GBM Data Products
The following tables list all the science data products created by the GIOC (the GBM's Instrument Operation Center) and provided to the FSSC. Some products are used by investigators in the Fermi-provided software, some are accessed by this software without the investigator's intervention, and others may be used by investigators independent of Fermi software.
Daily Data Product
The following data products are created daily by the GIOC and sent to the FSSC, regardless of whether a gamma-ray burst has been detected. These data products will be produced within 24 hours after the GIOC receives the last input data.
| ID | Name | Description |
|---|---|---|
| GS-001 | CTIME (daily version) | The counts accumulated every 0.256 s in 8 energy channels for each of the 14 detectors. |
| GS-002 | CSPEC (daily version) | The counts accumulated every 8.192 s in 128 energy channels for each of the 14 detectors. |
| GS-005 | GBM gain and energy resolution history | History of the detector gains and energy resolutions; required for calculating DRMs. |
| GS-006 | Fermi position and attitude history | History of Fermi's position and attitude, required for calculating DRMs |
CTIME and CSPEC are PHA FITS files (i.e., files with a format that is standard for spectra), and therefore users may have software that accesses these files. The GS-005 and GS-006 data products will be accessed by Fermi software.
Burst Data Products
The following data products are created by the GIOC and sent to the FSSC whenever a gamma-ray burst has been detected. These data products have a latency of 1 day; the catalog entry files will be updated after more information about a burst is available.
| ID | Name | Description |
|---|---|---|
| GS-101 | CTIME (burst version) | For each detector, the counts accumulated every 0.064 s in 8 energy channels |
| GS-102 | CSPEC (burst version) | For each detector, the counts accumulated every 1024 s in 128 energy channels. |
| GS-103 | GBM TTE | Event data for the burst. There is one file for each detector. |
| GS-104 | GBM DRMs | 8 and 128 energy channel Detector Response Matrices (DRMs) for all 14 detectors. |
| GS-105 | GBM Trigger Catalog Entry | Classification of GBM trigger with some characteristics. This file is used to set up the BROWSE table. |
| GS-106 | GBM Burst or Spectral Catalog Entry | Values of the quantities describing the burst (e.g., durations, fluences). This file is used to set up the BROWSE table. |
| GS-107 | GBM TRIGDAT | All the GBM's messages downlinked through TDRSS. These messages are the basis of the GCN Notices for the burst. |
| GS-108 | GBM Background Files | Background spectra for spectral fitting. |
The Fermi software analyzes the TTE data (GS-103) using the response functions (GS-104) and background spectrum (GS-108) specific to a particular burst.
Updates
The following data products are created by the GIOC and sent to the FSSC from time to time.
| ID | Name | Description | Latency |
|---|---|---|---|
| GS-007 | GBM PHA Look-Up Tables | Tables of the correspondence between CTIME and CSPEC energy channels and the photopeak energy for each detector | Every ~6 months |
| GS-008 | GBM Calibration | Tables of fiducial detector response parameters from which the burst-specific DRMs are calculated | Every ~6 months |
| GS-105 | GBM Trigger Catalog Entry | Classification of GBM trigger with some characteristics | Updated periodically |
| GS-106 | GBM Burst or Spectral Catalog Entry | Values of the quantities describing the burst (e.g., durations, fluences) | Updated periodically |
The first two data products are inputs to the calibration software, while the last two are updates to the catalog entries.