J/ApJ/845/157ivo://CDS.VizieR/J/ApJ/845/157doi:10.26093/cds/vizier.18450157CDSNewman A.B.Smith R.J.Conroy C.Villaume A.van Dokkum P.2018-07-16T08:42:53Z2018-05-22T08:55:29ZCDS support team

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

cds-question@unistra.frgravitational-lensinggalaxiesvisible-astronomyinfrared-astronomyspectroscopystellar-massesredshiftedWe present new observations of the three nearest early-type galaxy (ETG) strong lenses discovered in the SINFONI Nearby Elliptical Lens Locator Survey (SNELLS). Based on their lensing masses, these ETGs were inferred to have a stellar initial mass function (IMF) consistent with that of the Milky Way, not the bottom-heavy IMF that has been reported as typical for high-{sigma} ETGs based on lensing, dynamical, and stellar population synthesis techniques. We use these unique systems to test the consistency of IMF estimates derived from different methods. We first estimate the stellar M*/L using lensing and stellar dynamics. We then fit high-quality optical spectra of the lenses using an updated version of the stellar population synthesis models developed by Conroy & van Dokkum. When examined individually, we find good agreement among these methods for one galaxy. The other two galaxies show 2-3{sigma} tension with lensing estimates, depending on the dark matter contribution, when considering IMFs that extend to 0.08M_{sun}_. Allowing a variable low-mass cutoff or a nonparametric form of the IMF reduces the tension among the IMF estimates to <2{sigma}. There is moderate evidence for a reduced number of low-mass stars in the SNELLS spectra, but no such evidence in a composite spectrum of matched-{sigma} ETGs drawn from the SDSS. Such variation in the form of the IMF at low stellar masses (m<~0.3M_{sun}_), if present, could reconcile lensing/dynamical and spectroscopic IMF estimates for the SNELLS lenses and account for their lighter M*/L relative to the mean matched-{sigma} ETG. We provide the spectra used in this study to facilitate future comparisons.2017ApJ...845..157Nhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/845/157CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toV/139 : The SDSS Photometric Catalog, Release 9 (Adelman-McCarthy+, 2012)J/MNRAS/276/1341 : Spectroscopy of E and S0 galaxies (Jorgensen+, 1995)J/MNRAS/313/469 : Streaming motions of galaxy clusters. I. (Smith+, 2000)J/MNRAS/371/703 : MILES library of empirical spectra (Sanchez-Blazquez+, 2006)J/ApJ/682/964 : Sloan lens ACS survey. V. (Bolton+, 2008)J/ApJ/705/1099 : The Sloan Lens ACS (SLACS) Survey. IX. (Auger+, 2009)J/ApJ/690/670 : The Sloan lens ACS Survey. VIII. (Treu+, 2009)J/MNRAS/443/1231 : 6dF Galaxy Survey: Fundamental Plane data (Campbell+, 2014)J/A+A/568/A9 : 300-2500nm flux calibration ref. spectra (Moehler+, 2014)J/A+A/582/A97 : SSP in NIR. II. Synthesis models (Meneses-Goytia+, 2015)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/845/157https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/845/157http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/845/157https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/845/157https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/845/157http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/845/157GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/845/157/table1 (*Measured quantities for SNELLS lenses)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/845/157/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/845/157/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/845/157/table1?GETtext/xml+votable180.050000true205.8882917-38.1760.0055555555555555566/17519 43450 46079https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/845/157?format=asciiOpticalInfrareddefaultJ/ApJ/845/157/table1*Measured quantities for SNELLS lensesSpSpectrum interactive plotmeta.ref.urlchara2PLdouble power-law IMF at m<1M_{sun}_ (3)solMass/solLumphys.composition.massLightRatiofloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameLens system identifier (<[SLC2015] SNL-N> in Simbad)meta.id;pos.frame;meta.maincharprimaryNfNumber of flux measurements for this objectmeta.numberintnullablez[0.03/0.06] Redshiftsrc.redshiftfloatReEffective radius in J-bandarcsecphys.angSize;em.IR.Jfloattheta[2.2/2.9] Einstein radius {theta}_Ein_arcsecphys.angSize;srcfloatLr[1.6/3] Luminosity within {theta}_Ein_ in the SDSS r-band L_r,Ein_ (1)1e+10solLumphys.luminosity;em.optfloate_Lr[0.05/0.07] Lr uncertainty1e+10solLumstat.errorfloatsig[274/335] Velocity dispersion {sigma}_raw_ measured in 4"x1.8" X-shooter IFU aperturekm/sphys.veloc.dispersioninte_sigsig uncertaintykm/sstat.errorintSige[263/312] Aperture velocity dispersion {sigma}_e/2_; see section 4.4km/sphys.veloc.dispersion;instr.fovinte_SigeSige uncertaintykm/sstat.errorint(M/Lr)L[4.7/5.5] Total M_Ein_/L_r,Ein_ (2)solMass/solLumphys.composition.massLightRatiofloate_(M/Lr)L(M/Lr)L uncertaintysolMass/solLumstat.errorfloat(M/Lr)D? Total projected M/L within {theta}_Ein_ from stellar dynamical modeling onlysolMass/solLumphys.composition.massLightRatiofloatnullablee_(M/Lr)D? (M/Lr)D uncertaintysolMass/solLumstat.errorfloatnullable(M/Lr)L+E[3.5/4.7] Stellar M*/L based on dark matter fractions from EAGLEsolMass/solLumphys.composition.massLightRatiofloate_(M/Lr)L+E(M/Lr)L+E uncertaintysolMass/solLumstat.errorfloat(M/Lr)L+D? Stellar M*/L from joint lensing and dynamics modelsolMass/solLumphys.composition.massLightRatiofloatnullablee_(M/Lr)L+D? (M/Lr)L+D uncertaintysolMass/solLumstat.errorfloatnullable(M/Lr)MW[3.6/4.1] Spectroscopic M*/L from Kroupa IMFsolMass/solLumphys.composition.massLightRatiofloate_(M/Lr)MW(M/Lr)MW uncertaintysolMass/solLumstat.errorfloat(M/Lr)1PLSpectroscopic M*/L from single power-law IMF at m<1M_{sun}_solMass/solLumphys.composition.massLightRatiofloate_(M/Lr)1PL(M/Lr)1PL negative uncertaintysolMass/solLumstat.errorfloatE_(M/Lr)1PL(M/Lr)1PL positive uncertaintysolMass/solLumstat.error;stat.maxfloat(M/Lr)2PLSpectroscopic M*/L from double power-law IMF at m<1M_{sun}_solMass/solLumphys.composition.massLightRatiofloate_(M/Lr)2PL(M/Lr)2PL negative uncertaintysolMass/solLumstat.errorfloatE_(M/Lr)2PL(M/Lr)2PL positive uncertaintysolMass/solLumstat.error;stat.maxfloat(M/Lr)2PLcSpectroscopic M*/L from double power-law with low-mass cutoffsolMass/solLumphys.composition.massLightRatiofloate_(M/Lr)2PLc(M/Lr)2PLc negative uncertaintysolMass/solLumstat.errorfloatE_(M/Lr)2PLc(M/Lr)2PLc positive uncertaintysolMass/solLumstat.error;stat.maxfloat(M/Lr)np[3.8/6.3] Spectroscopic M*/L, nonparametric IMFsolMass/solLumphys.composition.massLightRatiofloate_(M/Lr)np(M/Lr)np negative uncertaintysolMass/solLumstat.errorfloatE_(M/Lr)np(M/Lr)np positive uncertaintysolMass/solLumstat.error;stat.maxfloataL+E[0.9/1.2] Mass factor {alpha} using the lensing mass and EAGLE dark matter contribution (3)solMass/solLumphys.composition.massLightRatiofloate_aL+EaL+E uncertaintysolMass/solLumstat.errorfloataL+D? Mass factor {alpha} from joint lensing and dynamical modeling (3)solMass/solLumphys.composition.massLightRatiofloatnullablee_aL+D? aL+D uncertaintysolMass/solLumstat.errorfloatnullableaL+noDTotal lensing mass; assumes no dark matter {alpha}_L+noDM_ (3)solMass/solLumphys.composition.massLightRatiofloate_aL+noDaL+noD uncertaintysolMass/solLumstat.errorfloataD+noD? Total dynamical mass; assumes no dark matter {alpha}_D+noDM_ (3)solMass/solLumphys.composition.massLightRatiofloatnullablee_aD+noD? aD+noD uncertaintysolMass/solLumstat.errorfloatnullablea1PLsingle power-law IMF at m<1M_{sun}_ (3)solMass/solLumphys.composition.massLightRatiofloate_a1PLa1PL negative uncertaintysolMass/solLumstat.errorfloatE_a1PLa1PL positive uncertaintysolMass/solLumstat.error;stat.maxfloate_a2PLa2PL negative uncertaintysolMass/solLumstat.errorfloatE_a2PLa2PL positive uncertaintysolMass/solLumstat.error;stat.maxfloata2PLcdouble power-law with low-mass cutoff {alpha}_2PL+cut_ (3)solMass/solLumphys.composition.massLightRatiofloate_a2PLca2PLc negative uncertaintysolMass/solLumstat.errorfloatE_a2PLca2PLc positive uncertaintysolMass/solLumstat.error;stat.maxfloatanp[1/1.6] nonparametric IMF {alpha}_non-p_ (3)solMass/solLumphys.composition.massLightRatiofloate_anpanp negative uncertaintysolMass/solLumstat.errorfloatE_anpanp positive uncertaintysolMass/solLumstat.error;stat.maxfloatSimbadSimbad column added by the CDSmeta.ref.urlchar_RARight Ascension (J2000) from SIMBAD (not part of the original data)degpos.eq.ra;meta.main_DEDeclination (J2000) from SIMBAD (not part of the original data)degpos.eq.dec;meta.mainJ/ApJ/845/157/table2Spectra of SNELLS lenses used in SPS analysisrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameGalaxy name (1)meta.id;meta.maincharlambda[3918.4/10543] Observed-frame wavelength in vacuum units (2)0.1nmem.wldoubleFlux[0/211] Flux density in arbitrary unitsphot.fluxdoublee_Flux[0/3.1] The 1{sigma} uncertainty in Fluxstat.error;phot.fluxdoubleFlag[0/1] Mask pixel from fit when Flag=0meta.code.errorintRes[32/89.3] Instrumental resolution; {sigma} of gaussiankm/sspect.resolutionfloat