TY  - JOUR
A1  - Richter, Philipp
A1  - Nuza, S. E.
A1  - Fox, Andrew J.
A1  - Wakker, Bart P.
A1  - Lehner, N.
A1  - Ben Bekhti, Nadya
A1  - Fechner, Cora
A1  - Wendt, Martin
A1  - Howk, J. Christopher
A1  - Muzahid, S.
A1  - Ganguly, R.
A1  - Charlton, Jane C.
T1  - An HST/COS legacy survey of high-velocity ultraviolet absorption in the
T2  - Astronomy and astrophysics : an international weekly journal
N2  - Context. The Milky Way is surrounded by large amounts of diffuse gaseous matter that connects the stellar body of our Galaxy with its large-scale Local Group (LG) environment. Aims. To characterize the absorption properties of this circumgalactic medium (CGM) and its relation to the LG we present the so-far largest survey of metal absorption in Galactic high-velocity clouds (HVCs) using archival ultraviolet (UV) spectra of extragalactic background sources. The UV data are obtained with the Cosmic Origins Spectrograph (COS) onboard the Hubble Space Telescope (HST) and are supplemented by 21 cm radio observations of neutral hydrogen. Methods. Along 270 sightlines we measure metal absorption in the lines of Si II, Si III, C II, and C IV and associated H I 21 cm emission in HVCs in the velocity range vertical bar v(LSR)vertical bar = 100-500 km s(-1). With this unprecedented large HVC sample we were able to improve the statistics on HVC covering fractions, ionization conditions, small-scale structure, CGM mass, and inflow rate. For the first time, we determine robustly the angular two point correlation function of the high-velocity absorbers, systematically analyze antipodal sightlines on the celestial sphere, and compare the HVC absorption characteristics with that of damped Lyman alpha absorbers (DLAs) and constrained cosmological simulations of the LG (CLUES project).
KW  - Galaxy: halo
KW  - Galaxy: structure
KW  - Galaxy: evolution
KW  - ISM: kinematics and dynamics
KW  - techniques: spectroscopic
KW  - ultraviolet: ISM
Y1  - 2017
UR  - https://publishup.uni-potsdam.de/frontdoor/index/index/docId/46180
SN  - 1432-0746
VL  - 607
PB  - EDP Sciences
CY  - Les Ulis
ER  -