Search Publications
The eccentric short-period orbit of the supergiant fast X-ray transient HD 74194 (=LM Vel)
Gamen, R.; Maíz Apellániz, J.; Alfaro, E. J. +5 more
Aims. We present the first orbital solution for the O-type supergiant star HD 74194, which is the optical counterpart of the supergiant fast X-ray transient IGR J08408-4503. Methods. We measured the radial velocities in the optical spectrum of HD 74194, and we determined the orbital solution for the first time. We also analysed the complex Hα prof…
Fragmentation and kinematics of dense molecular cores in the filamentary infrared-dark cloud G011.11-0.12
Henning, Thomas; Beuther, Henrik; Ragan, Sarah E. +2 more
We present new Plateau de Bure Interferometer observations of a region in the filamentary infrared-dark cloud (IRDC) G011.11-0.12 containing young, star-forming cores. In addition to the 3.2 mm continuum emission from cold dust, we map this region in the N2H+(1-0) line to trace the core kinematics with an angular resolution o…
A possible cyclotron resonance scattering feature near 0.7 keV in X1822-371
Sanna, A.; Robba, N. R.; Ferrigno, C. +9 more
Context. The source X1822-371 is a low-mass X-ray binary system (LMXB) viewed at a high inclination angle. It hosts a neutron star with a spin period of ~0.59 s, and recently, the spin period derivative was estimated to be (-2.43 ± 0.05) × 10-12 s/s.
Aims: Our aim is to address the origin of the large residuals below 0.8 keV previo…
Low CO/CO2 ratios of comet 67P measured at the Abydos landing site by the Ptolemy mass spectrometer
Mousis, O.; Andrews, D.; Morse, A. +4 more
Comets are generally considered to contain the best-preserved material from the beginning of our planetary system, although the mechanism of their formation and subsequent evolution are still poorly understood. Here we report the direct in situ measurement of H2O, CO, and CO2 by the Ptolemy mass spectrometer onboard the Phila…
Redshifted Fe Kα line from the unusual γ-ray source PMN J1603-4904
Stawarz, Ł.; Dauser, T.; Wilms, J. +13 more
Context. Multiwavelength observations have revealed the highly unusual properties of the γ-ray source PMN J1603-4904, which are difficult to reconcile with any other well-established γ-ray source class. The object is either a very atypical blazar or a compact jet source seen at a larger angle to the line of sight.
Aims: To determine the physi…
Calibration and in-orbit performance of the reflection grating spectrometer onboard XMM-Newton
Kaastra, J. S.; Raassen, A. J. J.; de Vries, C. P. +6 more
Context. XMM-Newton was launched on 10 December 1999 and has been operational since early 2000. One of the instruments onboard XMM-Newton is the reflection grating spectrometer (RGS). Two identical RGS instruments are available, with each RGS combining a reflection grating assembly and a camera with charge-coupled devices to record the spectra.
When is pile-up important in the XMM-Newton EPIC cameras?
Guainazzi, M.; Rodriguez-Pascual, P.; Stuhlinger, M. +2 more
Context. Pile-up in X-ray charged couple device (CCD) detectors is defined as the reconstruction of independent events in the same detection cell as a single event during a read-out cycle. Pile-up can seriously compromise the spectral performance, modifying both the flux and the spectral shape of celestial sources.
Aims: In this paper we defi…
A variable-density absorption event in NGC 3227 mapped with Suzaku and Swift
Guainazzi, M.; Elvis, M.; Miniutti, G. +15 more
Context. The morphology of the circumnuclear gas accreting onto supermassive black holes in Seyfert galaxies remains a topic of much debate. As the innermost regions of active galactic nuclei (AGN) are spatially unresolved, X-ray spectroscopy, and in particular line-of-sight absorption variability, is a key diagnostic to map out the distribution o…
The evolution of galaxy star formation activity in massive haloes
Finoguenov, A.; Berta, S.; Magnelli, B. +20 more
Context. There is now a large consensus that the current epoch of the cosmic star formation history (CSFH) is dominated by low mass galaxies while the most active phase, between redshifts 1 and 2, is dominated by more massive galaxies, which evolve more quickly.
Aims: Massive galaxies tend to inhabit very massive haloes, such as galaxy groups…
Anatomy of the AGN in NGC 5548. V. A clear view of the X-ray narrow emission lines
Kaastra, J. S.; Kriss, G. A.; Bianchi, S. +15 more
Context. Our consortium performed an extensive multi-wavelength campaign of the nearby Seyfert 1 galaxy NGC 5548 in 2013-14. The source appeared unusually heavily absorbed in the soft X-rays, and signatures of outflowing absorption were also present in the UV. He-like triplets of neon, oxygen and nitrogen, and radiative recombination continuum (RR…