Search Publications
The unusual γ-ray burst GRB 101225A from a helium star/neutron star merger at redshift 0.33
Im, M.; Fryer, C. L.; Choi, C. +31 more
Long γ-ray bursts (GRBs) are the most dramatic examples of massive stellar deaths, often associated with supernovae. They release ultra-relativistic jets, which produce non-thermal emission through synchrotron radiation as they interact with the surrounding medium. Here we report observations of the unusual GRB 101225A. Its γ-ray emission was exce…
High heat flow from Enceladus' south polar region measured using 10-600 cm-1 Cassini/CIRS data
Spencer, J. R.; Howett, C. J. A.; Pearl, J. +1 more
Analysis of 2008 Cassini Composite Infrared Spectrometer (CIRS) 10 to 600 cm-1 thermal emission spectra of Encleadus shows that for reasonable assumptions about the spatial distribution of the emission and the thermophysical properties of the solar-heated background surface, which are supported by CIRS observations of background tempera…
A Reservoir of Ionized Gas in the Galactic Halo to Sustain Star Formation in the Milky Way
Lehner, Nicolas; Howk, J. Christopher
Without a source of new gas, our Galaxy would exhaust its supply of gas through the formation of stars. Ionized gas clouds observed at high velocity may be a reservoir of such gas, but their distances are key for placing them in the galactic halo and unraveling their role. We have used the Hubble Space Telescope to blindly search for ionized high-…
Metallicity Gradient of a Lensed Face-on Spiral Galaxy at Redshift 1.49
Swinbank, A. M.; Richard, J.; Yuan, T. -T. +2 more
We present the first metallicity gradient measurement for a grand-design face-on spiral galaxy at z ~ 1.5. This galaxy has been magnified by a factor of 22× by a massive, X-ray luminous galaxy cluster MACS J1149.5+2223 at z = 0.544. Using the Laser Guide Star Adaptive Optics aided integral field spectrograph OSIRIS on KECK II, we target the Hα emi…
Supermassive black holes do not correlate with dark matter haloes of galaxies
Kormendy, John; Bender, Ralf
Supermassive black holes have been detected in all galaxies that contain bulge components when the galaxies observed were close enough that the searches were feasible. Together with the observation that bigger black holes live in bigger bulges, this has led to the belief that black-hole growth and bulge formation regulate each other. That is, blac…
A statistical and event study of magnetotail dipolarization fronts
Nakamura, R.; Baumjohann, W.; Volwerk, M. +2 more
A study of dipolarization fronts of the Earth's magnetotail has been performed using seven years (2001-2007) of Cluster data. Events both with and without high-speed earthward flows are included. A superposed epoch analysis of the data shows that the dipolarization is preceeded by a decrease of Bz before the increase. The duration of th…
The ultraviolet properties of star-forming galaxies - I. HST WFC3 observations of very high redshift galaxies
Wilkins, Stephen M.; Bunker, Andrew J.; Caruana, Joseph +2 more
The acquisition of deep near-IR imaging with Wide Field Camera 3 on the Hubble Space Telescope has provided the opportunity to study the very high redshift Universe. For galaxies up to z≈ 7.7 sufficient wavelength coverage exists to probe the rest-frame ultraviolet (UV) continuum without contamination from either Lyman α emission or the Lyman α br…
The SL2S Galaxy-scale Lens Sample. II. Cosmic Evolution of Dark and Luminous Mass in Early-type Galaxies
Treu, Tommaso; Gavazzi, Raphaël; Marshall, Philip J. +3 more
We present a joint gravitational lensing and stellar-dynamical analysis of 11 early-type galaxies (median deflector redshift z d = 0.5) from Strong Lenses in the Legacy Survey (SL2S). Using newly measured redshifts and stellar velocity dispersions from Keck spectroscopy with lens models from Paper I, we derive the total mass-density slo…
The Induced Magnetospheres of Mars, Venus, and Titan
Szego, K.; Fraenz, M.; Edberg, N. +4 more
This article summarizes and aims at comparing the main features of the induced magnetospheres of Mars, Venus and Titan. All three objects form a well-defined induced magnetosphere (IM) and magnetotail as a consequence of the interaction of an external wind of plasma with the ionosphere and the exosphere of these objects. In all three, photoionizat…
Planck early results. VI. The High Frequency Instrument data processing
Kneissl, R.; Miville-Deschênes, M. -A.; Boulanger, F. +163 more
We describe the processing of the 336 billion raw data samples from the High Frequency Instrument (HFI) which we performed to produce six temperature maps from the first 295 days of Planck-HFI survey data. These maps provide an accurate rendition of the sky emission at 100, 143, 217, 353, 545 and 857 GHz with an angular resolution ranging from 9.9…