Search Publications
Precision cosmology with a wide area XMM cluster survey
Pierre, M.; Clerc, N.; Pacaud, F. +4 more
We explore the cosmological constraints expected from wide area XMM-type cluster surveys covering 50-200 deg2, under realistic observing conditions. We perform a Fisher matrix analysis, based on cluster number counts in combination with estimates of the two-point cluster correlation function. The effect of the survey design is implement…
Spectroscopy of Luminous z > 7 Galaxy Candidates and Sources of Contamination in z > 7 Galaxy Searches
Kneib, J. -P.; Aussel, H.; Sanders, D. B. +22 more
We present three bright z +-dropout candidates selected from deep near-infrared (NIR) imaging of the COSMOS 2 deg2 field. All three objects match the 0.8-8 µm colors of other published z > 7 candidates but are 3 mag brighter, facilitating further study. Deep spectroscopy of two of the candidates covering 0.64-1.02 &m…
The Whole Heliosphere Interval in the Context of a Long and Structured Solar Minimum: An Overview from Sun to Earth
Thompson, B. J.; de Toma, G.; Riley, P. +9 more
Throughout months of extremely low solar activity during the recent extended solar-cycle minimum, structural evolution continued to be observed from the Sun through the solar wind and to the Earth. In 2008, the presence of long-lived and large low-latitude coronal holes meant that geospace was periodically impacted by high-speed streams, even thou…
MHD wave transmission in the Sun's atmosphere
Berrilli, F.; Del Moro, D.; Stangalini, M. +1 more
Magnetohydrodynamics (MHD) wave propagation inside the Sun's atmosphere is closely related to the magnetic field topology. For example, magnetic fields are able to lower the cutoff frequency for acoustic waves, thus allowing the propagation of waves that would otherwise be trapped below the photosphere into the upper atmosphere. In addition, MHD w…
The winds of hydrogen-rich central stars of planetary nebulae
Bianchi, L.; Herald, J. E.
We have modelled far-UV, UV and optical spectra of a sample of 10 hydrogen-rich central stars of planetary nebulae (CSPN) using stellar atmosphere codes to derive their photospheric and wind parameters. The resulting stellar temperatures range from 40 to 120 kK, well spanning the CSPN evolutionary phase and allowing certain trends to be discerned.…
The extremely high velocity outflow in quasar PG0935+417
Hamann, Fred; Hall, Patrick; Rodríguez Hidalgo, Paola
We report the detection of O VI λλ1031, 1037 and N V λλ1238, 1242 absorption in a system of ‘mini-broad' absorption lines (mini-BALs) previously reported to have variable C IV λλ1548, 1550 in the quasar PG0935+417. The formation of these lines in an extremely high velocity outflow (with v∼-50 000 km s-1) is confirmed by the line variabi…
X-Ray and Optical Observations of the Unique Binary System HD 49798/RX J0648.0-4418
Tiengo, A.; Mereghetti, S.; Stella, L. +5 more
We report the results of XMM-Newton observations of HD 49798/RX J0648.0-4418, the only known X-ray binary consisting of a hot sub-dwarf and a white dwarf. The white dwarf rotates very rapidly (P = 13.2 s) and has a dynamically measured mass of 1.28 ± 0.05 M sun. Its X-ray emission consists of a strongly pulsed, soft component, well fit …
2011 February 15: Sunquakes Produced by Flux Rope Eruption
Green, L. M.; Zharkova, V. V.; Matthews, S. A. +1 more
We present an analysis of the 2011 February 15 X-class solar flare, previously reported to produce the first sunquake in solar cycle 24. Using acoustic holography, we confirm the first, and report a second, weaker, seismic source associated with this flare. We find that the two sources are located at either end of a sigmoid, which indicates the pr…
A SINFONI view of flies in the Spiderweb: a galaxy cluster in the making
Pentericci, L.; Röttgering, H. J. A.; Miley, G. K. +8 more
The environment of the high-z radio galaxy PKS 1138-262 at z∼ 2.2 is a prime example of a forming galaxy cluster. We use deep Spectrograph for INtegral Field Observations in the Near Infrared (SINFONI) integral field spectroscopy to perform a detailed study of the kinematics of the galaxies within 60 kpc of the radio core and we link this to the k…
Energetic particle phase space densities at Saturn: Cassini observations and interpretations
Krupp, N.; Jackman, C. M.; Roussos, E. +4 more
Saturn's magnetosphere has been studied extensively by the Cassini spacecraft during the last 6 years. We present mission-averaged energetic proton and electron measurements obtained by the MIMI/LEMMS instrument onboard Cassini in an energy range from several 10 keV to several 10 MeV separated by equatorial pitch angle. We discuss the resulting ra…