Search Publications
Stellar and wind properties of LMC WC4 stars. A metallicity dependence for Wolf-Rayet mass-loss rates
Hillier, D. J.; Crowther, P. A.; Fullerton, A. W. +2 more
We use ultraviolet space-based (FUSE, HST) and optical/IR ground-based (2.3 m MSSSO, NTT) spectroscopy to determine the physical parameters of six WC4-type Wolf-Rayet stars in the Large Magellanic Cloud. Stellar parameters are revised significantly relative to Gräfener et al. (\cite{Grafener1998}) based on improved observations and more sophistica…
New distances to galaxies in the Centaurus A group
Sarajedini, A.; Dolphin, A. E.; Grebel, E. K. +7 more
We present Hubble Space Telescope/WFPC2 images of seventeen dwarf galaxies in the Centaurus A group. Their distances derived from the magnitudes of the tip of the red giant branch are 5.2 Mpc (KK112), 3.2 Mpc (ESO 321-014), 3.5 Mpc (KK179), 3.4 Mpc (NGC 5102), 4.6 Mpc (KK200), 3.7 Mpc (ESO 324-024), 4.7 Mpc (KK208), 4.6 Mpc (ESO 444-084), 4.4 Mpc …
The new emerging model for the structure of cooling cores in clusters of galaxies
Böhringer, H.; Churazov, E.; Chen, Y. +2 more
New X-ray observations with XMM-Newton show a lack of spectral evidence for large amounts of cooling and condensing gas in the centers of galaxy clusters believed to harbour strong cooling flows. This paper re-explores the cooling flow scenario in the light of the new observations. We explore the diagnostics of the temperature structure of cooling…
The mass profile of A1413 observed with XMM-Newton: Implications for the M-T relation
Arnaud, M.; Pratt, G. W.
We present an XMM-Newton et al. observation of A1413, a hot (kT = 6.5 kev ) galaxy cluster at z=0.143. We construct gas and temperature profiles over the radial range up to ~ 1700 kpc. This radius corresponds to a density contrast delta ~ 500 with respect to the critical density at the redshift of the cluster, or equivalently ~ 0.7 r200…
Crystalline silicate dust around evolved stars. II. The crystalline silicate complexes
Waters, L. B. F. M.; Tielens, A. G. G. M.; Molster, F. J.
This is the second paper in a series of three in which we present an exhaustive inventory of the solid state emission bands observed in a sample of 17 oxygen-rich dust shells surrounding evolved stars. The data were taken with the Short and Long Wavelength Spectrographs on board of the Infrared Space Observatory (ISO) and cover the 2 to 200 mu m w…
The very local Hubble flow
Sarajedini, A.; Dolphin, A. E.; Grebel, E. K. +8 more
We present Hubble Space Telescope/WFPC2 images of eighteen galaxies situated in the vicinity of the Local Group (LG) as part of an ongoing snapshot survey of nearby galaxies. Their distances derived from the magnitude of the tip of the red giant branch are 1.92±0.10 Mpc (ESO 294-010), 3.06±0.37 (NGC 404), 3.15±0.32 (UGCA 105), 1.36±0.07 (Sex B), 1…
Physical parameters of the high-mass X-ray binary 4U1700-37
Kaper, L.; Crowther, P. A.; Goodwin, S. P. +4 more
We present the results of a detailed non-LTE analysis of the ultraviolet and optical spectrum of the O6.5 Iaf+ star
X-ray spectral imaging and Doppler mapping of Cassiopeia A
Kaastra, J. S.; Vink, J.; Bleeker, J. A. M. +2 more
We present a detailed X-ray spectral analysis of Cas A using a deep exposure from the EPIC-MOS cameras on-board XMM-Newton. Spectral fitting was performed on a 15x15 grid of 20″ x 20″ pixels using a two component non-equilibrium ionisation model (NEI) giving maps of ionisation age, temperature, interstellar column density, abundances for Ne, Mg, S…
XMM-Newton observation of M 87. I. Single-phase temperature structure of intracluster medium
Finoguenov, A.; Böhringer, H.; Matsushita, K. +1 more
We report the results of a detailed analysis of the temperature structure of the X-ray emitting plasma halo of M 87, the cD galaxy of the Virgo Cluster. Using the MEKAL model, the data provide strong indications that the intracluster medium has a single phase structure locally, except the regions associated with the radio structures. The deproject…
Crystalline silicate dust around evolved stars. III. A correlations study of crystalline silicate features
Waters, L. B. F. M.; Tielens, A. G. G. M.; Koike, C. +2 more
We have carried out a quantitative trend analysis of the crystalline silicates observed in the ISO spectra of a sample of 14 stars with different evolutionary backgrounds. We have modeled the spectra using a simple dust radiative transfer model and have correlated the results with other known parameters. We confirm the abundance difference of the …