J/ApJ/951/133ivo://CDS.VizieR/J/ApJ/951/133doi:10.26093/cds/vizier/ba-xq-45CDSKerby S.Falcone A.D.2026-07-02T11:59:49Z2025-09-24T13:43:20ZCDS support team

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

cds-question@unistra.frbl-lacertae-objectsactive-galactic-nucleigamma-ray-astronomyx-ray-sourcesradio-sourcesspectral-energy-distributionRecent works have developed samples of blazars from among the Fermi Large Area Telescope unassociated sources via machine-learning comparisons with known blazar samples. Continued analysis of these new blazars tests the predictions of the blazar sequence and enables more flux-complete samples of blazars as a population. Using Fermi, Swift, Wide-field Infrared Survey Explorer, and archival radio data, we construct broadband spectral energy distributions for 106 recently identified blazars. Drawn from the unassociated 4FGL source sample, this new sample has a lower median flux than the overall sample of gamma-ray blazars. By measuring the synchrotron peak frequency, we compare our sample of new blazars with known blazars from the 4LAC catalog. We find that the bulk of the new blazars are similar to high-synchrotron-peaked BL Lac objects, with a higher median synchrotron peak; the sample has a median log({nu}_syn_/Hz)=15.5 via BLaST peak estimation, compared to log({nu}_syn_/Hz)=14.2 for the 4LAC BL Lacs. Finally, we conduct synchrotron self-Compton leptonic modeling, comparing fitted physical and phenomenological properties to brighter blazars. We find that the new blazars have smaller characteristic Lorentz factors {gamma}boost and fitted magnetic fields B, in agreement with blazar sequence predictions. The new blazars have slightly higher Compton dominance ratios than expected, which may point to alternative emission models for these dim blazars. Our results extend the predictions of the blazar sequence to a sample of dimmer blazars, confirming the broad predictions of that theory.2023ApJ...951..133Khttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/951/133CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toVIII/65 : 1.4GHz NRAO VLA Sky Survey (NVSS) (Condon+ 1998)VIII/78 : Sydney University Molonglo Sky Survey (SUMSS) (Mauch+ 2006)VIII/81 : Sydney University Molonglo Sky Survey (SUMSS V2.1) (Mauch+ 2008)IX/67 : Fermi LAT 4th source cat. (4FGL-DR3) (Fermi-LAT col., 2022)J/ApJ/722/520 : Gamma-ray light curves of Fermi blazars (Abdo+, 2010)J/ApJ/716/30 : SED of Fermi bright blazars (Abdo+, 2010)J/ApJS/247/33 : The Fermi LAT fourth source catalog (4FGL) (Abdollahi+, 2020)J/ApJ/892/105 : 4th catalog of Fermi LAT-detected AGNs (4LAC) (Ajello+, 2020)J/ApJ/923/75 : X-ray/UV/opt counterparts of 4FGL sources (Kerby+, 2021)J/ApJS/255/30 : VLASS QL Ep.1 Catalog, CIRADA version (Gordon+, 2021)J/ApJS/263/24 : The 4LAC-DR3 catalog (Ajello+, 2022)J/ApJ/943/167 : FSRQs & BL Lac objects from 4FGL blazar cand. (Kaur+, 2023)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/951/133https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/951/133http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/951/133https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/951/133https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/951/133http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/951/133GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/951/133/table2 (*Phenomological features of the broadband spectral energy distributions (SEDs) from agnpy fitting unless otherwise noted)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/951/133/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/951/133/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/951/133/table2?GETtext/xml+votable180.050000true1.1420833-40.010.005555555555555556Cone search capability for table J/ApJ/951/133/table3 (*Synchrotron-self-Compton fits via agnpy with fixed z=0.34)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/951/133/table3?