Search Publications
Deep X-ray survey of the young open cluster NGC 2516 with XMM-Newton
Micela, G.; Sciortino, S.; Pillitteri, I. +1 more
Aims.We report a deep X-ray survey of the young (~140 Myr), rich open cluster NGC 2516 obtained with the EPIC camera on board the XMM-Newton satellite.
Methods: .By combining data from six observations, a high sensitivity, greater than a factor of 5 with respect to recent Chandra observations, has been achieved. Kaplan-Meier estimators of the …
High spatial resolution mid-infrared spectroscopy of the starburst galaxies NGC 3256, II Zw 40 and Henize 2-10
Schaerer, D.; Sauvage, M.; Tielens, A. G. G. M. +2 more
Aims.In order to show the importance of high spatial resolution observations of extra-galactic sources when compared to observations obtained with larger apertures such as ISO, we present N-band spectra (8-13 µm) of some locations in three starburst galaxies. In particular, we show the two galactic nuclei of the spiral galaxy NGC 3256, the c…
A statistical study of the characteristics of type II doublet radio bursts
Subramanian, K. R.; Ebenezer, E.
Aims.We study the characteristics of doublet type II radio bursts in which two type II bursts occur in sequence and investigate their drivers.
Methods: .37 type II bursts reported by the Culgoora radio observatory in the Solar Geophysical data for the period September 1994-July 2004 were used to determine their time and frequency characterist…
Integral Field Spectroscopy of the Extended Emission-Line Region of 3C 249.1
Fu, Hai; Stockton, Alan
We present Gemini Multiobject Spectrograph integral field spectroscopy of the extended emission-line region associated with quasar 3C 249.1. The kinematics of the ionized gas measured from the [O III] λ5007 line is rather complex and cannot be explained globally by a simple dynamical model, but some clouds can be modeled individually as having loc…
On the complex X-ray structure tracing the motion of Geminga
Caraveo, P. A.; Bignami, G. F.; de Luca, A. +2 more
A deep (100 ks) XMM-Newton observation of Geminga has shown two faint tails of diffuse X-ray emission, extending for ~2' behind the pulsar, well aligned with the proper motion (PM) direction. We report here on a recent ~20 ks Chandra observation, which unveils a new structure, ~25'' long and ~5'' thick, starting at the pulsar position and perfectl…
The Hyades Binary θ2 Tauri: Confronting Evolutionary Models with Optical Interferometry
Hajian, Arsen R.; Hummel, C. A.; Johnston, K. J. +5 more
We determine the masses and magnitude difference of the components of the Hyades spectroscopic binary θ2 Tauri. We find that both components appear to be less massive and/or brighter than predicted from some recent evolutionary models. The rapid rotation and unknown rotational inclination of both components introduce uncertainty in thei…
Searching for the sources responsible for cosmic reionization: Probing the redshift range 7 < z < 10 and beyond
Stark, Daniel P.; Ellis, Richard S.
We review recent observations that suggest that the global star formation rate density of UV-bright galaxies is declining monotonically with redshift over 3 < z < 7 and illustrate the challenges that a continuation of this decline poses in explaining the assembled stellar mass in several z ∼ 6 galaxies deduced from recent Spitzer data. A pla…
A Spectroscopic Observation of a Magnetic Reconnection Site in a Small Flaring Event
Hara, Hirohisa; Ichimoto, Kiyoshi; Delaboudinière, Jean-Pierre +1 more
We have observed two types of coronal bidirectional flows in a flare with a small energy release through a spectroscopic observation of the Fe X emission line at 6374 Å with a ground-based coronagraph at the Norikura Solar Observatory. We find a bidirectional flow of +/-3 km s-1 above the top of a flare loop. Remarkable increases of the…
Response of the mid-altitude cusp to rapid rotations of the IMF
Escoubet, C. P.; Pitout, F.; Fazakerley, A. N. +3 more
On 12 August 2003, the four Cluster spacecraft crossed the mid-altitude cusp one after the other a minute or two apart. Shortly after the cusp crossing, two of the Cluster observed three structures poleward of the cusp that appeared and grew in successive satellite passes. In these structures, high fluxes of low-energy magnetosheath-like ions and …
Comments on the amplitude-phase relationship of asteroid lightcurves. Effects of topography, surface scattering properties, and obliquity
Rodrigo, R.; Gutiérrez, P. J.; Ortiz, J. L. +2 more
Aims.We present a theoretical study on the amplitude-phase relationship (APR) for lightcurves of simulated asteroids.
Methods: .In support of the Rosetta (ESA) mission, we developed a numerical model for the investigation of the light reflectance properties of asteroidal bodies. The code is able to deal with irregular and chemically inhomogene…