Search Publications
Catching the fish - Constraining stellar parameters for TX Piscium using spectro-interferometric observations
Verhoelst, T.; Marigo, P.; Hron, J. +4 more
Context. Stellar parameter determination is a challenging task when dealing with galactic giant stars. The combination of different investigation techniques has proven to be a promising approach.
Aims: We analyse archive spectra obtained with the Short Wavelength Spectrometer (SWS) onboard ISO, and new interferometric observations from the Ve…
Irregular time series in astronomy and the use of the Lomb-Scargle periodogram
Andreani, P.; Vio, R.; Diaz-Trigo, M.
Detection of a signal hidden by noise within a time series is an important problem in many astronomical searches, i.e. for light curves containing the contributions of periodic/semi-periodic components due to rotating objects and all other astrophysical time-dependent phenomena. One of the most popular tools for use in such studies is the periodog…
Solar wind reflection from the lunar surface: The view from far and near
Barabash, S.; Wurz, P.; McComas, D. J. +7 more
The Moon appears bright in the sky as a source of energetic neutral atoms (ENAs). These ENAs have recently been imaged over a broad energy range both from near the lunar surface, by India's Chandrayaan-1 mission (CH-1), and from a much more distant Earth orbit by NASA's Interstellar Boundary Explorer (IBEX) satellite. Both sets of observations hav…
Stellar Populations in Compact Galaxy Groups: A Multi-wavelength Study of HCGs 16, 22, and 42, their Star Clusters, and Dwarf Galaxies
Konstantopoulos, I. S.; Mulchaey, J. S.; Gallagher, S. C. +10 more
We present a multi-wavelength analysis of three compact galaxy groups, Hickson compact groups (HCGs) 16, 22, and 42, which describe a sequence in terms of gas richness, from space- (Swift, Hubble Space Telescope (HST), and Spitzer) and ground-based (Las Campanas Observatory and Cerro Tololo Inter-American Observatory) imaging and spectroscopy. We …
Star formation and dust heating in the FIR bright sources of M83
Boquien, M.; Cooray, A.; Lebouteiller, V. +16 more
We investigate star formation and dust heating in the compact far-infrared (FIR) bright sources detected in the Herschel maps of M83. We use the source extraction code GETSOURCES to detect and extract sources in the FIR, as well as their photometry in the mid-infrared and Hα. By performing infrared spectral energy distribution fitting and applying…
Statistical properties of planetary heavy-ion precipitations toward the Martian ionosphere obtained from Mars Express
Barabash, Stas; Futaana, Yoshifumi; Seki, Kanako +5 more
The interplanetary magnetic field (IMF) embedded in the solar wind interacts with the Martian crustal magnetic field and atmosphere. The IMF orientation is one of the important parameters to control the acceleration and precipitation of planetary heavy ions (PHIs). We statistically investigate the effects of the IMF orientation on PHI precipitatio…
Analysis of Sunspot Area over Two Solar Cycles
de Toma, G.; Chapman, G. A.; Preminger, D. G. +1 more
We examine changes in sunspots and faculae and their effect on total solar irradiance during solar cycles 22 and 23 using photometric images from the San Fernando Observatory. We find important differences in the very large spots between the two cycles, both in their number and time of appearance. In particular, there is a noticeable lack of very …
Global view of inner magnetosphere composition during storm time
Ilie, R.; Glocer, A.; Skoug, R. M. +2 more
Plasma dynamics in the inner magnetosphere are greatly affected by variations in the ion composition. The ratio of hydrogen to oxygen has been shown to be highly dependent on geomagnetic activity. To investigate this dependence, we examine the timing of the injection and subsequent evolution of O+ in the ring current during the storm of…
The smallest particles in Saturn’s A and C Rings
Nicholson, Philip D.; Hedman, Matthew M.; Harbison, Rebecca A.
Radio occultations of Saturn’s main rings by spacecraft suggest a power law particle size-distribution down to sizes of the order of 1 cm (Marouf, E.A., Tyler, G.L., Zebker, H.A., Simpson, R.A., Eshleman, V.R. [1983]. Icarus 54, 189-211; Zebker, H.A., Marouf, E.A., Tyler, G.L. [1985]. Icarus 64, 531-548.). The lack of optical depth variations betw…
Dynamics of X-Ray-emitting Ejecta in the Oxygen-rich Supernova Remnant Puppis A Revealed by the XMM-Newton Reflection Grating Spectrometer
Katsuda, Satoru; Koyama, Katsuji; Uchida, Hiroyuki +4 more
Using the unprecedented spectral resolution of the reflection grating spectrometer (RGS) on board XMM-Newton, we reveal dynamics of X-ray-emitting ejecta in the oxygen-rich supernova remnant Puppis A. The RGS spectrum shows prominent K-shell lines, including O VII Heα forbidden and resonance, O VIII Lyα, O VIII Lyβ, and Ne IX Heα resonance, from a…