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/951/133/table3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/951/133/table3?GETtext/xml+votable180.050000true1.1420833-40.010.0055555555555555566/50 760 836 973 1153 2167 2324 3721 5193 5421 5800 6477 7137 7237 7940 7958 8603 9321 9642 9759 9914 10468 11156 12668 12856 13986 14274 14477 16385 16541 16560 16650 17270 17734 18626 19431 20221 22341 22482 23427 23728 24004 24789 25403 25512 25525 26767 26933 27074 27964 30262 30473 30498 32394 32420 32578 32909 33087 33482 33514 33596 33795 34949 35343 35395 36394 37629 37744 38092 38127 38130 38476 38488 38492 38837 39139 39431 39459 40025 40366 40808 41253 41359 42099 44129 44751 44986 45077 45375 45859 45974 46209 46239 46444 46480 46622 47392 48200https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/951/133?format=asciiGamma-rayX-rayRadiodefaultJ/ApJ/951/133/table2*Phenomological features of the broadband spectral energy distributions (SEDs) from agnpy fitting unless otherwise notedrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordint4FGLFermi-LAT 4FGL DR3 position-based identifiermeta.id.assoccharm_4FGLNumber of XRT sources for this 4FGLmeta.numberintnullableXRTSwift-XRT position-based identifiermeta.id;meta.maincharprimarySimbadNameSimbad column added by the CDSmeta.idcharnullablelognuCom[20.9/25.9] Log, high-energy peak frequencylog(Hz)em.freqfloatlognuBLaST[12.2/17.3] Log, synchrotron peak frequency, from BLaST (log({nu}_syn,BLaST_)) (1)log(Hz)em.freqfloate_lognuBLaST[0.4/2.4] lognuBLaST uncertainty (log({delta}{nu}_syn,BLaST_)) (1)log(Hz)stat.error;em.freqfloatlognusyn[12.8/18.3] Log, synchrotron peak frequency (log({nu}_syn))log(Hz)em.freqfloatlognuFnusyn[-13.7/-9.8] Log, synchrotron peak flux, erg/s/cm2log(mW.m**-2)phot.flux.density;em.gamma.hardfloatlognuFnuCom[-13.3/-11] Log, high-energy peak flux, erg/s/cm2log(mW.m**-2)phot.flux.density;em.gamma.hardfloatlogFbol[-10.5/-8] Log, bolometric flux, erg/s/cm2log(mW.m**-2)phot.flux.bolfloatKCatDisplay data from Kerby+ 2021, J/ApJ/923/75 and Kaur+ 2023, J/ApJ/943/167meta.ref.urlintnullableSEDDownload the SED (ecsv file)meta.ref.urlchar_RAPositions from XRT names (right ascension part)degpos.eq.ra;meta.main_DEPositions from XRT names (declination part)degpos.eq.dec;meta.mainJ/ApJ/951/133/table3*Synchrotron-self-Compton fits via agnpy with fixed z=0.34p2[1.3/8] agnpy SSC parameter, power-law index above breakspect.indexfloatloggam[2/5.6] agnpy SSC parameter, break Lorentz factorstat.fit.paramfloatloggamMax[5/8] agnpy SSC parameter, minimum electron factorphys.electron;arith.factor;stat.maxfloatloggamMin[1/4] agnpy SSC parameter, maximum electron factorphys.electron;arith.factor;stat.minfloatdD[4/41.2] agnpy SSC parameter, Doppler factor, {delta}_D_spect.dopplerParamfloatlogB[-2/0.2] agnpy SSC parameter, magnetic field strengthlog(G)phys.magFieldfloatlogtvar[4/6.1] agnpy SSC parameter, variability timescalelog(s)src.var;time.scalefloatchi2r[0.28/4] Reduced {chi}^2^ of fitstat.fit.chi2float_RAPositions from XRT names (right ascension part)degpos.eq.ra;meta.main_DEPositions from XRT names (declination part)degpos.eq.dec;meta.mainXRTSwift-XRT position-based identifiermeta.id;meta.maincharprimaryrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordint4FGLFermi-LAT 4FGL DR3 position-based identifiermeta.id.assoccharlogke[-8.9/-0.26] agnpy synchrotron self-Compton (SSC) parameter, scaling factorarith.factorfloatp1[-1.8/4] agnpy SSC parameter, power-law index below breakspect.indexfloat