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Fine Structures in the White-Light Solar Corona at the 2006 Eclipse
Rušin, V.; Druckmüller, M.; Saniga, M. +1 more
Observations of the total solar eclipse of 2006 March 29, as it crossed Africa from southwest to northeast into a Greek island and beyond, allowed correlations with near-simultaneous coronal observations from several spacecraft, including SOHO and TRACE. New methods of compositing images allow the recovery of higher resolution (1"-2") on coronal f…
Hard X-Ray Emission of the Microquasar GX 339-4 in the Low/Hard State
Rodriguez, J.; Malzac, J.; Joinet, A. +4 more
We present the analysis of the high-energy emission of the Galactic black hole binary GX 339-4 in a low/hard state at the beginning of its 2004 outburst. The data from 273 ks of INTEGRAL observations, spread over 4 weeks, are analyzed, along with the existing simultaneous RXTE HEXTE and PCA data. During this period, the flux increases by a factor …
The Plasma Structure of the Cygnus Loop from the Northeastern Rim to the Southwestern Rim
Miller, Eric D.; Katsuda, Satoru; Tsunemi, Hiroshi +1 more
The Cygnus Loop was observed from the northeast to the southwest with XMM-Newton. We divided the observed region into two parts, the north and the south path, and studied the X-ray spectra along the two. The spectra can be well fitted either by a one-component nonequilibrium ionization (NEI) model or by a two-component NEI model. The rim regions c…
The Cause of Photospheric and Helioseismic Responses to Solar Flares: High-Energy Electrons or Protons?
Kosovichev, A. G.
Analysis of the hydrodynamic and helioseismic effects in the photosphere during the solar flare of 2002 July 23, observed by MDI/SOHO, and high-energy images from RHESSI show that these effects are closely associated with sources of the hard X-ray emission but that no such effects existed in the centroid region of the flare's gamma-ray emission. T…
A Shell of Thermal X-Ray Emission Surrounding the Young Crab-like Remnant 3C 58
Gotthelf, E. V.; Helfand, D. J.; Newburgh, L.
Deep X-ray imaging spectroscopy of the bright pulsar wind nebula 3C 58 confirms the existence of an embedded thermal X-ray shell surrounding the pulsar PSR J0205+6449. Radially resolved spectra obtained with the XMM-Newton telescope are well characterized by a power-law model with the addition of a soft thermal emission component in varying propor…
The Planet Host Star γ Cephei: Physical Properties, the Binary Orbit, and the Mass of the Substellar Companion
Torres, Guillermo
The bright, K1 III-IV star γ Cep has been reported previously to have a possibly substellar companion in a ~2.5 yr orbit, as well as an unseen stellar companion at a larger separation. We determine for the first time the three-dimensional orbit of the latter, accounting also for the perturbation from the closer object. We combine new and existing …
Revealing the Nature of Algol Disks through Optical and UV Spectroscopy, Synthetic Spectra, and Tomography of TT Hydrae
Peters, Geraldine J.; Miller, Brendan; Budaj, Ján +2 more
We have developed a systematic procedure to study the disks in Algol-type binaries using spectroscopic analysis, synthetic spectra, and tomography. We analyzed 119 Hα spectra of TT Hya, an Algol-type eclipsing interacting binary, collected from 1985 to 2001. The new radial velocities enabled us to derive reliable orbital elements, including a smal…
Speed of Meridional Flows and Magnetic Flux Transport on the Sun
Zhao, Junwei; Kosovichev, Alexander G.; Švanda, Michal
We use the magnetic butterfly diagram to determine the speed of the magnetic flux transport on the solar surface toward the poles. The manifestation of the flux transport is clearly visible as elongated structures extended from the sunspot belt to the polar regions. The slopes of these structures are measured and interpreted as meridional magnetic…
Hydrogen Peroxide on Enceladus
Buratti, B. J.; Jaumann, R.; Momary, T. W. +2 more
Scientists have recently discovered a dynamic, geologically active world in Saturn's icy moon, Enceladus. This small satellite has a south polar hot spot at least 70 K hotter than surrounding regions and a plume of water vapor and ice particles surging from the ``tiger stripe'' cracks that flank the pole. Spectral data of the surface of Enceladus …
New Insights on Interstellar Gas-Phase Iron
Snow, Theodore P.; Jensen, Adam G.
In this paper we report on the gas-phase abundance of singly ionized iron (Fe II) for 51 lines of sight, using data from FUSE. Fe II column densities are derived by measuring the equivalent widths of several UV absorption lines and subsequently fitting those to a curve of growth. Our derivation of Fe II column densities and abundances creates the …