Search Publications
Dynamics of thin current sheets associated with magnetotail reconnection
Balogh, A.; RèMe, H.; Fazakerley, A. N. +7 more
We have examined the detailed structure of thin current sheets and their evolution during a substorm interval on 24 August 2003, when Cluster experienced several rapid current sheet crossings within a couple of ion gyrotimes. These crossings took place during an interval of high-speed ion flows with BZ reversals and signatures of accele…
Confirmation of the planet hypothesis for the long-period radial velocity variations of β Geminorum
Guenther, E. W.; Hatzes, A. P.; Cochran, W. D. +8 more
Aims.Our aim is to confirm the nature of the long period radial velocity measurements for β Gem first found by Hatzes & Cochran (1993).
Methods: .We present precise stellar radial velocity measurements for the K giant star β Gem spanning over 25 years. An examination of the Ca II K emission, spectral line shapes from high resolution data …
20-100 keV properties of cataclysmic variables detected in the INTEGRAL/IBIS survey
Hill, A. B.; Knigge, C.; Bird, A. J. +5 more
Analysis of INTEGRAL/IBIS survey observations has revealed that the rare intermediate polar and asynchronous polar cataclysmic variables (CVs) are consistently found to emit in the 20-100 keV energy band, whereas synchronous polars and the common non-magnetic CVs rarely do so. From the correlation of a candidate INTEGRAL/IBIS survey source list wi…
Using the Evolution of Coronal Dimming Regions to Probe the Global Magnetic Field Topology
Mandrini, C. H.; Dasso, S.; Harra, L. K. +4 more
We demonstrate that study of the evolving magnetic nature of coronal dimming regions can be used to probe the large-scale magnetic structure involved in the eruption of a coronal mass ejection (CME). We analyse the intensity evolution of coronal dimming regions using 195 Å data from the Extreme ultraviolet Imaging Telescope (EIT) on board the Sola…
In situ evidence for the structure of the magnetic null in a 3D reconnection event in the Earth's magnetotail
Escoubet, C. P.; Balogh, A.; Glassmeier, K. H. +12 more
Magnetic reconnection is one of the most important processes in astrophysical, space and laboratory plasmas. Identifying the structure around the point at which the magnetic field lines break and subsequently reform, known as the magnetic null point, is crucial to improving our understanding of reconnection. But owing to the inherently three-dimen…
Cooling of the quasi-persistent neutron star X-ray transients KS 1731-260 and MXB 1659-29
Homan, Jeroen; Miller, Jon M.; Cackett, Edward M. +3 more
We present Chandra and XMM-Newton X-ray observations that monitor the neutron star cooling of the quasi-persistent neutron star X-ray transients KS 1731-260 and MXB 1659-29 for approximately 4 yr after these sources returned to quiescence from prolonged outbursts. In both sources the outbursts were long enough to significantly heat the neutron sta…
Gusev crater: Wind-related features and processes observed by the Mars Exploration Rover Spirit
Arvidson, R. E.; Christensen, P. R.; Greeley, Ronald +19 more
Wind-related features observed by the rover Spirit in Gusev crater, Mars, include patches of soil on the surface, some of which are organized into bed forms. Windblown grains include dust (inferred to be <3 µm in diameter), sands (up to a few hundred µm in diameter), and granules (>2 mm in diameter). Microscopic Imager data show …
The Mass of the Central Black Hole in the Seyfert Galaxy NGC 4151
Peterson, Bradley M.; Onken, Christopher A.; Metzroth, Kyle G.
In order to improve the reverberation-mapping-based estimate of the mass of the central supermassive black hole in the Seyfert 1 galaxy NGC 4151, we have reanalyzed archival ultraviolet monitoring spectra from two campaigns undertaken with the International Ultraviolet Explorer. We measure emission-line time delays for four lines, C IV λ1549, He I…
The Physical and Photometric Properties of High-Redshift Galaxies in Cosmological Hydrodynamic Simulations
Papovich, C.; Davé, R.; Finlator, K. +1 more
We study the physical and photometric properties of galaxies at z=4 in cosmological hydrodynamic simulations of a ΛCDM universe. We focus on galaxies satisfying the ``B dropout'' criteria of the Great Observatories Origins DEEP Survey (GOODS). Our simulations predict that high-redshift galaxies show strong correlations in star formation rate (SFR)…
The Pure Noncollisional Blue Straggler Population in the Giant Stellar System ω Centauri
Pancino, E.; Bellazzini, M.; Origlia, L. +3 more
We have used high spatial resolution data from the Hubble Space Telescope (HST) and wide-field ground-based observations to search for blue straggler stars (BSSs) over the entire radial extent of the large stellar system ω Centauri. We have detected the largest population of BSSs ever observed in any stellar system. Even though the sample is restr…