Search Publications
The brightness of magnetic field concentrations in the quiet Sun
Schnerr, R. S.; Spruit, H. C.
In addition to the "facular" brightening of active regions, the quiet Sun also contains a small scale magnetic field with associated brightenings in continuum radiation. We measure this contribution of quiet regions to the Sun's brightness from high spatial resolution (0.16 arcsec-0.32 arcsec) observations of the Swedish 1-m Solar Telescope (SST) …
High ions towards white dwarfs: circumstellar line shifts and stellar temperature
Barstow, M. A.; Lallement, R.; Welsh, B. Y. +1 more
Aims: Our aim is to gain new insights into highly ionized gas towards nearby hot white dwarfs (WDs). The detection of absorption lines of highly ionized interstellar (IS) species in their spectra is the main diagnostic tool of the hot IS gas phase. This requires disentangling IS ions from photospheric or circumstellar (CS) ions, and thus thei…
Transiting exoplanets from the CoRoT space mission. XVII. The hot Jupiter CoRoT-17b: a very old planet
Mazeh, T.; Aigrain, S.; Alonso, R. +49 more
We report on the discovery of a hot Jupiter-type exoplanet, CoRoT-17b, detected by the CoRoT satellite. It has a mass of 2.43 ± 0.30 MJup and a radius of 1.02 ± 0.07 RJup, while its mean density is 2.82 ± 0.38 g/cm3. CoRoT-17b is in a circular orbit with a period of 3.7681 ± 0.0003 days. The host star is an old (10…
Dark matter halos around isolated ellipticals
Babić, A.; Memola, E.; Salucci, P.
Aims: We investigate the distribution of the luminous and the dark matter components in the isolated ellipticals NGC 7052 and NGC 7785, which are embedded in an emitting hot gas halo, by means of relevant X-ray and photometric data.
Methods: To calculate the dark matter distribution in these rare objects, we performed an improved X-ray a…
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…