Search Publications
Numerical modeling of the magnetic topology near Mars auroral observations
Barabash, S.; Lundin, R.; Winningham, J. D. +6 more
Magnetohydrodynamic (MHD) simulations of the Mars magnetic field topology are presented for the auroral observations reported from the Mars Express SPICAM instrument. It is found that the field lines closest to the assumed emission location are open. That is, they are connected to the interplanetary magnetic field, thus allowing access for solar w…
The Globular Cluster System in NGC 5866: Optical Observations from Hubble Space Telescope Advanced Camera for Surveys
Blakeslee, John P.; Cantiello, Michele; Raimondo, Gabriella
We perform a detailed study of the globular cluster (GC) system in the galaxy NGC 5866 based on F435W, F555W, and F625W (~B, V, and R) Hubble Space Telescope Advanced Camera for Surveys images. Adopting color, size, and shape selection criteria, the final list of GC candidates comprises 109 objects, with small estimated contamination from backgrou…
Evidence for the Importance of Resonance Scattering in X-Ray Emission Line Profiles of the O Star ζ Puppis
Leutenegger, Maurice A.; Kahn, Steven M.; Owocki, Stanley P. +1 more
We fit the Doppler profiles of the He-like triplet complexes of O VII and N VI in the X-ray spectrum of the O star ζ Pup, using XMM-Newton RGS data collected over ~400 ks of exposure. We find that they cannot be well fit if the resonance and intercombination lines are constrained to have the same profile shape. However, a significantly better fit …
PAHs in the halo of NGC 5529
Madden, S.; Parkin, T.; Irwin, J. A. +1 more
We present sensitive ISO λ 6.7~µm observations of the edge-on galaxy, NGC 5529, finding an extensive MIR halo around NGC 5529. The emission is dominated by PAHs in this band. The PAH halo has an exponential scale height of 3.7 kpc but can still be detected as far as ≈10 kpc from the plane to the limits of the high dynamic range (1770/1) data…
Direct imaging of the young spectroscopic binary HD 160934
Henning, T.; Brandner, W.; Hormuth, F. +2 more
Context: Members of nearby moving groups are promising candidates for the detection of stellar or substellar companions by direct imaging. Mass estimates and magnitude measurements of detected companions to young stars are valuable input data to facilitate the refinement of existing pre-main-sequence stellar models. In this paper we report on our …
The Stellar Content of the COSMOS Field as Derived from Morphological and SED-based Star/Galaxy Separation
Kneib, J. -P.; Aussel, H.; Taniguchi, Y. +12 more
We report on the stellar content of the COSMOS two degree field, as derived from a rigorous star-galaxy separation approach developed for using stellar sources to define the point-spread function variation map used in a study of weak galaxy lensing. The catalog obtained in one filter from the ACS (Advanced Camera for Surveys on the Hubble Space Te…
Solitary Electromagnetic Pulses Detected with Super-Alfvénic Flows in Earth's Geomagnetic Tail
Dandouras, I.; Lucek, E.; Rème, H. +11 more
Solitary nonlinear (δB/B≫1) electromagnetic pulses have been detected in Earth’s geomagnetic tail accompanying plasmas flowing at super-Alfvénic speeds. The pulses in the current sheet had durations of ∼5s, were left-hand circularly polarized, and had phase speeds of approximately the Alfvén speed in the plasma frame. These pulses were associated …
Charged particle environment of Titan during the T9 flyby
Coates, A. J.; Crary, F.; Sittler, E. C. +6 more
The ion measurements of the Cassini Plasma Spectrometer are presented which were acquired on 26 December 2005, during the T9 flyby at Titan. The plasma flow and magnetic field directions in the distant plasma environment of the moon were distinctly different from the other flybys. The near-Titan environment, dominated by ions of Titan origin, had …
The variable X-ray light curve of GRB 050713A: the case of refreshed shocks
Covino, S.; Campana, S.; Tagliaferri, G. +21 more
We present a detailed study of the spectral and temporal properties of the X-ray and optical emission of GRB050713a up to 0.5 day after the main Gamma Ray Burst (GRB) event. The X-ray light curve exhibits large amplitude variations with several rebrightenings superposed on the underlying three-segment broken power-law that is often seen in Swift G…
A NewModel for the Structure of the DACs and SACs Regions in the Oe and Be Stellar Atmospheres
Antoniou, A.; Danezis, E.; Lyratzi, E. +4 more
In this paper we present a new mathematical model for the density regions where a specific spectral line and its SACs/DACs are created in the Oe and Be stellar atmospheres. In the calculations of final spectral line function we consider that the main reasons of the line broadening are the rotation of the density regions creating the spectral line …