scholarly journals Solar-metallicity gas in the extended halo of a galaxy at z ∼ 0.12

2020 ◽  
Vol 493 (1) ◽  
pp. 250-266 ◽  
Author(s):  
Jayadev Pradeep ◽  
Sriram Sankar ◽  
T M Umasree ◽  
Anand Narayanan ◽  
Vikram Khaire ◽  
...  

ABSTRACT We present the detection and analysis of a weak low-ionization absorber at z = 0.121 22 along the sightline of the blazar PG 1424+240, using spectroscopic data from both HST/COS and STIS. The absorber is a weak Mg ii analogue, with an incidence of weak C ii and Si ii, along with multicomponent C iv and O vi. The low ions are tracing a dense (nH ∼ 10−3 cm−3) parsec-scale cloud of solar or higher metallicity. The kinematically coincident higher ions are either from a more diffuse (nH ∼ 10−5–10−4 cm−3) photoionized phase of kiloparsec-scale dimensions or are tracing a warm (T ∼ 2 × 105 K) collisionally ionized transition temperature plasma layer. The absorber resides in a galaxy overdense region, with 18 luminous (>L*) galaxies within a projected radius of 5 Mpc and velocity of 750 km s−1. The multiphase properties, high metallicity, and proximity to a 1.4L* galaxy, at ρ ∼ 200 kpc and separation |Δv| = 11 km s−1, favour the possibility of the absorption tracing circumgalactic gas. The absorber serves as an example of weak Mg ii–O vi systems as a means to study multiphase high-velocity clouds in external galaxies.

1998 ◽  
Vol 11 (1) ◽  
pp. 86-89
Author(s):  
Ulysses J. Sofia

Abstract The well measured gas-phase abundances in the low halo suggest that this region of the Galaxy has total (gas plus dust) metal abundances which are close to those in the solar neighborhood. The gas-phase abundances in the halo are generally higher than those seen in the disk, however, this affect is likely due to the destruction of dust in the halo clouds. Observations of high velocity clouds (HVCs) in the halo suggest that these clouds have metal abundances which are substantially lower than those measured for the local interstellar medium. These determinations, however, are often of lower quality than those for the low halo because of uncertainties in the hydrogen abundances along the sightlines, in the incorporation of elements into dust, and in the partial ionization of the clouds.


2014 ◽  
Vol 563 ◽  
pp. A99 ◽  
Author(s):  
S. Faridani ◽  
L. Flöer ◽  
J. Kerp ◽  
T. Westmeier

2017 ◽  
Author(s):  
Ana Laura Müller ◽  
Gustavo Esteban Romero ◽  
Maŕıa Victoria del Valle

2015 ◽  
Vol 575 ◽  
pp. A126 ◽  
Author(s):  
M. Bellazzini ◽  
G. Beccari ◽  
G. Battaglia ◽  
N. Martin ◽  
V. Testa ◽  
...  

2002 ◽  
Vol 392 (2) ◽  
pp. 417-451 ◽  
Author(s):  
V. de Heij ◽  
R. Braun ◽  
W. B. Burton

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