J/MNRAS/498/883ivo://CDS.VizieR/J/MNRAS/498/883doi:10.26093/cds/vizier.74980883CDSGrasha K.Darling J.Leroy A.K.Bolatto A.D.2024-08-21T20:16:13Z2023-11-03T08:51:17ZCDS support team

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

cds-question@unistra.frradio-sourcesquasarsh-i-line-emissionradio-astronomyredshiftedastrometryWe present the results of a blind search for intervening HI 21cm absorption towards 260 radio sources in the redshift range 0<z<2.74 with the Green Bank Telescope. The survey has the sensitivity to detect sub-damped Ly {alpha} (DLA) systems for HI spin temperatures T_s_/f=100K, and despite the successful re-detection of 10 known 21cm absorbers in the sample, we detect no new absorption lines in the full survey. Sources detected in 21cm absorption were also searched for hydroxyl (OH) 18cm absorption and we re-detect 1667MHz OH absorption towards PKS 1830-211. We searched for intervening HI 21cm absorption along the line of sight in each source achieving a total redshift coverage of {Delta}z=88.64 (comoving absorption path of {Delta}X=159.5) after removing regions affected by radio frequency interference. We compute a 95 per cent confidence upper limit on the column density frequency distribution f(N_HI_) and set a statistical constraint on the spin temperature T_s_ in the range 100-1000K, consistent with prior redshifted optical DLA surveys and HI 21cm emission observations at the same redshifts. We infer a value for the cosmological mass density of neutral gas, {Omega}_HI_. Through comparison with prior {Omega}_HI_ measurements, we place a statistical constraint on the mean spin temperature of T_s_/f=175K. Our derived {Omega}_HI_ values support a relative mild evolution in {Omega}_HI_ over the last 11Gyr and are consistent with other methods that measure {Omega}_HI_.2020MNRAS.498..883Ghttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/498/883CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toVIII/17 : The North 20cm Survey (White+ 1992)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/498/883https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/498/883http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/498/883https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/498/883https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/498/883http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/498/883GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/498/883/table1 (Journal of Observations)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/498/883/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/498/883/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/498/883/table1?GETtext/xml+votable180.050000true4.940791773.45833330.0055555555555555566/110 124 180 375 532 556 579 700 911 946 1509 1521 1546 1701 1709 1711 2143 2245 2323-2324 2331 2397 2402 2414 2704 2710 2827 2836 3820 3886 4695 4770 4924 5130 5154 5392 5413 5448 5458 5533 5617 5673 5693 5758 5767 5806 5817 6164 6230 6252 6496 6536 6633 6641 6853 7181 7296 7349 7351 7389 7426 7570 7653 7881 7969 8031 8057 8207 8299 8487 8717 8858 9299 9403 9442 9460 9632-9633 9709 9723 9813 10006 10052 10163 10249 10260 10422 10432 10529 10925 11320 11377 11430 11502 11639 11715 12047 12094 12301 12338 12352 12684 12740 13320 13410 13478 13496 13663 13693 13722 13891 14737 14842 15023 15067 15286 15300 15494 15823 15936 16027 16093 16221 16281 16298 17184 17215 17516 17541 17639 17734 17909 18002 18005 18035 18214 18506 18624 18661 18669 18713 18824 18895 18907 19088 19101 19166 19190 19398 19498 19609 19685 19857 20099 20202 21012 21049 21121 21266 21358 21437 