摘要:

The spectrometer SPI is one of the main detectors of ESA’s INTEGRAL mission. The instrument offers two interesting and valuable capabilities for the detection of the prompt emission of Gamma‐ray bursts. Within a field of view of 16 degrees, SPI is able to localize Gamma‐ray bursts with an accuracy of 10 arcmin. The large anticoincidence shield, ACS, consisting of 512 kg of BGO crystals, detects Gamma‐ray bursts quasi omnidirectionally above ∼70keV. Burst alerts from SPI/ACS are distributed to the interested community via the INTEGRAL Burst Alert System. The ACS data have been implemented into the 3rd Interplanetary Network and have proven valuable for the localization of bursts using the triangulation method. During the first 8 months of the mission approximately one Gamma‐ray burst per month was localized within the field of flew of SPI and 145 Gamma‐ray burst candidates were detected by the ACS from which 40 &percent; have been confirmed by other instruments. © 2004 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1810921

出版商:AIP    

年代:1904

数据来源: AIP

摘要:

The first year of full SXC operations has resulted in the detection of over a dozen GRBs and XRFs, and the SXC GRB catalog continues to grow at a rate of approximately 1/month. The small error circles, rapid position dissemination, and most importantly, aggressive follow up observations have led to a remarkable trend: nearly all SXC detections have an associated optical/IR/radio/X‐ray counterpart. The systematic errors dominating the SXC astrometry are being reduced, and recent recalibration efforts will result in smaller error radii sent out to the GCN. Flight localizations calculated tens of seconds after the burst onset will also enable large telescopes with small fields of view to engage in rapid, deep searches. These two factors will aid in building a unique database of GRBs with associated transients. © 2004 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1810922

出版商:AIP    

年代:1904

数据来源: AIP

摘要:

The High Energy Transient Explorer (HETE‐2) has been in orbit for nearly three years. After a slow startup, the operation of the spacecraft and its instrumentation is now stable and efficient. GRBs are being localized at a rate of ∼25 per year, and the Soft X‐ray Camera (SXC) is determining burst positions with arcminute precision on a regular basis. As described elsewhere in this conference, HETE‐2 has essentially solved the mystery of the “dark bursts” and helped confirm the connection between long GRBs and type Ic supernovae. Because of its excellent low‐energy response, HETE has proven to be a capable detector of X‐ray rich GRBs and X‐ray flashes. In this paper, we give an update on the spacecraft and instruments and describe some of the more significant developments of the last 6‐12 months. We also highlight issues which, although described in part on the HETE web page (http: //space.mit.edu/HETE), may not be clear to many observers. © 2004 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1810923

出版商:AIP    

年代:1904

数据来源: AIP

摘要:

Swift is a first‐of‐its‐kind multiwavelength transient observatory for GRB astronomy. It has the optimum capabilities for the next breakthroughs in determining the origin of GRBs and their afterglows, as well as using bursts to probe the early Universe. Swift will also perform the first sensitive hard X‐ray survey of the sky. The mission is being developed by an international collaboration and consists of three instruments, the Burst Alert Telescope (BAT), the X‐ray Telescope (XRT), and the Ultraviolet and Optical Telescope (UVOT). The BAT, a wide‐field gamma‐ray detector, will detect > 100 GRBs per year with a sensitivity >2 times that of BATSE. The sensitive narrow‐field XRT and UVOT will be autonomously slewed to the burst location in 20 to 75 seconds to determine 0.3–5.0 arcsec positions and perform optical, UV, and X‐ray spectrophotometry. Strong education/public outreach and follow‐up programs will help to engage the public and astronomical community. The Swift launch is planned for mid 2004. © 2004 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1810924

出版商:AIP    

年代:1904

数据来源: AIP

摘要:

