Search Publications
On the Nature of the Spectral Line Broadening in Solar Coronal Dimmings
Zhukov, A. N.; Dolla, L. R.
We analyze the profiles of iron emission lines observed in solar coronal dimmings associated with coronal mass ejections, using the EUV Imaging Spectrometer on board Hinode. We quantify line profile distortions with empirical coefficients (asymmetry and peakedness) that compare the fitted Gaussian to the data. We find that the apparent line broade…
Recent tectonics and subsidence on Mars: Hints from Aureum Chaos
van Gasselt, Stephan; Hauber, Ernst; Rossi, Angelo Pio +1 more
High spatial and spectral resolution imagery and topography collected during the last decade are changing our vision of Mars into that of a geologically active planet, even in recent times. However, the connection between internal activity such as faulting and other recent geomorphic processes and deposits, such as eolian or mass wasting units, is…
Atmospheric angular momentum variations of Earth, Mars and Venus at seasonal time scales
Lambert, S.; Rosenblatt, P.; Le Maistre, S. +4 more
Atmospheric angular momentum variations of a planet are associated with the global atmospheric mass redistribution and the wind variability. The exchange of angular momentum between the fluid layers and the solid planet is the main cause for the variations of the planetary rotation at seasonal time scales. In the present study, we investigate the …
A molecular cloud within the light echo of V838 Monocerotis
Deguchi, S.; Tylenda, R.; Kamiński, T.
Context. V838 Mon is an eruptive variable, which exploded in 2002. It displayed the most spectacular light echo ever observed. However, neither the origin of the reflecting matter nor the nature of the 2002 outburst have been firmly constrained.
Aims: We investigate the nature of the CO radio emission detected in the field of the light echo. …
Plasma Heating in the Very Early and Decay Phases of Solar Flares
Siarkowski, M.; Falewicz, R.; Rudawy, P.
In this paper, we analyze the energy budgets of two single-loop solar flares under the assumption that non-thermal electrons (NTEs) are the only source of plasma heating during all phases of both events. The flares were observed by RHESSI and GOES on 2002 September 20 and 2002 March 17, respectively. For both investigated flares we derived the ene…
X-ray spectroscopy of the Compton-thick Seyfert 2 ESO 138 - G1
Fiore, F.; Bianchi, S.; Vignali, C. +2 more
We report on our analysis of XMM-Newton observations of the Seyfert 2 galaxy ESO 138-G1(z = 0.0091). These data reveal a complex spectrum in both its soft and hard portions. The 0.5-2 keV band is characterized by a strong "soft-excess" component with several emission lines, as commonly observed in other narrow-line AGN. Above 3 keV, a power-law fi…
Non-LTE radiative transfer for sub-millimeter water lines in Comet 67P/Churyumov-Gerasimenko
Kamp, Lucas; Gulkis, Samuel; Lee, Seungwon +2 more
The European Space Agency (ESA) Rosetta spacecraft (Schulz, R., Alexander, C., Boehnhardt, H., Glassmeier, K.H. (Eds.) [2009]. "ROSETTA - ESA") will encounter Comet 67P/Churyumov-Gerasimenko in 2014 and spend the next 18 months in the vicinity of the comet, permitting very high spatial and spectral resolution observations of the coma and nucleus. …
The high resolution X-ray spectrum of SNR 0506-68 using XMM-Newton
Vink, J.; Broersen, S.; Raymond, J. +1 more
Aims: We study the supernova remnant 0506-68 in order to obtain detailed information about, among other things, the ionisation state and age of the ionised plasma.
Methods: Using the Reflection Grating Spectrometer (RGS) onboard the XMM-Newton satellite we are able to take detailed spectra of the remnant. In addition, we use the MOS data…
The planetary nebulae population in the central regions of M32: the SAURON view
Bacon, Roland; Emsellem, Eric; Sarzi, Marc +4 more
Extragalactic planetary nebulae (PNe) are not only useful as distance signposts or as tracers of the dark matter content of their host galaxies, but constitute also good indicators of the main properties of their parent stellar populations. Yet, so far, the properties of PNe in the optical regions of galaxies where stellar population gradients can…
NICMOS Polarimetry of "Polar-scattered" Seyfert 1 Galaxies
Alexander, D. M.; Batcheldor, D.; Young, S. +5 more
The nuclei of Seyfert 1 galaxies exhibit a range of optical polarization characteristics that can be understood in terms of two scattering regions producing orthogonal polarizations: an extended polar scattering region (PSR) and a compact equatorial scattering region (ESR), located within the circum-nuclear torus. Here we present NICMOS 2.0 µ…