Search Publications
The 2008 May burst activation of SGR1627-41
Sakamoto, T.; Tiengo, A.; de Luca, A. +16 more
In 2008 May, the soft gamma-ray repeater (SGR) SGR1627-41 resumed its bursting activity after nearly a decade of quiescence. After detection of a bright burst, Swift pointed its X-ray telescope in the direction of the source in less than five hours and followed it for over five weeks. In this Letter, we present an analysis of the data from these S…
Low-mass X-ray binaries in the bulge of the Milky Way
Sunyaev, R.; Revnivtsev, M.; Sazonov, S. +4 more
We study the population of low-mass X-ray binaries (LMXBs) in the Galactic bulge using the deep survey of this region by the IBIS telescope aboard the INTEGRAL observatory. Thanks to the increased sensitivity with respect to previous surveys of this field, we succeeded in probing the luminosity function (LF) of LMXBs down to ~7×1034 erg…
Transient layers in the topside ionosphere of Mars
Gurnett, D. A.; Morgan, D. D.; Kopf, A. J. +1 more
Radar soundings from the MARSIS instrument on board the Mars Express spacecraft have shown that distinct layers can occur in the topside ionosphere of Mars, well above the main photo-ionization layer. These layers appear as cusps, or sometimes steps, in plots of the time delay as a function of frequency. Usually only one topside layer is observed,…
WFPC2 LRF Imaging of Emission-Line Nebulae in 3CR Radio Galaxies
Chiaberge, M.; Privon, G. C.; Sparks, W. +5 more
We present Hubble Space Telescope WFPC2 Linear Ramp Filter images of high surface brightness emission lines (either [O II], [O III], or H α + [N II]) in 80 3CR radio sources. We overlay the emission-line images on high-resolution VLA radio images (eight of which are new reductions of archival data) in order to examine the spatial relationship betw…
Changes of Magnetic Structure in Three Dimensions Associated with the X3.4 Flare of 2006 December 13
Jing, Ju; Wang, Haimin; Kubo, Masahito +2 more
Recent observations demonstrated that sunspot structure can change rapidly and irreversibly after flares. One of the most puzzling results is the increase in magnetic shear around the flaring magnetic polarity inversion line after flares. However, all these observations were made at the photosphere level. In this Letter, we study the altitude vari…
Quantitative spectroscopy of Deneb
Przybilla, N.; Schiller, F.
Context: Quantitative spectroscopy of luminous BA-type supergiants offers a high potential for modern astrophysics. Detailed studies allow the evolution of massive stars, galactochemical evolution, and the cosmic distance scale to be constrained observationally.
Aims: A detailed and comprehensive understanding of the atmospheres of BA-type sup…
Simulations of the Dynamical and Light-Scattering Behavior of Saturn's Rings and the Derivation of Ring Particle and Disk Properties
Dones, Luke; Porco, Carolyn C.; Weiss, John W. +3 more
We study the light-scattering behavior of Saturn's rings for the purpose of deducing the nature and distribution of the particles comprising them and the collisional and dynamical environments in which they reside. To this end, we have developed two complex numerical codes to apply to this objective. One is a geometric ray-tracing code that scatte…
Magnetic field emergence in quiet Sun granules
Bellot Rubio, L. R.; Tsuneta, S.; del Toro Iniesta, J. C. +1 more
Aims:We describe a new form of small-scale magnetic flux emergence in the quiet Sun. This process seems to take vertical magnetic fields from subsurface layers to the photosphere, where they appear above granular convection cells.
Methods: High-cadence time series of spectropolarimetric measurements obtained by Hinode in a quiet region near di…
Comparing Suzaku and XMM-Newton Observations of the Soft X-Ray Background: Evidence for Solar Wind Charge Exchange Emission
Henley, David B.; Shelton, Robin L.
We present an analysis of a pair of Suzaku spectra of the soft X-ray background (SXRB), obtained from pointings on and off a nearby shadowing filament in the southern Galactic hemisphere. Because of the different Galactic column densities in the two pointing directions, the observed emission from the Galactic halo has a different shape in the two …
IMAGES IV: strong evolution of the oxygen abundance in gaseous phases of intermediate mass galaxies from z ~ 0.8
Cesarsky, C.; Östlin, G.; Yang, Y. +22 more
Context: Intermediate mass galaxies (> 1010 M_⊙) at z ~ 0.6 are the likeliest progenitors of the present-day, numerous population of spirals. There is growing evidence that they have evolved rapidly in the last 6 to 8 Gyr, and likely already have formed a significant fraction of their stellar mass, often showing perturbed morphologie…