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Solar chromospheric spicules from the leakage of photospheric oscillations and flows
De Pontieu, Bart; Erdélyi, Robert; James, Stewart P.
Spicules are dynamic jets propelled upwards (at speeds of ~20kms-1) from the solar `surface' (photosphere) into the magnetized low atmosphere of the Sun. They carry a mass flux of 100 times that of the solar wind into the low solar corona. With diameters close to observational limits (< 500km), spicules have been largely unexplained …
X-ray astronomy of stellar coronae
Güdel, Manuel
X-ray emission from stars in the cool half of the Hertzsprung-Russell diagram is generally attributed to the presence of a magnetic corona that contains plasma at temperatures exceeding 1 million K. Coronae are ubiquitous among these stars, yet many fundamental mechanisms operating in their magnetic fields still elude an interpretation through a d…
Massive Dark Matter Halos and Evolution of Early-Type Galaxies to z ~ 1
Treu, Tommaso; Koopmans, Léon V. E.
The combination of gravitational lensing and stellar dynamics breaks the mass-anisotropy degeneracy and provides stringent constraints on the distribution of luminous and dark matter in early-type (E/S0) galaxies out to z~1. We present new observations and models of three lens systems (CFRS 03.1077, HST 14176+5226, HST 15433+5352) and the combined…
GEMS: Galaxy Evolution from Morphologies and SEDs
Bell, Eric F.; Somerville, Rachel S.; Wisotzki, Lutz +13 more
GEMS (Galaxy Evolution from Morphologies and SEDs) is a large-area (800 arcmin2) two-color (F606W and F850LP) imaging survey with the Advanced Camera for Surveys on the Hubble Space Telescope. Centered on the Chandra Deep Field-South, it covers an area of ~28'×28', or about 120 Hubble Deep Field areas, to a depth o…
The Size Distribution of Trans-Neptunian Bodies
Brown, M. E.; Bernstein, G. M.; Trilling, D. E. +3 more
We search 0.02 deg2 of the invariable plane for trans-Neptunian objects (TNOs) 25 AU or more distant using the Advanced Camera for Surveys (ACS) aboard the Hubble Space Telescope. With 22 ks per pointing, the search is more than 50% complete for m606W<=29.2. Three new objects are discovered, the faintest with mean magnitud…
The Mass Accretion Rates of Intermediate-Mass T Tauri Stars
Gordon, Karl D.; Hartmann, Lee; Calvet, Nuria +4 more
We present Hubble Space Telescope ultraviolet spectra and supporting ground-based data for a sample of nine intermediate-mass T Tauri stars (IMTTSs; 1.5-4 Msolar). The targets belong to three star-forming regions: T Tau, SU Aur, and RY Tau in the Taurus clouds; EZ Ori, P2441, and V1044 Ori in the Ori OB1c association surrounding the Ori…
Preliminary Parallaxes of 40 L and T Dwarfs from the US Naval Observatory Infrared Astrometry Program
Brinkmann, J.; Kirkpatrick, J. Davy; Fan, X. +12 more
We present preliminary trigonometric parallaxes and proper motions for 22 L dwarfs and 18 T dwarfs measured using the ASTROCAM infrared imager on the US Naval Observatory (USNO) 1.55 m Strand Astrometric Reflector. The results presented here are based on observations obtained between 2000 September and 2002 November; about half of the objects have…
The Size Evolution of High-Redshift Galaxies
Dickinson, Mark; Ferguson, Henry C.; Giavalisco, Mauro +14 more
Hubble Space Telescope images of high-redshift galaxies selected via color and photometric redshifts are used to examine the size and axial ratio distribution of galaxies as a function of redshift at look-back times t>8 Gyr. These parameters are measured at rest-frame UV wavelengths (1200 Å < λ < 2000 Å) on images with a rest-frame resolu…
Comparing the temperatures of galaxy clusters from hydrodynamical N-body simulations to Chandra and XMM-Newton observations
Rasia, E.; Mazzotta, P.; Moscardini, L. +1 more
Theoretical studies of the physical processes guiding the formation and evolution of galaxies and galaxy clusters in the X-ray region are mainly based on the results of numerical hydrodynamical N-body simulations, which in turn are often directly compared with X-ray observations. Although trivial in principle, these comparisons are not always simp…
The Cassini Visual And Infrared Mapping Spectrometer (Vims) Investigation
Sotin, C.; Brown, R. H.; Baines, K. H. +19 more
The Cassini visual and infrared mapping spectrometer (VIMS) investigation is a multidisciplinary study of the Saturnian system. Visual and near-infrared imaging spectroscopy and high-speed spectrophotometry are the observational techniques. The scope of the investigation includes the rings, the surfaces of the icy satellites and Titan, and the atm…