Search Publications
IMF, SFR and stellar depletion in the local Galactic plane, based on improved Hipparcos samples of single stars
Schröder, K. -P.; Dawson, S. A.
We have used the recently reduced Hipparcos data and the Washington Double Star catalogue to derive two volume- and magnitude-limited samples of single stars in the Galactic plane. The star count method has been used to compare synthetic to empirical samples of stars within both the main sequence and the evolved regions of the Hertzsprung-Russell …
Chorus wave generation near the dawnside magnetopause due to drift shell splitting of substorm-injected electrons
Keika, Kunihiro; Lee, Jeongwoo; Min, Kyungguk
We study the relationship between the electron injection and the chorus waves during a substorm event on 23 March 2007. The chorus waves were detected at high geomagnetic latitude (∼70°S) Antarctic observatories in the range of 0600-0900 h in magnetic local time (MLT). Electrons drifting from the injection event were measured by two LANL spacecraf…
Suzaku Wide-Band X-Ray Observation of the Narrow-Line Seyfert 1 Galaxy Ton S180
Hayashida, Kiyoshi; Anabuki, Naohisa; Takahashi, Hiroaki
We observed the luminous narrow-line Seyfert 1 galaxy Ton S180 with Suzaku, and obtained its wide-band (0.25-55 keV) X-ray spectra for the first time. The spectra were modeled with three components: a power-law component, a reflection from a highly ionized disk component, and an extra soft component either of a disk blackbody or a cutoff power-law…
Ultraviolet study of the active interacting binary star R Arae using archival IUE data
Sahade, Jorge; Guinan, Edward F.; Reed, Phillip A. +7 more
The eclipsing and strongly interacting binary star system R Arae (HD 149730) is in a very active and very short-lived stage of its evolution. R Ara consists of a B9V primary and an unknown secondary. We have collected the International Ultraviolet Explorer (IUE) archival data on R Ara, with most of the data being studied for the first time. There …
Suzaku Observations of the Galactic Center Microquasar 1E 1740.7-2942
Miller, Jon M.; Reynolds, Mark T.
We present two Suzaku observations of the Galactic center microquasar 1E 1740.7-2942 separated by approximately 700 days. The source was observed on both occasions after a transition to the spectrally hard state. Significant emission from 1E 1740.7-2942 is detected out to an energy of 300 keV, with no spectral break or turnover evident in the data…
Hot and cool: two emission-line stars with constrasting behaviours in the same XMM-Newton field
Nazé, Y.; Rauw, G.; Ud-Doula, A.
High-energy emissions are good indicators of peculiar behaviours in stars. We have therefore obtained an XMM-Newton observation of HD 155806 and 1RXS J171502.4-333344, and derived their spectral properties for the first time. The X-ray spectrum of HD 155806 appears soft, even slightly softer than usual for O-type stars (as shown by a comparison wi…
An empirical relationship between coronal mass ejection initial speed and solar wind dynamic pressure
Cho, K. -S.; Kim, K. -H.; Moon, Y. -J. +3 more
Interplanetary shocks that precede coronal mass ejections (CMEs) are mainly responsible for sudden impulses, which are characterized by a simple step-like increase in the horizontal H component. Such a magnetic field change has been explained as a compression of the magnetosphere by the passage of a sudden increase in the solar wind dynamic pressu…
Detecting the widths of shock fronts preceding coronal mass ejections
Eselevich, M. V.
The perturbed zones and shocks preceding coronal mass ejections (CMEs) are studied using the data of the Mark 4, LASCO C2, and LASCO C3 coronagraphs. Detection of the perturbed zone indicating the presence or absence of the shock is most reliable in a frame moving with the frontal structure of the CME. The ability to correctly measure the width δ …
The selection and characterization of the Phobos-Soil landing sites
Basilevsky, A. T.; Shingareva, T. V.
This paper shortly describes the selection technique for the landing sites of the Phobos-Soil spacecraft, the characteristics of the Phobos relief, the history of choosing the potential landing sites in the process of working on the project, and the suggestions to shift the landing sites to the region recently imaged by the Mars Express spacecraft…
Astrometry with Carte du Ciel plates, San Fernando zone . II. CdC-SF: a precise proper motion catalogue
Girard, T. M.; Abad, C.; Vicente, B. +1 more
Context. The historic plates of the Carte du Ciel, an international cooperative project launched in 1887, offer valuable first-epoch material for the determination of absolute proper motions.
Aims: We present the CdC-SF, an astrometric catalogue of positions and proper motions derived from the Carte du Ciel plates of the San Fernando zone, ph…