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Discovery of Hard X-Ray Delays in the X-Ray Emission of the Seyfert 1 Galaxy Markarian 110: Possible Evidence of Comptonization
Rao, A. R.; Dasgupta, Surajit
We report the discovery of hard X-ray delays in the X-ray emission of the Seyfert 1 galaxy Mrk 110, based on a long XMM-Newton observation. Cross-correlation between the X-ray light curves of different energy bands reveals an energy-dependent delay ranging from a few minutes to an hour. We find that the energy spectrum can be modeled by Comptoniza…
Astrometric observations of Phobos and Deimos with the SRC on Mars Express
Oberst, J.; Neukum, G.; Hoffmann, H. +4 more
Observations of Phobos and Deimos, carried out by the SRC (Super Resolution Channel) on the Mars Express spacecraft between May 2004-April 2005, were used to determine the center-of-figure positions of the two Satellites with accuracies of 0.5-5 km (Phobos) and 1.0 km (Deimos). We find that the Phobos and Deimos orbit predictions from NASA-JPL (Je…
Titan: Preliminary results on surface properties and photometry from VIMS observations of the early flybys
Sotin, C.; Brown, R. H.; Baines, K. H. +10 more
Cassini observations of the surface of Titan offer unprecedented views of its surface through atmospheric windows in the 1-5 µm region. Images obtained in windows for which the haze opacity is low can be used to derive quantitative photometric parameters such as albedo and albedo distribution, and physical properties such as roughness and pa…
X-Rays from Radio Millisecond Pulsars: Comptonized Thermal Radiation
Bogdanov, Slavko; Grindlay, Jonathan E.; Rybicki, George B.
X-ray emission from many rotation-powered millisecond pulsars (MSPs) is observed to be of predominantly thermal nature. In PSR J0437-4715, the nearest MSP known, an additional faint power-law tail is observed above 2.5 keV, commonly attributed to nonthermal magnetospheric radiation. We propose that the hard emission in this and other similar MSPs …
XMM-Newton X-ray and optical observations of the globular clusters M 55 and NGC 3201
Wheatley, P. J.; Webb, N. A.; Barret, D.
We have observed two low concentration Galactic globular clusters with the X-ray observatory XMM-Newton. We detect 47 faint X-ray sources in the direction of
Proper Motion of the Crab Pulsar Revisited
Ng, C. -Y.; Romani, Roger W.
It has been suggested that the Crab pulsar's proper motion is aligned with the symmetry axis of the pulsar wind nebula. We have revisited this question, examining >6 years of F547M WFPC2 chip 3 images to obtain a best-fit value of µ*=14.9+/-0.8 mas yr-1 at P.A. 278deg+/-3deg. At 26deg…
Discovery of a Metal-Line Absorber Associated with a Local Dwarf Starburst Galaxy
York, Donald G.; Stocke, John T.; Keeney, Brian A. +2 more
We present optical and near-infrared images, H I 21 cm emission maps, optical spectroscopy, and Hubble Space Telescope Space Telescope Imaging Spectrograph ultraviolet spectroscopy of the QSO/galaxy pair SBS 1122+594/IC 691. The QSO sight line lies at a position angle of 27° from the minor axis of the nearby dwarf starburst galaxy IC 691 (czg…
Deep X-ray survey of the young open cluster NGC 2516 with XMM-Newton
Micela, G.; Sciortino, S.; Pillitteri, I. +1 more
Aims.We report a deep X-ray survey of the young (~140 Myr), rich open cluster NGC 2516 obtained with the EPIC camera on board the XMM-Newton satellite.
Methods: .By combining data from six observations, a high sensitivity, greater than a factor of 5 with respect to recent Chandra observations, has been achieved. Kaplan-Meier estimators of the …
High spatial resolution mid-infrared spectroscopy of the starburst galaxies NGC 3256, II Zw 40 and Henize 2-10
Schaerer, D.; Sauvage, M.; Tielens, A. G. G. M. +2 more
Aims.In order to show the importance of high spatial resolution observations of extra-galactic sources when compared to observations obtained with larger apertures such as ISO, we present N-band spectra (8-13 µm) of some locations in three starburst galaxies. In particular, we show the two galactic nuclei of the spiral galaxy NGC 3256, the c…
A statistical study of the characteristics of type II doublet radio bursts
Subramanian, K. R.; Ebenezer, E.
Aims.We study the characteristics of doublet type II radio bursts in which two type II bursts occur in sequence and investigate their drivers.
Methods: .37 type II bursts reported by the Culgoora radio observatory in the Solar Geophysical data for the period September 1994-July 2004 were used to determine their time and frequency characterist…