J/A+A/646/A170ivo://CDS.VizieR/J/A+A/646/A170doi:10.26093/cds/vizier.36460170CDSGong Y.Belloche A.Du F.J.Menten K.M.Henkel C.Li G.X.Wyrowski F.,Mao R.Q.2021-07-05T07:58:45Z2021-02-23T08:49:36ZCDS support team

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

cds-question@unistra.frmolecular-cloudsinterstellar-mediumradio-astronomyThe Serpens filament, a prominent elongated structure in a relatively nearby molecular cloud, is believed to be at an early evolutionary stage, so studying its physical and chemical properties can shed light on filament formation and early evolution. The main goal is to address the physical and chemical properties as well as dynamical state of the Serpens filament at a spatial resolution of ~0.07pc and a spectral resolution of ~0.1~km/s. We performed ^13^CO (1-0), C^18^O (1-0), C^17^O (1-0), ^13^CO (2-1), C^18^O (2-1), and C^17^O (2-1) imaging observations toward the Serpens filament with the IRAM-3 m and APEX telescopes. Widespread narrow ^13^CO (2-1) self-absorption is observed in this filament, causing the ^13^CO morphology to be different from the filamentary structure traced by C^18^O and C^17^O. Our excitation analysis suggests that the opacities of C^18^O transitions become higher than unity in most regions, and this analysis confirms the presence of widespread CO depletion. Further we show that the local velocity gradients have a tendency to be perpendicular to the filament's long axis in the outskirts and parallel to the large-scale magnetic field direction. The magnitudes of the local velocity gradients decrease toward the filament's crest. The observed velocity structure can be a result of gravity-driven accretion flows. The isochronic evolutionary track of the C^18^O freeze-out process indicates the filament is young with an age of <~2Myr. We propose that the Serpens filament is a newly-formed slightly-supercritical structure which appears to be actively accreting material from its ambient gas.2021A&A...646A.170Ghttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/646/A170CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/646/A170https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/646/A170http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/646/A170https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/646/A170https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/646/A170http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/646/A170GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/646/A170/list (List of fits datacubes)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/646/A170/list?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/646/A170/list?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/646/A170/list?GETtext/xml+votable180.050000true277.210.832980.0055555555555555566/30363https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/646/A170?format=asciiRadiodefaultJ/A+A/646/A170/listList of fits datacubesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000Right Ascension of center (J2000)degpos.eq.ra;meta.mainDEJ2000Declination of center (J2000)degpos.eq.dec;meta.mainNxNumber of pixels along X-axismeta.numberintNyNumber of pixels along Y-axismeta.numberintNzNumber of slicesmeta.numberintnuRest frequencyMHzem.freqdoubleFWHMBeam sizearcsecphys.angSize;instr.beamintbVRADLower value of VRAD intervalm/sphys.veloc;pos.heliocentricdoubleBVRADUpper value of VRAD intervalm/sphys.veloc;pos.heliocentricfloatdVRADVRAD resolutionm/sspect.resolutiondoublesizeSize of FITS fileKibytephys.size;meta.fitsintFileNameName of FITS file, in subdirectory fitsmeta.id;meta.fitscharTitleTitle of the FITS filemeta.title;meta.fits