Search Publications
Injection of solar energetic particles into both loop legs of a magnetic cloud
Temmer, M.; Veronig, A.; Gómez-Herrero, R. +4 more
Context. Each of the two Solar TErrestrial RElations Observatory (STEREO) spacecraft carries a Solar Electron and Proton Telescope (SEPT) which measures electrons and protons. Anisotropy observations are provided in four viewing directions: along the nominal magnetic field Parker spiral in the ecliptic towards the Sun (SUN) and away from the Sun (…
Level of helium enhancement among M3's horizontal branch stars
Contreras Ramos, R.; Catelan, M.; Alonso-García, J. +2 more
Context. The color and luminosity distribution of horizontal branch (HB) stars in globular clusters (GCs) are sensitive probes of the original helium abundances of those clusters. In this sense, recently the distributions of HB stars in GC color-magnitude diagrams (CMDs) have been extensively used as indicators of possible variations in the helium…
Quasars can be used to verify the parallax zero-point of the Tycho-Gaia Astrometric Solution
Michalik, Daniel; Lindegren, Lennart
Context. The Gaia project will determine positions, proper motions, and parallaxes for more than one billion stars in our Galaxy. It is known that Gaia's two telescopes are affected by a small but significant variation of the basic angle between them. Unless this variation is taken into account during data processing, e.g. using on-board metrology…
The 3XMM/SDSS Stripe 82 Galaxy Cluster Survey. I. Cluster catalogue and discovery of two merging cluster candidates
Takey, A.; Durret, F.; Mahmoud, E. +1 more
We present a galaxy cluster survey based on XMM-Newton observations that are located in Stripe 82 of the Sloan Digital Sky Survey (SDSS). The survey covers an area of 11.25 deg2. The X-ray cluster candidates were selected as serendipitously extended detected sources from the third XMM-Newton serendipitous source catalogue (3XMM-DR5). A …
First stars of the ρ Ophiuchi dark cloud. XMM-Newton view of ρ Oph and its neighbors
Pillitteri, I.; Wolk, S. J.; Goodman, A. +1 more
Star formation in molecular clouds can be triggered by the dynamical action of winds from massive stars. Furthermore, X-ray and UV fluxes from massive stars can influence the life time of surrounding circumstellar disks. We present the results of a 53 ks XMM-Newton observation centered on the ρ Ophiuchi A+B binary system. ρ Ophiuchi lies in the ce…
Observations of solar flares with IRIS and SDO
Innes, D. E.; Li, D.; Ning, Z. J.
Flare kernels brighten simultaneously in all Solar Dynamics Observatory (SDO) Atmospheric Imaging Assembly (AIA) channels making it difficult to determine their temperature structure. The Interface Region Imaging Spectrograph (IRIS) is able to spectrally resolve Fe xxi emission from cold chromospheric brightenings, so it can be used to infer the a…
Glancing through the accretion column of EXO 2030+375
Klochkov, Dmitry; Ferrigno, Carlo; Zdziarski, Andrzej A. +3 more
Context. The current generation of X-ray instruments progressively reveals more and more details about the complex magnetic field topology and the geometry of the accretion flows in highly magnetized accretion-powered pulsars.
Aims: We took advantage of the large collecting area and good timing capabilities of the EPIC cameras onboard XMM-New…
The segregation of starless and protostellar clumps in the Hi-GAL ℓ = 224° region
Elia, D.; Olmi, L.; Cunningham, M. +1 more
Context. Stars form in dense, dusty structures, which are embedded in larger clumps of molecular clouds often showing a clear filamentary structure on large scales (≳1 pc). The origin (e.g., turbulence or gravitational instabilities) and evolution of these filaments, as well as their relation to clump and core formation, are not yet fully understo…
Velocity resolved [C II] spectroscopy of the center and the BCLMP 302 region of M 33 (HerM 33es)
Braine, J.; Ossenkopf, V.; van der Werf, P. +8 more
Context. The forbidden fine structure transition of C+ at 158 µm is one of the major cooling lines of the interstellar medium (ISM).
Aims: We aim to understand the contribution of the ionized, atomic, and molecular phases of the ISM to the [C II] emission from clouds near the dynamical center and the BCLMP302 H II region in t…
Mildly obscured active galaxies and the cosmic X-ray background
Walter, R.; Esposito, V.
Context. The diffuse cosmic X-ray background (CXB) is the sum of the emission of discrete sources, mostly massive black-holes accreting matter in active galactic nuclei (AGN). The CXB spectrum differs from the integration of the spectra of individual sources, calling for a large population, undetected so far, of strongly obscured Compton-thick AGN…