Search Publications
X-ray Evolution of Pulsar Wind Nebulae
Dotani, Tadayasu; Ebisawa, Ken; Vink, Jacco +4 more
During the search for counterparts of very high energy gamma-ray sources, we serendipitously discovered large, extended, low surface brightness emission from pulsar wind nebulae (PWNe) around pulsars with the ages up to ~100 kyr, a discovery made possible by the low and stable background of the Suzaku X-ray satellite. A systematic study of a sampl…
Cosmic Evolution of Virial and Stellar Mass in Massive Early-type Galaxies
Treu, Tommaso; Bradač, Maruša; Gavazzi, Raphaël +7 more
We measure the average mass properties of a sample of 41 strong gravitational lenses at moderate redshift (z ~ 0.4-0.9) and present the lens redshift for six of these galaxies for the first time. Using the techniques of strong and weak gravitational lensing on archival data obtained from the Hubble Space Telescope, we determine that the average ma…
Suzaku Observations of Hard X-ray-selected Seyfert 2 Galaxies
Fiore, F.; Vignali, C.; Gilli, R. +4 more
We present Suzaku observations of five hard X-ray-selected nearby Seyfert 2 galaxies. All the sources were clearly detected with the PIN Hard X-ray Detector up to several tens of keV, allowing for a fairly good characterization of the broadband X-ray continuum. We find that a unique model, even including multiple components, fails to represent the…
Projected Central Dark Matter Fractions and Densities in Massive Early-type Galaxies from the Sloan Digital Sky Survey
Grillo, C.
We investigate in massive early-type galaxies the variation of their two-dimensional central fraction of dark over total mass and dark matter density as a function of stellar mass, central stellar velocity dispersion, effective radius, and central surface stellar mass density. We use a sample of approximately 1.7 × 105 galaxies from the…
Physical Properties and Morphology of a Newly Identified Compact z = 4.04 Lensed Submillimeter Galaxy in Abell 2218
Richard, Johan; Kneib, Jean-Paul; Egami, Eiichi +2 more
We present the identification of a bright submillimeter (submm) source, SMM J163555.5+661300, detected in the lensing cluster Abell 2218, for which we have accurately determined the position using observations from the Submillimeter Array (SMA). The identified optical counterpart has a spectroscopic redshift of z = 4.044 ± 0.001 if we attribute th…
Intermittency and Multifractality Spectra of the Magnetic Field in Solar Active Regions
Yurchyshyn, Vasyl; Abramenko, Valentyna
We present the results of a study of intermittency and multifractality of magnetic structures in solar active regions (ARs). Line-of-sight magnetograms for 214 ARs of different flare productivity observed at the center of the solar disk from 1997 January until 2006 December are utilized. Data from the Michelson Doppler Imager (MDI) instrument on b…
Discovery of a Highly Energetic Pulsar Associated with IGR J14003-6326 in the Young Uncataloged Galactic Supernova Remnant G310.6-1.6
Tomsick, J. A.; Rodriguez, J.; Gotthelf, E. V. +6 more
We report the discovery of 31.18 ms pulsations from the INTEGRAL source IGR J14003-6326 using the Rossi X-ray Timing Explorer (RXTE). This pulsar is most likely associated with the bright Chandra X-ray point source lying at the center of G310.6-1.6, a previously unrecognized Galactic composite supernova remnant (SNR) with a bright central non-ther…
Multi-Epoch Hubble Space Telescope Observations of IZw18: Characterization of Variable Stars at Ultra-Low Metallicities
Saha, A.; Tosi, M.; Clementini, G. +7 more
Variable stars have been identified for the first time in the very metal-poor blue compact dwarf galaxy IZw18, using deep multi-band (F606W, F814W) time-series photometry obtained with the Advanced Camera for Surveys on board the Hubble Space Telescope. We detected 34 candidate variable stars in the galaxy. We classify three of them as Classical C…
Scaling Laws and Temperature Profiles for Solar and Stellar Coronal Loops with Non-uniform Heating
Martens, P. C. H.
The bulk of solar coronal radiative loss consists of soft X-ray emission from quasi-static loops at the cores of active regions. In order to develop diagnostics for determining the heating mechanism of these loops from observations by coronal imaging instruments, I have developed analytical solutions for the temperature structure and scaling laws …
The Double-degenerate Nucleus of the Planetary Nebula TS 01: A Close Binary Evolution Showcase
Wilms, Jörn; Rauch, Thomas; Tomsick, John +8 more
We present a detailed investigation of SBS 1150+599A, a close binary star hosted by the planetary nebula PN G135.9+55.9 (TS 01). The nebula, located in the Galactic halo, is the most oxygen-poor known to date and is the only one known to harbor a double degenerate core. We present XMM-Newton observations of this object, which allowed the detection…