J/MNRAS/480/210ivo://CDS.VizieR/J/MNRAS/480/210doi:10.26093/cds/vizier.74800210CDSLopez-Sanchez A.R.Lagos C.D.P.Young T.Jerjen H.2024-08-18T20:21:05Z2022-05-17T12:54:17ZCDS support team

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

cds-question@unistra.frgalaxiesstar-forming-regionsh-i-line-emissionSpatially resolved HI studies of dwarf galaxies have provided a wealth of precision data. However these high-quality, resolved observations are only possible for handful of dwarf galaxies in the Local Volume. Future HI surveys are unlikely to improve the current situation. We therefore explore a method for estimating the surface density of the atomic gas from global HI parameters that are conversely widely available. We perform empirical tests using galaxies with resolved HI maps, and find that our approximation produces values for the surface density of atomic hydrogen within typically 0.5dex of the true value. We apply this method to a sample of 147 galaxies drawn from modern near-infrared stellar photometric surveys. With this sample we confirm a strict correlation between the atomic gas surface density and the star formation rate surface density, which is vertically offset from the Kennicutt-Schmidt relation by a factor of 10-30, and significantly steeper than the classical N=1.4 of Kennicutt (1998ARA&A..36..189K). We further infer the molecular fraction in the sample of low surface brightness, predominantly dwarf galaxies by assuming that the star formation relationship with molecular gas observed for spiral galaxies also holds in these galaxies, finding a molecular-to-atomic gas mass fraction within the range of 5-15 per cent. Comparison of the data to available models shows that a model in which the thermal pressure balances the vertical gravitational field captures better the shape of the {Sigma}_SFR_-{Sigma}_gas_ relationship. However, such models fail to reproduce the data completely, suggesting that thermal pressure plays an important role in the discs of dwarf galaxies.2018MNRAS.480..210Lhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/480/210CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/480/210https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/480/210http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/480/210https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/480/210https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/480/210http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/480/210GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/480/210/table1 (Externally obtained properties required to compute the surface densities for the KRDJ08 and YJLK14 NIR samples.)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/480/210/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/480/210/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/480/210/table1?GETtext/xml+votable180.050000true201.15-30.97222220.0055555555555555566/2130 3381 3389 3436 4650 5607 5978 7604 7799 7946 8028 8908 10532 10538 10607 10659 10793 11019 11041 11120 13637 16414 16416 16441 16459 16519 16544 16687 16695 16697 16744 16833 19779 19990 20510 20532 20605 20929 21026 21395 22427 22495 24602 24632 26047 26803 26858 27351 27926 28631 28636 28666 29718 33193 33215 33277 33571 33655-33656 33685 33742 33986 34189 34270 35214 35243 35452 35482 36900 36974 37429 37437 38102 38259 38329 38673 38941 39043 39575 40156 40158 40323 40328 40335 40358 41122 41432 41917 41946 41949 41987 43245 43333 43420 43430 43499 43605 43634 43706 43727 43763 43878 43883-43884 43924-43925 43972 45305 46339 46460 46545 46549 46597 46947 47952 48942https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/480/210?format=asciiRadiodefaultJ/MNRAS/480/210/table1Externally obtained properties required to compute the surface densities for the KRDJ08 and YJLK14 NIR samples.SimbadNameSimbad column added by the CDSmeta.idcharnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSampleSample namemeta.id;src.samplecharNameGalaxy namemeta.id;meta.maincharRAJ2000? Right Ascension (J2000)pos.eq.ra;meta.mainnullableDEJ2000? Declination (J2000)pos.eq.dec;meta.mainnullableMTypeMorphology, using the classification scheme by de Vaucouleurs et al. (1991, Cat. VII/155)src.morph.typecharDistRadial distance in Mpc (1)Mpcpos.distancefloatr_Dist? Distance reference (2)meta.ref;pos.framecharMethod? Derivation method of the radial distancemeta.notecharFUV? Far-Ultraviolet Fluxmagphot.flux;em.UVfloatnullabler_FUV? FUV reference (3)meta.ref;pos.framecharL(24um)? 24{mu}m luminosity1e-07Wphys.luminosity;em.IRfloatnullableFHI? HI FluxJy.km/sphot.flux.density;em.radio.750-1500MHzfloatnullabler_FHI? FHI reference (4)meta.ref;pos.framecharABB-band galactic extinctionmagphys.absorptionfloatBmag? Total observed luminosity in the B-bandmagphot.mag;em.opt.Bfloatnullabler_Bmag? Bmag reference (5)meta.ref;pos.framecharB-H? B-H colour corrected for extinctionmagphot.color;em.opt.B;em.IR.HfloatnullableB-Ks? B-Ks colour corrected for extinctionmagphot.color;em.opt;em.IRfloatnullableJ/MNRAS/480/210/table2Computed quantities for the NIR catalogue galaxiesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSampleSample namemeta.id;src.samplecharNameGalaxy namemeta.id;meta.maincharFUVcorr? Far-Ultraviolet Flux corrected (1)1e-07Wphot.flux;em.UVfloatnullableSFR? Star Formation ratesolMass/yrphys.SFRfloatnullableMHI? Total HI mass in galaxysolMassphys.massfloatnullableR26.5eqNear-infrared equivalent Holmberg radiuspcphys.size.radiusintlogSigHI? HI surface densitylog(solMass.pc**-2)phot.flux.density.sbfloatnullablelogSigSFR? Star formation rate surface densitylog(solMass.yr**-1.kpc**-2)phys.SFRfloatnullable