Search Publications
Pulsar timing for the Fermi gamma-ray space telescope
Camilo, F.; Dumora, D.; Guillemot, L. +25 more
We describe a comprehensive pulsar monitoring campaign for the Large Area Telescope (LAT) on the Fermi Gamma-ray Space Telescope (formerly GLAST). The detection and study of pulsars in gamma rays give insights into the populations of neutron stars and supernova rates in the Galaxy, into particle acceleration mechanisms in neutron star magnetospher…
Coronal magnetic field measurement using loop oscillations observed by Hinode/EIS
Young, P. R.; Nakariakov, V. M.; Verwichte, E. +1 more
We report the first spectroscopic detection of a kink MHD oscillation of a solar coronal structure by the Extreme-Ultraviolet Imaging Spectrometer (EIS) on the Japanese Hinode satellite. The detected oscillation has an amplitude of 1 km s-1 in the Doppler shift of the FeXII 195 Å spectral line (1.3~MK), and a period of 296~s. The unique…
Study of nonlinear ion- and electron-acoustic waves in multi-component space plasmas
Lakhina, G. S.; Singh, S. V.; Verheest, F. +2 more
Large amplitude ion-acoustic and electron-acoustic waves in an unmagnetized multi-component plasma system consisting of cold background electrons and ions, a hot electron beam and a hot ion beam are studied using Sagdeev pseudo-potential technique. Three types of solitary waves, namely, slow ion-acoustic, ion-acoustic and electron-acoustic soliton…
Non-LTE line formation for heavy elements in four very metal-poor stars
Zhao, G.; Mashonkina, L.; Aoki, W. +6 more
Aims:Stellar parameters and abundances of Na, Mg, Al, K, Ca, Sr, Ba, and Eu are determined for four very metal-poor (VMP) stars (-2.15 ≥ [Fe/H] ≥ -2.66). For two of them, HD 84937 and HD 122563, the fraction of the odd isotopes of Ba derived for the first time.
Methods: Determination of an effective temperature, surface gravity, and element ab…
Formation of Solar Magnetic Flux Tubes with Kilogauss Field Strength Induced by Convective Instability
Tsuneta, Saku; Shimizu, Toshifumi; Lites, Bruce W. +11 more
Convective instability has been a mechanism used to explain the formation of solar photospheric flux tubes with kG field strength. However, the turbulence of the Earth's atmosphere has prevented ground-based observers from examining the hypothesis with precise polarimetric measurement on the subarcsecond scale flux tubes. Here we discuss observati…
The Hubble Space Telescope/Advanced Camera for Surveys Atlas of Protoplanetary Disks in the Great Orion Nebula
Robberto, M.; Ricci, L.; Soderblom, D. R.
We present the atlas of protoplanetary disks in the Orion Nebula based on the Wide Field Channel of the Advanced Camera for Surveys (ACS/WFC) images obtained for the Hubble Space Telescope (HST) Treasury Program on the Orion Nebula Cluster. The observations have been carried out in five photometric filters nearly equivalent to the standard B, V, H…
Processes and mechanisms governing the initiation and propagation of CMEs
Vršnak, B.
The most important observational characteristics of coronal mass ejections (CMEs) are summarized, emphasizing those aspects which are relevant for testing physical concepts employed to explain the CME take-off and propagation. In particular, the kinematics, scalings, and the CME-flare relationship are stressed. Special attention is paid to 3-dimen…
Circumnuclear Gas in Seyfert 1 Galaxies: Morphology, Kinematics, and Direct Measurement of Black Hole Masses
Malkan, Matthew A.; Hicks, Erin K. S.
The two-dimensional (2D) distribution and kinematics of the molecular, ionized, and highly ionized gas in the nuclear regions of Seyfert 1 galaxies have been measured using high spatial resolution (~0.09'') near-infrared spectroscopy from NIRSPEC with adaptive optics on the Keck telescope. Molecular hydrogen, H2, is detected in all nine…
A new activity phase of the blazar 3C 454.3 . Multifrequency observations by the WEBT and XMM-Newton in 2007-2008
Lee, C. -U.; Pian, E.; Lähteenmäki, A. +72 more
Aims: The Whole Earth Blazar Telescope (WEBT) consortium has been monitoring the blazar
Methods: We present and analyse the multifrequency results of the 2007-2008 observing season, including XMM-Newton observations and near…
The UV colours of high-redshift early-type galaxies: evidence for recent star formation and stellar mass assembly over the last 8 billion years
van Dokkum, P. G.; Gawiser, E.; Urry, C. M. +7 more
We combine deep optical and NIR (UBVRIzJK) photometry from the Multiwavelength Survey by Yale-Chile (MUSYC) with redshifts from the COMBO-17 survey to perform a large-scale study of the rest-frame ultraviolet (UV) properties of 674 high-redshift (0.5 < z < 1) early-type galaxies, drawn from the Extended Chandra Deep Field-South (E-CDFS). Gal…