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Strong dust processing in circumstellar discs around 6 RV Tauri stars. Are dusty RV Tauri stars all binaries?
Waters, L. B. F. M.; Dominik, C.; Dejonghe, H. +2 more
We present extended Spectral Energy Distributions (SEDs) of seven classical RV Tauri stars, using newly obtained submillimetre continuum measurements and Geneva optical photometry supplemented with literature data. The broad-band SEDs show a large IR excess with a black-body slope at long wavelengths in six of the seven stars, R Sct being the noti…
On the Stellar Populations in NGC 185 and NGC 205 and the Nuclear Star Cluster in NGC 205 from Hubble Space Telescope Observations
Martínez-Delgado, D.; Butler, D. J.
We present the first detailed analysis of resolved stellar populations in the dwarf galaxies NGC 185 and NGC 205 based on archival V- and I-band WFPC2 pointings. For NGC 185 we deduce from the brightest main-sequence and blue-loop stars that star formation was probably still active about 4×108 yr ago and have three key abundance-related…
The broad-band spectrum of the persistent emission from SGR 1806-20
Hurley, K.; Sunyaev, R.; Revnivtsev, M. +3 more
We present the results of an analysis of the quiescent X-ray emission from the Soft Gamma-Ray Repeater SGR 1806-20, taken during an INTEGRAL ultra-deep survey of the Galactic center region in Aug.-Sep. 2003. The total effective exposure time spent on the source by the IBIS telescope during these observations was 1.6 million seconds. Combining the …
Supernova Explosions, 511 keV Photons, Gamma Ray Bursts and Mirror Matter
Foot, R.; Silagadze, Z. K.
There are three astroparticle physics puzzles which fire the imagination: the origin of the "Great Positron Producer" in the galactic bulge, the nature of the gamma-ray bursts central engine and the mechanism of supernova explosions. We show that the mirror matter model has the potential to solve all three of these puzzles in one beautifully simpl…
Magnetopause and Boundary Layer
Lundin, R.; Vaivads, A.; Owen, C. J. +6 more
The Far-Infrared Emission Line and Continuum Spectrum of the Seyfert Galaxy NGC 1068
Smith, Howard A.; González-Alfonso, Eduardo; Spinoglio, Luigi +2 more
We report on the analysis of the first complete far-infrared spectrum (43-197 µm) of the Seyfert 2 galaxy NGC 1068 as observed with the Long Wavelength Spectrometer (LWS) on board the Infrared Space Observatory (ISO). In addition to the seven expected ionic fine-structure emission lines, the OH rotational lines at 79, 119, and 163 µm w…
High heat flux on ancient Mars: Evidence from rift flank uplift at Coracis Fossae
Neukum, G.; Hauber, E.; Grott, M. +2 more
We have identified flexural uplift at the flanks of the Coracis Fossae Rift valley. Modeling the topography the elastic thickness is constrained to 10.3-12.5 km, the corresponding mechanical thickness and thermal gradient are 15-19 km and 27-33 K km-1, respectively. The time of rifting is dated by evaluating the crater size-frequency di…
A Photometric Redshift Galaxy Catalog from the Red-Sequence Cluster Survey
Gladders, M. D.; Yee, H. K. C.; Hsieh, B. C. +1 more
The Red-Sequence Cluster Survey (RCS) provides a large and deep photometric catalog of galaxies in the z' and Rc bands for 90 deg2 of sky, and supplemental V and B data have been obtained for 33.6 deg2. We compile a photometric redshift catalog from these four-band data by utilizing the empirical quadrat…
INTEGRAL SPI Limits on Electron-Positron Annihilation Radiation from the Galactic Plane
Hornstrup, A.; Parmar, A. N.; Güdel, M. +25 more
The center of our Galaxy is a known strong source of electron-positron 511 keV annihilation radiation. Thus far, however, there have been no reliable detections of annihilation radiation outside of the central radian of our Galaxy. One of the primary objectives of the INTEGRAL (International Gamma-Ray Astrophysics Laboratory) mission, launched in …
The Hot Intergalactic Medium-Galaxy Connection: Two Strong O VI Absorbers in the Sight Line toward PG 1211+143
Shull, J. Michael; Stocke, John T.; Tumlinson, Jason +1 more
We present Hubble Space Telescope (HST) Space Telescope Imaging Spectrograph (STIS) and Far Ultraviolet Spectroscopic Explorer (FUSE) spectra of the QSO PG 1211+143 (zem=0.081) and a galaxy survey of the surrounding field. This sight line shows two strong intergalactic absorption systems at cz~=15,300 and 19,300 km s-1. This …