Search Publications
Energy dissipation by whistler turbulence: Three-dimensional particle-in-cell simulations
Chang, Ouliang; Wang, Joseph; Peter Gary, S.
Three-dimensional particle-in-cell simulations of whistler turbulence are carried out on a collisionless, homogeneous, magnetized plasma model. The simulations use an initial ensemble of relatively long wavelength whistler modes and follow the temporal evolution of the fluctuations as they cascade into a broadband, anisotropic, turbulent spectrum …
Distribution of Electric Currents in Sunspots from Photosphere to Corona
Gosain, Sanjay; Démoulin, Pascal; López Fuentes, Marcelo
We present a study of two regular sunspots that exhibit nearly uniform twist from the photosphere to the corona. We derive the twist parameter in the corona and in the chromosphere by minimizing the difference between the extrapolated linear force-free field model field lines and the observed intensity structures in the extreme-ultraviolet images …
Dynamical star-disk interaction in the young stellar system V354 Monocerotis
Bouvier, J.; Favata, F.; Alencar, S. H. P. +2 more
Aims: The main goal of this work is to characterize the mass accretion and ejection processes of the classical T Tauri star
Methods: In March 2008, photometric and spectroscopic observations of
Water distribution in shocked regions of the NGC 1333-IRAS 4A protostellar outflow
Liseau, R.; Codella, C.; van Dishoeck, E. F. +11 more
Context. Water is a key molecule in protostellar environments because its line emission is very sensitive to both the chemistry and the physical conditions of the gas. Observations of H2O line emission from low-mass protostars and their associated outflows performed with HIFI onboard the Herschel Space Observatory have highlighted the c…
Potential solar axion signatures in X-ray observations with the XMM-Newton observatory
Read, A. M.; Carter, J. A.; Sembay, S. +2 more
The soft X-ray flux produced by solar axions in the Earth's magnetic field is evaluated in the context of the European Space Agency's XMM-Newton observatory. Recent calculations of the scattering of axion-conversion X-rays suggest that the sunward magnetosphere could be an observable source of 0.2-10 keV photons. For XMM-Newton, any conversion X-r…
Discovery of a Strong Lensing Galaxy Embedded in a Cluster at z = 1.62
Koekemoer, Anton M.; Kacprzak, Glenn G.; Tran, Kim-Vy H. +9 more
We identify a strong lensing galaxy in the cluster IRC 0218 (also known as XMM-LSS J02182-05102) that is spectroscopically confirmed to be at z = 1.62, making it the highest-redshift strong lens galaxy known. The lens is one of the two brightest cluster galaxies and lenses a background source galaxy into an arc and a counterimage. With Hubble Spac…
The scale of the magnetotail reconnecting current sheet in the presence of O+
Kistler, L. M.; Mouikis, C. G.; Liu, Y. H. +2 more
The reconnection current layer thickness is expected to scale with either the ion inertial length or the ion gyroradius. Both of these quantities scale with the mass of the ions present. During geomagnetically disturbed times, the reconnection layer in the magnetotail can contain a significant amount of O+. Using Cluster multi-spacecraf…
Ion composition in interchange injection events in Saturn's magnetosphere
Thomsen, M. F.; Wilson, R. J.; Tokar, R. L. +10 more
Interchange injection events are commonly observed by the Cassini spacecraft in the region between about 6 and 12 Rs (1 Rs = 60,268 km) and even frequently beyond. In this study, 13 examples of interchange injection events are identified in Cassini/Cassini Plasma Spectrometer data under special conditions such that time-of-fl…
The VISTA Carina Nebula Survey . I. Introduction and source catalog
Preibisch, T.; Roccatagliata, V.; Ratzka, T. +2 more
Context. The Carina Nebula is one of the most massive and active star-forming regions in our Galaxy and has been studied with numerous multiwavelength observations in the past five years. However, most of these studies were restricted to the inner parts (≲1 square-degree) of the nebula, and thus covered only a small fraction of the whole cloud com…
The molecular circumnuclear disk (CND) in Centaurus A. A multi-transition CO and [CI] survey with Herschel, APEX, JCMT, and SEST
Weiss, A.; van der Werf, P.; Stutzki, J. +8 more
This paper presents emission line intensities of CO and C° from the compact circumnuclear disk in the center of NGC 5128 (Centaurus A) obtained with the Herschel Space Observatory in the 400-1000 GHz range as well as previously unpublished measurements obtained with the ground-based observatories SEST, JCMT and APEX in the 90-800 GHz range. The re…