21564 21768 21924 21935 21960 21968 22363-22364 22396 22659 22917 22943 22950 22959 22970 23099 23121 23127 24084 24116 24571 24775 24796 24845 24936 25196 25255 25302 25630 25742 25870 25905 25953 26100 26115 26131 26292 26301 26511 26932 26966 27060 27102 27241 27310 27583 27872 28083 28167 28339 28376 28479 28492 29016 29072 29570 29675 29714 30010 30160 31211 31333-31334 31430 31451 31559 31664 31686 31730 31940 31951 32322 32325 32338 36100 36139 36188 36417 36829 38763 40060 40344 40479 40527 40730 42901 42980 44776 44805 44899 44908 45011 46964 47080 48023 48496 48595 48798 48846 489652.9817312276497e-25 9.459244390355668e-25https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/498/883?format=asciiRadiodefaultJ/MNRAS/498/883/table1Journal of ObservationsSimbadNameSimbad column added by the CDSmeta.idcharnullablee_z? Error on zstat.error;src.redshiftdoublenullableT1.4Total integration time spent on the reduced spectrum for the 1.4GHz bandpass (2)stime.expointrms1.4? Average measured spectral noise level for the 1.4GHz bandpass (2)mJyinstr.det.noise;stat.meanfloatnullablef_rms1.4[*] Flag on rms1.4 (3)meta.codecharS1.4? Flux limit measured as closely to 1420 MHz (2)Jyphot.flux.density;em.radio.750-1500MHzfloatnullablel_NHI1.4Limit flag on NHI1.4meta.code.errorcharNHI1.4? Column density limit measured as closely to 1420 MHz (2)1e+18cm**-2phys.columnDensityfloatnullableT1.0Total integration time spent on the reduced spectrum for the 1.0GHz bandpass (4)stime.expointrms1.0? Average measured spectral noise level for the 1.0GHz bandpass (4)mJyinstr.det.noise;stat.meanfloatnullablef_rms1.0[*] Flag on rms1.0 (3)meta.codecharS1.0? Flux limit measured as closely to 1000 MHz (4)Jyphot.flux.density;em.radio.750-1500MHzfloatnullablel_NHI1.0Limit flag on NHI1.0meta.code.errorcharNHI1.0? Column density limit measured as closely to 1000MHz (4)1e+18cm**-2phys.columnDensityfloatnullableT800Total integration time spent on the reduced spectrum for the 800MHz bandpass (5)stime.expointrms800? Average measured spectral noise level for the 800MHz bandpass (5)mJyinstr.det.noise;stat.meanfloatnullablef_rms800[*] Flag on rms800 (3)meta.codecharS800? Flux limit measured as closely to 800 MHz (5)Jyphot.flux.density;em.radio.750-1500MHzfloatnullablee_S800? Error on S800Jystat.errorfloatnullablel_NHI800Limit flag on NHI800meta.code.errorcharNHI800? Column density limit measured as closely to 800MHz (5)1e+18cm**-2phys.columnDensityfloatnullableT450Total integration time spent on the reduced spectrum for the 450MHz bandpass (6)stime.expointrms450? Average measured spectral noise level for the 450MHz bandpass (6)mJyinstr.det.noise;stat.meanfloatnullablef_rms450[*] Flag on rms450 (3)meta.codecharS450? Flux limit measured as closely to 450MHz (6)Jyphot.flux.density;em.radio.400-750MHzfloatnullablel_NHI450Limit flag on NHI450meta.code.errorcharNHI450? Column density limit measured as closely to 450MHz (6)1e+18cm**-2phys.columnDensityfloatnullableDztot? Total redshift searched per source in all the receiverssrc.redshift;pos.heliocentricfloatnullablef_Dztot[*] Flag on Dztot (3)meta.codecharMoreLink to Tables 2 and 3meta.ref.urlcharNameSource namemeta.id;meta.maincharprimaryf_Name[abc] Flag on Name (1)meta.codecharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000Right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Declination (J2000)pos.eq.dec;meta.mainzOptical redshift of the background radio objectsrc.redshiftdoubleJ/MNRAS/498/883/table2Sources with HI 21cm absorptione_nuError on nuMHzstat.errorfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameSource namemeta.id;meta.maincharnuCentral