Search Publications
A four-year XMM-Newton/Chandra monitoring campaign of the Galactic centre: analysing the X-ray transients
Maccarone, T. J.; Degenaar, N.; Wijnands, R. +5 more
We report on the results of a four-year long X-ray monitoring campaign of the central 1.2 square degrees of our Galaxy, performed with Chandra and XMM-Newton between 2005 and 2008. Our study focuses on the properties of transient X-ray sources that reach 2-10 keV luminosities of LX ≳ 1034 erg s-1 for an assumed dis…
Flare-generated Type II Burst without Associated Coronal Mass Ejection
Zhukov, A. N.; Magdalenić, J.; Vršnak, B. +2 more
We present a study of the solar coronal shock wave on 2005 November 14 associated with the GOES M3.9 flare that occurred close to the east limb (S06° E60°). The shock signature, a type II radio burst, had an unusually high starting frequency of about 800 MHz, indicating that the shock was formed at a rather low height. The position of the radio so…
Saturn's inner magnetospheric convection pattern: Further evidence
Gurnett, D. A.; Thomsen, M. F.; Tokar, R. L. +7 more
Observations of the radial locations of satellite absorption microsignatures in energetic particle data at Saturn have suggested the existence of an average convection pattern, fixed in local time, that is superimposed on the dominant near-corotation of the inner magnetosphere. Such a pattern should have additional observational consequences, and …
Substructure in the most massive GEEC groups: field-like populations in dynamically active groups
Mulchaey, John S.; Balogh, Michael L.; Harris, William E. +6 more
The presence of substructure in galaxy groups and clusters is believed to be a sign of recent galaxy accretion and can be used to probe not only the assembly history of these structures, but also the evolution of their member galaxies. Using the Dressler-Shectman (DS) test, we study substructure in a sample of intermediate-redshift (z∼ 0.4) galaxy…
Modelling the dust emission from dense interstellar clouds: disentangling the effects of radiative transfer and dust properties
Abergel, A.; Bernard, J. -P.; Juvela, M. +9 more
Context. Dust emission is increasingly used as a tracer of the mass in the interstellar medium. With the combination of Planck and Herschel observatories, we now have both the spectral coverage and the angular resolution required to observe dense and cold molecular clouds. However, as these clouds are optically thick at short wavelengths but optic…
The Herschel view of the on-going star formation in the Vela-C molecular cloud
Hill, T.; White, G. J.; Rygl, K. L. J. +24 more
Aims: As part of the Herschel guaranteed time key programme "HOBYS", we present the PACS and SPIRE photometric survey of the star-forming region Vela-C, one of the nearest sites of low-to-high-mass star formation in the Galactic plane. Our main objectives are to take a census of the cold sources and to derive their mass distribution down to a…
The Birth of an Ultraluminous X-Ray Source in M83
Soria, Roberto; Blair, William P.; Whitmore, Bradley C. +4 more
A previously undetected (LX < 1036 erg s-1) source in the strongly star-forming galaxy M83 entered an ultraluminous state between 2009 August and 2010 December. It was first seen with Chandra on 2010 December 23 at LX ≈ 4 × 1039 erg s-1 and has remained ultraluminous through our …
Multi-color observations of short GRB afterglows: 20 events observed between 2007 and 2010
Greiner, J.; McBreen, S.; Hartmann, D. H. +18 more
We report on follow-up observations of 20 short-duration gamma-ray bursts (GRBs; T90 < 2 s) performed in g'r'i'z'JHKs with the Gamma-Ray Burst Optical Near-Infrared Detector (GROND) between mid-2007 and the end of 2010. This is one of the most comprehensive data sets on GRB afterglow observations of short bursts published …
Ion resonance acceleration by dipolarization fronts: analytic theory and spacecraft observation
Petrukovich, A. A.; Artemyev, A. V.; Lutsenko, V. N.
In this paper, we consider the mechanism of ion acceleration by dipolarization fronts in the Earth's magnetotail. The statistics of dipolarization front observations by Interball-tail have been collected from 1995 to 1998 (51 events). We demonstrate that near dipolarization fronts bursts of energetic ions are often observed with an average energy …
The ACS Nearby Galaxy Survey Treasury. X. Quantifying the Star Cluster Formation Efficiency of nearby Dwarf Galaxies
Johnson, L. Clifton; Fouesneau, Morgan; Seth, Anil C. +6 more
We study the relationship between the field star formation and cluster formation properties in a large sample of nearby dwarf galaxies. We use optical data from the Hubble Space Telescope and from ground-based telescopes to derive the ages and masses of the young (t age <~ 100 Myr) cluster sample. Our data provide the first constrain…