Showing papers by "Joanne E. Hill published in 2004"
Goddard Space Flight Center1, Brera Astronomical Observatory2, University of Milan3, University College London4, Pennsylvania State University5, University of Leicester6, Sonoma State University7, University of California, Berkeley8, Universities Space Research Association9, National Research Council10, University of Southampton11, Los Alamos National Laboratory12, National Radio Astronomy Observatory13, Space Telescope Science Institute14, Max Planck Society15, California Institute of Technology16, University of Texas at Austin17, French Alternative Energies and Atomic Energy Commission18, University of Toronto19, University of Maryland, College Park20, Princeton University21, Lawrence Livermore National Laboratory22, University of Cambridge23, University of California, Santa Barbara24, Rice University25, University of Tokyo26, Saitama University27, University of Florence28
TL;DR: The Swift mission as discussed by the authors is a multi-wavelength observatory for gamma-ray burst (GRB) astronomy, which is a first-of-its-kind autonomous rapid-slewing satellite for transient astronomy and pioneers the way for future rapid-reaction and multiwavelength missions.
Abstract: The Swift mission, scheduled for launch in 2004, is a multiwavelength observatory for gamma-ray burst (GRB) astronomy. It is a first-of-its-kind autonomous rapid-slewing satellite for transient astronomy and pioneers the way for future rapid-reaction and multiwavelength missions. It will be far more powerful than any previous GRB mission, observing more than 100 bursts yr � 1 and performing detailed X-ray and UV/optical afterglow observations spanning timescales from 1 minute to several days after the burst. The objectives are to (1) determine the origin of GRBs, (2) classify GRBs and search for new types, (3) study the interaction of the ultrarelativistic outflows of GRBs with their surrounding medium, and (4) use GRBs to study the early universe out to z >10. The mission is being developed by a NASA-led international collaboration. It will carry three instruments: a newgeneration wide-field gamma-ray (15‐150 keV) detector that will detect bursts, calculate 1 0 ‐4 0 positions, and trigger autonomous spacecraft slews; a narrow-field X-ray telescope that will give 5 00 positions and perform spectroscopy in the 0.2‐10 keV band; and a narrow-field UV/optical telescope that will operate in the 170‐ 600 nm band and provide 0B3 positions and optical finding charts. Redshift determinations will be made for most bursts. In addition to the primary GRB science, the mission will perform a hard X-ray survey to a sensitivity of � 1m crab (� 2;10 � 11 ergs cm � 2 s � 1 in the 15‐150 keV band), more than an order of magnitude better than HEAO 1 A-4. A flexible data and operations system will allow rapid follow-up observations of all types of
3,753 citations
03 Feb 2004
TL;DR: The Swift X-ray Telescope (XRT) as mentioned in this paper is designed to make astrometric, spectroscopic, and photometric observations of Xray emission from Gamma-ray Bursts and their afterglows in the energy band 0.2-10 keV.
Abstract: The Swift X-ray Telescope (XRT) is designed to make astrometric, spectroscopic, and photometric observations of Xray emission from Gamma-ray Bursts and their afterglows in the energy band 0.2-10 keV. In order to provide rapidresponse, automated observations of these randomly occurring objects without ground intervention, the XRT must be able to observe objects covering some seven orders of magnitude in flux, extracting the maximum possible science from each one. This requires a variety of readout modes designed to optimise the information collected in response to shifting scientific priorities as the flux from the burst diminishes. The XRT will support four major readout modes: imaging, two timing modes and photon-counting, with several submodes. We describe in detail the readout modes of the XRT. We describe the flux ranges over which each mode will operate, the automated mode switching that will occur and the methods used for collection of bias information for this instrument. We also discuss the data products produced from each mode.
238 citations
03 Feb 2004
TL;DR: Moretti et al. as discussed by the authors measured the PSF of the SWIFTX-RTPoint Spread Function (PSF) as measured during the end-to-end calibration campaign at the Panter X-Ray b eam line facility.
