Search Publications
Near-infrared Structure of Fast and Slow-rotating Disk Galaxies
Bershady, Matthew A.; Schechtman-Rook, Andrew
We investigate the stellar disk structure of six nearby edge-on spiral galaxies using high-resolution JHK s-band images and three-dimensional radiative transfer models. To explore how mass and environment shape spiral disks, we selected galaxies with rotational velocities between 69 km s-1 <V rot < 245 km s
Isothermal magnetosheath electrons due to nonlocal electron cross talk
Schwartz, S. J.; Mitchell, J. J.
Heating of the various plasma species at the Earth's collisionless bow shock is not fully understood. Although the total amount of heating is constrained by the one-fluid Rankine-Hugoniot relations in terms of local plasma conditions, the partition of energy between, e.g., electrons and ions, is influenced by particle kinetics which are not consid…
The Hard X-Ray Continuum of Cen A Observed With INTEGRAL SPI
Jourdain, Elisabeth; Roques, Jean-Pierre; Evans, Daniel A. +1 more
We revisit the average hard X-ray spectrum from the active galactic nucleus (AGN) of Centaurus A (Cen A) using 10 yr worth of observations with INTEGRAL SPI. This source has the highest flux observed from any AGNs in the SPI bandpass (23 keV-8 MeV). The 10 year light curve of Cen A is presented, and hardness ratios confirm that the spectral shape …
Coronal loops above an active region: Observation versus model
Peter, Hardi; Bingert, Sven; Bourdin, Philippe-A.
We conducted a high-resolution numerical simulation of the solar corona above a stable active region. The aim is to test the field line braiding mechanism for a sufficient coronal energy input. We also check the applicability of scaling laws for coronal loop properties like the temperature and density. Our 3D MHD model is driven from below by Hino…
CoRoT-22 b: a validated 4.9 R⊕ exoplanet in 10-d orbit
Mazeh, T.; Aigrain, S.; Alonso, R. +37 more
The CoRoT satellite has provided high-precision photometric light curves for more than 163 000 stars and found several hundreds of transiting systems compatible with a planetary scenario. If ground-based velocimetric observations are the best way to identify the actual planets among many possible configurations of eclipsing binary systems, recent …
The structure of the Venusian current sheet
Malova, H. V.; Petrukovich, A. A.; Zelenyi, L. M. +7 more
We investigate the current sheet (CS) of the Venusian magnetotail using the data collected by the Venus Express mission in 2006-2010. We have found that the observed profiles of the main magnetic field component Bx have single-scale or double-scale structures. For single-scale CSs the Bx profile is well approximated by the Ha…
The SUMER Data in the SOHO Archive
Bocchialini, K.; Wilhelm, K.; Curdt, W. +5 more
We have released an archive of all observational data of the VUV spectrometer Solar Ultraviolet Measurements of Emitted Radiation (SUMER) on SOHO that have been acquired until now. The operational phase started with `first light' observations on 27 January 1996 and will end in 2014. Future data will be added to the archive when they become availab…
Separable Solutions of Force-Free Spheres and Applications to Solar Active Regions
Mangalam, A.; Ravindra, B.; Prasad, A.
We present a systematic study of the force-free field equation for simple axisymmetric configurations in spherical geometry and apply it to the solar active regions. The condition of separability of solutions in the radial and angular variables leads to two classes of solutions: linear and nonlinear force-free fields (NLFF). We have studied these …
Hubble Space Telescope Far Ultraviolet Spectroscopy of the Recurrent Nova T Pyxidis
Williams, Robert E.; Livio, Mario; Woodward, Charles E. +5 more
With six recorded nova outbursts, the prototypical recurrent nova T Pyxidis (T Pyx) is the ideal cataclysmic variable system to assess the net change of the white dwarf mass within a nova cycle. Recent estimates of the mass ejected in the 2011 outburst ranged from a few ~10-5 M ⊙ to 3.3 × 10-4 M ⊙, and a…
The virtual observatory service TheoSSA: Establishing a database of synthetic stellar flux standards . II. NLTE spectral analysis of the OB-type subdwarf Feige 110
Rauch, T.; Werner, K.; Kruk, J. W. +3 more
Context. In the framework of the Virtual Observatory (VO), the German Astrophysical VO (GAVO) developed the registered service TheoSSA (Theoretical Stellar Spectra Access). It provides easy access to stellar spectral energy distributions (SEDs) and is intended to ingest SEDs calculated by any model-atmosphere code, generally for all effective temp…