HETE Burst U11552

Burst U11552 summary

  • Trigger time is
    • UTC=20040805_102615
    • GRB=GRB040805+37575
  • Triggering instrument was unknown
  • Trigger timescale was 9999.0 seconds
  • Trigger detected in unknown keV band


Evaluation GRB040805



grb; substantial grs1915+105 contamination makes it problematic
Very little band C emission: possible XRF.



The color of trigger U11552, defined by the ratio of total counts in Fregate band C (30-400 keV) to band A (7-40 keV) vs. band B (7-80 keV) to band A, overlaid on a the color-color plot of all localized bursts detected to date. Note the separation of XRFs, XRRs, and GRBs.

The signal to noise in Fregate band C (30-400 keV) of trigger U11552 in relation to the S/N of band C of other localized HETE triggers. We find empirically that most XRFs are faint and soft: the fact that localized bursts require a minimum S/N in the 2-25 keV band means that the band C S/N should be low. We find a cutoff in the band C S/N of 6.5 delineates the XRF/non-XRF population with high reliability.

Link to Jochen Greiner's web page on

Skymap for HETE trigger U11552