AAS Jan05 DBurrows

Slide1: 

Swift X-ray Telescope Status & Observations of the Afterglow of GRB 041223 David Burrows - PSU

The Swift Observatory: 

The Swift Observatory Launched: 20 November 2004 XRT turned on: 23 November 2004 XRT First Light: 11 December 2004 First BAT Burst: 17 December 2004 First XRT Afterglow: 23 December 2004 XRT First Light: Cas A

Slide3: 

XRT Thermal Tests UVOT Activation Beginning XRT Thermal Control TEC Power Heating CCD

XRT First Light Observations: 

XRT First Light Observations Cas A: (13 ks) Focus is perfect!! 2% shift in gain M. Goad, UL A. Moretti, OAB J. Hill, PSU Mkn 421:

Preliminary Crab spectral fit: 

Preliminary Crab spectral fit NH = 0.35 ± 0.04 Γ = 2.10 ± 0.01

GRB 041223: 

Offset from optical transient: 2.1 arcseconds GRB 041223 Discovered by BAT at 14:06:18 on 23 December 2004 XRT was in midst of thermal tests, taking data in PC mode Slewed to GRB 4.6 hrs after burst as ToO Observed on 3 consecutive orbits for total of about one hour on-target XRT position: RA(J2000) = 06:40:47.5 Dec (J2000) = -37:04:22.5 SWIFT J064047.5-370423 Offset from BAT position: 50 arcseconds

Lightcurve: 

Lightcurve X-ray source was uncatalogued. X-ray source faded rapidly. Data extracted with ximage from 20” radius circle. Background extracted from 47” radius circle. Only used times when pointing was stable and background was low. 520 counts in 3504 seconds.

Spectrum: 

Spectrum NH = (1.5 ± 0.5) x 1021 Γ = 2.02 ± 0.21 (90%) χ2 / ν = 15.4 / 22 Fx = 6.5 x 10-12 (0.5-10 keV)

Broad-band SED: 

Broad-band SED (VLT observations from MISTICI collaboration) For Fν(t) = t -α and F(ν) = ν -β Spectral break suggests that cooling frequency lies between the X-ray and optical bands. (68% confidence errors)

Broad-band SED: 

Broad-band SED If αx and αNIR are constant, then νNIR < νc < νx and ν c  t –α, where α = 1.0 ± 0.2 to fit data

Conclusions: 

Conclusions NIR and X-ray data are consistent with the following scenario: Jet has two components: narrow component that produces X-rays and broader component that produces optical Jet break of narrow component occurs before X-ray observations Produces self-consistent model with electron power-law index of about 1.9 – 2.0 XRT is working well and producing excellent data in spite of higher operating temperature Images are spectacular Spectroscopy is better than Chandra at beginning of GTO phase Spectroscopy expected to remain better than ASCA over life High resolution timing available (up to 140 microseconds)

Co-Authors: 

Co-Authors Penn State: David Burrows Joanne Hill Judith Racusin Shiho Kobayashi Peter Meszaros John Nousek Jamie Kennea David Morris Claudio Pagani OAB: Guido Chincarini Gianpiero Tagliaferri Sergio Campana Alberto Moretti Patrizia Romano Daniele Malesani Stefano Covino Paolo D’Avanzo UL: Paul O’Brien Alan Wells Julian Osborne Tony Abbey Andy Beardmore Mike Goad Kim Page Dick Willingale GSFC: Neil Gehrels Lorella Angelini UNLV: Bing Zhang OAR (Rome): Luigi Stella Angelo Antonelli ASDC: Paolo Giommi Milvia Capalbi

Centroiding: 

Centroiding Her X-1 Cyg X-3 Cyg X-1 On-board calculation Pipeline processing 10” x 10” box, centered on source position