J/A+A/698/A116ivo://CDS.VizieR/J/A+A/698/A116doi:10.26093/cds/vizier.36980116CDSPessa I.Tejos N.Martinez-Acosta K.Lopez S.Werk J.Prochaska J.X.2025-07-16T20:01:12Z2025-06-03T11:33:48ZCDS support team

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

cds-question@unistra.frgalaxiesredshiftedvisible-astronomysloan-photometryspectrophotometryA large fraction of the baryon budget at z<1 resides in large-scale filaments in the form of diffuse intergalactic gas, and numerous studies have reported a significant correlation between the strength of the absorptions produced by this gas in the spectra of bright background sources, and impact the parameter to cosmic filaments intersected by these sightlines. However, a similar relation is harder to determine for the warm-hot phase of the intergalactic gas, since its higher Doppler parameter and significantly lower neutral gas fraction makes this gas difficult to detect in absorption. We use a sample of 13 broad Ly{alpha} absorbers (BLAs) detected in the HST/COS spectrum of a single QSO (z~0.2685), whose sightline intersects several intercluster axes, to study the relation between BLAs and the large-scale structure of the Universe. Given their Doppler parameters of b>40km/s, BLAs are good tracers of warm-hot intergalactic gas. We use VLT/MUSE and VLT/VIMOS data to infer local overdensities of galaxies at the redshifts of the BLAs, and to assess the potential association of the BLAs with nearby galaxies. We find that out of the 13 BLAs in our sample, four are associated with a strong overdensity of galaxies, and four with tentative overdensities. The remaining five are located at redshifts where we do not identify any excess of galaxies. We find that these overdensities of galaxies at the redshift of BLAs (+/-1000km/s) are local, and they vanish when larger cosmic volumes are considered, in terms of a larger velocity offset to the BLA or larger impact parameter to the QSO sightline. Finally, we find a positive correlation between the total hydrogen column densities inferred from the BLAs, and the relative excess of galaxies at the same redshifts, consistent with the picture in which warm-hot gas resides deep within the gravitational potential well of cosmic filaments.2025A&A...698A.116Phttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/698/A116CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toV/154 : Sloan Digital Sky Surveys (SDSS), Release 16 (DR16) (Ahumada+, 2020)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/698/A116https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/698/A116http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/698/A116https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/698/A116https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/698/A116http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/698/A116GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/698/A116/tablea1 (Sources in our VLT/MUSE survey)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/698/A116/tablea1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/698/A116/tablea1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/698/A116/tablea1?GETtext/xml+votable180.050000true244.9124225.721860.005555555555555556Cone search capability for table J/A+A/698/A116/tablec1 (Sources in our VLT/VIMOS survey)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/698/A116/tablec1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/698/A116/tablec1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/698/A116/tablec1?GETtext/xml+votable180.050000true244.8828625.704610.0055555555555555566/9260-92612.381800341673347e-19 4.653515163505597e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/698/A116?format=asciiOpticaldefaultJ/A+A/698/A116/tablea1Sources in our VLT/MUSE surveyrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintID[1/40] ID of sourcemeta.idintn_ID[*] Note on ID (for ID=14) (1)meta.notecharNameName of the object, JHHMMSS.ss+DDMMSS.smeta.id;meta.maincharRAJ2000Right ascension (J2000)degpos.eq.ra;meta.mainDEJ2000Declination (J2000)degpos.eq.dec;meta.mainbImpact parameter to the QSO SDSS J161940.56+254323.0 sightline, in arcsecarcsecsrc.impactParamintbkpc? Impact parameter to the QSO SDSS J161940.56+254323.0 sightline, in kpckpcsrc.impactParamintnullablermag? r apparent magnitude computed from the MUSE data (AB) (2)magphot.mag;em.opt.RfloatnullablerMAG? Absolute r magnitudemagphys.magAbsfloatnullablezRedshift (3)src.redshiftfloatClassSpectral classification of each galaxy (4)meta.code.classcharRelReliability assigned to the redshift classificationmeta.code.qualcharn_Rel[t] Note on reliability (5)meta.notecharJ/A+A/698/A116/tablec1Sources in our VLT/VIMOS surveyzRedshift (2)src.redshiftfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintID[1/244] ID of sourcemeta.idintNameName of the object, JHHMMSS.ss+DDMMSS.smeta.id;meta.maincharRAJ2000Right ascension (J2000)degpos.eq.ra;meta.mainDEJ2000Declination (J2000)degpos.eq.dec;meta.mainbImpact parameter to the QSO SDSS J161940.56+254323.0 sightline, in arcsecarcsecsrc.impactParamintbkpc? Impact parameter to the QSO SDSS J161940.56+254323.0 sightline, in kpckpcsrc.impactParamintnullablegmag? g apparent magnitude taken from the SDSS DR16 surveymagphot.mag;em.opt.Bfloatnullablermag? r apparent magnitude taken from the SDSS DR16 surveymagphot.mag;em.opt.Rfloatnullableimag? i apparent magnitude taken from the SDSS DR16 surveymagphot.mag;em.opt.IfloatnullableiMAG? Rest-frame i-band absolute magnitude (1)magphys.magAbsfloatnullableRelReliability assigned to the redshift classificationmeta.code.qualcharn_RelNote on reliability (3)meta.notechar