Search Publications
The Nucleosynthesis of 26Al and 60Fe in Solar Metallicity Stars Extending in Mass from 11 to 120 Msolar: The Hydrostatic and Explosive Contributions
Limongi, Marco; Chieffi, Alessandro
We present the 26Al and 60Fe yields produced by a generation of solar metallicity stars ranging in mass between 11 and 120 Msolar. We discuss the production sites of these γ-ray emitters and quantify the relative contributions of the various components. We provide the contributions of the wind, the C convective she…
Discovery of Luminous Pulsed Hard X-Ray Emission from Anomalous X-Ray Pulsars 1RXS J1708-4009, 4U 0142+61, and 1E 2259+586 by INTEGRAL and RXTE
Kuiper, L.; Hermsen, W.; den Hartog, P. R. +1 more
We investigated the time-averaged high-energy spectral characteristics of the persistent anomalous X-ray pulsars (AXPs) 1RXS J1708-4009, 4U 0142+61, 1E 2259+586, and 1E 1048.1-5937, using RXTE PCA (2-60 keV), RXTE HEXTE (15-250 keV), and INTEGRAL IBIS ISGRI (20-300 keV) data. We discovered hard spectral tails for energies above 10 keV in the total…
Unveiling Supergiant Fast X-Ray Transient Sources with INTEGRAL
Hill, A. B.; Bird, A. J.; Ubertini, P. +9 more
Supergiant high-mass X-ray binaries (SGXBs) are believed to be rare objects, as stars in the supergiant phase have a very short lifetime and to date only about a dozen of them have been discovered. They are known to be persistent and bright X-ray sources. INTEGRAL is changing this classical picture, as its observations are revealing the presence o…
Discovery of an Extraordinarily Massive Cluster of Red Supergiants
MacKenty, John W.; Figer, Donald F.; Kudritzki, Rolf P. +4 more
We report the discovery of an extraordinarily massive young cluster of stars in the Galaxy, having an inferred total initial cluster mass comparable to the most massive young clusters in the Galaxy. Using IRMOS, 2MASS, and Spitzer observations, we conclude that there are 14 red supergiants in the cluster, compared with five, in what was previously…
Models for the Type Ic Hypernova SN 2003lw associated with GRB 031203
Della Valle, Massimo; Tominaga, Nozomu; Nomoto, Ken'ichi +10 more
The gamma-ray burst GRB 031203 at a redshift z=0.1055 revealed a highly reddened Type Ic supernova, SN 2003lw, in its afterglow light. This is the third well-established case of a link between a long-duration GRB and a Type Ic SN. The SN light curve is obtained by subtracting the galaxy contribution and is modeled together with two spectra at near…
A Multiwavelength Study of Sgr A*: The Role of Near-IR Flares in Production of X-Ray, Soft γ-Ray, and Submillimeter Emission
Dowell, C. D.; Bélanger, G.; Goldwurm, A. +8 more
Although Sgr A* is known to be variable in radio, millimeter, near-IR, and X-rays, the correlation of the variability across its spectrum has not been fully studied. Here we describe highlights of the results of two observing campaigns in 2004 to investigate the correlation of flare activity in different wavelength regimes, using a total of nine g…
Nonthermal High-Energy Emission from Colliding Winds of Massive Stars
Reimer, A.; Reimer, O.; Pohl, M.
Colliding winds of massive star binary systems are considered as potential sites of nonthermal high-energy photon production. Motivated by the detection of synchrotron radio emission from the colliding wind location, we here investigate the properties of high-energy photon production in colliding winds of long-period WR+OB systems. Analytical form…
The Second IBIS/ISGRI Soft Gamma-Ray Survey Catalog
Hill, A. B.; Mas-Hesse, J. M.; Walter, R. +21 more
In this paper we report the second soft gamma-ray source catalog obtained with the IBIS/ISGRI gamma-ray imager on board the INTEGRAL satellite. The scientific data set is based on more than 10 Ms of high-quality observations performed during the first 2 years of Core Program and public IBIS/ISGRI observations, and covers ~50% of the whole sky. The…
Gamma-Ray Imaging of the 2003 October/November Solar Flares
Krucker, S.; Lin, R. P.; Smith, D. M. +3 more
We present RHESSI imaging of three flares (2003 October 28 and 29 and November 2) in the 2.223 MeV neutron-capture gamma-ray line with angular resolution as high as 35". Comparisons of imaged and spatially integrated fluences show that in all cases most, if not all, of the emission was confined to compact sources with size scales of tens of arcsec…
The Signature of 44Ti in Cassiopeia A Revealed by IBIS/ISGRI on INTEGRAL
Knödlseder, J.; Decourchelle, A.; Vink, J. +9 more
We report the detection of both the 67.9 and 78.4 keV 44Sc γ-ray lines in Cassiopeia A with the INTEGRAL IBIS/ISGRI instrument. Besides the robustness provided by spectroimaging observations, the main improvements compared to previous measurements are a clear separation of the two 44Sc lines together with an improved signific…