Neil Gehrels Swift Observatory

Swift Observatory logo

Launch Date: November 20, 2004

Extended Mission Lifetime: 2025+ (Pending NASA Senior Review)

End of Operations: No specific requirement (no consumables, no significant degradation)

Data Archive: https://swift.gsfc.nasa.gov/archive/

Swift is a MidEx class mission operated by NASA in partnership with agencies in Italy and the United Kingdom. BAT autonomously detects gamma-ray transients, and Swift autonomously begins a sequence of follow-up observations with XRT and UVOT. All three instruments provide alerts to GCN autonomously upon the detection of transients.

InstrumentsEnergy RangeField of ViewLocalization
Burst Alert Telescope (BAT)15-350 keV2 ster≤ 1–3′ radius (statistical, 90%)
X-ray Telescope (XRT)0.3–10 keV23.6′×23.6′1–3″
Ultraviolet/Optical Telescope UVOT170–650 nm17′×17′<1″

GCN Notice Types in GCN Classic and GCN Classic Over Kafka: Detailed Descriptions and Examples

Type Typical Latency Since Burst Location Precision Description
Flight Generated:
SWIFT_BAT_GRB_ALERT~7 secondsN/AFirst Notice, Timestamp Alert
SWIFT_BAT_QL_POS13–30 seconds1–3′QuickLook Position Notice (subset of BAT_POS info)
SWIFT_BAT_GRB_POS_ACK13–30 seconds1–3′First Position Notice, the BAT Position
SWIFT_BAT_GRB_POS_NACK30–60 secondsN/AOnly if no position was found
SWIFT_BAT_SUB_THRESHOLD13–30 seconds1–4′Sub-threshold triggers (Position)
SWIFT_BAT_GRB_LC~220 seconds1–3′Lightcurve (also has the position)
SWIFT_FOM_OBS14–41 seconds1–3′FOM decision: Observe or Not
SWIFT_SC_SLEW14–41 seconds1–3′Spacecraft decision: Slew or Not
SWIFT_XRT_POSITION30–80 seconds<7″XRT afterglow location
SWIFT_XRT_CENTROID30–80 secondsN/ACould not find an XRT afterglow location
SWIFT_XRT_IMAGE31–81 seconds<7″2′×2′ FOV (5-30 s integration)
SWIFT_XRT_SPECTRUM40–81 secondsN/ASpectrum (few-to-100 s integration)
SWIFT_XRT_LC141–910 secondsN/AThe x-ray lightcurve (106–826 s)
SWIFT_UVOT_FCHART~260 secondsN/AThresholded pixel clusters
SWIFT_UVOT_DBURST~320 secondsN/AAll pixels from an 80×80 pixel subarray
SWIFT_UVOT_POS1–3 hours<2″UVOT afterglow location (Gnd-generated only)
SWIFT_UVOT_POS_NACK1–3 hoursN/ACould not find an UVOT afterglow location
Ground Processed:
SWIFT_BAT_GRB_LC_PROC~225 seconds1–3′Lightcurve (also has the position)
SWIFT_XRT_IMAGE_PROC40–70 seconds<6″2′×2′ FOV (~10 s integration)
SWIFT_XRT_SPECTRUM_PROC50–90 secondsN/AThe spectrum from that integration (~10 s)
SWIFT_UVOT_FCHART_PROC~280 secondsN/AThresholded pixel clusters
SWIFT_UVOT_DBURST_PROC~340 secondsN/AAll pixels from an 80×80 pixel subarray
Special:
SWIFT_BAT_SLEW_POS1–6 hours1–7′Bursts & Transient found in the slew data (BATSS)
SWIFT_BAT_MONITOR1–12 hours1–7′Flares from known sources
SWIFT_BAT_SUBSUB1–12 hours1–7′Sub-Sub-Threshold blips in all image produced on-board
SWIFT_BAT_KNOWN_SRC1–12 hours1–7′Peaks of known-sources found in all image produced on-board

Common GCN Circular Types:

TypeLatencyExample
Swift identification of a GRB30 minutesGRB 210517A
XRT enhanced GRB positionhoursGRB 210517A
UVOT follow-up of a GRBhoursGRB 210517A
BAT refined analysis of a GRB12 hoursGRB 210517A
XRT refined analysis of a GRB12 hoursGRB 210517A
BAT GUANO localization of a GRB6 hoursGRB 210827A
BAT GUANO recovery of a GRB6 hoursGRB 211105A
Swift ToO observations12 hoursGRB 210704A
Swift BAT observations of a GW trigger12 hoursLIGO/Virgo S200114f
Swift tiling of a GW trigger1 dayLIGO/Virgo S200114f

Annual Trigger Rates:

InstrumentLong GRBsShort GRBsDescription
BAT70–807–9On-board trigger rate
XRT60–6540–50XRT follow-up detections
UVOT20–250–1UVOT follow-up detections
BAT8–102–4GUANO arcminute recovery rate

Trigger Rates determined from cataloged information including the Swift-BAT Third GRB Catalog and the Swift GRB Lookup Table. GUANO results are from the online summary table.