Bibcode
Centurion, M.; Vladilo, G.; de Boer, K. S.; Herbstmeier, U.; Schwarz, U. J.
Referencia bibliográfica
Astronomy and Astrophysics (ISSN 0004-6361), vol. 292, no. 1, p. 261-270
Fecha de publicación:
12
1994
Número de citas
14
Número de citas referidas
12
Descripción
We present a study of high-velocity gas in the direction of 13 halo
sub-dwarfs located at absolute value of z approximately equals 0.5-2 kpc
and of 8 early-type stars in the Galactic disk at d approximately equals
1-4 kpc. For each line of sight of our sample we collected Ca II and Na
I absorption spectra with the 2.5-m Isaac Newton Telescope at La Palma
(Spain) and H I 21-cm emission profiles with the 100-m radiotelescope at
Effelsberg (Germany). The faint sub-dwarfs (mv approximately
equals 11-14) are observed for the first time at relatively high
spectral resolution (approximately equals 25-30 km/s) in the optical. By
comparing the optical absorptions (or upper limits) with the 21-cm
emissions, we constrain the distances to the concentrations of neutral
gas at high velocity named Complex C, Complex H, and for high velocity
gas located between the Cohen Stream and the Magellanic Stream. We find
new evidence for gas at intermediate velocity in the halo and in the
disk of our Galaxy.