Search Publications
A Jovian-Mass Planet in Microlensing Event OGLE-2005-BLG-071
Bennett, D. P.; Gal-Yam, A.; Soszyński, I. +34 more
We report the discovery of a several-Jupiter-mass planetary companion to the primary lens star in microlensing event OGLE-2005-BLG-071. Precise (<~1%) photometry at the peak of the event yields an extremely high signal-to-noise ratio detection of a deviation from the light curve expected from an isolated lens. The planetary character of this de…
Solar-like Oscillations in α Centauri B
Butler, R. Paul; Bedding, Timothy R.; Marcy, Geoffrey W. +6 more
We have made velocity observations of the star α Centauri B from two sites, allowing us to identify 37 oscillation modes with l=0-3. Fitting to these modes gives the large and small frequency separations as a function of frequency. The mode lifetime, as measured from the scatter of the oscillation frequencies about a smooth trend, is similar to th…
The Luminosity, Stellar Mass, and Number Density Evolution of Field Galaxies of Known Morphology from z = 0.5 to 3
Papovich, Casey; Conselice, Christopher J.; Blackburne, Jeffrey A.
The evolution of rest-frame B-band luminosities, stellar masses, and number densities of field galaxies in the Hubble Deep Fields North and South are studied as a function of rest-frame B-band morphological type out to redshift z~3 using a sample of 1231 I<27 galaxies with spectroscopic and photometric redshifts. We find that the comoving and r…
The structural and scaling properties of nearby galaxy clusters. I. The universal mass profile
Arnaud, M.; Pointecouteau, E.; Pratt, G. W.
We present the integrated mass profiles for a sample of ten nearby (z<~0.15), relaxed galaxy clusters, covering a temperature range of [2-9] keV, observed with XMM-Newton. The mass profiles were derived from the observed gas density and temperature profiles under the hypothesis of spherical symmetry and hydrostatic equilibrium. All ten mass pro…
Longitudinal Magnetic Field Changes Accompanying Solar Flares
Harvey, J. W.; Sudol, J. J.
We have used Global Oscillation Network Group (GONG) magnetograms to characterize the changes in the photospheric longitudinal magnetic field during 15 X-class solar flares. An abrupt, significant, and persistent change in the magnetic field occurred in at least one location within the flaring active region during each event. We have identified a …
Radio and Plasma Wave Observations at Saturn from Cassini's Approach and First Orbit
Gurnett, D. A.; Persoon, A. M.; Hospodarsky, G. B. +24 more
We report data from the Cassini radio and plasma wave instrument during the approach and first orbit at Saturn. During the approach, radio emissions from Saturn showed that the radio rotation period is now 10 hours 45 minutes 45 +/- 36 seconds, about 6 minutes longer than measured by Voyager in 1980 to 1981. In addition, many intense impulsive rad…
The Local Group and Other Neighboring Galaxy Groups
Karachentsev, I. D.
Over the last few years, rapid progress has been made in distance measurements for nearby galaxies based on the magnitude of stars on the tip of the red giant branch. Current CCD surveys with the Hubble Space Telescope (HST) and large ground-based telescopes bring ~10% accurate distances for roughly a hundred galaxies within 5 Mpc. The new data on…
Cassini Radar Views the Surface of Titan
Stiles, B.; Kelleher, K.; Callahan, P. +32 more
The Cassini Titan Radar Mapper imaged about 1% of Titan's surface at a resolution of ~0.5 kilometer, and larger areas of the globe in lower resolution modes. The images reveal a complex surface, with areas of low relief and a variety of geologic features suggestive of dome-like volcanic constructs, flows, and sinuous channels. The surface appears …
Gamma-Ray Constraint on Galactic Positron Production by MeV Dark Matter
Bertone, Gianfranco; Beacom, John F.; Bell, Nicole F.
The Galactic positrons, as observed by their annihilation gamma-ray line at 0.511 MeV, are difficult to account for with astrophysical sources. It has been proposed that they are produced instead by dark matter annihilation or decay in the inner Galactic halo. To avoid other constraints, these processes are required to occur “invisibly,” such that…
Spectroscopy of polycyclic aromatic hydrocarbons and very small grains in photodissociation regions
Joblin, C.; Rapacioli, M.; Boissel, P.
We have coupled a singular value decomposition method with a Monte Carlo search algorithm to analyse the mid-infrared ISOCAM spectral maps of photodissociation regions (PDRs) in NGC 7023 and ρ Oph-SR3.Three different spectra and their associated spatial distribution were extracted from this analysis. It is shown that they can be associated with po…