| Description: ! The BAT Hard X-ray Survey data is a product of the BAT instrument on the Swift observatory. Swift/BAT is a wide field-of-view (70x100 degrees) hard X-ray imager consisting of a coded mask and large array of CdZnTe detectors (5000 cmsup2/sup). The primary purpose of BAT is the detection gamma-ray bursts and the BAT survey data is collected during the search for gamma-ray bursts. p BAT is sensitive in the energy range 14-195 keV. The data from the first 9 months of the survey is divided into 4 energy channels: 14-24, 24-50, 50-100, and 100-195 keV. Each of these is represented as separate survey, and an averaged survey over all bands is also given. p The all sky maps are presented in two forms, the significance maps and the flux maps. The significance maps are the count rate divided by the noise (sigma RMS) in a region of the map around the position. The noise is variable across the sky due to variable exposure and systematic noise. The noise is Gaussian and and the significances can be interpreted with the usual Gaussian probabilities. A threshold of 4.8 sigma for the blind detection of sources in the BAT survey corresponds to about 1 false detection on the whole sky. p The BAT flux map is scaled from the Crab rate in the survey and normalized to an assumed Crab spectrum of 10.4 Esup-2.15/sup photons.cmsup2/sup/sec/keV. Due to the large number of randomly distributed gamma-ray burst pointings that contribute to any point in the image, this is an accurate characterization for the whole sky. The 4.8 sigma threshold in the 9-month survey covers 80% of the sky at flux threshold of 3.5x10sup-11/sup ergs/cmsup2/sup/s in the 14-195 keV band and covers 1/3 of the sky near the ecliptic poles at 2.5x10sup-11/sup ergs/cmsup2/sup/s. ]] |
| Completely compliant |
| Service URL |
| Input Parameter | Required | Present |
|---|---|---|
| Regular parameters: | ||
| POS | MUST | Yes |
| SIZE | MUST | Yes |
| INTERSECT | MAY | No |
| NAXIS | MAY | Yes |
| CFRAME | MAY | Yes |
| EQUINOX | MAY | Yes |
| CRPIX | MAY | No |
| CRVAL | MAY | No |
| CDELT | MAY | No |
| ROTANG | MAY | No |
| PROJ | MAY | Yes |
| FORMAT | MUST | Yes |
| Service specific parameters | ||
| INTERPOLATION | MAY | Yes |
| big | MAY | Yes |
| small | MAY | Yes |
| Field UCD | Required | Present | Required datatype |
Actual datatype |
|---|---|---|---|---|
| Regular fields: | ||||
| VOX:Image_Title | MUST | Yes | char | char |
| INST_ID | SHOULD | No | char | |
| VOX:Image_MJDateObs | SHOULD | No | double | |
| POS_EQ_RA_MAIN | MUST | Yes | double | double |
| POS_EQ_DEC_MAIN | MUST | Yes | double | double |
| VOX:Image_Naxes | MUST | Yes | int | int |
| VOX:Image_Naxis | MUST | Yes | int | int |
| VOX:Image_Scale | MUST | Yes | double | double |
| VOX:Image_Format | MUST | Yes | char | char |
| VOX:STC_CoordRefFrame | SHOULD | No | char | |
| VOX:STC_CoordEquinox | MAY | No | double | |
| VOX:WCS_CoordProjection | SHOULD | No | char | |
| VOX:WCS_CoordRefPixel | SHOULD | No | double | |
| VOX:WCS_CoordRefValue | SHOULD | No | double | |
| VOX:WCS_CDMatrix | SHOULD | No | double | |
| VOX:BandPass_ID | SHOULD | No | char | |
| VOX:BandPass_Unit | SHOULD | No | char | |
| VOX:BandPass_RefValue | SHOULD | No | double | |
| VOX:BandPass_HiLimit | SHOULD | No | double | |
| VOX:BandPass_LoLimit | SHOULD | No | double | |
| VOX:Image_PixFlags | SHOULD | Yes | char | char |
| VOX:Image_AccessReference | MUST | Yes | char | char |
| Service specific fields: | ||||
| VOX:LogicalName | MAY | YES | char | |