Search Publications
Determining the Physical Properties of the B Stars. II. Calibration of Synthetic Photometry
Fitzpatrick, E. L.; Massa, D.
We present a new calibration of optical (UBV, Strömgren uvbyβ, and Geneva) and near-IR (Johnson RIJHK and Two Micron All Sky Survey) photometry for B and early A stars derived from Kurucz ATLAS9 model atmospheres. Our sample of stars consists of 45 normal nearby B and early A stars that have high-quality, low-resolution IUE spectra and accurate Hi…
HST/STIS low dispersion spectroscopy of three Compact Steep Spectrum sources. Evidence for jet-cloud interaction
Capetti, A.; Koekemoer, A. M.; Morganti, R. +9 more
We present Hubble Space Telescope Imaging Spectrograph long-slit spectroscopy of the emission line nebulae in the compact steep spectrum radio sources
Hubble Space Telescope ACS Weak-Lensing Analysis of the Galaxy Cluster RDCS 1252.9-2927 at z = 1.24
Ford, H. C.; Demarco, R.; Rosati, P. +12 more
We present a weak-lensing analysis of one of the most distant massive galaxy clusters known, RDCS 1252.9-2927, at z=1.24, using deep images from the Advanced Camera for Surveys (ACS) on board the Hubble Space Telescope (HST). By taking advantage of the depth and angular resolution of the ACS images, we detect for the first time at z>1 a clear w…
Coordinated Cluster/Double Star observations of dayside reconnection signatures
Escoubet, C. P.; Pitout, F.; Zong, Q. -G. +18 more
The recent launch of the equatorial spacecraft of the Double Star mission, TC-1, has provided an unprecedented opportunity to monitor the southern hemisphere dayside magnetopause boundary layer in conjunction with northern hemisphere observations by the quartet of Cluster spacecraft. We present first results of one such situation where, on 6 April…
Halos of Spiral Galaxies. III. Metallicity Distributions
Ferguson, H. C.; Rich, R. M.; Mouhcine, M. +2 more
We report results of a campaign to image the stellar populations in the halos of highly inclined spiral galaxies, with the fields roughly 10 kpc (projected) from the nuclei. We use the F814W (I) and F606W (V) filters in the Wide Field Planetary Camera 2 on board the Hubble Space Telescope. We unambiguously resolve the stellar halos 1 to 2 mag fain…
Unusual X-ray transients in the Galactic Centre
Decourchelle, A.; Warwick, R. S.; Wang, Q. D. +1 more
We report the discovery in the Galactic Centre region of two hard X-ray sources, designated as XMM J174457-2850.3 and XMM J174544-2913.0, which exhibit flux variations in the 2-10 keV band in excess of a factor of 100 in observations spanning roughly a year. In both cases the observed hydrogen column density is consistent with a location near to t…
Space Telescope Imaging Spectrograph Ultraviolet/Optical Spectroscopy of ``Warm'' Ultraluminous Infrared Galaxies
Veilleux, S.; Sanders, D. B.; Surace, J. A. +2 more
We present high spatial resolution ultraviolet and optical spectroscopy, obtained using the Space Telescope Imaging Spectrograph on board the Hubble Space Telescope, of nuclear structures within four ``warm'' ultraluminous infrared galaxies (ULIRGs). We find an active galactic nucleus (AGN) in at least three and probably all four in our sample, ho…
XMM-Newton observations of the supernova remnant RX J0852.0-4622/GRO J0852-4642
Haberl, F.; Aschenbach, B.; Dennerl, K. +2 more
RX J0852.0-4622 is a supernova remnant discovered in the ROSAT all-sky survey. Spatially coincident 1.157 MeV γ-ray line emission was detected with the COMPTEL instrument on-board CGRO. The analysis combining the X-ray and γ-ray data suggests that RX J0852.0-4622 is a close-by and young supernova remnant. Follow-up observations with ASCA show that…
The Transformation of Cluster Galaxies at Intermediate Redshift
Ford, H. C.; Demarco, R.; Infante, L. +40 more
We combine imaging data from the Advanced Camera for Surveys (ACS) with VLT/FORS optical spectroscopy to study the properties of star-forming galaxies in the z=0.837 cluster Cl 0152-1357. We have morphological information for 24 star-forming cluster galaxies, which range in morphology from late-type and irregular to compact early-type galaxies. We…
Wind-wind collision in the η Carinae binary system: a shell-like event near periastron
Falceta-Gonçalves, D.; Jatenco-Pereira, V.; Abraham, Z.
The exact nature of η Carinae is still an open issue. Strict periodicity in the light curves at several wavelengths seem to point to a binary system, but the observed radial velocities, measured from space with high spatial resolution, are in conflict with the ground-based observations used to calculate the binary orbit. Also, the observed 2-10 ke…