Search Publications
Dust Distribution in the β Pictoris Circumstellar Disks
Artymowicz, Pawel; Croll, Bryce; Ahmic, Mirza
We present three-dimensional models of dust distribution around β Pictoris that produce the best fits to the Hubble Space Telescope/Advanced Camera for Surveys' images obtained by Golimowski and coworkers. We allow for the presence of either one or two separate axisymmetric dust disks. The density models are analytical, radial two power laws joine…
Temperature and Metallicity in the Intra-Cluster Medium of Abell 262 Observed with Suzaku
Sato, Kosuke; Gastaldello, Fabio; Matsushita, Kyoko
We studied the temperature and abundance distributions of the intra-cluster medium (ICM) in the Abell 262 cluster of galaxies observed with Suzaku. Abell 262 is a bright, nearby poor cluster with an ICM temperature of ∼2keV, thus providing useful information about the connection of ICM properties between groups and clusters of galaxies. With the X…
Fog phenomena on Mars
Formisano, Vittorio; Möhlmann, Diedrich T. F.; Wolkenberg, Paulina +2 more
Mars Express High Resolution Stereo Camera (HRSC) images show impressive morning fog features in Valles Marineris and other regions of the surface of Mars. Temperatures have been determined, simultaneously to the imaging, by Mars Express Planetary Fourier Spectrometer (PFS). This identifies water ice rather than frozen CO 2 as the cause…
Coordinated Study on Solar Wind Turbulence During the Venus-Express, ACE and Ulysses Alignment of August 2007
Orsini, S.; Baumjohann, W.; Bavassano, B. +14 more
At the end of August 2007, Venus, Earth and Ulysses were aligned within a few degrees. This unusual event gives the opportunity to attempt a coordinated study on the radial evolution of solar wind turbulence and coronal transients like CMEs between 0.7 and 1.4 AU. Interplanetary magnetic field data and moments of proton velocity distribution funct…
Are Coronal Loops Isothermal or Multithermal?
Mason, H. E.; Schmelz, J. T.; DeLuca, E. E. +5 more
Surprisingly few solar coronal loops have been observed simultaneously with TRACE and SOHO/Coronal Diagnostics Spectrometer (CDS), and even fewer analyses of these loops have been conducted and published. The SOHO Joint Observing Program 146 was designed in part to provide the simultaneous observations required for in-depth temperature analysis of…
Spectral Analysis of the Accretion Flow in NGC 1052 with Suzaku
Kadler, M.; Kerp, J.; Ros, E. +10 more
We present an analysis of the 101 ks, 2007 Suzaku spectrum of the low ionization nuclear emission region galaxy NGC 1052. The 0.5-10 keV continuum is well modeled by a power-law continuum modified by Galactic and intrinsic absorption, and it exhibits a soft, thermal emission component below 1 keV. Both a narrow core and a broader component of Fe K…
Saturn Atmospheric Structure and Dynamics
Baines, Kevin H.; Achterberg, Richard K.; Flasar, F. Michael +4 more
Saturn inhabits a dynamical regime of rapidly rotating, internally heated atmospheres similar to Jupiter. Zonal winds have remained fairly steady since the time of Voyager except in the equatorial zone and slightly stronger winds occur at deeper levels. Eddies supply energy to the jets at a rate somewhat less than on Jupiter and mix potential vort…
XMM-Newton View of the Multiphase Warm Absorber in Seyfert 1 Galaxy NGC 985
Elvis, Martin; Nicastro, Fabrizio; Mathur, Smita +6 more
We present an analysis of a new XMM-Newton observation of the Seyfert 1 galaxy NGC 985. The European Photon Imaging Camera (EPIC) spectra present strong residuals to a single power-law model, indicating the presence of ionized absorbing gas and a soft excess. A broadband fit to the EPIC and RGS spectra shows that the continuum can be well fitted w…
On the sizes of neutral hydrogen regions giving rise to damped Lyα absorption systems
Rao, S.; Turnshek, D. A.; Monier, E. M.
Using quasi-stellar object (QSO) absorption-line spectra obtained along closely spaced sightlines, we examine the transverse sizes of regions containing large columns of neutral hydrogen gas at redshifts z ~ 1.5. The observations are primarily of intervening damped Lyα (DLA) and sub-DLA absorption-line systems in gravitationally lensed QSOs. In pa…
An Absence of X-ray Accretion Shock Instability Signatures in TW Hydrae
Drake, Jeremy J.; Raymond, John; Laming, J. Martin +1 more
Gas accreting onto T Tauri stars should form shocks that are susceptible to the classical radiative shock instability. The instability should give rise to strong periodic modulation in the X-ray emission from the shock-heated plasma. Time series analysis of soft X-rays thought to arise predominantly in an accretion shock on the classical T Tauri s…