Search Publications
New deep XMM-Newton observations to the west of the σ Orionis cluster
Caballero, J. A.; López-Santiago, J.
Aims: The objective of this study is to determine the general X-ray properties of the young stars in the external regions of the σ Orionis cluster (τ ~ 3 Ma, d ~ 385 pc) and determine constraints on the X-ray emission of brown dwarfs.
Methods: We carried out a careful analysis of public data obtained from an unexplored region to the west of th…
Doppler imaging an X-ray flare on the ultrafast rotator BO Mic. A contemporaneous multiwavelength study using XMM-Newton and VLT
Schmitt, J. H. M. M.; Wolter, U.; Robrade, J. +1 more
We present an analysis of contemporaneous photospheric, chromospheric and coronal structures on the
highly active K-dwarf star BO Mic (Speedy Mic). We concentrate on a moderate flare that we localize in the stellar atmosphere and study its energetics, size and thermal behavior. The analysis is based on strictly simultaneous X-r…INTEGRAL detection of the pulsar wind nebula in PSR J1846-0258
de Rosa, A.; Hill, A. B.; Bird, A. J. +6 more
Aims:We communicate the detection of soft (20-200 keV) γ-rays from the pulsar and pulsar wind nebula of PSR J1846-0258 and aim to identify the component of the system which is responsible for the γ-ray emission.
Methods: We combine spectral information from the INTEGRAL γ-ray mission with archival data from the Chandra X-ray Observatory to pin…
Evidence for metallicity spreads in three massive M 31 globular clusters
Jablonka, P.; Sarajedini, A.; Meylan, G. +3 more
Aims: We quantify the intrinsic width of the red giant branches of three massive globular clusters in M 31 in a search for metallicity spreads within these objects.
Methods: We present HST/ACS observations of three massive clusters in M 31, G78, G213, and G280. A thorough description of the photometry extraction and calibration is presented. A…
A reinterpretation of the energy balance in active region loops following new results from Hinode EIS
Bradshaw, S. J.
Context: New observations made by the Hinode EUV Imaging Spectrometer have revealed persistent redshifts in solar active region loops in the temperature range 105.6 ≤ T ≤ 106.4 K. The presence of redshifts, interpreted as bulk downflows, indicates that the loops are undergoing radiative cooling rather than continuous heating.…
XMM-Newton observations of ζ Orionis (O9.7 Ib): a collisional ionization equilibrium model
Raassen, A. J. J.; van der Hucht, K. A.; Cassinelli, J. P. +1 more
We present XMM-Newton observations of the O supergiant ζ Orionis (O9.7 Ib). The spectra are rich in emission lines over a wide range of ionization stages. The rgs spectra show for the first time lines of low ion stages such as C VI, N VI, N VII, and O VII. The line profiles are symmetric and rather broad ({{FWHM}}≈ 1500 km s-1) and show…
XMM-Newton observations of the Small Magellanic Cloud: Long term evolution of frequently observed Be/X-ray binaries
Haberl, F.; Eger, P.
Aims: To follow the long term evolution of Be/X-ray binaries in the Small Magellanic Cloud (SMC) we analyzed twenty-two XMM-Newton observations towards the calibration target 1E 0102.2-7218 and seven observations towards the neighboring region around the eclipsing binary HD 5980.
Methods: The data from the European Photon Imaging Cameras (EPIC…
XMM-Newton observations of the Galactic globular clusters NGC 2808 and NGC 4372
Servillat, M.; Webb, N. A.; Barret, D.
Aims:Galactic globular clusters harbour binary systems that are detected as faint X-ray sources. These close binaries are thought to play an important role in the stability of the clusters by liberating energy and delaying the inevitable core collapse of globular clusters. The inventory of close binaries and their identification is therefore essen…
Embedded clusters in NGC 1808 central starburst. Near-infrared imaging and spectroscopy
Alloin, D.; Galliano, E.
Context: In the course of a mid-infrared imaging campaign of close-by active galaxies, we discovered the mid-infrared counterparts of bright compact radio sources in the central star-forming region of NGC 1808.
Aims: We aim at confirming that these sources are deeply embedded, young star clusters and at deriving some of their intrinsic propert…
Imaging ejecta from the final flash star V605 Aquilae
Lebzelter, T.; Hinkle, K. H.; Joyce, R. R. +4 more
Aims:We investigated the cloud of ejecta resulting from the mass loss associated with the final helium shell flash in V605 Aql.
Methods: V605 Aql was imaged at high spatial resolution in both optical emission lines and the infrared continuum using HST/WFPC2 and Gemini/Hokupa'a+QUIRC, respectively. The He I 10 830 Å spectrum was also observed. …