J/ApJ/931/121ivo://CDS.VizieR/J/ApJ/931/121doi:10.26093/cds/vizier.19310121CDSAppleton P.N.Emonts B.Lisenfeld U.Falgarone E.Guillard P.,Boulanger F.Braine J.Ogle P.Struck C.Vollmer B.Yeager T.2024-11-06T20:25:35Z2024-05-14T15:29:23ZCDS support team

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

cds-question@unistra.frinteracting-galaxiesco-line-emissionradial-velocitystar-forming-regionsinfrared-sourcesh-ii-regionsWe present Atacama Large Millimeter/submillimeter Array observations at a spatial resolution of 0.2" (60pc) of CO emission from the Taffy galaxies (UGC 12914/5). The observations are compared with narrowband Pa{alpha}, mid-IR, radio continuum and X-ray imaging, plus optical spectroscopy. The galaxies have undergone a recent head-on collision, creating a massive gaseous bridge that is known to be highly turbulent. The bridge contains a complex web of narrow molecular filaments and clumps. The majority of the filaments are devoid of star formation, and fall significantly below the Kennicutt-Schmidt relationship for normal galaxies, especially for the numerous regions undetected in Pa{alpha} emission. Within the loosely connected filaments and clumps of gas we find regions of high velocity dispersion that appear gravitationally unbound for a wide range of likely values of X_CO_. Like the "Firecracker" region in the Antennae system, they would require extremely high external dynamical or thermal pressure to stop them dissipating rapidly on short crossing timescales of 2-5Myr. We suggest that the clouds may be transient structures within a highly turbulent multiphase medium that is strongly suppressing star formation. Despite the overall turbulence in the system, stars seem to have formed in compact hotspots within a kiloparsec-sized extragalactic HII region, where the molecular gas has a lower velocity dispersion than elsewhere, and shows evidence for a collision with an ionized gas cloud. Like the shocked gas in the Stephan's Quintet group, the conditions in the Taffy bridge shows how difficult it is to form stars within a turbulent, multiphase, gas.2022ApJ...931..121Ahttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/931/121CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toB/hst : HST Archived Exposures Catalog (STScI, 2007)J/AJ/109/960 : Young star clusters in The Antennae (Whitmore+ 1995)J/AJ/126/1607 : IRAS Revised Bright Galaxy Sample (Sanders+, 2003)J/ApJ/611/821 : A2125 in X-ray (Wang+, 2004)J/ApJ/671/333 : Aperture photometry in NGC 5194 (Kennicutt+, 2007)J/ApJ/714/1256 : Far-IR star formation rate indicators (Calzetti+, 2010)J/AJ/140/75 : Antennae galaxies (NGC 4038/4039) revisited (Whitmore+, 2010)J/A+A/550/A106 : Low-velocity shocks models (Lesaffre+, 2013)J/ApJ/846/71 : M51 ISM structures from the CO maps of PAWS (Leroy+, 2017)J/ApJ/872/16 : Star formation law revisited. I. (de los Reyes+, 2019)J/A+A/647/A138 : Taffy system CO(1-0) datacube (Vollmer+, 2021)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/931/121https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/931/121http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/931/121https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/931/121https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/931/121http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/931/121GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/931/121/table3 (Properties of the extracted regions)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/931/121/table3?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/931/121/table3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/931/121/table3?GETtext/xml+votable180.050000true0.422829223.49363890.0055555555555555566/20237https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/931/121?format=asciiInfraredRadiodefaultJ/ApJ/931/121/table3Properties of the extracted regionsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRegRegion identifiermeta.id;meta.maincharRAJ2000[0] Hour of Right Ascension (J2000)pos.eq.ra;meta.mainDEJ2000[23] Degree of Declination (J2000)pos.eq.dec;meta.mainVsysCO[4154/4591]? Heliocentric radial velocity, CO(2-1) (2)km/sspect.dopplerVeloc;pos.heliocentric;em.line.COintnullableFWHM[25/146]? FWHM corrected for instrumental resolution (2)km/sspect.line.widthfloatnullablee_FWHM[2/29]? Uncertainty in FWHM (2)km/sstat.error;phys.angSizeintnullableSVdV[0.06/0.8]? Integrated flux of the CO(2-1) profile, {Sigma}S_V_{Delta}VJy.km/sphot.flux.density;em.mm.200-400GHzfloatnullablee_SVdV[0.01/0.1]? Uncertainty in SVdVJy.km/sstat.errorfloatnullableSQual[0/1] Quality factor of CO spectrum (3)meta.code.qualfloatlogMol[1.7/2.8]? Molecular surface density (4)log(solMass.pc**-2)phot.flux.density.sbfloatnullablee_logMol[0.05/0.2]? Uncertainty in logMollog(solMass.pc**-2)stat.errorfloatnullablef_logMolFlag on logMol (1)meta.codecharPaalpha[0.4/43]? Surface flux, Pa{alpha}, in 10^-16^erg/s/cm^2^/arcsec^2^ (5)1e-16mW.m**-2.arcsec**-2phot.mag.sb;em.IRfloatnullablef_PaalphaFlag on Paalpha (1)meta.codechare_Paalpha[0.2/1.2]? Uncertainty in Paalpha1e-16mW.m**-2.arcsec**-2stat.error;spect.linefloatnullablelogSFR[-1.8/0.3]? Log of surface star formation rate (5)log(solMass.yr**-1.kpc**-2)meta.idfloatnullablef_logSFRFlag on logSFR (1)meta.codecharfPaa[-1/1]? Pa{alpha} detection flags (6)meta.codeintnullable