Search Publications

Inferring the Coronal Density Irregularity from EUV Spectra

Hahn, M.; Savin, D. W.

Understanding the density structure of the solar corona is important for modeling both coronal heating and the solar wind. Direct measurements are difficult because of line-of-sight integration and possible unresolved structures. We present a new method for quantifying such structures using density-sensitive extreme ultraviolet line intensities to…

Cosmic ray dose monitoring using RadFET sensors of the Rosetta instruments SESAME and COSIMA

Fischer, Henning; Koch, Andreas; Seidensticker, Klaus J. +5 more

On its more than 10 years journey to comet 67P/Churyumov-Gerasimenko, Rosetta carried RadFET ionising dose monitors in the central electronics of the orbiter instrument COSIMA and the lander instrument SESAME. The readings of the dosimeters were corrected for the temperature of the devices during measurements. Because the sensitivity of RadFETs de…

Abundance analysis of the supergiant stars HD 80057 and HD 80404 based on their UVES Spectra

Baştürk, Ö.; Tanrıverdi, T.

This study presents elemental abundances of the early A-type supergiant HD 80057 and the late A-type supergiant HD 80404. High resolution and high signal-to-noise ratio spectra published by the UVES Paranal Observatory Project (Bagnulo et al., 2003) were analyzed to compute their elemental abundances using ATLAS9 (Kurucz, 1993; 2005; Sbordone et a…

Fine structures at pore boundary

Bharti, L.; Quintero Noda, C.; Joshi, C. +2 more

We present high resolution observations of fine structures at pore boundaries. The inner part of granules towards umbra show dark striations which evolve into a filamentary structure with dark core and `Y' shape at the head of the filaments. These filaments migrate into the umbra similar to penumbral filaments. These filaments show higher temperat…

Command and data management system (CDMS) of the Philae lander

Schmidt, W.; Balázs, A.; Baksa, A. +9 more

The paper covers the principal requirements, design concepts and implementation of the hardware and software for the central on-board computer (CDMS) of the Philae lander in the context of the ESA Rosetta space mission, including some technical details. The focus is on the implementation of fault tolerance, autonomous operation and operational fle…

Radial velocity dispersions of star groups in M 67

Vereshchagin, S. V.; Chupina, N. V.

High-precision measurements of radial velocities of the M 67 cluster members are used to calculate the radial-velocity dispersions in the stellar groups found earlier in the cluster's corona. The previously detected feature in one of the groups (Group 60) consisting of stars with almost identical space velocities was confirmed. The possibility of …

Ion energy distributions and densities in the plume of Enceladus

Omidi, Nojan; Waite, J. Hunter; Cravens, Thomas E. +2 more

Enceladus has a dynamic plume that is emitting gas, including water vapor, and dust. The gas is ionized by solar EUV radiation, charge exchange, and electron impact and extends throughout the inner magnetosphere of Saturn. The charge exchange collisions alter the plasma composition. Ice grains (dust) escape from the vicinity of Enceladus and form …

Rough-Wall Heat Flux Augmentation Analysis Within the ExoMars Project

Gülhan, A.; Neeb, D.; Merrifield, J. A.

The Intragroup versus the Intracluster Medium

Lapi, A.; Cavaliere, A.; Fusco-Femiano, R.

Galaxy groups differ from clusters primarily by way of their lower masses, M ∼ 10¹⁴ M _⊙ versus M ∼ 10¹⁵ M _⊙. We discuss how mass affects the thermal state of the intracluster or the intragroup medium, specifically as to their entropy levels and radial profiles. We show that entropy is produced in both ca…

A Search for Coronal Activity Among Two Metal-poor Subdwarfs and One Subgiant

Dupree, Andrea K.; Smith, Graeme H.; Günther, Hans Moritz

A search has been made using the XMM-Newton satellite for coronal soft X-ray emission from HD 19445, HD 25329, and HD 140283, three Population II stars in the Galactic halo having metallicities of {{[Fe/H]}}∼ -2. The program stars, consisting of two subdwarfs and one metal-poor subgiant, were pre-selected from ground-based observations to have He …