Search Publications
Thermal to Nonthermal Energy Partition at the Early Rise Phase of Solar Flares
Fleishman, Gregory D.; Altyntsev, Alexander A.; Lesovoi, Sergey V. +1 more
In some flares, the thermal component appears much earlier than the nonthermal component in the X-ray range. Using sensitive microwave observations, we revisit this finding made by Battaglia et al. based on a thorough analysis of RHESSI data. We have found that nonthermal microwave emission produced by accelerated electrons with energy of at least…
High-velocity stars in the cores of globular clusters: the illustrative case of NGC 2808
Kruijssen, J. M. D.; Kissler-Patig, M.; de Zeeuw, P. T. +7 more
Context. We report the detection of five high-velocity stars in the core of the globular cluster NGC 2808. The stars lie on the red giant branch and show total velocities between 40 and 45 km s-1. For a core velocity dispersion σc = 13.4 km s-1, this corresponds to up to 3.4σc. These velocities are close…
Control of ion loss from Mars during solar minimum
Brecht, Stephen H.; Ledvina, Stephen A.
A hybrid particle code has been used to examine the interaction of the solar wind with Mars during solar minimum. The results were surprising as they produced ion loss rates from Mars far in excess of what is estimated from MEX. The results are analyzed and found to be consistent with the competition between photochemical rates and advection of th…
The Central Engine Structure of 3C120: Evidence for a Retrograde Black Hole or a Refilling Accretion Disk
Reynolds, Christopher S.; Cowperthwaite, Philip S.
The broad-line radio galaxy 3C120 is a powerful source of both X-ray and radio emission including superluminal jet outflows. We report on our reanalysis of 160 ks of Suzaku data taken in 2006, previously examined by Kataoka et al. Spectral fits to the X-ray Imaging Spectrometer and Hard X-ray Detector/positive intrinsic negative data over a range …
The properties of the brightest Lyα emitters at z=5.7
Schaerer, D.; Meisenheimer, K.; Lidman, C. +5 more
We use deep Very Large Telescope (VLT) optical and near-infrared spectroscopy and deep Spitzer/IRAC imaging to examine the properties of two of the most luminous Lyα emitters at z= 5.7. The continuum redward of the Lyα line is clearly detected in both objects, thus facilitating a relatively accurate measurement (10-20 per cent uncertainties) of th…
Precipitation of highly energetic protons by helium branch electromagnetic ion cyclotron triggered emissions
Omura, Yoshiharu; Shoji, Masafumi
In the equatorial region of the Earth's inner magnetosphere, the electromagnetic ion cyclotron (EMIC) triggered emissions are generated through interaction with energetic protons. We investigate the generation process of the EMIC triggered emissions in the He+branch and associated precipitation of the energetic protons using a one-dimen…
Global mapping of Titan‧s surface using an empirical processing method for the atmospheric and photometric correction of Cassini/VIMS images
Nicholson, Philip D.; Sotin, Christophe; Barnes, Jason W. +8 more
We have processed all images of Titan's surface acquired by the Visual and Infrared Mapping Spectrometer between 2004 and 2010, with the objective of producing seamless global mosaics of the surface in the six infrared atmospheric windows at 1.08, 1.27, 1.59, 2.03, 2.6-2.7 and 5 µm. A systematic study of the photometry at 5 µm, where h…
Variable stars in the Cetus dwarf spheroidal galaxy: population gradients and connections with the star formation history
Stetson, P. B.; Bono, G.; Fiorentino, G. +7 more
We investigate the variable star content of the isolated, Local Group, dwarf spheroidal (dSph) galaxy Cetus. Multi-epoch, wide-field images collected with the Very Large Telescope/Visible Multiobject Spectrograph camera allowed us to detect 638 variable stars (630 RR Lyrae stars and eight anomalous Cepheids), 475 of which are new detections. We pr…
Sub-millimetre spectroscopy of Saturn's trace gases from Herschel/SPIRE
Fletcher, L. N.; Hartogh, P.; Lellouch, E. +15 more
Aims: We provide an extensive new sub-millimetre survey of the trace gas composition of Saturn's atmosphere using the broad spectral range (15-51 cm-1) and high spectral resolution (0.048 cm-1) offered by Fourier transform spectroscopy by the Herschel/SPIRE instrument (Spectral and Photometric Imaging REceiver). Observat…
Testing Nonstandard Cosmological Models with SNLS3 Supernova Data and Other Cosmological Probes
Li, Zhengxiang; Wu, Puxun; Yu, Hongwei
We investigate the implications for some nonstandard cosmological models using data from the first three years of the Supernova Legacy Survey (SNLS3), assuming a spatially flat universe. A comparison between the constraints from the SNLS3 and those from other SN Ia samples, such as the ESSENCE, Union2, SDSS-II, and Constitution samples, is given a…