J/A+A/702/A183ivo://CDS.VizieR/J/A+A/702/A183doi:10.26093/cds/vizier/bc-ny/lbidCDSHatziminaoglou E.Messias H.Souza R.Borkar A.Farrah D.Feltre A.,Magdis G.Pitchford L.K.Perez-Fournon I.2026-08-03T06:57:59Z2025-10-20T07:46:56ZCDS support team

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

cds-question@unistra.frquasarsmillimeter-astronomysubmillimeter-astronomyphotometryOver the past 15 years, studies of quasars in the far-infrared (FIR) have reported host luminosities ranging from 10^12^ to 10^14^ solar luminosities. These luminosities, often derived from Herschel/SPIRE photometry, suggest star formation rates (SFRs) of up to several thousand solar masses per year, positioning them among the most luminous starburst galaxies in the Universe. However, due to the limited spatial resolution of SPIRE, there is considerable uncertainty regarding whether the FIR emission originates from the quasar itself, nearby sources at the same redshift, or unrelated sources within the SPIRE beam. To resolve this uncertainty, high-resolution observations at wavelengths close to the SPIRE coverage are required to pinpoint the true source of the FIR emission. The aim of the present work is to unambiguously identify the submillimeter (submm) counterparts of a statistical sample of FIR-bright SDSS quasars and estimate the real multiplicity rates among these systems. We study the evolution of the incidence of multiplicities with redshift, FIR properties and "balnicity". Based on these multiplicities, we assess the importance of mergers as triggers for concomitant accretion onto supermassive black holes (SMBHs) and extreme star formation. We conducted ALMA Band 7 continuum observations of 152 SDSS FIR-bright quasars in Stripe 82, covering redshifts between 1 and 4, with a spatial resolution of 0.8". We identified all the sources detected in the Band 7 maps at or above 5 sigma and performed forced photometry on the phase centre for the few quasars that were not detected otherwise. Additionally, we examined the coarse Band 7 spectra for any serendipitous detections of CO and other transitions. We find that in approximately 60% of all cases, the submm emission originates from a single counterpart within the SPIRE beam, centred on the optical coordinates of the quasar. The rate of multiplicity increases with redshift, rising by a factor of 2.5 between redshifts 1 and 2.5. The incidence of multiplicities is consistent among broad absorption line (BAL) quasars and non-BAL quasars. The multiplicities observed in a fraction of the sample indicate that, while mergers are known to enhance gas inflow efficiency, there must be viable alternatives for driving synchronous SMBH growth and intense star formation in isolated systems. Additionally, we report the serendipitous detection of two CO(6-5) and three CO(7-6) transitions in five quasars at redshifts between 1 and 1.4, out of the eight such transitions expected based on the spectral setup and the redshifts of the objects in the sample. Higher transitions, although expected in a fraction of the sample, are not detected, indicating that the quasars are not exciting sufficiently the gas in their hosts. Finally, we also detect a potential emission of H2O, HCN(10-9) or a combination of both in the spectrum of a quasar at redshift 1.67.2025A&A...702A.183Hhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/702/A183CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/525/A37 : Variability indexes of QSOs in SDSS Stripe 82J/MNRAS/440/476 : Low-redshift quasars in SDSS Stripe 82 (Falomo+, 2014)J/MNRAS/441/1802 : Low-redshift QSOs in SDSS Stripe 82 (Karhunen+, 2014)J/ApJ/768/105 : z~5 QSO luminosity function from SDSS Stripe 82J/ApJ/824/70 : UV-FIR SED results of SDSS QSOs and their hostsJ/AJ/154/269 : A new photo-z method for quasars in Stripe 82 (Yang+, 2017)J/ApJ/861/37 : Luminous WISE-selected quasars in SDSS Stripe 82J/A+A/611/A97 : Photometric quasar candidates in Stripe 82J/ApJ/900/58 : Opt-IR LC compilation of DES Stripe 82 quasars (Yang+, 2020)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/702/A183https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/702/A183http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/702/A183https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/702/A183https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/702/A183http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/702/A183GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/702/A183/table1 (ALMA Band 7 detections)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/702/A183/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/702/A183/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/702/A183/table1?GETtext/xml+votable180.050000true27.4624167-1.05393330.0055555555555555565/4453-4454 4458 4505 6/17661-17663 17725-17727 17768 17770-17771 17774 17806-17807 17809-17810 17820-17822 17826-17829 17831 17836-17837 17840-17842 17850 17857-17858 17997-17999 18002-18003 18005-18006 18009-18013 18017 18019 18028-18029 18032 18034-18035 18176-181782.283270615984385e-22 2.283270615984385e-22https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/702/A183?format=asciiMillimeterdefaultJ/A+A/702/A183/table1ALMA Band 7 detectionsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSDSSSDSS Name (HHMMSS.ss+DDMMSS,s)meta.id;meta.maincharRA_ICRSRight Ascension (ICRS) at Ep=J2000pos.eq.ra;meta.mainDE_ICRSDeclination (ICRS) at Ep=J2000pos.eq.dec;meta.mainSapIntegrated flux at 870um, aperture photometrymJyphot.flux.density;em.mm.200-400GHzfloate_SapError on SapmJystat.errorfloatIimfit? Peak intensity at 870um, IMFITmJy/beamphot.flux;em.mm.200-400GHzfloatnullablee_Iimfit? Error on IimfitmJy/beamstat.errorfloatnullableSimfit? Integrated flux at 870um, IMFITmJyphot.flux.density;em.mm.200-400GHzfloatnullablee_Simfit? Error on SimfitmJystat.errorfloatnullableSimbadSimbad column added by the CDSmeta.ref.urlcharD2PDistance to Phase Centrearcsecpos.angDistancefloatSNRSignal-to-noise ratiostat.snrfloatIapPeak intensity at 870um, aperture photometrymJy/beamphot.flux;em.mm.200-400GHzfloate_IapError on IapmJy/beamstat.errorfloat