Search Publications
Identification of the OGLE-2003-BLG-235/MOA-2003-BLG-53 Planetary Host Star
Anderson, Jay; Udalski, Andrzej; Gould, Andrew +2 more
We present the results of HST observations of the host star for the first definitive extrasolar planet detected by microlensing. The light-curve model for this event predicts that the lens star should be separated from the source star by ~6 mas at the time of the HST images. If the lens star is a late G, K, or early M dwarf, then it will be visibl…
Europa's atmosphere, gas tori, and magnetospheric implications
Smyth, William H.; Marconi, Max L.
A two-dimensional kinetic model calculation for the water group species (H 2O, H 2, O 2, OH, O, H) in Europa's atmosphere is undertaken to determine its basic compositional structure, gas escape rates, and velocity distribution information to initialize neutral cloud model calculations for the most important gas to…
Multivariate analysis of globular cluster horizontal branch morphology: searching for the second parameter
Djorgovski, S. G.; Recio-Blanco, A.; Piotto, G. +2 more
Aims.The interpretation of globular cluster horizontal branch (HB) morphology is a classical problem that can significantly blur our understanding of stellar populations.
Methods: .We present a new multivariate analysis connecting the effective temperature extent of the HB with other cluster parameters. The work is based on Hubble Space Telesc…
The Enceladus and OH Tori at Saturn
Tokar, R. L.; Johnson, R. E.; Sittler, E. C. +4 more
The remarkable observation that Enceladus, a small icy satellite of Saturn, is actively venting has led to the suggestion that ejected water molecules are the source of the toroidal atmosphere observed at Saturn for over a decade using the Hubble Space Telescope (HST). Here we show that the venting leads directly to a new feature, a narrow Encelad…
Plasma Morphology at Mars. Aspera-3 Observations
Barabash, S.; Lundin, R.; Winningham, J. D. +6 more
A total of about of 400 orbits during the first year of the ASPERA-3 operation onboard the Mars Express spacecraft were analyzed to obtain a statistical pattern of the main plasma domains in the Martian space environment. The environment is controlled by the direct interaction between the solar wind and the planetary exosphere/ionosphere which res…
The XMM Large-Scale Structure survey: the X-ray pipeline and survey selection function
Chiappetti, L.; Altieri, B.; Valtchanov, I. +11 more
We present the X-ray pipeline developed for the purpose of the cluster search in the XMM Large-Scale Structure (XMM-LSS) survey. It is based on a two-stage procedure via a dedicated handling of the Poisson nature of the signal: (i) source detection on multiresolution wavelet filtered images and (ii) source analysis by means of a maximum likelihood…
On the origin and excitation of the extended nebula surrounding NGC1275
Fabian, A. C.; Johnstone, R. M.; Crawford, C. S. +1 more
We use line-of-sight velocity information on the filamentary emission-line nebula of NGC1275 to infer a dynamical model of the nebula's flow through the surrounding intracluster gas. We detect outflowing gas and flow patterns that match simulations of buoyantly rising bubbles from which we deduce that some of the nebula filaments have been drawn o…
Transiting extrasolar planetary candidates in the Galactic bulge
Brown, Thomas M.; Casertano, Stefano; Livio, Mario +13 more
More than 200 extrasolar planets have been discovered around relatively nearby stars, primarily through the Doppler line shifts owing to reflex motions of their host stars, and more recently through transits of some planets across the faces of the host stars. The detection of planets with the shortest known periods, 1.2-2.5 days, has mainly result…
Spatial mapping of ices in the Ophiuchus-F core. A direct measurement of CO depletion and the formation of CO_2
Pontoppidan, K. M.
Aims.Ices in dense star-forming cores contain the bulk of volatile molecules apart from H2 and thus represent a large fraction of dark cloud chemistry budget. Mm observations of gas provide indirect evidence for significant freeze-out of CO in the densest cores. To directly constrain the freeze-out profile of CO, the formation route of CO2 and the…
New Chandra Observations of the Jet in 3C 273. I. Softer X-Ray than Radio Spectra and the X-Ray Emission Mechanism
Meisenheimer, Klaus; Jester, Sebastian; Harris, D. E. +1 more
The jet in 3C 273 is a high-power quasar jet with radio, optical, and X-ray emission, whose size and brightness allow a detailed study of the emission processes acting in it. We present deep Chandra observations of this jet and analyze the spectral properties of the jet emission from radio through X-rays. We find that the X-ray spectra are signifi…