Abstract: SWIFTXRTPointSpreadFunctionmeasuredattheanterend-to-endtestsA.Morettia,S.CampanaG. TagliaferriA.F.Abb eycR.M.AmbrosiL. AngelinighBeardmorec,H.W.BrauningereW.BurkertD.N. BurrowsbM.Capalbid,G.ChincariniaO.Citterioa,G. CusumanofM.J.Freyb ergeP.GiommidG.D.Hartner, J.E.HillbK. Mori,D.MorrisbK.MukerjeecJ.A.NousekJ. Osb orneA.D.T.ShortF.TamburellidD.J.Watsonc,A.ellsaINAFOsservatorio Astronomico di Brera,ItalybPennsylvania StateUniversity,USAcUniversityof Leicester,UKdAgenzia Spaziale Italiana, ItalyeMax-Planck-Institutfur ExtraterrestrischePhysik,GermanyfCNRIstituto diFisica Cosmica edApplicazioni dell' Informatica, ItalygLHEA,GSFC/NASAhUSRAABSTRACTTheSWIFTX{rayTelescop e (XRT) is designed to make astrometric, sp ectroscopic and photometric observa-tions of the X{ray emission from Gamma{ray bursts and their afterglows, in the energy band 0.2-10 keV. Herewe rep ort the results of the analysis ofSWIFTXRTPoint Spread Function (PSF) as measured during the end-to-end calibration campaign at the Panter X{Ray b eam line facility.The analysis comprises the study of thePSF b oth on{axis and o {axis.We compare the lab oratory results with the exp ectations from the ray{tracingsoftwareandfromthemirrormo duletestedasasingleunit.WeshothatmeasuredHEWmeetsmission scienti c requirements.On the basis of the calibration data we build an analytical mo del which is ableto repro duce the PSF as a function of the energy and the p osition within the detector.Keywords:Swift, XRT, PSF1. INTRODUCTIONThe XRT1is a sensitive, autonomous X-ray CCD imaging sp ectrometer designed to measure the ux, sp ectrum,and light curve of GRBs and afterglowover a wide ux range coering more than seven orders of magnitude inux.XRT utilizes the third ight mirror mo dule (FM3) develop ed for the JET{X program2:it consists of 12nested,confo caland coaxial mirror shells having a WolterI con guration.The mirror diameters range from191 mmto300 mm,thenominalfo callengthis 3500 mm,total eldofview isab out40 arcminutes (at50% vignetting level) and the e ectivearea at1.5 keV is165 cm2.The XRT imaging arrayis aMAT-22CCD consisting of 600 x 600 pixels, each40m40m with a nominal plate scale of 2.36 arcseconds p er pixel,whichmakes the e ective eld of view of the system24 arcmin.1The instrumentresponseof 1 counts secSend corresp ondence to moretti@merate.mi.astro.it
78 citations
03 Feb 2004
TL;DR: The Swift Gamma-Ray Explorer (XRT) as mentioned in this paper is a state-of-the-art XMM/EPIC MOS CCD detector with an effective area of 135 cm2 at 1.5 keV and an angular resolution of 18 arcseconds.
Abstract: The Swift Gamma-Ray Explorer is designed to make prompt multiwavelength observations of Gamma-Ray Bursts (GRBs) and GRB Afterglows. The X-ray Telescope (XRT) provides key capabilities that permit Swift to determine GRB positions with a few arcseconds accuracy within 100 seconds of the burst onset. The XRT utilizes a superb mirror set built for JET-X and a state-of-the-art XMM/EPIC MOS CCD detector to provide a sensitive broad-band (0.2-10 keV) X-ray imager with effective area of 135 cm2 at 1.5 keV, field of view of 23.6 x 23.6 arcminutes, and angular resolution of 18 arcseconds (HEW). The detection sensitivity is 2x10-14 erg/cm2/s in 104 seconds. The instrument is designed to provide automated source detection and position reporting within 5 seconds of target acquisition. It can also measure redshifts of GRBs for bursts with Fe line emission or other spectral features. The XRT will operate in an auto-exposure mode, adjusting the CCD readout mode automatically to optimize the science return for each frame as the source fades. The XRT will measure spectra and lightcurves of the GRB afterglow beginning about a minute after the burst and will follow each burst for days as it fades from view.
62 citations
01 Oct 2004
TL;DR: 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 afterglove intensity.
Abstract: 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.