The X‐ray Telescope (XRT) for the SWIFT mission, built by the international consortium from Pennsylvania State University (US), University of Leicester (UK) and Osservatorio Astronomico di Brera (Italy), is already installed on the SWIFT spacecraft. The XRT has two key functions on SWIFT; to determine locations of GRBs to better than 5 arc seconds within 100 seconds of initial detection of a burst and to measure spectra and light curves of the X‐ray afterglow over around four orders of magnitude of decay in the afterglow intensity. This paper summarises the XRT performance, operating modes and sensitivity for the detection of prompt and extended X‐ray afterglows from gamma‐ray bursts. The performance characteristics have been determined from data taken during the ground calibration campaign at MPE’s Panter facility in September 2002. © 2004 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1810925

出版商:AIP    

年代:1904

数据来源: AIP

摘要:

We present the current on‐orbit calibration and operational plans for theSwiftXRT. The XRT is a largely autonomous instrument and requires very little manual commanding for normal operations. A detailed calibration plan is being developed to verify the instrumental performance on‐orbit, including effective area, point spread function, vignetting, spectroscopic performance, and timing accuracy. Operational plans include regular calibration measurements using on‐board calibration sources as well as periodic calibration observations using celestial targets. © 2004 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1810926

出版商:AIP    

年代:1904

数据来源: AIP

摘要:

The Ultra‐Violet/Optical Telescope (UVOT), one of three telescopes to fly on the Swift Gamma‐ray Burst Observatory, is capable of detecting the early UV/optical photons and performing long‐term UV/optical observations of GRB afterglows. The UVOT is a Ritchey‐Chretien telescope with MCP intensified CCD detectors which operate in either a photon‐timing or an imaging mode while providing sub‐arcsecond resolution. A filter wheel accommodates broadband UV and visual filters for photometric studies including determination of photometric redshifts. UV and visual grisms for low‐resolution spectroscopy are also housed in the filter wheel. We present a brief overview of the UVOT, calibration results, and science to be carried out. © 2004 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1810927

出版商:AIP    

年代:1904

数据来源: AIP

摘要:

The Burst Alert Telescope (BAT) on the Swift gamma ray burst mission will perform the first new all sky hard X‐ray survey since 1977. Swift will perform pointings covering >64&percent; of the sky each day and achieve an integrated systematics limited sensitivity in three years of 0.6 milliCrabs for sources well off the galactic plane. This survey is expected to identify hundreds of new highly obscured AGN. BAT will also serve as a sensitive rapid response X‐ray outburst and transient monitor. © 2004 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1810928

出版商:AIP    

年代:1904

数据来源: AIP

摘要:

The Burst Alert Telescope (BAT) on the Swift gamma‐ray burst mission serves as the GRB trigger for Swift as well as a sensitive imaging telescope for the energy range of 15–150 keV. All BAT data products will be available to the astronomical community along with a complete set of analysis tools. Gamma‐ray burst data products include rapid discovery messages delivered immediately via the GRB Coordinates Network, and event‐by‐event data from which light curves and spectra of the burst are generated. During nominal operations, the instrument provides accumulated survey histograms with 5‐minute time sampling and appropriate energy resolution. These survey accumulations are analyzed in a pipeline to detect new sources and derive light curves of known sources. The 5‐minute surveys will also be combined to produce the BAT all sky hard X‐ray survey. In addition, the instrument accumulates high time resolution light curves of the brightest BAT sources in multiple energy bands, which are merged into a source light curve database on the ground. The BAT science data products and analysis tools will be described in this paper. © 2004 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1810929

出版商:AIP    

年代:1904

数据来源: AIP

摘要:

The BAT instrument tellsSwiftwhere to point to make immediate follow‐up observations of GRBs. The science software on board must efficiently process &ggr;‐ray events coming in at up to 34 kHz, identify rate increases that could be due to GRBs while disregarding those from known sources, and produce images to accurately and rapidly locate new Gamma‐ray sources. © 2004 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1810930

出版商:AIP    

年代:1904

数据来源: AIP