| SOURCE | TIME DELAY | ERROR BOX SIZE | RATE | COMMENTS |
|---|---|---|---|---|
| BATSE_Original | 5 sec | 5-20deg dia | 1/day | Dedicated, automated, wide FOV. |
| BATSE_Final | 37 sec | 5-18deg dia | 1/day | Dedicated, automated, wide FOV. |
| BATSE_Lightcurve | 5 min | n/a | 1/day | Useful for burst assessment. |
| BATSE_MAXBC | 10 min | 5-20deg dia | 1/day | Fast response, wide FOV. |
| BATSE_LOCBURST | 15-35 min | 4-8deg dia | 7/month | Medium response, medium FOV. |
| BATSE_MSFC_Admin | 1-3 days | 2-5deg dia | 1/day | Final report |
| IPN_RAW | 0.5-1.5 days | n/a | 2/week | Timestamps only. |
| IPN_SEG | 0.5-3 days | 4'x4-8deg | 3/month | Small FOV with tiling. |
| COMPTEL | 20-30 min | 3-5deg dia | 6/year | Medium response, medium FOV. |
| SAX-WFC | 2-3 hours | 6-20' dia | 8/year | Small FOV telescopes |
| SAX-NFI | 12-48 hours | 100" dia | 4/year | Small FOV telescopes |
| MILAGRO | 30 sec | 0.5 deg | 5/week | Fast and Small |
| HETE_SC_ALERT | 10-20 sec | n/a | 8/month | Small FOV. |
| HETE_SC_UPDATE | 10-60 sec | 30' dia (WXM) | 2/month | Small FOV. |
| HETE_SC_LAST | 20-60 sec | 15' dia (WXM) | 1/month | Small FOV. |
| HETE_GNDANA | 1-3 hr | 2-5' dia (WXM) | 2/month | Small FOV. |
| RXTE-ASM | 1-2 hours | 4'x15-150' | 8/year | Small FOV telescopes. |
| RXTE-PCA | 3-5 hours | 6-40' dia | 6/year | Small FOV telescopes. |
| ALEXIS (extreme UV) | 12-24-48 hours | 0.38deg radius | 20/year | Small FOV telescopes. No longer available. |
| XTE-ASM hard x-ray TRANS | 1-2 hours | 4'x15-150' | 1-8/year | Small FOV telescopes. No longer available. |
| MILAGRO | 30 sec | 0.5 deg | 5/week | Fast and Small |
2.3) DISCONTINUED MISSIONS
2.3a) CGRO-BATSE GRB LOCATIONS (no longer available):
Original
This is the original form of GRB locations distributed to the then BACODINE sites.
(Now this, as are all the other notice types, is distributed to the GCN sites.)
The positions in these location notices are derived using the "ideal physics"
response functions for the LADs
and therefore have the largest location uncertainties. However, they are
also available to the follow-up community with the shortest time delays
from the start of the GRB -- typically less than 5 sec, which is shorter than
the duration of more than half the GRBs.
Click for more information on Original Coordinates Notices.
Final
Unlike the Original location which uses only
the first 1 or 2 seconds of data in the GRB, this Final location is based
on the integral of the light curve for up to 32 seconds of the GRB.
The Final Notices report the peak intensity and the fluence during the 32
seconds. These two parameters allow the user to assess the "importance"
of the burst.
With more counting statistics, there is slight improvement in the
location uncertainty (i.e. it is somewhat systematics dominated).
Click for more information on Final Coordinates Notices.
MAXBC
The MAXBC locations are derived from the 16 "Maximum Burst Channels" that
are determined by the on-board BATSE flight software. The 16 rates are
available to the GCN (BACODINE) system at T+10 minutes after the trigger. They
are useful for those situations when the initial GRB BATSE trigger happened
within a telemetry gap, making the generation of the Original Notice
impossible.
The location uncertainty is comparable to the Original locations.
Click for more information on MAXBC Coordinates Notices.
LOCBURST
This source of GRB location information improves the location uncertainty
by a factor of 2-5x over the Original and MAXBC locations. It uses the
LOCBURST algorithm developed by the BATSE team at MSFC.
The GCN (BACODINE) system
captures the BATSE telemetry data during a GRB, automatically ftp's it to
MSFC, pages an "on call" person, who then applies the Locburst algorithm
plus the advantages of a human-in-the-loop for data better selection,
calculates a location, sends it back to the GCN (BACODINE) system.
The GCN (BACODINE) system monitors for these incoming Locburst locations and
distributes them. This whole process takes only 15-35 minutes!
