An Overview of the Swift Observatory Liz Puchnarewicz Mullard Space Science Laboratory University College London
The Observatory Three telescopes: • BAT - g-ray Burst Alert Telescope • XRT – X-Ray Telescope • UVOT – UV/Optical Telescope
BAT g-ray Burst Alert Telescope coded mask 15 -150 ke. V fov = 1. 4 ster psf = 20 arcmin burst position to 4 arcmin notifies GCN slews to target in ~ 60 secs
XRT X-Ray Telescope Jet-X telescope XMM-EPIC CCD 0. 2 -10 ke. V fov 24 x 24 arcmin psf 15 arcsec hew burst position to ~ 5 arcsec time resolution down to 5 ms
UVOT UV/Optical Telescope XMM-OM 170 -600 nm fov 17 x 17 arcmin psf 0. 9 arcsec fwhm burst position to ~0. 3 arcsec 6 colours UV grism spectroscopy
Observing strategy BAT • detects bursts • calculates positions to 1 -4 arcmin • triggers autonomous spacecraft slews Spacecraft slews to position in ~ 60 secs XRT imaging refines position to 5 arcsec and takes 0. 2 -10 ke. V spectra UVOT makes finding chart (100 sec exposure) and searches for optical counterpart down to m. V~24
“Off-duty” science • BAT hard X-ray (15 -150 ke. V) survey down to ~2 x 10 -11 erg cm-2 s-1 • Absorbed AGN population (400 -600 sources anticipated; currently only ~20 AGN significant at energies > 30 ke. V) • Soft g-ray repeaters (SGRs) • Rapid multiwavelength response via TDRSS uplink for, eg. , AGN flares, X-ray transients, pulsar glitches, outbursts from dwarf novae and stellar flares • Enormous potential for serendipitous science
Data availability • Previous GRB studies largely conducted via To. Os. • With 2 -3 bursts expected per week, scheduled observation time is now possible. • To encourage follow-up, precise positions will be distributed via the GCN and are public immediately. • Swift project already has in place a team of 25+ scientists to collaborate on follow-up observations. • “Burst advocates” assigned 24/7 to ensure optimum exploitation of individual bursts. • Observers are encouraged to make their data available on a web-accessible database
A Whole New Approach • As a “response” observatory and a public facility, Swift demands a new kind of scientific co-operation • There is a responsibility on post-launch support teams to best exploit subsequent follow-up by Swift • Led to formation of “mini-MOCs” at Leicester and MSSL (in the UK; also US and Italy) • Burst advocates at mini-MOCs will co-ordinate efforts for individual bursts so are first points of contact for follow-up observers re Swift observatory planning. • Communication and co-operation between Swift team and scientists will be key to success of GRB science
An Overview of the Swift Observatory Useful web addresses: http: //swift. gsfc. nasa. gov/ http: //www. mssl. ucl. ac. uk/pages/general/projects/swift/SWIFT 6. html http: //www. src. le. ac. uk/projects/swift/ http: //gcn. gsfc. nasa. gov/gcn/ http: //msp. gsfc. nasa. gov/tdrss/oview. html
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