TABLE OF CONTENTS:
INTRODUCTION AND BACKGROUND:
The first notice type distributed, by the then called BACODINE system, was
the BATSE-Original Notice type. It had a GRB location based on the first
1 or 2 seconds of the burst light curve after the BATSE trigger. Obviously,
integrating the burst light curve for longer intervals would be useful,
but in those early days minimizing the time delay between the burst and
the delivery to the sites was paramount.
THE NEW "FINAL" NOTICE TYPE:
I have now added a new notice type to the GCN system that integrates
the BATSE burst light curve for up to 32 seconds. It is called the
BATSE-Final Notice. The GCN program (actually the old original BACODINE portion
of the program) continues on from the first 1-2 seconds of the Original
Notice to follow the light curve for 32 seconds. To reduce the effect of
summing up unwanted noise for bursts which are shorter than the 32-sec
interval, the program only integrates the source-only count rates (in the
usual 50-300 keV band) for those 1.024-sec rate samples that are more than
3 sigma above background. It then calculates
a location based on those improved counting statistics (improved only if
the burst was longer than 1-2 sec). It also scans
for the peak intensity and calculates the (3-sigma thresholded) fluence.
The location plus
the intensity and fluence are included in the new BATSE-Final Notice.
The Final Notice is available for distribution at T+32sec after the
start of the burst.
For every Original Notice issued, there will be a Final Notice (even if
it was a short burst and no new rate samples were added to the integration
of the light curve).
IMPORTANCE OF THIS FINAL NOTICE:
The utility of these Final Notices is that the peak intensity and
fluence of the burst allows the user to assess the "importance" of the burst.
The Original Notice has only the intensity of the first 1-2 seconds
and since most bursts last longer than 2 seconds, the user could not know
if this burst got to be much brighter a few seconds later (e.g. it might
have been the "burst of the year" or it might have been a common
run-of-the-mill burst). This information is important in making decissions
to use limited resources to make (or not) a follow-up observation.
LOCATION ERROR:
Unfortunately, the dominant terms in these GCN/BATSE burst locations are the
the systematics of the distortions in the LAD count rates due to scattering
from the Earth's atmosphere and the spacecraft. As such the error distribution
for the Final Notices is only slightly improved over the Original Notices.
This will improve when Geoff Pendleton and I complete the addition
of the BATSE-team's "locburst" algorithm into the program.
More information is available here.
DISTRIBUTION METHODS and FILTER FUNCTIONS:
As with all the GCN notice types, these BATSE-Final Notices
are available to the GCN community via the Internet socket, e-mail,
alpha-numeric pager (long and short versions), phone/modem, and cell-phone
distribution methods.
The same filter functions that apply to the Orignal Notices
also apply to the Final Notices.
The available filter functions are: ALL, VISIBLE, NIGHT, and various
custom filters.
See for more details on the filter capabilities.
FORMATS:
The format of the e-mail form (attached below) is very similar to the
BATSE-Original. It is based on the "TOKEN: value" scheme to allow for
both the easy reading by humans and the easy parsing by computer daemons.
The details of the format and content of this form are described in
E-mail Definition Document.
Examples of the pager, short_pager and subject-only forms are also attached below.
The packing format and content of the socket packet method is also very
similar to that used in the Original packets. Those GCN sites using the
Internet socket method should refer to the
socket definition document
to get the details (this is packet_type=22).
SIGN UP ACTION ITEM:
As with all the new Notice Types that have been added to GCN, each site
must elect to receive BATSE-Final Notices -- the default setting in the
"sites.cfg" file is for this notice type to be DISABLED. If you wish
to receive these Final Notices, please contact me and it is a simple
60-sec procedure to add these to you current list of notice types you receive.
This may seem like I am belaboring the point, but there was some confusion
on the previous announcements of new notice types. Some people thought
they would automatically be getting those notices, but like these Final
Notices, the default setting in the sites.cfg file is "disabled". You must
choose to get them. You can call or e-mail me or Paul Butterworth
and we will be happy to "flip the bit" to enable your site for Final's.
RECOGNITION:
Sites are encouraged to include Scott D. Barthelmy and Paul Butterworth
in the author list of IAU Circulars, journal papers and conference
presentations
based on observations using these new GCN/BATSE-Final locations.
FURTHER HELP:
For more information, please contact me:
Phone: 301-286-3106
E-mail: scott@lheamail.gsfc.nasa.gov
TITLE: BACODINE FINAL BURST POSITION NOTICE
NOTICE_DATE: Thu 02 Oct 97 17:43:09 UT
NOTICE_TYPE: Final
TRIGGER_NUM: 6408
GRB_RA: 17.84d {+01h 11m 22s} (J2000),
17.81d {+01h 11m 14s} (current),
17.11d {+01h 08m 26s} (1950)
GRB_DEC: +48.71d {+48d 42' 43"} (J2000),
+48.70d {+48d 42' 00"} (current),
+48.45d {+48d 26' 47"} (1950)
GRB_ERROR: 6.0 [deg radius]
GRB_FLUENCE: 3402 [cnts] Peak=588 [cnts/sec] Del_t=4.6 [sec]
GRB_TIME: 63698.14 SOD {17:41:38.14} UT
GRB_DATE: 10723 TJD; 275 DOY; 97/10/02
GRB_SC_AZ: 100.57 [deg] {XScan=21.28}
GRB_SC_EL: -68.33 [deg] {Zenith_angle=158.33} {Scan=-175.83}
SC_X_RA: 165.67 [deg] (J2000)
SC_X_DEC: 32.46 [deg]
SC_Z_RA: 164.33 [deg]
SC_Z_DEC: -57.52 [deg]
SUN_POSTN: 188.79d {+12h 35m 09s} -3.79d {-03d 47' 21"}
SUN_DIST: 134.43 [deg]
MOON_POSTN: 200.44d {+13h 21m 46s} -5.72d {-05d 43' 21"}
MOON_DIST: 136.96 [deg]
PROG_VERSION: 5.16
PROG_LEVEL: 1
COMMENTS: Definite GRB.
COMMENTS: This notice is based on 6 1.024-sec samples of the light curve.
BACODINE FINAL GRB RA=17.81d DEC=+48.70d TIME: 17:41:38.14 UT FLUENCE=3402 Definite GRB.
FINAL RA=17.11 DEC=+48.45
FINAL RA=17.81 DEC=+48.70