Search Publications
Search for grain growth toward the center of L1544
Désert, F. -X.; Spaans, M.; Caselli, P. +4 more
In dense and cold molecular clouds dust grains are surrounded by thick icy mantles. It is not clear, however, if dust growth and coagulation take place before the protostar switches on. This is an important issue as the presence of large grains may affect the chemical structure of dense cloud cores, including the dynamically important ionization f…
[Ultra] luminous infrared galaxies selected at 90 µm in the AKARI deep field: a study of AGN types contributing to their infrared emission
Buat, V.; Małek, K.; Burgarella, D. +6 more
Aims: The aim of this work is to characterize physical properties of ultra luminous infrared galaxies (ULIRGs) and luminous infrared galaxies (LIRGs) detected in the far-infrared (FIR) 90 µm band in the AKARI Deep Field-South (ADF-S) survey. In particular, we want to estimate the active galactic nucleus (AGN) contribution to the LIRGs a…
Hydrogen in diffuse molecular clouds in the Milky Way. Atomic column densities and molecular fraction along prominent lines of sight
Menten, K. M.; Gerin, M.; Wyrowski, F. +6 more
Context. Recent submillimeter and far-infrared wavelength observations of absorption in the rotational ground-state lines of various simple molecules against distant Galactic continuum sources have opened the possibility of studying the chemistry of diffuse molecular clouds throughout the Milky Way. In order to calculate abundances, the column den…
XMM-Newton spectroscopy of the accreting magnetar candidate 4U0114+65
Torrejón, J. M.; Postnov, K.; Oskinova, L. +3 more
Aims: 4U0114+65 is one of the slowest known X-ray pulsars. We present an analysis of a pointed observation by the XMM-Newton X-ray telescope in order to study the nature of the X-ray pulsations and the accretion process, and to diagnose the physical properties of the donor's stellar wind.
Methods: We analysed the energy-resolved light cu…
Temperature and density structure of a recurring active region jet
Del Zanna, Giulio; Mulay, Sargam M.; Mason, Helen
Aims: We present a study of a recurring jet observed on October 31, 2011 by the Atmosphereic Imaging Assembly (AIA) on board the Solar Dynamic Observatory, the X-ray Telescope (XRT) and EUV Imaging Spectrometer (EIS) on board Hinode. We discuss the physical parameters of the jet that are obtained using imaging and spectroscopic observations, …
Far-UV spectroscopy of two extremely hot, helium-rich white dwarfs
Rauch, T.; Werner, K.; Kruk, J. W.
A large proportion of hot post-asymptotic giant branch stars and white dwarfs (WDs) are hydrogen-deficient. Two distinct evolutionary sequences have been identified. One of them comprises stars of spectral type [WC] and PG1159, and it originates from a late helium-shell flash, creating helium-rich stellar atmospheres with significant admixtures of…
From the core to the outskirts: structure analysis of three massive galaxy clusters
Böhringer, H.; Chon, G.; Foëx, G.
Aims: The hierarchical model of structure formation is a key prediction of the Λ cold dark matter model, which can be tested by studying the large-scale environment and the substructure content of massive galaxy clusters. We present here a detailed analysis of the clusters RXC J0225.9-4154, RXC J0528.9-3927, and RXC J2308.3-0211, as part of a…
Comparison of acoustic travel-time measurements of solar meridional circulation from SDO/HMI and SOHO/MDI
Gizon, Laurent; Liang, Zhi-Chao; Birch, Aaron C. +2 more
Context. Time-distance helioseismology is one of the primary tools for studying the solar meridional circulation, especially in the lower convection zone. However, travel-time measurements of the subsurface meridional flow suffer from a variety of systematic errors, such as a center-to-limb variation and an offset due to the position angle (P-angl…
Hale cycle and long-term trend in variation of galactic cosmic rays related to solar rotation
Mursula, K.; Gil, A.
Context. Galactic cosmic ray (GCR) intensities around solar minimum times are modulated by magnetic drifts that depend on the overall solar polarity. GCR intensities reach a higher but more narrow peak during negative minima than during positive minima. However, despite these higher intensities, the variation of GCRs over timescales of solar rotat…
Interplay of dust alignment, grain growth, and magnetic fields in polarization: lessons from the emission-to-extinction ratio
Boulanger, F.; Guillet, V.; Jones, A. P. +1 more
Context. Polarized extinction and emission from dust in the interstellar medium (ISM) are hard to interpret, as their dependence on dust optical properties, grain alignment, and magnetic field orientation is complex. This is particularly true in molecular clouds. The aforementioned phenomena are usually considered independently in polarization stu…