SIMBAD references

2021MNRAS.503.3243A - Mon. Not. R. Astron. Soc., 503, 3243-3261 (2021/May-3)

Pair lines of sight observations of multiphase gas bearing O VI in a galaxy environment.

ANSHUL P., NARAYANAN A., MUZAHID S., BECKETT A. and MORRIS S.L.

Abstract (from CDS):

Using HST/COS spectra of the twin quasar lines of sight Q 0107-025A & Q 0107-025B, we report on the physical properties, chemical abundances, and transverse sizes of a multiphase medium in a galaxy field at z = 0.399. The angular separation between the quasars corresponds to a physical separation of 520 kpc at the absorber redshift. The absorber towards Q 0107-025B is a partial Lyman limit system (pLLS) with logN(H I)/cm^-2^~16.8. The H I column density in the absorber along the other sightline is ≃ 2 orders of magnitude lower. The O VI along both sightlines have comparable column densities and broad b-values (b > 30 km s–1) whereas the low ionization lines are considerably narrower. The low ionization gas is inconsistent with the O VI when modelled assuming photoionization from the same phase. In both lines of sight, O VI and the broad H I coinciding, are best explained through collisional ionization in a cooling plasma with solar metallicity. Ionization models infer 1/10th solar metallicity for the pLLS and solar metallicity for the lower column density absorber along the other sightline. Within ± 250 km s–1 and 2 Mpc of projected distance from the sightlines 12 galaxies are identified, of which five are within 500 kpc. The twin sightlines are at normalized impact parameters of ρ ∼ 1.1Rvir, and ρ ∼ 0.8Rvir from a M* ∼ 1010.7 M☉, L ∼ 0.07L*, and star formation rate (SFR) < 0.1 M☉ yr–1 galaxy, potentially probing its CGM (circumgalactic medium). The next closest in normalized separation are a dwarf galaxy with M* ∼ 108.7 M☉, and SFR ∼ 0.06 M☉ yr–1, and an intermediate mass galaxy with M* ∼ 1010.0 M☉, and SFR ∼ 3 M☉ yr–1. Along both sightlines, O VI could be either tracing narrow transition temperature zones at the interface of low ionization gas and the hot halo of nearest galaxy, or a more spread-out warm component that could be gas bound to the circumgalactic halo or the intragroup medium. The latter scenarios lead to a warm gas mass limit of M >= 4.5 x 109 M☉.

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

Simbad objects: 20

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