Search Publications
Galaxy populations of double cluster RX J1053.7+5735 at z = 1.13
Hasinger, G.; Schmidt, M.; Hashimoto, Yasuhiro +2 more
We present a study of the galaxy population in the cluster RX J1053.7+5735, one of the most distant X-ray selected clusters of galaxies and one which also shows an unusual double-lobed X-ray morphology, indicative of a possible equal-mass cluster merger. The cluster was discovered during the ROSAT deep pointings in the direction of the Lockman Hol…
INTEGRAL observations of the Be/X-ray binary EXO 2030+375 during outburst
Connell, P.; Beckmann, V.; Blay, P. +4 more
We present a type-I outburst of the high-mass X-ray binary EXO 2030+375, detected during INTEGRAL's Performance and Verification phase in December 2002 (on-source time about 106 s). In addition, six more outbursts have been observed during INTEGRAL's Galactic Plane Scans. X-ray pulsations have been detected with a pulse period of 41.691…
Eclipsing binary statistics Theory and observation
Söderhjelm, S.; Dischler, J.
The expected distributions of eclipse-depth versus period for eclipsing binaries of different luminosities are derived from large-scale population synthesis experiments. Using the rapid Hurley et al. BSE binary evolution code, we have evolved several hundred million binaries, starting from various simple input distributions of masses and orbit-siz…
HST observations of the pulsating white dwarf GD 358
Kepler, S. O.; Winget, D. E.; Koester, D. +2 more
We used time-resolved ultraviolet spectroscopy obtained with the FOS and STIS spectrographs of the Hubble Space Telescope (HST), together with archival IUE observations to measure the effective temperature (Teff), surface gravity (log g) and distance (d) of the pulsating DB white dwarf GD 358 with unprecedented accuracy, and to show tha…
Dynamics of solar mesogranulation
Hanslmeier, A.; Hirzberger, J.; Pötzi, W. +2 more
Using a 45.5-h time series of photospheric flow fields generated from a set of high-resolution continuum images (SOHO/MDI) we analyze the dynamics of solar mesogranule features. The series was prepared applying a local correlation tracking algorithm with a 4.8´´ FWHM window. By computing 1-h running means in time steps of 10 min we generate 267 av…
Indirect calculation of the magnetic reconnection rate from flare loops
Ireland, J.; Walsh, R. W.; Noglik, J. B.
High time resolution Transition Region And Coronal Explorer (TRACE) 171 and 195 Å observations of the evolution of flare loops on 1999 March 18 have been investigated. Given the location of the magnetic loops on the northeast solar limb and the cadence of the TRACE observations (~50 s), an estimation of the footpoint velocity due to ongoing reconn…
The star formation history of the LSB galaxy UGC 5889
Bomans, D. J.; Vallenari, A.; Schmidtobreick, L.
We present HST photometry of the LSB galaxy UGC 889 and derive its recent star formation history. In the last 200 Myr the star formation proceeded in modest bursts at a rate of the order of 10-2-10-3 M⊙/yr, with periods of extremely low SFR or even quiescence. The rate derived from the present study for the last 20…
HST/NICMOS observations of a proto-brown dwarf candidate
Henning, T.; Apai, D.; Lemke, D. +3 more
We present deep HST/NICMOS observations peering through the outflow cavity of the protostellar candidate IRAS 04381+2540 in the Taurus Molecular Cloud-1. A young stellar object as central source, a jet and a very faint and close (0.6'') companion are identified. The primary and the companion have similar colours, consistent with strong reddening. …
Metastable hydrogen absorption in ejecta close to η Carinae
Gull, T. R.; Johansson, S.; Hartman, H. +1 more
Spectroscopy with the high spatial resolution of the Hubble Space Telescope (HST) reveals narrow absorption in the hydrogen Balmer lines in spectra of Eta Carinae and the nearby nebular-scattered starlight. While hydrogen Balmer absorption lines are seen in stellar photospheres and winds, we are not aware of such being seen in galactic nebulae. Th…
ISO observations and models of galaxies with hidden broad line regions
Siebenmorgen, R.; Efstathiou, A.
We present ISO mid-infrared spectrophotometry and far-infrared photometry of galaxies with Hidden Broad Line Regions (HBLR). We also present radiative transfer models of their spectral energy distributions which enable us to separate the contributions from the dusty disc of the AGN and the dusty starbursts. We find that the combination of tapered …