J/ApJ/895/L23ivo://CDS.VizieR/J/ApJ/895/L23doi:10.26093/cds/vizier.1895023CDSCoppejans D.L.Margutti R.Terreran G.Nayana A.J.Coughlin E.R.,Laskar T.Alexander K.D.Bietenholz M.Caprioli D.Chandra P.,Drout M.R.Frederiks D.Frohmaier C.Hurley K.H.Kochanek C.S.,MacLeod M.Meisner A.Nugent P.E.Ridnaia A.Sand D.J.Svinkin D.,Ward C.Yang S.Baldeschi A.Chilingarian I.V.Dong Y.Esquivia C.,Fong W.Guidorzi C.Lundqvist P.Milisavljevic D.Paterson K.,Reichart D.E.Shappee B.Stroh M.C.Valenti S.Zauderer B.A.Zhang B.2022-05-18T13:54:10Z2022-04-06T08:52:26ZCDS support team

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

cds-question@unistra.frradio-sourcesradio-spectroscopyWe present X-ray and radio observations of the Fast Blue Optical Transient CRTS-CSS161010J045834-081803 (CSS161010 hereafter) at t=69-531days. CSS161010 shows luminous X-ray (Lx~5x1039erg/s) and radio (L{nu}~1029erg/s/Hz) emission. The radio emission peaked at ~100days post-transient explosion and rapidly decayed. We interpret these observations in the context of synchrotron emission from an expanding blast wave. CSS161010 launched a mildly relativistic outflow with velocity {Gamma}{beta}c>~0.55c at ~100days. This is faster than the non- relativistic AT 2018cow ({Gamma}{beta}c~0.1c) and closer to ZTF18abvkwla ({Gamma}{beta}c>~0.3c at 63days). The inferred initial kinetic energy of CSS161010 (Ek>~1051erg) is comparable to that of long gamma-ray bursts, but the ejecta mass that is coupled to the mildly relativistic outflow is significantly larger (~0.01-0.1M{odot}). This is consistent with the lack of observed {gamma}-rays. The luminous X-rays were produced by a different emission component to the synchrotron radio emission. CSS161010 is located at ~150Mpc in a dwarf galaxy with stellar mass M*~107M{sun} and specific star formation rate sSFR~0.3/Gyr. This mass is among the lowest inferred for host galaxies of explosive transients from massive stars. Our observations of CSS161010 are consistent with an engine-driven aspherical explosion from a rare evolutionary path of a H-rich stellar progenitor, but we cannot rule out a stellar tidal disruption event on a centrally located intermediate-mass black hole. Regardless of the physical mechanism, CSS161010 establishes the existence of a new class of rare (rate<0.4% of the local core-collapse supernova rate) H-rich transients that can launch mildly relativistic outflows.2020ApJ...895L..23Chttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/895/L23CatalogResearchIsServedByTAP VizieR generic servicerelated-toVIII/65 : 1.4GHz NRAO VLA Sky Survey (NVSS) (Condon+ 1998)VIII/76 : Leiden/Argentine/Bonn (LAB) Survey of Galactic HI (Kalberla+ 2005)VII/233 : The 2MASS Extended sources (IPAC/UMass, 2003-2006)J/A+A/479/49 : Supernova rates from STRESS (Botticella+, 2008)J/ApJ/696/870 : Catalina Real-time Transient Survey (CRTS) (Drake+, 2009)J/other/Nat/463.513 : Radio observations of SN 2009bb (Soderberg+, 2010)J/ApJ/746/156 : Radio afterglow observations of GRBs (Chandra+, 2012)J/MNRAS/428/729 : GRB Swift X-ray light curves analysis (Margutti+, 2013)J/ApJ/794/23 : Pan-STARRS1 transients optical photometry (Drout+, 2014)J/ApJ/813/82 : z<0.06 broad-line AGN emission-line measures (Reines+, 2015)J/ApJ/819/35 : Light curves of 4 transients from PTF & SNLS (Arcavi+, 2016)J/MNRAS/455/2918 : Photometry & line luminosities ASASSN-14li (Holoien+, 2016)J/ApJ/844/46 : Photometry of transient event iPTF16fnl (Blagorodnova+, 2017)J/ApJ/836/25 : Swift UVOT light curves of ASASSN-15lh (Margutti+, 2017)J/ApJ/851/107 : iPTF 16asu photometry follow-up (Whitesides+, 2017)J/A+A/618/A104 : NGC3278, SN2009bb host, ATCA & MUSE data (Michalowski+,2018)J/ApJ/853/62 : Optical and NIR spectra & LCs of SN2016ija (Tartaglia+, 2018)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/895/L23https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/895/L23http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/895/L23https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/895/L23https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/895/L23http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/895/L23GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapRadiodefaultJ/ApJ/895/L23/tablea1Radio observations of CSS161010TelTelescope (1)meta.id;instr.telcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintObs[2016/2018] Start Date, YYYYtime.startJD[69/531] Julian Date; JD-2457668dtime.epochintFreq[0.33/25] FrequencyGHzem.freqfloatBand[0.03/4.1] BandwidthGHzinstr.bandpassfloatl_FluxLimit flag for Fluxmeta.code.error;phot.fluxcharFlux[0.01/7.1] Flux DensitymJyphot.flux.density;em.radiofloate_Flux[0.008/0.7]? Uncertainty in FluxmJystat.error;phot.fluxfloatnullable