Search Publications
Long-term pulse profile study of the Be/X-ray pulsar SAX J2103.5+4545
Reglero, V.; Wilson, C. A.; Finger, M. H. +1 more
Aims:We present the first long-term pulse profile study of the X-ray pulsar SAX J2103.5+4545. Our main goal is to study the pulse shape correlation either with luminosity, time or energy.
Methods: This Be/X-ray binary system was observed from 1999 to 2004 by RXTE PCA, and by INTEGRAL from 2002 to 2005, during the Performance and Verification (…
The Radio Emission, X-Ray Emission, and Hydrodynamics of G328.4+0.2: A Comprehensive Analysis of a Luminous Pulsar Wind Nebula, Its Neutron Star, and the Progenitor Supernova Explosion
Gelfand, Joseph D.; Hughes, John P.; Gaensler, B. M. +3 more
We present new observational and modeling results obtained for the Galactic nonthermal radio source G328.4+0.2. Using X-ray data obtained by XMM-Newton, we confirm that its X-ray emission is heavily absorbed, has a spectrum best fitted by a power-law model of photon index Γ=2 with no evidence for a thermal component, comes from a region significan…
Gaps in the Cloud Cover? Comparing Extinction Measures in Spiral Disks
Smith, J. D.; Calzetti, D.; Kennicutt, R. C. +11 more
Dust in galaxies can be mapped either by the FIR/submillimeter emission, the optical or infrared reddening of starlight, or the extinction of a known background source. We compare two dust extinction measurements for a set of 15 sections in 13 nearby galaxies to determine the scale of the dusty interstellar medium (ISM) responsible for disk opacit…
A Common Origin for Quasar Extended Emission-Line Regions and Their Broad-Line Regions
Fu, Hai; Stockton, Alan
We present a correlation between the presence of luminous extended emission-line regions (EELRs) and the metallicity of the broad-line regions (BLRs) of low-redshift quasars. The result is based on ground-based [O III] λ5007 narrowband imaging and Hubble Space Telescope UV spectra of 12 quasars at 0.20<=z<=0.45. Quasars showing luminous EELR…
Constraining and validating the Oct/Nov 2003 X-class EUV flare enhancements with observations of FUV dayglow and E-region electron densities
Meier, R. R.; Lean, J. L.; Paxton, L. J. +10 more
Near peak activity of two X-class solar flares, on 28 October and 4 November 2003, the Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED)/Solar EUV Experiment (SEE) instrument recorded order of magnitude increases in solar EUV irradiance, the TIMED/Global Ultraviolet Imager (GUVI) observed simultaneous increases in upper atmosphere…
Status of identification of VHE γ-ray sources
Funk, Stefan
With the recent advances made by Cherenkov telescopes such as H.E.S.S. the field of very high-energy (VHE) γ-ray astronomy has recently entered a new era in which for the first time populations of Galactic sources such as e.g. Pulsar wind nebulae (PWNe) or Supernova remnants (SNRs) can be studied. However, while some of the new sources can be asso…
The highly ionized disk wind of GRO J1655-40
Haberl, F.; Greiner, J.; Sala, G. +3 more
Aims:The galactic superluminal microquasar
Methods: We observed
Physical parameters of a mid-latitude streamer during the declining phase of the solar cycle
Susino, R.; Landi, E.; Spadaro, D. +2 more
Context: Investigating the physical properties of solar coronal streamers is important for understanding their role in the global magnetic structure of the extended solar atmosphere, as well as in the generation of the slow solar wind.
Aims: We hope to contribute as completely as possible to the ongoing SOHO instruments campaign devoted to the…
Correlated modulation between the redshifted Fe Kα line and the continuum emission in NGC 3783
Cappi, M.; Ponti, G.; Iwasawa, K. +5 more
Aims:It has been suggested that X-ray observations of rapidly variable Seyfert galaxies may hold the key to probe the gas orbital motions in the innermost regions of accretion discs around black holes and, thus, trace flow patterns under the effect of the hole strong gravitational field.
Methods: We explore this possibility by re-analyzing the…
Density holes in the upstream solar wind
Dandouras, I.; Lucek, E.; Rème, H. +11 more
Larmor size transient structures with depletions as large as 99% of ambient solar wind density levels occur commonly upstream of Earth's collisionless bow shock. These ``density holes'' have a mean duration of ~17.9 +/- 10.4s but holes as short as 4s have been observed. The average fractional density depletion (δn/n) inside the holes is ~0.68 +/- …