Search Publications
Measurements of spectral lines observed with Hinode/EIS as implications for coronal heating
Li, Ying; Ding, Ming-De
We have measured the line widths and nonthermal velocities in 12 solar regions using high resolution EUV data taken by Hinode/EIS. We find that there exists a positive correlation between the intensity and nonthermal velocity for the Fe XII emission line as well as some other lines. The correlation coefficients decrease from the disk center to the…
Analysis of extremely low signal-to-noise ratio data from INTEGRAL/PICsIT
Lubiński, P.
Context: The PICsIT detector onboard the INTEGRAL satellite was designed to provide information about emission in the soft γ-ray band for many bright sources. Due to strong and variable instrumental background, only 4 objects have been detected so far using standard software.
Aims: The moderate sensitivity of PICsIT can be compensated for in t…
Implications of Temporal Development of Localized Ultraviolet and Hard X-ray Emission for Large Solar Flares
Alexander, David; Coyner, Aaron J.
Ultraviolet and hard X-ray (HXR) emissions in solar flares provide observational signatures of the interaction of flare-accelerated particles with the chromospheric plasma. Earlier studies have shown clear evidence of temporal and spatial relationships between UV and HXR emission, suggesting a common physical origin. However, more recent spatially…
Processes of auroral thermal structure at Jupiter: Analysis of multispectral temperature observations with the Jupiter Thermosphere General Circulation Model
Waite, J. H.; Gladstone, G. R.; Bougher, S. W. +1 more
We use our three-dimensional Jupiter Thermosphere General Circulation Model (JTGCM) to quantify thermal processes that take place in the auroral thermosphere. These processes tend to control the thermal budget in the Jovian ovals and polar caps and maintain thermospheric temperatures consistent with those derived from multispectral observations of…
The supergiant fast X-ray transient IGRJ18483-0311 in quiescence: XMM-Newton, Swift and Chandra observations
Campana, S.; Israel, G.; Stella, L. +7 more
IGRJ18483-0311 was discovered with INTEGRAL in 2003 and later classified as a supergiant fast X-ray transient. It was observed in outburst many times, but its quiescent state is still poorly known. Here, we present the results of XMM-Newton, Swift and Chandra observations of IGRJ18483-0311. These data improved the X-ray position of the source, and…
On the Origin of TeV Gamma-Ray Emission from HESS J1834-087
Gotthelf, E. V.; Mukherjee, R.; Halpern, J. P.
We present an X-ray study of the field containing the extended TeV source HESS J1834-087 using data obtained with the XMM-Newton telescope. Previously, the coincidence of this source with both the shell-type supernova remnant (SNR) W41 and a giant molecular cloud (GMC) was interpreted as favoring π0-decay γ-rays from interaction of the …
On the Accretion Rates of SW Sextantis Nova-like Variables
Sion, Edward M.; Ballouz, Ronald-Louis
We present accretion rates for selected samples of nova-like variables having IUE archival spectra and distances uniformly determined using an infrared method by Knigge. A comparison with accretion rates derived independently with a multiparametric optimization modeling approach by Puebla et al. is carried out. The accretion rates of SW Sextantis …
Ionospheric corrections of MARSIS subsurface sounding signals with filters including collision frequency
Nielsen, Erling; Orosei, Roberto; Zhang, Zhenfei +2 more
Ionospheric corrections of Mars advanced radar for subsurface and ionosphere sounding (MARSIS) subsurface sounding signals are necessary before they can be further analyzed. Usually the ionosphere correction only considers the phase dispersion owing to the electron densities. In this paper we show that if the electron-neutral collision frequency i…
What Physical Processes Drive the Interstellar Medium in the Local Bubble?
Dettbarn, C.; Breitschwerdt, D.; Fuchs, B. +1 more
Recent 3D high-resolution simulations of the interstellar medium in a star forming galaxy like the Milky Way show that supernova explosions are the main driver of the structure and evolution of the gas. Its physical state is largely controlled by turbulence due to the high Reynolds numbers of the average flows. For a constant supernova rate a dyna…
Discovery of a rapidly pulsating subdwarf B star candidate in ω Centauri
Bono, G.; Calamida, A.; Randall, S. K.
We report the discovery of the first variable extreme horizontal branch star in a globular cluster (ω Cen). The oscillation uncovered has a period of 114 s and an amplitude of 32 mmag. A comparison between horizontal branch models and observed optical colours indicates an effective temperature of 31 500 ± 6300 K for this star, placing it within th…