Search Publications
CoRoT 102699796, the first metal-poor Herbig Ae pulsator: a hybrid δ Sct-γ Dor variable?
Catala, C.; Ventura, P.; Ripepi, V. +7 more
We present the analysis of the time series observations of CoRoT 102699796 obtained by the Convection, Rotation and planetary Transits (CoRoT) satellite that show the presence of five independent oscillation frequencies in the range 3.6-5 c d-1. Using spectra acquired with FLAMES@VLT, we derive the following stellar parameters: spectral…
Location of Decimetric Pulsations in Solar Flares
Vilmer, Nicole; Benz, Arnold O.; Battaglia, Marina
This work investigates the spatial relation between coronal X-ray sources and coherent radio emissions, both generally thought to be signatures of particle acceleration. Two limb events were selected during which the radio emission was well correlated in time with hard X-rays. The radio emissions were of the type of decimetric pulsations as determ…
Ultraviolet Discoveries at Asteroid (21) Lutetia by the Rosetta Alice Ultraviolet Spectrograph
Scherrer, J. R.; Stern, S. A.; Feldman, P. D. +11 more
The NASA Alice ultraviolet (UV) imaging spectrograph on board the ESA Rosetta comet orbiter successfully conducted a series of flyby observations of the large asteroid (21) Lutetia in the days surrounding Rosetta's closest approach on 2010 July 10. Observations included a search for emission lines from gas, and spectral observations of the Lutetia…
Anatomy of a Solar Flare: Measurements of the 2006 December 14 X-class Flare with GONG, Hinode, and RHESSI
Zharkova, V. V.; Matthews, S. A.; Zharkov, S.
Some of the most challenging observations to explain in the context of existing flare models are those related to the lower atmosphere and below the solar surface. Such observations, including changes in the photospheric magnetic field and seismic emission, indicate the poorly understood connections between energy release in the corona and its imp…
Emission sparks around M 81 and in some dwarf spheroidal galaxies
Makarova, Lidia; Kaisin, Serafim; Karachentsev, Igor +1 more
We use Hα images of three clumps of young stars situated between M 81 and NGC 3077 to estimate their star formation rate. Radial velocities of the clumps measured by us, as well as the velocity of the H II region in the dwarf spheroidal (dSph) galaxy KDG 61, are compatible with their location at the outskirts of a large rotating gaseous disc aroun…
The statistical studies of the inner boundary of plasma sheet
Dandouras, I.; Cao, J. B.; Ding, W. Z. +4 more
The penetration of plasma sheet ions into the inner magnetosphere is very important to the inner magnetospheric dynamics since plasma sheet ions are one of the major particle sources of ring current during storm times. However, the direct observations of the inner boundary of the plasma sheet are fairly rare due to the limited number of satellites…
Extended Hard X-Ray Emission from the Vela Pulsar Wind Nebula
Götz, D.; Ponti, G.; Bouchet, L. +8 more
The nebula powered by the Vela pulsar is one of the best examples of an evolved pulsar wind nebula, allowing access to the particle injection history and the interaction with the supernova ejecta. We report on the INTEGRAL discovery of extended emission above 18 keV from the Vela nebula. The northern side has no known counterparts and it appears l…
Spectroscopic Study of the HST/ACS PEARS Emission-line Galaxies
Pirzkal, Norbert; Xia, Lifang; Malhotra, Sangeeta +6 more
We present spectroscopy of 76 emission-line galaxies (ELGs) in Chandra Deep Field South taken with the LDSS3 spectrograph on the Magellan Telescope. These galaxies are selected because they have emission lines with the Advanced Camera for Surveys (ACS) grism data in the Hubble Space Telescope Probing Evolution and Reionization Spectroscopically (P…
Evolution of the fundamental plane of 0.2 < z < 1.2 early-type galaxies in the EGS
Cepa, J.; Bongiovanni, A.; Pérez García, A. M. +5 more
Context. The fundamental plane links the structural properties of early-type galaxies such as its surface brightness and effective radius with its dynamics. The study of the fundamental plane evolution therefore has important implications for models of galaxy formation and evolution.
Aims: This work aims to identify signs of evolution of earl…
SWIFT observations of the Arp 147 ring galaxy system
Salter, G.; Davies, R. L.; Thatte, N. +6 more
We present observations of Arp 147, a galaxy system comprising a collisionally created ring galaxy and an early-type galaxy, using the Oxford SWIFT integral field spectrograph (IFS) at the 200-inch Hale telescope. We derive spatially resolved kinematics from the IFS data and use these to study the interaction between the two galaxies. We find the …