemeta.id;spect.linecharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameGalaxy pair name (JHHMM+DDMM)meta.id;meta.maincharn_Name[AB] Multiplicity index on Namemeta.notecharRAJ2000Right ascension (J2000)degpos.eq.ra;meta.mainDEJ2000Declination (J2000)degpos.eq.dec;meta.mainRestFreqRest frequencyHzem.freqdoubleImgFreqImage frequencyHzem.freqdoubleVelVelocitym/sphys.velocdoublen_VelVelocity reference (RADI-HEL or RADI-LSR)meta.notecharDVelVelocity resolutionm/sphys.veloc;spect.resolutiondoubleObs.DateObservation datetime.epoch;obsnullable