Search Publications
Missions
Journals
Publication Years
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…
XMM-Newton observations of the heavily absorbed Seyfert 1 galaxy IC 4329A
Kaastra, J. S.; Behar, E.; Sako, M. +5 more
We detect seven distinct absorbing systems in the high-resolution X-ray spectrum of the Seyfert 1 galaxy IC 4329A, taken with XMM-Newton. Firstly we detect absorption due to cold gas in our own Galaxy and warm gas in the Galactic halo or the Local Group. This local warm gas is only detected through O VII absorption, from which we deduce a temperat…
Optical and near-infrared integral field spectroscopy of the SCUBA galaxy N2 850.4
Ivison, R. J.; Smail, Ian; Swinbank, A. M. +7 more
We present optical and near-infrared integral field spectroscopy of the SCUBA galaxy SMMJ163650.43+405734.5 (ELAIS N2 850.4) at z= 2.385. We combine Lyα and Hα emission line maps and velocity structure with high-resolution HST ACS and NICMOS imaging to probe the complex dynamics of this vigorous starburst galaxy. The imaging data show a complex mo…
Extragalactic Source Counts in the 20-50 keV Energy Band from the Deep Observation of the Coma Region by INTEGRAL IBIS
Sunyaev, R.; Krivonos, R.; Churazov, E. +3 more
We present the analysis of serendipitous sources in a deep, 500 ks, hard X-ray observation of the Coma Cluster region with the IBIS instrument on board INTEGRAL. In addition to the Coma Cluster, the final 20-50 keV image contains 12 serendipitous sources with statistical significance >4 σ. We use these data (after correcting for expected number…
The cloud structure of the jovian atmosphere as seen by the Cassini/CIRS experiment
Flasar, F. Michael; Conrath, Barney J.; Gierasch, Peter J. +1 more
We analyze the thermal infrared spectra of Jupiter obtained by the Cassini-CIRS instrument during the 2000 flyby to infer temperature and cloud density in the jovian stratosphere and upper troposphere. We use an inversion technique to derive zonal mean vertical profiles of cloud absorption coefficient and optical thickness from a narrow spectral w…