Search Publications
A New Measurement of the Stellar Mass Density at z~5: Implications for the Sources of Cosmic Reionization
Bunker, A. J.; Stark, D. P.; Ellis, R. S. +2 more
We present a new measurement of the integrated stellar mass per comoving volume at redshift 5 determined via spectral energy fitting drawn from a sample of 214 photometrically selected galaxies with z'850LP<26.5 in the southern GOODS field. Following recent procedures introduced by Eyles et al., we estimate stellar masses …
X-rays from solar system objects
Snowden, Steven L.; Bhardwaj, Anil; Branduardi-Raymont, Graziella +11 more
During the last few years our knowledge about the X-ray emission from bodies within the solar system has significantly improved. Several new solar system objects are now known to shine in X-rays at energies below 2 keV. Apart from the Sun, the known X-ray emitters now include planets (Venus, Earth, Mars, Jupiter, and Saturn), planetary satellites …
RPC-MIP: the Mutual Impedance Probe of the Rosetta Plasma Consortium
Schmidt, W.; Eriksson, A.; Décréau, P. M. E. +18 more
The main objective of the Mutual Impedance Probe (MIP), part of the Rosetta Plasma Consortium (RPC), is to measure the electron density and temperature of Comet 67P/Churyumov-Gerasimenko’s coma, in particular inside the contact surface. Furthermore, MIP will determine the bulk velocity of the ionised outflowing atmosphere, define the spectral dist…
Constraining the Equation of State of Supranuclear Dense Matter from XMM-Newton Observations of Neutron Stars in Globular Clusters
Webb, Natalie A.; Barret, Didier
We report on the detailed modeling of the X-ray spectra of three likely neutron stars. The neutron stars, observed with XMM-Newton, are found in three quiescent X-ray binaries in the globular clusters: ω Cen, M13, and NGC 2808. Whether they are accreting at very low rates or radiating energy from an accretion-heated core, their X-ray spectra are e…
First Space-Based Microlens Parallax Measurement: Spitzer Observations of OGLE-2005-SMC-001
Bennett, D. P.; Griest, K.; Reach, W. T. +20 more
We combine Spitzer and ground-based observations to measure the microlens parallax of OGLE-2005-SMC-001, the first such space-based determination since S. Refsdal proposed the idea in 1966. The parallax measurement yields a projected velocity v∼~230 km s-1, the typical value expected for halo lenses, but an order of magnitude smaller th…
RPC-ICA: The Ion Composition Analyzer of the Rosetta Plasma Consortium
Kallio, E.; Fedorov, A.; Koskinen, H. +9 more
The Ion Composition Analyzer (ICA) is part of the Rosetta Plasma Consortium (RPC). ICA is designed to measure the three-dimensional distribution function of positive ions in order to study the interaction between the solar wind and cometary particles. The instrument has a mass resolution high enough to resolve the major species such as protons, he…
The first observation of AX J1749.1-2733 in a bright X-ray state—Another fast transient revealed by INTEGRAL
Sunyaev, R. A.; Grebenev, S. A.
An intense outburst of hard radiation (with a peak flux of ∼50 mCrab) was detected from the X-ray transient AX J1749.1-2733 by the IBIS/ISGRI gamma-ray telescope onboard the INTEGRAL observatory when the Galactic center field was monitored on September 8 10, 2003. Previously, this source had never been observed in a bright X-ray state. During the …
The PN.S Elliptical Galaxy Survey: Data Reduction, Planetary Nebula Catalog, and Basic Dynamics for NGC 3379
Freeman, K. C.; Capaccioli, M.; Napolitano, N. R. +9 more
We present results from Planetary Nebula Spectrograph (PN.S) observations of the elliptical galaxy NGC 3379 and a description of the data reduction pipeline. We detected 214 planetary nebulae, of which 191 are ascribed to NGC 3379 and 23 to the companion galaxy NGC 3384. Comparison with data from the literature shows that the PN.S velocities have …
Oxygen compounds in Titan's stratosphere as observed by Cassini CIRS
Fletcher, L.; Lellouch, E.; Irwin, P. G. J. +10 more
We have investigated the abundances of Titan's stratospheric oxygen compounds using 0.5 cm-1 resolution spectra from the Composite Infrared Spectrometer on the Cassini orbiter. The CO abundance was derived for several observations of far-infrared nadir spectra, taken at a range of latitudes (75° S-35° N) and emission angles (0°-60°), us…
Deposition and degradation of a volatile-rich layer in Utopia Planitia and implications for climate history on Mars
Reiss, Dennis; van Gasselt, Stephan; Hauber, Ernst +3 more
We investigate the surface morphology of a study area in western Utopia Planitia, Mars, which is characterized by a variety of landforms that resemble those of terrestrial periglacial landscapes. Polygonally fractured ground and thermokarst-like depressions are found to be located in a young mantling deposit with a thickness of several tens of met…