Zobrazeno 1 - 10
of 29
pro vyhledávání: '"de Boer, Klaas. S."'
Observations show that the ISM contains sub-structure on scales less than 1 pc, detected in the form of spatial and temporal variations in column densities or optical depth. Despite the number of detections, the nature and ubiquity of the small-scale
Externí odkaz:
http://arxiv.org/abs/1006.5450
Autor:
Maintz, Gisela, de Boer, Klaas S.
RR Lyrae stars in the Milky Way are good tracers to study the kinematic behaviour and spatial distribution of older stellar populations. A recently established well documented sample of 217 RR Lyr stars with V<12.5 mag, has been used to reinvestigate
Externí odkaz:
http://arxiv.org/abs/astro-ph/0507604
Autor:
de Boer, Klaas S.
Publikováno v:
Astron.Astrophys. 419 (2004) 527-531
The origin of gas falling from the halo toward the disk of the Milky Way is still largely unclear. Here the amount of gas shed by the (older) halo red giants is estimated. The distribution of red giants (RGs) in the halo is not known but that of a su
Externí odkaz:
http://arxiv.org/abs/astro-ph/0402630
Publikováno v:
Astron.Astrophys. 398 (2003) 983-992
FUSE spectra of the four brightest H II regions in M 33 show absorption by interstellar gas in the Galaxy and in M 33. On three lines of sight molecular hydrogen in M 33 is detected. This is the first measurement of diffuse H_2 in absorption in a Loc
Externí odkaz:
http://arxiv.org/abs/astro-ph/0211540
Autor:
Bluhm, Hartmut, de Boer, Klaas S.
FUSE and IUE observations of Sk -69 246, a WN 6 star to the north of 30 Dor, reveal the existence of LMC interstellar gas in at least 3 velocity components.In one of these components FUSE spectra show strong absorption by molecular hydrogen with a co
Externí odkaz:
http://arxiv.org/abs/astro-ph/0109297
In front of the LMC molecular hydrogen is found in absorption near 0 km/s, being local disk gas, near +60 km/s in an intermediate velocity cloud, and near +120 km/s, in a high velocity halo cloud. The nature of the gas is discussed based on four ORFE
Externí odkaz:
http://arxiv.org/abs/astro-ph/0012238
Autor:
Marggraf, Ole, de Boer, Klaas S.
Publikováno v:
A&A 363,733-743 (2000)
We present an extended analysis of the high dispersion IUE spectra of SN 1993J in M81, based on the improved data in the IUE final archive. Eight interstellar absorption components can be identified in the velocity range from -200 km/s to +200 km/s.
Externí odkaz:
http://arxiv.org/abs/astro-ph/0009300
The huge supergiant shell (SGS) LMC4, next to the giant HII region 30 Doradus the second most impressive feature of the Large Magellanic Cloud (LMC), has been the subject of many studies and was used to test various models of star forming mechanisms.
Externí odkaz:
http://arxiv.org/abs/astro-ph/0006060
Autor:
Altmann, Martin, de Boer, Klaas S.
Field Horizontal branch (HB) stars can be used as tracers for the study of early stages of the evolution of our galaxy. Since the age of individual HB stars is not known a priori, we have studied the kinematics of a sample of field HB stars measured
Externí odkaz:
http://arxiv.org/abs/astro-ph/9911456
Autor:
de Boer, Klaas S.
Horizontal-branch stars play an important role in defining the absolute distance scale in the universe. For that one has to know Mv at relevant B-V with well defined [M/H] for each type of horizontal-branch star. The nature of the horizontal-branch s
Externí odkaz:
http://arxiv.org/abs/astro-ph/9811077