Search Publications
The discovery of the 401 Hz accreting millisecond pulsar IGR J17498-2921 in a 3.8 h orbit
Belloni, T.; Ferrigno, C.; Papitto, A. +6 more
We report on the detection of a 400.99018734(1) Hz coherent signal in the Rossi X-ray Timing Explorer (RXTE) light curves of the recently discovered X-ray transient,
Fe Kα line emission from the Arches cluster region - evidence for ongoing particle bombardment?
Capelli, R.; Warwick, R. S.; Porquet, D. +2 more
Context. Bright Fe-Kα line emission at 6.4 keV is a unique characteristic of some of the dense molecular complexes present in the Galactic center region. Whether this X-ray fluorescence is due largely to the irradiation of the clouds by X-ray photons or is, at least in part, the result of cosmic-ray particle bombardment, remains an inte…
Inhomogeneous metal distribution in the intracluster medium
Lovisari, L.; Schindler, S.; Kapferer, W.
Context. The hot gas that fills the space between galaxies in clusters is rich in metals. In their large potential wells, galaxy clusters accumulate metals over the whole cluster history and hence retain important information on cluster formation and evolution.
Aims: We use a sample of five cool core clusters to study the distribution of meta…
The mid-infrared diameter of W Hydrae
Quirrenbach, A.; Lopez, B.; Leinert, C. +2 more
Aims: Asymptotic giant branch (AGB) stars are among the largest distributors of dust into the interstellar medium, and it is therefore important to understand the dust formation process and sequence in their strongly pulsating extended atmosphere. By monitoring the AGB star W Hya interferometrically over a few pulsations cycles, the upper atm…
The globular cluster systems of Abell 1185
Côté, P.; Blakeslee, J. P.; Jordán, A. +4 more
We examine the properties of a previously discovered population of globular clusters in the heart of the rich galaxy cluster Abell 1185 that might be intergalactic in nature. Deep images obtained with the Advanced Camera for Surveys (ACS) aboard Hubble Space Telescope (HST) confirm the presence of ~1300 globular clusters brighter than IF814W<…
IGR J17361-4441: a possible new accreting X-ray binary in NGC 6388
Rodriguez, J.; Ferrigno, C.; Papitto, A. +7 more
IGR J17361-4441 is a newly discovered INTEGRAL hard X-ray transient, located in the globular cluster NGC 6388. We report here the results of the X-ray and radio observations performed with Swift, INTEGRAL, RXTE, and the Australia Telescope Compact Array (ATCA) after the discovery of the source on 2011 August 11. In the X-ray domain, IGR J17361-444…
Diagnostics of the κ-distribution using Si III lines in the solar transition region
Dzifčáková, E.; Kulinová, A.
Aims: The solar transition region satisfies the conditions for appearance of the non-thermal κ-distribution. We aim to prove the occurrence of the non-thermal κ-distribution in the solar transition region and diagnose its parameters.
Methods: The intensity ratios of Si iii lines observed by SUMER in 1100-1320 Å region do not correspond t…
Quiet-Sun imaging asymmetries in Na I D1 compared with other strong Fraunhofer lines
Leenaarts, J.; Carlsson, M.; Rouppe van der Voort, L. H. M. +3 more
Imaging spectroscopy of the solar atmosphere using the Na I D1 line yields marked asymmetry between the blue and red line wings: sampling a quiet-Sun area in the blue wing displays reversed granulation, whereas sampling in the red wing displays normal granulation. The Mg I b2 line of comparable strength does not show this asy…
X-ray observations of PKS 0745-191 at the virial radius: are we there yet?
Rossetti, M.; Molendi, S.; Gastaldello, F. +1 more
Aims: We reassess the properties of the ICM at large radii in the galaxy cluster PKS 0745-191 in light of recent Suzaku measurements.
Methods: We analyze an archival 10.5 ks ROSAT/PSPC observation to extract the surface-brightness profile of PKS 0745-191 and infer the deprojected density profile. We then compare the ROSAT surface-brightn…
A large Hα line forming region for the massive interacting binaries β Lyrae and υ Sagitarii
Chesneau, O.; Goldfinger, P. J.; Sturmann, J. +16 more
Aims: This study aims at constraining the properties of two interacting binary systems by measuring their continuum-forming region in the visible and the forming regions of some emission lines, in particular Hα, using optical interferometry.
Methods: We have obtained visible medium (R ~ 1000) spectral resolution interferometric observati…