~420MHz uGMRT obs. of MIR selected radio-loud AGN

DOI

We present results from a spectroscopically blind search for associated and intervening HI 21cm and OH 18cm absorption lines toward 88 active galactic nuclei (AGN) at 2<z2. The detection rate (1.6_-1.4_^+3.8^%) suggests a low covering factor of the cold neutral medium (CNM; T~100K) associated with these powerful AGN. The intervening absorption line search, with a sensitivity to detect the CNM in damped Ly{alpha} systems (DLAs), has comoving absorption path lengths of {Delta}X=130.1 and 167.7 for HI and OH, respectively. The corresponding number of absorbers per unit comoving path length are <=0.014 and 2. Our AGN sample is optically fainter compared to the quasars used to search for DLAs in the past. In our optical spectra obtained using SALT and NOT, we detect five intervening (redshift path ~9.3) and two proximate DLAs. This is slightly excessive compared to the statistics based on optically selected quasars. The nondetection of HI 21cm absorption from these DLAs suggests a small CNM covering fraction around galaxies at z>2.

Cone search capability for table J/ApJS/255/28/table1 (the 88 z>2 MIR-selected radio sources observed with uGMRT)

Identifier
DOI http://doi.org/10.26093/cds/vizier.22550028
Source https://dc.g-vo.org/rr/q/lp/custom/CDS.VizieR/J/ApJS/255/28
Related Identifier https://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJS/255/28
Related Identifier https://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJS/255/28
Metadata Access http://dc.g-vo.org/rr/q/pmh/pubreg.xml?verb=GetRecord&metadataPrefix=oai_b2find&identifier=ivo://CDS.VizieR/J/ApJS/255/28
Provenance
Creator Gupta N.; Srianand R.; Shukla G.; Krogager J-.K.; Noterdaeme P.; Combes F.,Dutta R.; Fynbo J.P.U.; Hilton M.; Momjian E.; Moodley K.; Petitjean P.
Publisher CDS
Publication Year 2021
Rights https://cds.unistra.fr/vizier-org/licences_vizier.html
OpenAccess true
Contact CDS support team <cds-question(at)unistra.fr>
Representation
Resource Type Dataset; AstroObjects
Discipline Astrophysics and Astronomy; Cosmology; Galactic and extragalactic Astronomy; High Energy Astrophysics; Interdisciplinary Astronomy; Natural Sciences; Observational Astronomy; Physics