Search Publications
Accurate photometry of extended spherically symmetric sources
Gieles, M.; de Grijs, R.; Anders, P.
We present a new method to derive reliable photometry of extended spherically symmetric sources from HST images (WFPC2, ACS/WFC and NICMOS/NIC2 cameras), extending existing studies of point sources and marginally resolved sources. We develop a new approach to accurately determine intrinsic sizes of extended spherically symmetric sources, such as s…
Mission operations for the new Rosetta
Ferri, Paolo
The International Rosetta Mission, a cornerstone mission of the European Space Agency Scientific Programme, was scheduled for launch in January 2003 on Ariane 5, but it missed its 19 days launch window due to the suspension of Ariane 5 launches following the failure of flight 517 in December 2002. The search for a new mission opportunity started i…
Hubble Space Telescope Faint Object Spectrograph Spectral Mapping of V2051 Ophiuchi in a Low State
Saito, R. K.; Baptista, R.
We report a study of the spectra and structure of the accretion disk of the dwarf nova V2051 Ophiuchi while the star was in an unusual faint brightness state during 1996. The differences between the UV resonant lines and continuum disk surface brightness distributions indicate a vertically extended disk with the emission from these lines arising f…
Iron in Hot DA White Dwarfs
Vennes, Stéphane; Lanz, Thierry; Chayer, Pierre +1 more
We present a study of the iron abundance pattern in hot, hydrogen-rich (DA) white dwarfs. The study is based on new and archival far-ultraviolet spectroscopy of a sample of white dwarfs in the temperature range 30,000 K<~Teff<~64,000 K. The spectra obtained with the Far Ultraviolet Spectroscopic Explorer, along with spectra obtain…
The nature of ultraviolet spectra of AG Pegasi and other symbiotic stars: locations, origins, and excitation mechanisms of emission lines
Wahlgren, G. M.; Johansson, S.; Eriksson, M.
A detailed study of ultraviolet spectra of the symbiotic star AG Peg has been undertaken to derive the atomic excitation mechanisms and origin of formation for the lines common in symbiotic systems. More than 600 emission lines are observed in spectra from {IUE}, {HST} and {FUSE} of which 585 are identified. Population mechanisms and origin of for…
A Search for Early Optical Emission at Gamma-Ray Burst Locations by the Solar Mass Ejection Imager (SMEI)
Band, David L.; Jackson, Bernard V.; Buffington, Andrew +2 more
The Solar Mass Ejection Imager (SMEI) views nearly every point on the sky once every 102 minutes and can detect point sources as faint as R~10 mag. Therefore, SMEI can detect or provide upper limits for the optical afterglow from gamma-ray bursts in the tens of minutes after the burst, when different shocked regions may emit optically. Here we pro…
Enhanced transport in the polar mesosphere of Jupiter: Evidence from Cassini UVIS helium 584 Å airglow
Parkinson, C. D.; Stewart, A. I. F.; Wong, A. S. +2 more
The eddy diffusion profile (K) in the auroral regions of Jupiter is not well determined. However, because of the intense auroral energy input, eddy mixing is expected to be much more effective and may be responsible for the enhancement of heavy hydrocarbon production in the polar region. In this paper, we estimate the increased eddy mixing in the …
Non-Uniform Temperature Distribution in the Galaxy Clusters 2A 0335+096 and Abell 496 Observed by XMM-Newton
Kunieda, Hideyo; Furuzawa, Akihiro; Tawara, Yuzuru +2 more
We present the XMM-Newton results of the galaxy clusters 2A 0335+096 and A496. From an investigation of 2-dimensional ICM profiles, we obtained new features related to dynamical activities in the ICM. In 2A 0335+096, we found a spiral cool tail around the central cold core, which is trailing from the opposite side of the cold front observed by Cha…
Nucleosynthesis of 60Fe in massive stars
Limongi, Marco; Chieffi, Alessandro
We discuss certain aspects of the production of 60Fe in massive stars in the range between 11 and 120M⊙, both in the hydrostatic and explosive stages. We also compare the 60Fe/26Al γ-ray line flux ratio obtained in the present calculations to the detected value reported by INTEGRAL/SPI.
X-Ray Emission from the Double Neutron Star Binary B1534+12: Powered by the Pulsar Wind?
Garmire, G. P.; Pavlov, G. G.; Kargaltsev, O.
We report the detection of the double neutron star binary (DNSB) B1534+12 (=J1537+1155) with the Chandra X-Ray Observatory. This DNSB (Porb=10.1 hr) consists of the millisecond (recycled) pulsar J1537+1155A (PA=37.9 ms) and a neutron star not detected in the radio. After the remarkable double pulsar binary J0737-3039, it is t…