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The Host Galaxy of GRB 031203: Implications of Its Low Metallicity, Low Redshift, and Starburst Nature
Chen, Hsiao-Wen; Graham, James R.; Dressler, Alan +6 more
We present Keck/NIRSPEC near-IR images and Magellan/IMACS optical spectroscopy of the host galaxy of GRB 031203. The host is an actively star-forming galaxy at z=0.1055+/-0.0001. This is the lowest redshift GRB to date, aside from GRB 980425. From the hydrogen Balmer lines, we infer an extinction of AV=3.62+/-0.25 or a total reddening E…
Discovery of Hard Nonthermal Pulsed X-Ray Emission from the Anomalous X-Ray Pulsar 1E 1841-045
Kuiper, L.; Hermsen, W.; Mendez, M.
We report the discovery of nonthermal pulsed X-ray/soft gamma-ray emission up to ~150 keV from the anomalous 11.8 s X-ray pulsar AXP 1E 1841-045 located near the center of supernova remnant Kes 73 using Rossi X-Ray Timing Explorer (RXTE) Proportional Counter Array and High Energy X-Ray Timing Experiment (HEXTE) data. The morphology of the double-p…
The First IBIS/ISGRI Soft Gamma-Ray Galactic Plane Survey Catalog
Hill, A. B.; Walter, R.; Malaguti, G. +16 more
We report the first high-energy survey catalog obtained with the IBIS gamma-ray imager on board INTEGRAL. The analysis has been performed on the first-year Core Program ISGRI data comprising both Galactic Plane Scan and Galactic Centre Deep Exposure pointings for a total exposure time exceeding 5 Ms. This initial survey has revealed the presence o…
The Optical/Near-Infrared Counterpart of the INTEGRAL Obscured Source IGR J16318-4848: An sgB[e] in a High-Mass X-Ray Binary?
Filliatre, P.; Chaty, S.
The X-ray source IGR J16318-4848 was the first source discovered by INTEGRAL on 2003 January 29. The high-energy spectrum exhibits such a high column density that the source is undetectable in X-rays below 2 keV. On 2003 February 23-25, we triggered our Target of Opportunity (ToO) program using the EMMI and SOFI instruments on the New Technology T…
Hypernovae/Gamma-Ray Bursts in the Galactic Center as Possible Sources of Galactic Positrons
Schanne, S.; Cordier, B.; Paul, J. +1 more
The observation of a strong and extended positron-electron line annihilation emission in the central regions of the Galaxy by the SPectrometer on the International Gamma-Ray Astrophysical Laboratory (INTEGRAL/SPI), consistent with the Galactic bulge geometry and without any counterpart in the gamma-ray range, neither at high energy nor in the 1809…
RHESSI e+-e- Annihilation Radiation Observations: Implications for Conditions in the Flaring Solar Chromosphere
Smith, David M.; Lin, Robert P.; Share, Gerald H. +2 more
RHESSI has measured the positron-electron annihilation line and continuum in three solar flares: 2002 July 23, 2003 October 28, and 2003 November 2. The 511 keV line was broad (~4-8 keV) in all three flares, consistent with annihilations in an ambient ionized medium at temperatures above 105 K. The measured continuum from positronium an…
Detection of Hard X-Ray Emission from the Galactic Nuclear Region with INTEGRAL
Goldoni, P.; Parmar, A. N.; Ubertini, P. +13 more
This Letter presents the first results of an observational campaign to study the Galactic center with INTEGRAL, the International Gamma-Ray Astrophysics Laboratory. Mosaicked images were constructed using data obtained with ISGRI, the soft gamma-ray instrument of the coded aperture IBIS imager, in the energy ranges 20-40 and 40-100 keV. These give…
INTEGRAL and XMM-Newton Spectral Studies of NGC 4388
Gehrels, N.; Petrucci, P. -O.; Walter, R. +4 more
We present INTEGRAL and XMM-Newton observations of a Seyfert galaxy, the type 2 active galactic nucleus (AGN) NGC 4388. Several INTEGRAL observations performed in 2003 allow us to study the spectrum in the 20-300 keV range. In addition, two XMM-Newton observations give detailed insight into the 0.2-10 keV emission. The measurements presented here …
Collisions among Clouds inside Dusty Tori in Active Galactic Nuclei:Observational Consequences
Wang, Jian-Min
A geometrically thick dusty torus in NGC 1068 has been unambiguously resolved by an infrared interferometry telescope. This implies that clouds composing the dusty torus are undergoing supersonic collisions with each other. We show that the collisions form strong nonrelativistic shocks, which accelerate populations of relativistic electrons. The t…