Search Publications
Modulated X-ray emission of the magnetic O8.5V-star Tr16-22
Wade, Gregg A.; Nazé, Yaël; Petit, Véronique
Using an extensive X-ray dataset, we analyzed the X-ray emission of the massive O-star Tr16-22, which was recently found to be magnetic. Its bright X-ray emission is found to be modulated with a ~54 d period. This timescale should represent the rotational timescale of the star, as it does for other magnetic massive stars. In parallel, new spectrop…
The Herschel Virgo Cluster Survey. XV. Planck submillimetre sources in the Virgo Cluster
Clements, D. L.; González-Nuevo, J.; Herranz, D. +21 more
We cross-correlate the Planck Catalogue of Compact Sources (PCCS) with the fully sampled 84 deg2Herschel Virgo Cluster Survey (HeViCS) fields. We search for and identify the 857 and 545 GHz PCCS sources in the HeViCS fields by studying their FIR/submm and optical counterparts. We find 84 and 48 compact Planck sources in the HeViCS field…
Non-LTE models for synthetic spectra of type Ia supernovae. III. An accelerated lambda-iteration procedure for the mutual interaction of strong spectral lines in SN Ia models with and without energy deposition
Pauldrach, A. W. A.; Hoffmann, T. L.; Hultzsch, P. J. N.
Context. In type Ia supernova (SN Ia) envelopes a huge number of lines of different elements overlap within their thermal Doppler widths, and this problem is exacerbated by the circumstance that up to 20% of these lines can have a line optical depth higher than 1. The stagnation of the lambda iteration in such optically thick cases is one of the f…
Multifrequency constraints on the nonthermal pressure in galaxy clusters
Colafrancesco, S.; Marchegiani, P.; Mhlahlo, N. +1 more
Context. The origin of radio halos in galaxy clusters is still unknown and is the subject of a vibrant debate from both observational and theoretical points of view. In particular, the amount and the nature of nonthermal plasma and of the magnetic field energy density in clusters hosting radio halos is still unclear.
Aims: The aim of this pap…
Solar wind He pickup ions as source of tens-of-keV/n neutral He atoms observed by the HSTOF/SOHO detector
Hilchenbach, M.; Czechowski, A.; Grzedzielski, S. +1 more
Context. Since 1996, during periods of low solar activity, the HSTOF instrument on board the SOHO satellite has been measuring weak fluxes of He atoms of 28-58 keV/n (helium energetic neutral atoms, He ENAs). The probable source region is the inner heliosheath.
Aims: We aim to understand the emission mechanism of He ENAs based on knowledge of…
PRISM: Recovery of the primordial spectrum from Planck data
Starck, J. -L.; Sureau, F.; Bobin, J. +3 more
Aims: The primordial power spectrum describes the initial perturbations that seeded the large-scale structure we observe today. It provides an indirect probe of inflation or other structure-formation mechanisms. In this Letter, we recover the primordial power spectrum from the Planck PR1 dataset, using our recently published algorithm PRISM. …
Earth occultation imaging of the low energy gamma-ray sky with GBM
Wilson-Hodge, C. A.; Camero-Arranz, A.; Rodi, J. +5 more
Aims: The Earth Occultation Technique (EOT) has been applied to Fermi's Gamma-ray Burst Monitor (GBM) to perform all-sky monitoring for a predetermined catalog of hard X-ray/soft γ-ray sources. In order to search for sources not in the catalog, thus completing the catalog and reducing a source of systematic error in EOT, an imaging method has…
Disk emission and atmospheric absorption lines in black hole candidate 4U 1630-472
Różańska, A.; Madej, J.; Bagińska, P. +2 more
Context. We analyzed Suzaku data of the black hole candidate 4U 1630-472 when it was in the high/soft state. The source, known for X-ray outbursts and for absorption dips, has an X-ray continuum spectrum that is interpreted correctly as emission from an accretion disk. Additionally, two absorption lines from He and H-like iron have been clearly de…
Phase-resolved X-ray spectroscopy and spectral energy distribution of the X-ray soft polar RS Caeli
Burwitz, V.; Walter, F. M.; Schwope, A. D. +3 more
Context. RS Cae is the third target in our series of XMM-Newton observations of soft X-ray-dominated polars.
Aims: Our observational campaign aims to better understand and describe the multiwavelength data, the physical properties of the system components, and the short- and long-term behavior of the component fluxes in RS Cae.
Methods: …
The young binary HD 102077: Orbit, spectral type, kinematics, and moving group membership
Henning, Thomas; Reffert, Sabine; Schlieder, Joshua E. +4 more
The K-type binary star HD 102077 was proposed as a candidate member of the TW Hydrae association (TWA) which is a young (5-15 Myr) moving group in close proximity (~50 pc) to the solar system. The aim of this work is to verify this hypothesis by different means. We first combine diffraction-limited observations from the ESO NTT 3.5 m telescope in …