[vsnet-grb-info 7804] GRB 090510: Fermi-LAT follow-up analysis

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  9350
SUBJECT: GRB 090510: Fermi-LAT follow-up analysis
DATE:    09/05/11 21:33:14 GMT
FROM:    Nicola Omodei at INFN(Pisa)/GLAST  <nicola.omodei at pi.infn.it>

N. Omodei (INFN Pisa), J. Granot (University of Hertfordshire),
P. Meszaros (PSU), J. McEnery (GSFC), F. Piron (LPTA), S. Razzaque (NRL)
H. Tajima (SLAC), V. Vasileiou (GSFC/UMBC), D. Williams (UCSC),
report on behalf of the Fermi LAT Collaboration.

A follow-up analysis of the short bright Fermi GRB 090510 (Ohno et al.,
GCN 9334, Guiriec et al., GCN 9336) has been performed by the Fermi-LAT
team.

Fermi LAT has detected more than 50 events above 100 MeV (>10 above 1
GeV) during the first second and more than 150 events above 100 MeV (>20
above 1 GeV) in the first minute after the GBM trigger.
All these events are positionally consistent (within the 95% containment
radius of the LAT point spread function) with the position reported by
Swift (Goad et al. GCN 9339). They indicate extended emission above GeV
energies, making this burst an absolute priority for follow-up searches,
especially a redshift determination.

The points of contact for this burst is:
Masanori Ohno ohno at astro.isas.jaxa.jp

The Fermi LAT is a pair conversion telescope designed to
cover the energy band from 20 MeV to greater than 300 GeV.
It is the product of an international collaboration between NASA and DOE
in the U.S. and many scientific institutions across France, Italy, Japan 
and Sweden.