J/A+A/608/A98ivo://CDS.VizieR/J/A+A/608/A98doi:10.26093/cds/vizier.36080098CDSSalome Q.Salome P.Miville-Deschenes M.-A.Combes F.Hamer S.2019-09-04T12:12:41Z2017-12-12T09:37:49ZCDS support team

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

cds-question@unistra.frradio-galaxiesradio-astronomyNGC 5128 (Centaurus A) is one of the best targets to study AGN feedback in the local Universe. At 13.5kpc from the galaxy, optical filaments with recent star formation lie along the radio jet direction. This region is a testbed for positive feedback, here through jet-induced star formation. Atacama Pathfinder EXperiment (APEX) observations have revealed strong CO emission in star-forming regions and in regions with no detected tracers of star formation activity. In cases where star formation is observed, this activity appears to be inefficient compared to the Kennicutt-Schmidt relation. We used the Atacama Large Millimeter/submillimeter Array (ALMA) to map the 12CO(1-0) emission all along the filaments of NGC 5128 at a resolution of 1.3"~23.8pc. We find that the CO emission is clumpy and is distributed in two main structures: (i) the Horseshoe complex, located outside the HI cloud, where gas is mostly excited by shocks and where no star formation is observed, and (ii) the Vertical filament, located at the edge of the HI shell, which is a region of moderate star formation. We identified 140 molecular clouds using a clustering method applied to the CO data cube. A statistical study reveals that these clouds have very similar physical properties, such as size, velocity dispersion, and mass, as in the inner Milky Way. However, the range of radius available with the present ALMA observations does not enable us to investigate whether or not the clouds follow the Larson relation. The large virial parameter {alpha}_vir_ of the clouds suggests that gravity is not dominant and clouds are not gravitationally unstable. Finally, the total energy injection in the northern filaments of Centaurus A is of the same order as in the inner part of the Milky Way. The strong CO emission detected in the northern filaments is an indication that the energy injected by the jet acts positively in the formation of dense molecular gas. The relatively high virial parameter of the molecular clouds suggests that the injected kinetic energy is too strong for star formation to be efficient. This is particularly the case in the Horseshoe complex, where the virial parameter is the largest and where strong CO is detected with no associated star formation. This is the first evidence of AGN positive feedback in the sense of forming molecular gas through shocks, associated with low star formation efficiency due to turbulence injection by the interaction with the radio jet.2017A&A...608A..98Shttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/608/A98CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/595/A65 : APEX spectra of Centaurus A (Salome+, 2016)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/608/A98https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/608/A98http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/608/A98https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/608/A98https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/608/A98http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/608/A98GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/608/A98/catalog (Catalogue of the molecular clouds extracted from the ALMA data (from catalogue.fits))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/608/A98/catalog?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/608/A98/catalog?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/608/A98/catalog?GETtext/xml+votable180.050000true201.59062-42.822460.0055555555555555566/43263https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/608/A98?format=asciiRadiodefaultJ/A+A/608/A98/catalogCatalogue of the molecular clouds extracted from the ALMA data (from catalogue.fits)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintID[1/144] Clump sequential number (ID)meta.recordintRAJ2000Right ascension (J2000) (RA)degpos.eq.ra;meta.maine_RAJ2000rms uncertainty on RAdeg (dRA)degstat.error;pos.eq.radoubleDEJ2000Declination (J2000) (Dec)degpos.eq.dec;meta.maine_DEJ2000rms uncertainty on DEdeg (dDec)degstat.error;pos.eq.decdoublePAPosition angle (ANGLE)degpos.posAngdoubleNpixNumber of pixels on the sky (NPIXELS)meta.numberintVcentCentroid velocity relative to Cen A (V_LSR_~545km/s) (VCENT)km/sphys.velocdoublesigmaVeloctiy dispersion (SIGV)km/sinstr.dispersiondoubleSCODvTotal integrated emission of the cloud (SCODV)Jy.km/sphot.flux.density;em.radiodoubleLCOCO luminosity (LCO)K.km.s**-1.pc**2phys.luminosity;em.radiodoubleMassHydrogen molecular mass (MASS)solMassphys.massdoubleAreaAngular area (AREA_DEG2)deg**2phys.angAreadoubleAreapc2Linear area (AREA_PC2)pc**2pos.distance;phys.areadoubleMajorMajor axis(LMAX)degphys.angSizedoubleMinorMinor axis (LMIN)degphys.angSizedoubleRadiusRadius used in the paper (RADIUS)pcphys.size.radiusfloatReffEffective radius from Clumpfind (R_EFF)degphys.angSizefloatSigmaH2Hydrogen molecular surface density (SIGMA_H2)solMass.pc**-2phot.flux.density.sbdoubleSimbadSimbad column added by the CDSmeta.ref.urlchar