Search Publications
Suzaku confirms NGC 3660 is an unabsorbed Seyfert 2
Nandra, Kirpal; Ueda, Yoshihiro; Bianchi, Stefano +3 more
An enigmatic group of objects, unabsorbed Seyfert 2s may have intrinsically weak broad line regions, obscuration in the line of sight to the BLR but not to the X-ray corona, or so much obscuration that the X-ray continuum is completely suppressed and the observed spectrum is actually scattered into the line of sight from nearby material. NGC 3660 …
Critical pitch angle for electron acceleration in a collisionless shock layer
Narita, Y.; Motschmann, U.; Comişel, H.
Collisionless shock waves in space and astrophysical plasmas can accelerate electrons along the shock layer by an electrostatic potential, and scatter or reflect electrons back to the upstream region by the amplified magnetic field or turbulent fluctuations. The notion of the critical pitch angle is introduced for non-adiabatic electron accelerati…
Prometheus Induced Vorticity in Saturn's F Ring
Sutton, Phil J.; Kusmartsev, Feo V.
Saturn's rings are known to show remarkable real time variability in their structure. Many of which can be associated to interactions with nearby moons and moonlets. Possibly the most interesting and dynamic place in the rings, probably in the whole Solar System, is the F ring. A highly disrupted ring with large asymmetries both radially and azimu…
The shape of Saturn's Huygens ringlet viewed by Cassini ISS
Spitale, J. N.; Hahn, J. M.
A new model for the shape of the prominent eccentric ringlet in the gap exterior to Saturn's B ring is developed based on Cassini imaging observations taken over about 8 years. Unlike previous analyses, the new model treats each edge of the ringlet separately. The Keplerian component of the model is consistent with results derived from Voyager obs…
Ultraviolet spectral variations of symbiotic nova PU Vul during and after second eclipse
Sanad, M. R.
I have analyzed spectral data of the symbiotic nova PU Vul observed with the International Ultraviolet Explorer (IUE) during the period 1993–1996. The study concentrated on the two sources of nebular emitting regions, the first is a nebula around the white dwarf partially eclipsed by a cool giant star and the second is a very extended nebular regi…
The orbital phase resolved spectroscopy of X-ray binary 4U 1822-371 with Suzaku
Ji, Li; Nowak, Michael A.; Schulz, Norbert S. +3 more
4U 1822-371 is a typical edge-on eclipsing low mass X-ray binary and the prototype of accretion disk coronal sources. We report on the results of a spectral analysis over the energy range 0.5-45 keV observed by Suzaku in 2006. We extract spectra from five orbital phases. The spectra can be equally well described by various previously proposed mode…
Cosmic rays from multi-wavelength observations of the Galactic diffuse emission
Orlando, Elena
Cosmic rays (CRs) generate diffuse emission while interacting with the Galactic magnetic field (B-field), the interstellar gas and the radiation field. This diffuse emission extends from radio, microwaves, through X-rays, to high-energy gamma rays. Diffuse emission has considerably increased the interest of the astrophysical community due to recen…
A Search for the Far-Infrared Ghost of C/2010 X1 (Elenin) with Herschel
Altieri, Bruno; Müller, Thomas; Kidger, Mark R. +1 more
Observations of Comet C/2010 X1 (Elenin) in August 2011 showed a pattern of evolution of coma morphology into an expanding, amorphous cloud of rapidly decreasing surface brightness shortly before perihelion passage, similar to C/1999 S4 (LINEAR) in 2000. However, the comet's difficult viewing geometry at the time of disruption made it impossible t…
Rosetta mission: Space oddity
Georgescu, Iulia
Identifying Surface Changes on HRSC Images of the Mars South Polar Residual CAP (sprc)
Muller, Jan-Peter; Putri, Alfiah Rizky Diana; Sidiropoulos, Panagiotis
The surface of Mars has been an object of interest for planetary research since the launch of Mariner 4 in 1964. Since then different cameras such as the Viking Visual Imaging Subsystem (VIS), Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC), and Mars Reconnaissance Orbiter (MRO) Context Camera (CTX) and High Resolution Imaging Science Experim…