frequency of each componentMHzem.freqdoublezRedshift of each absorption featuresrc.redshiftdoublee_zError on zstat.error;src.redshiftdoubleFcontContinuum flux densityJyphot.flux.density;em.radiofloate_FcontError on FcontJystat.errorfloatFWHMObserved width of the linekHzspect.line.widthfloate_FWHMError on FWHMkHzstat.error;phys.angSizefloatFWHMrfRest-frame line widthkm/sspect.line.widthfloate_FWHMrfError on FWHMrfkm/sstat.errorfloatDepthDepth of the absorption linemJyphys.absorption.opticalDepth;spect.lineinte_DepthError on DepthmJystat.error;phys.absorption.opticalDepthinttauPeak optical depthphys.absorption.opticalDepth;stat.maxfloate_tauError on taustat.errorfloatNHIDerived HI column density N_HI_/ (T_s_/f)1e+18cm**-2.K**-1phys.columnDensityfloate_NHIError on NHI1e+18cm**-2.K**-1stat.errorfloatNHIlit? Measured HI column density N_HI_/(T_s_/f) from previous 21 cm observations1e+18cm**-2.K**-1phys.columnDensityfloatnullablee_NHIlit? Error on NHIlit1e+18cm**-2.K**-1stat.errorfloatnullabler_NHIlitReference for NHIlit (2)meta.ref;pos.framecharTs/f? Measured T_s_/f values constrained from Ly{alpha} and VLA observations from Kanekar et al. (2014MNRAS.438.2131K)Kphys.temperatureintnullablef_Name[a] Flag on Name (1)meta.codecharCompNumbered Gaussian componentmeta.code.multipcharJ/MNRAS/498/883/table3Properties of the HI 21cm and OH 18cm Line Observationsf_rmsOH1720[*] Flag on rmsOH1612 (3)meta.codecharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameSource namemeta.id;meta.maincharzabsRedshift of known intervening 21cm absorbers (2)src.redshiftdoublee_zabs? Error on zabsstat.errorfloatnullablenuHIObserved frequency for the HI 21cm lineMHzem.freqdoublee_nuHI? Error on nuHIMHzstat.errorfloatnullablermsHI? Measured rms noise over the searched region for the HI 21cm linemJyinstr.det.noisefloatnullablecontHI? Continuum flux density for the HI 21cm lineJyphot.flux.density;em.radiofloatnullablee_contHI? Error on contHIJystat.errorfloatnullableNHI? Derived 3{sigma} upper limit to the HI column density1e+18cm**-2.K**-1phys.columnDensityfloatnullablee_NHI? Error on NHI1e+18cm**-2.K**-1stat.errorfloatnullablenuOH1612Observed frequency for the OH 1612MHz lineMHzem.freqfloatrmsOH1612? Measured rms noise over the searched region for the OH 1612MHz linemJystat.stdev;instr.det.noise;obs.fieldfloatnullablenuOH1667Observed frequency for the OH 1667MHz lineMHzem.freqfloatrmsOH1667? Measured rms noise over the searched region for the OH 1667MHz linemJystat.stdev;instr.det.noise;obs.fieldfloatnullablenuOH1720Observed frequency for the OH 1720MHz lineMHzem.freqfloatrmsOH1720? Measured rms noise over the searched region for the OH 1720MHz linemJystat.stdev;instr.det.noise;obs.fieldfloatnullablecontOH? OH continuum flux density (4)Jyphot.flux.density;em.radiofloatnullablee_contOH? Error on contOHJystat.errorfloatnullablel_NOHLimit flag on NOHmeta.code.errorcharNOH? Derived 3{sigma} upper limit to the HI column density (4)1e+13cm**-2.K**-1phys.columnDensityfloatnullablee_NOH? Error on NOH1e+13cm**-2.K**-1stat.errorintnullablef_NOH[c] Flag on NOH (5)meta.codecharf_NameFlag on Name (1)meta.codecharDvHIVelocity range for the HI 21cm line searchkm/sspect.dopplerVeloccharf_rmsHI[*] Flag on rmsHI (3)meta.codecharl_NHILimit flag on NHImeta.code.errorcharDvOH1612Velocity range for the OH 1612MHz line searchkm/sspect.dopplerVeloccharf_rmsOH1612[*] Flag on rmsOH1612 (3)meta.codecharDvOH1667Velocity range for the OH 1667MHz line searchkm/sspect.dopplerVeloccharf_rmsOH1667[*] Flag on rmsOH1612 (3)meta.codecharDvOH1720Velocity range for the OH 1720MHz line searchkm/sspect.dopplerVelocchar