J/ApJ/810/107ivo://CDS.VizieR/J/ApJ/810/107doi:10.26093/cds/vizier.18100107CDSMostardi R.E.Shapley A.E.Steidel C.C.Trainor R.F.Reddy N.A.,Siana B.2018-04-04T06:03:48Z2017-10-11T09:36:08ZCDS support team

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

cds-question@unistra.frgalaxiesphotometryhst-photometryredshiftedWe present U_336_V_606_J_125_H_160_ follow-up Hubble Space Telescope (HST) observations of 16 z~3 candidate Lyman continuum (LyC) emitters in the HS1549+1919 field. With these data, we obtain high spatial-resolution photometric redshifts of all sub-arcsecond components of the LyC candidates in order to eliminate foreground contamination and identify robust candidates for leaking LyC emission. Of the 16 candidates, we find one object with a robust LyC detection that is not due to foreground contamination. This object (MD5) resolves into two components; we refer to the LyC-emitting component as MD5b. MD5b has an observed 1500 {AA} to 900 {AA} flux-density ratio of (F_UV_/F_LyC_)_obs_=4.0+/-2.0, compatible with predictions from stellar population synthesis models. Assuming minimal IGM absorption, this ratio corresponds to a relative (absolute) escape fraction of f_esc,rel_^MD5b^=75%-100% (f_esc,abs_^MD5b^=14%-19%). The stellar population fit to MD5b indicates an age of <~50 Myr, which is in the youngest 10% of the HST sample and the youngest third of typical z~3 Lyman break galaxies, and may be a contributing factor to its LyC detection. We obtain a revised, contamination-free estimate for the comoving specific ionizing emissivity at z=2.85, indicating (with large uncertainties) that star-forming galaxies provide roughly the same contribution as QSOs to the ionizing background at this redshift. Our results show that foreground contamination prevents ground-based LyC studies from obtaining a full understanding of LyC emission from z~3 star-forming galaxies. Future progress in direct LyC searches is contingent upon the elimination of foreground contaminants through high spatial-resolution observations, and upon acquisition of sufficiently deep LyC imaging to probe ionizing radiation in high-redshift galaxies.2015ApJ...810..107Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/810/107CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/ApJ/592/728 : Lyman break galaxies at redshift z~3 (Steidel+, 2003)J/A+A/461/823 : Candidate Ly{alpha} emitting galaxies (Venemans+, 2007)J/A+A/498/13 : Lyman-{alpha} emitters from redshifts z~2-3 (Nilsson+, 2009)J/ApJ/765/47 : Lyman-break galaxies and LAEs at z~3 (Nestor+, 2013)J/MNRAS/430/425 : VLT LBG Redshift Survey. III. (Bielby+, 2013)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/810/107https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/810/107http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/810/107https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/810/107https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/810/107http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/810/107GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/810/107/table3 (LBG and LAE Photometry)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/810/107/table3?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/810/107/table3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/810/107/table3?GETtext/xml+votable180.050000true237.9382333319.170905830.0055555555555555566/8552 85531.1898101823923579e-19 6.38256151359919e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/810/107?format=asciidefaultJ/ApJ/810/107/table3LBG and LAE PhotometrySimbadNameSimbad column added by the CDSmeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDObject identifier (1)meta.id;meta.maincharRAJ2000Hour of Right Ascension (J2000) (2)pos.eq.ra;meta.mainDEJ2000Degree of Declination (J2000) (2)pos.eq.dec;meta.mainl_U336[>] Limit flag on U336meta.code.errorcharU336HST WFC3/UVIS isophotal magnitude U336 (AB)magphot.mag;em.opt.Ufloatn_U336[g] Note on U336 (3)meta.notecharE_U336? Upper 3{sigma} limit uncertainty in U336magstat.error;stat.maxfloatnullablee_U336? Lower 3{sigma} limit uncertainty in U336magstat.errorfloatnullableV606HST ACS/WFC isophotal magnitude V606 (AB)magphot.mag;em.opt.RfloatE_V606Upper 3{sigma} limit uncertainty in V606magstat.error;stat.maxfloate_V606Lower 3{sigma} limit uncertainty in V606magstat.errorfloatl_J125[>] Limit flag on J125meta.code.errorcharJ125HST WFC3/IR isophotal magnitude J125 (AB)magphot.mag;em.IR.JfloatE_J125? Upper 3{sigma} limit uncertainty in J125magstat.error;stat.maxfloatnullablee_J125? Lower 3{sigma} limit uncertainty in J125magstat.errorfloatnullablel_H160[>] Limit flag on H160meta.code.errorcharH160HST WFC3/IR isophotal magnitude H160 (AB)magphot.mag;em.IR.HfloatE_H160? Upper 3{sigma} limit uncertainty in H160magstat.error;stat.maxfloatnullablee_H160? Lower 3{sigma} limit uncertainty in H160magstat.errorfloatnullablezspec? Spectroscopic redshift (4)src.redshiftfloatnullablen_zspec[f] Note on zspec (5)meta.notecharzPEGPEGASE photometric redshiftsrc.redshift.photfloatzBPASSBPASS photometric redshiftsrc.redshift.photfloatType[acr-] SED type (6)src.classchar