Click for more information on LOCBURST Coordinates Notices.
MSFC Admin
These reports come out 1-3 days after the burst. They are based on the
full data set(s) availalble, with the cleanest data chosen, and have the
smallest error boxes (of the BATSE-derived Notices). These are the best
BATSE-derived locations available until the periodic BATSE Burst Catalog
is issued. These GRB locations are not distributed via the normal distribution
methods. They are available only in the GRB Locations
Web Page Table.
Light Curves
The GCN program produces several forms of light curve information for
the BATSE triggers (GRBs and non-GRBs alike).
Currently, these light curves are only available through the
GRB Web Page Table.
There is a column that has links to the various forms and formats
of the light curves:
(1) there are the planewave light curves in the 4 DISCLA energy windows
and the IPN light curve in the 20-100 keV window, and (2) the formats
are ascii text, postscript, and soon jpeg.
Soon, GCN will also have the ability
to e-mail the text and postscript forms of the light curves directly to those
sites that request this form of information.
2.3b) CGRO-COMPTEL GRB LOCATIONS (no longer available)
The COMPTEL instrument also on CGRO also can localize GRB -- particularly the brighter GRBs and those with harder spectrums. Click for a description of the CGRO-COMPTEL GRB location notices. And click to see the Table of COMPTEL Locations.
2.3c RXTE GRB LOCATIONS (for all practical purposes no longer available)
ASM_GRB_Position
The RXTE-ASM instrument detects several GRBs per year in its FOV.
The locations for these are automatically processed and made available
to the follow-up community through the GCN.
Click for a description
of the RXTE-ASM GRB location notices.
And click to see the Table of RXTE-PCA/-ASM Locations.
PCA_GRB_Position
The RXTE-PCA team has started a program to make ToO observations of bright
GRBs detected by BATSE.
Click for a description
of the RXTE-PCA GRB location notices.
And click to see the Table of RXTE-PCA/-ASM Locations.
2.3d) BeppoSAX-WFC/-NFI GRB LOCATIONS (no longer available)
The BeppoSAX-WFC/-NFI teams have a program to detect GRBs in the WFC FOV and quickly analyse the WFC data to yield a location. And if operational constraints permit, then a TOO is invoked with the NFI instruments. Click for a description of the BeppoSAX-PCA/-NFI GRB location notices. And click to see the Table of SAX-WFC/-NFI Locations.
2.3e) MILAGRO GRB LOCATIONS (no longer available)
The MILAGRO instrument detects hi-energy (>100 GeV) air showers from gamma-rays and cosmic rays and localizes the direction of these showers. See the MILAGRO (GCN) page. And click to see the Table of MILAGRO Notices.
2.3f) HETE2 GRB LOCATIONS (no longer available)
The HETE mission is the first purpose-built mission for GRBs. It is run by HETE (MIT). Because HETE GRB error boxes are small (0.3 deg, X-ray Monitor), traditional narrow-FOV telescopes with much fainter sensitivities can be used to make follow-up observations. See the HETE (GCN) page. And click to see the Table of HETE Locations.
2.3g) ALEXIS Extreme-UV TRANSIENT LOCATIONS (no longer available)
Ok, these are not strictly GRB locations, but since the identity of the extrame-UV transients in not known, we will put them in with the GRB position missions for now. Click for a description of the ALEXIS location notices on the extreme-UV (66-93 eV) transients. And click to see the Table of ALEXIS Transient Locations.
a) The first is the BATSE Triggers and Locations page. All of the latest and greatest information about the GRB locations from BATSE triggers is listed here. Only the BATSE Triggers are listed (Original, Final, MAXBC, LOCBURST, Light Curves, and ADMIN Reports). And if any of the BATSE GRBs are detected by other instruments (e.g. RXTE-PCA/-ASM, COMPTEL, and the IPN) these locations are also listed.
b) There is page with all the Notices from the COMPTEL instrument on CGRO (even the ones not detected by BATSE). It is called the COMPTEL GRB Locations page. This contains both the Detection (position) and non-detection notices.
c) There is page which contains all the Notices from the BeppoSAX spacecraft. It is called the SAX GRB Locations page. This contains the POSITION Notices from both the SAX-WFC and -NFI instruments.
d) There is also a real-time page of the ALEXIS Notices and Locations. It is called the ALEXIS UV Transients Locations page.
e) There is page which contains all the Notices from the HETE spacecraft. It is called the HETE GRB Locations page. This contains the POSITION Notices from both the HETE-WXM and -SXC instruments.