Search Publications
Current structure and nonideal behavior at magnetic null points in the turbulent magnetosheath
Adrian, M. L.; Wendel, D. E.
The Poincaré index indicates that the Cluster spacecraft tetrahedron entraps a number of 3-D magnetic nulls during an encounter with the turbulent magnetosheath. Previous researchers have found evidence for reconnection at one of the many filamentary current layers observed by Cluster in this region. We find that many of the entrained nulls are al…
An unidentified emission in Titan's upper atmosphere
López-Puertas, M.; D'Aversa, E.; García-Comas, M. +4 more
We have analyzed limb daytime observations of Titan's upper atmosphere at 3.3 µm, acquired by the visual-infrared mapping spectrometer (VIMS) on Cassini. They were previously studied by García-Comas et al. (2011) to derive CH4 densities. Here, we report an unidentified emission peaking around 3.28 µm, hidden under the methan…
Stochastic Coupling of Solar Photosphere and Corona
Coyner, Aaron J.; Ofman, Leon; Davila, Joseph M. +1 more
The observed solar activity is believed to be driven by the dissipation of nonpotential magnetic energy injected into the corona by dynamic processes in the photosphere. The enormous range of scales involved in the interaction makes it difficult to track down the photospheric origin of each coronal dissipation event, especially in the presence of …
Response of the low ionosphere to X-ray and Lyman-α solar flare emissions
Dammasch, Ingolf E.; Kretzschmar, Matthieu; Raulin, Jean-Pierre +4 more
Using soft X-ray measurements from detectors onboard the Geostationary Operational Environmental Satellite (GOES) and simultaneous high-cadence Lyman-α observations from the Large Yield Radiometer (LYRA) onboard the Project for On-Board Autonomy 2 (PROBA2) ESA spacecraft, we study the response of the lower part of the ionosphere, the D region, to …
The Complex Physics of Dusty Star-forming Galaxies at High Redshifts as Revealed by Herschel and Spitzer
Berta, S.; Magnelli, B.; Lutz, D. +29 more
We combine far-infrared photometry from Herschel (PEP/HerMES) with deep mid-infrared spectroscopy from Spitzer to investigate the nature and the mass assembly history of a sample of 31 luminous and ultraluminous infrared galaxies ((U)LIRGs) at z ~ 1 and 2 selected in GOODS-S with 24 µm fluxes between 0.2 and 0.5 mJy. We model the data with a…
SWIFT J1910.2-0546: A Possible Black Hole Binary with a Retrograde Spin or Truncated Disk
Degenaar, N.; Miller, J. M.; Reis, R. C. +4 more
We present the first results from a long (51 ks) XMM-Newton observation of the Galactic X-ray binary SWIFT J1910.2-0546 in an intermediate state, obtained during its 2012 outburst. A clear, asymmetric iron emission line is observed and physically motivated models are used to fully describe the emission-line profile. Unlike other sources in their i…
Resolving the coronal line region of NGC 1068 with near-infrared integral field spectroscopy
Komossa, S.; McGregor, Peter J.; Rodríguez-Ardila, A. +1 more
We present adaptive optics-assisted J- and K-band integral field spectroscopy of the inner 300 × 300 pc of the Seyfert 2 galaxy NGC 1068. The data were obtained with the Gemini Near-infrared Integral-Field Spectrograph integral field unit spectrometer, which provided us with high-spatial and high-spectral resolution sampling. The wavelength range …
A Detailed Comparison between the Observed and Synthesized Properties of a Simulated Type II Spicule
Martínez-Sykora, Juan; De Pontieu, Bart; Hansteen, Viggo +7 more
We have performed a three-dimensional radiative MHD simulation of the solar atmosphere. This simulation shows a jet-like feature that shows similarities to the type II spicules observed for the first time with Hinode's Solar Optical Telescope. Rapid blueshifted events (RBEs) on the solar disk are associated with these spicules. Observational resul…
Quantifying Mass Segregation and New Core Radii for 54 Milky Way Globular Clusters
Heyl, Jeremy; Richer, Harvey; Goldsbury, Ryan
We present core radii for 54 Milky Way globular clusters determined by fitting King-Michie models to cumulative projected star count distributions. We find that fitting star counts rather than surface brightness profiles produces results that differ significantly due to the presence of mass segregation. The sample in each cluster is further broken…
Electric structure of dipolarization fronts associated with interchange instability in the magnetotail
Zhang, T. L.; Nakamura, R.; Cao, J. B. +6 more
electric structure of dipolarization fronts (DFs) is very important to both DF dynamics and particle acceleration. We performed two-dimensional Hall MHD simulation to study the electric structure of DF produced by interchange instability on the scale of ion inertial length in the flow braking region of near-Earth tail. The results indicate that th…