Search Publications
The role of the LIRG and ULIRG phases in the evolution of Ks-selected galaxies
Le Floc'h, E.; Dole, H.; Lagache, G. +5 more
Aims.We investigate the role of the luminous infrared galaxy (LIRG) and ultra-luminous infrared galaxy (ULIRG) phases in the evolution of K_s-selected galaxies and, in particular, Extremely Red Galaxies (ERGs).
Methods: .With this aim, we compare the properties of a sample of 2905 K_s<21.5 (Vega mag) galaxies in the GOODS/CDFS with the sub-…
SS 433: a phenomenon imitating a Wolf-Rayet star
Ábrahám, P.; Fuchs, Y.; Koch Miramond, L.
We present mid-infrared (2-12 µm) spectra of the microquasar SS 433 obtained with the Infrared Space Observatory (spectroscopic mode of ISOPHOT and ISOCAM). We compare them to the spectra of four Wolf-Rayet stars: WR 78, WR 134, WR 136, and WR 147 in the same wavelength range. The mid-infrared spectrum of SS 433 mainly shows ion{H}{i} and io…
A Stellar-Mass Black Hole in the Ultraluminous X-Ray Source M82 X-1?
Okajima, Takashi; Ebisawa, Ken; Kawaguchi, Toshihiro
We have analyzed the archival XMM-Newton data of the bright ultraluminous X-ray source M82 X-1 with a 105 ks exposure when the source was in the steady state. Thanks to the high photon statistics from the large effective area and long exposure, we were able to discriminate different X-ray continuum spectral models. Neither the standard accretion d…
High-redshift galaxy populations
Cowie, Lennox L.; Hu, Esther M.
We now see many galaxies as they were only 800 million years after the Big Bang, and that limit may soon be exceeded when wide-field infrared detectors are widely available. Multi-wavelength studies show that there was relatively little star formation at very early times and that star formation was at its maximum at about half the age of the Unive…
Role of the Sun's Nonaxisymmetric Open Flux in Cosmic-Ray Modulation
Rouillard, A. P.; Sheeley, N. R., Jr.; Wang, Y. -M.
We reexamine the empirical relationship between the Sun's open magnetic flux and the cosmic-ray (CR) intensity over the solar cycle. The single parameter that correlates best with the inverted CR rate is found to be the nonaxisymmetric or longitudinally varying component of the total open flux, rather than the sunspot number or the rate of coronal…
Image-Subtraction Photometry of Variable Stars in the Globular Clusters NGC 6388 and NGC 6441
Catelan, M.; Stetson, Peter B.; Pritzl, Barton J. +4 more
We have applied Alard's image-subtraction method (ISIS ver. 2.1) to the observations of the globular clusters NGC 6388 and NGC 6441 previously analyzed using standard photometric techniques (DAOPHOT and ALLFRAME). In this reanalysis of observations obtained at the Cerro Tololo Inter-American Observatory, besides recovering the variables previously…
SCUBA observations of the Horsehead nebula - what did the horse swallow?
Bontemps, S.; Ward-Thompson, D.; Nutter, D. +2 more
We present observations taken with the Submillimetre Common-User Bolometer Array (SCUBA) on the James Clerk Maxwell Telescope (JCMT) of the Horsehead nebula in Orion (B33), at wavelengths of 450 and 850 µm. We see bright emission from that part of the cloud associated with the photon-dominated region (PDR) at the `top' of the horse's head, w…
Optical Polarimetry of the Jets of Nearby Radio Galaxies. I. The Data
Baum, Stefi A.; O'Dea, Christopher P.; Perlman, Eric S. +11 more
We present an overview of new HST imaging polarimetry of six nearby radio galaxies with optical jets. These observations triple the number of extragalactic jets with subarcsecond-resolution optical polarimetry. We discuss the polarization characteristics and optical morphology of each jet. We find evidence of high optical polarization, averaging 2…
A Comprehensive Search for Gamma-Ray Lines in the First Year of Data from the INTEGRAL Spectrometer
Teegarden, B. J.; Watanabe, K.
We have carried out an extensive search for gamma-ray lines in the first year of public data from the spectrometer (SPI) on the INTEGRAL mission. INTEGRAL has spent a large fraction of its observing time in the Galactic plane with particular concentration in the Galactic center (GC) region (~3 Ms in the first year). Hence the most sensitive search…
Energization of Plasma Species by Intermittent Kinetic Alfvén Waves
Goossens, Marcel; Voitenko, Yuriy
We propose a new phase-mixing sweep model of coronal heating and solar wind acceleration based on dissipative properties of kinetic Alfvén waves (KAWs). The energy reservoir is provided by the intermittent ∼1 Hz MHD Alfvén waves excited at the coronal base by magnetic restructuring. These waves propagate upward along open magnetic field lines, pha…