Overview

This catalog gives information on the triggered events detected by the PVO instrument from 9/14/78 to 7/21/88. This catalog was taken from the Ph.D. thesis of Kuan-Wen Chuang (UC-Riverside, 1990).

Instrument Information

The Gamma Burst Detector aboard the Pioneer Venus Orbiter was designed to record gamma ray burst intensity profiles with high time resolution. The Detector consists of two identical sensors placed at the periphery of the spacecraft equipment platform. They are diametrically opposite each other, giving all sky coverage. Each sensor consists of a CsI scintillator, which is bonded to a shell of Pilot B plastic scintillator used for charged particle suppression. This assembly is optically coupled to a photomultiplier tube. The amplified pulses are analyzed at five discriminator levels, corresponding to energy bands of 100 - 200 keV, 200 - 500 keV, 500 - 1000 keV, and 1.0 - 2.0 MeV. High intensity events trigger the electronics to record in a high time resolution mode. For these triggered events, spectral data are recorded concurrently in each of the 4 energy channels at 187 ms or better resolution. A time-to-spill algorithm records the total intensity in time bins of 11.7 ms to 0.25 ms, depending on the count rate. For further details of the instrumentation, see Klebesadel et al. (1980). Through 13 years of continuous operation, the detectors and the trigger mechanism have remained stable, resulting in a data base free from systematic effects.

Parameters

Name
The date of the observation in format yy.mm.dd.

Time
The time that the burst was recorded.

Fluence
Energy flux in units (ergs/cm**2) X 10**-5.

Max_Flux
The maximum energy flux in units (ergs/cm**2-s) X 10**-5.

Peak_Count_Rate
The peak count flux in units counts/0.25 s.

Average_Background_Rate
Average background count rate in units counts/0.25 s.

Confirmed
Whether the burst was recorded by at least one other spacecraft.

Confirmations
Numbers indicate which other spacecraft also observed the burst.  The key for 
the confirming satellites is as follows:
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  1.    Prognoz - 7
  2.    Venera - 11 (Siene Experiment)
  3.    Venera - 12 (Siene Experiment)
  4.    Pioneer Venus Orbiter
  5.    International Sun - Earth Explorer
  6.    Vela
  7.    Venera - 11 (Konus Experiment)
  8.    Venera - 12 (Konus Experiment)
  9.    Helios - 2
 10.    Solar Maximum Mission/Gamma Ray Spectrometer 
 11.    Prognoz - 9
 12.    Venera - 13 (Siene Experiment)
 13.    Venera - 14 (Siene Experiment)
 14.    Konus 13
 15.    Konus 14
 16.    Konus Experiment. Lab., or Prognoz - 9 experiment
 17.    HEAO - 3
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References

Klebesadel, R., Evans, W., Glore, J., Spalding, R., and Wymer, F., 1980 IEEE Trans on Geoscience and Remote Sensing, GE-18, 76.

Contact Person

Questions regarding the PVOTRIG database table can be addressed to the HEASARC User Hotline.

Page Author: Browse Software Development Team
Last Modified: 18-Jul-2002