2021MNRAS.505..738N -
Mon. Not. R. Astron. Soc., 505, 738-754 (2021/July-3)
A partial Lyman limit system tracing intragroup gas at z ≃ 0.8 towards HE 1003 + 0149.
NARAYANAN A., MUZAHID S., JOHNSON S.D., UDHWANI P., CHARLTON J.C., MAUERHOFER V., SCHAYE J. and YADAV M.
Abstract (from CDS):
We present analysis of the galaxy environment and physical properties of a partial Lyman limit system at z = 0.83718 with H I and metal-line components closely separated in redshift space (|Δv| ≃ 400 km s–1) towards the background quasar HE 1003 + 0149. The HST/COS far-ultraviolet spectrum provides coverage of lines of oxygen ions from O I to O V. Comparison of observed spectral lines with synthetic profiles generated from Bayesian ionization modelling reveals the presence of two distinct gas phases in the absorbing medium. The low-ionization phase of the absorber has sub-solar metallicities (∼1/10 solar) with indications of [C/O] <0 in each of three components. The O IV and O V trace a more diffuse higher ionization medium with predicted H I column densities that are ≃2 dex lower. The quasar field observed with VLT/MUSE reveals three dwarf galaxies with stellar masses of M* ∼ 108-109 M☉, and with star formation rates of ≃0.5-1 M☉ yr–1, at projected separations of ρ/Rvir ≃ 1.8-3.0 from the absorber. Over a wider field with projected proper separation of <=5 Mpc and radial velocity offset of |Δv| <= 1000 km s–1 from the absorber, 21 more galaxies are identified in the VLT/VIMOS and Magellan deep galaxy redshift surveys, with 8 of them within 1 Mpc and 500 km s–1, consistent with the line of sight penetrating a group of galaxies. The absorber presumably traces multiple phases of cool (T ∼ 104 K) photoionized intragroup medium. The inferred [C/O] <0 hint at preferential enrichment from core-collapse supernovae, with such gas displaced from one or more of the nearby galaxies, and confined to the group medium.
Abstract Copyright:
© 2021 The Author(s) Published by Oxford University Press on behalf of Royal Astronomical Society
Journal keyword(s):
galaxies: groups: general - galaxies: haloes - intergalactic medium - quasars: absorption lines
Status at CDS
:
Examining the need for a new acronym.
Simbad objects:
2
Full paper
View the references in ADS
To bookmark this query, right click on this link: simbad:2021MNRAS.505..738N and select 'bookmark this link' or equivalent in the popup menu