[vsnet-grb-info 14748] Retraction of the Fermi/LAT high-energy counterpart for GRB 130330A

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  16062
SUBJECT: Retraction of the Fermi/LAT high-energy counterpart for GRB 130330A
DATE:    14/03/31 19:47:21 GMT
FROM:    Giacomo Vianello at SLAC  <giacomov at slac.stanford.edu>

G. Vianello (Stanford U.), D. Kocevski (NASA/Goddard), J. Racusin
(NASA/Goddard), R. Ojha (NASA/GSFC/UMBC/CRESST) <Roopesh.Ojha at gmail.com>,
and S. Ciprini (ASDC) report on behalf of the Fermi-LAT team:

The analysis of new data downloaded from Fermi has shown that emission from
the proposed high-energy counterpart of GRB 140330A (Vianello et al., GCN
16048; Pittori et al., GCN 16058) has continued up to at least 40 ks after
the GBM trigger. This is very unusual for a faint burst such as GRB
130330A. Also, our localization of the LAT excess has improved, and it is
now:

R.A., Dec. = 325.40, -64.13 with an error radius of 0.14 (90 % c.l.,
statistical only),

which is well outside the IPN error box (Hurley et al., GCN 16051).

Moreover, a search in Fermi archival data has shown a variable emission
from a source compatible with our position, which was detected in several
occasions in 2012 and 2013, and also detected on March 28 and 29, 2014.
This source has been tentatively associated with the extra-galactic radio
source PKS 2136-642 in the past (ATel #5695; Mauch et al. 2003, MNRAS, 342,
1117).

Therefore, we believe that the high-energy source detected by Fermi and by
AGILE (Pittori et al., GCN 16058) is unrelated to GRB 130330A.

Further analysis is ongoing.