[vsnet-grb-info 24940] ZTF20aajnksq: Upper limits from Konus-Wind observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  27039
SUBJECT: ZTF20aajnksq: Upper limits from Konus-Wind observations
DATE:    20/02/12 13:04:21 GMT
FROM:    Anna Ridnaia at Ioffe Institute  <ridnaia at mail.ioffe.ru>

A. Ridnaia, S. Golenetskii, R.Aptekar, D. Frederiks,
M. Ulanov, D. Svinkin, A. Tsvetkova, A. Lysenko, and T. Cline,
on behalf of the Konus-Wind team, report:

Konus-Wind (KW) was observing the whole sky between the last 
non-detection and the first detection of ZTF20aajnksq (2020-01-28 
06:43:20 UTC, hereafter T0; Anna Ho, GCN Circ. 26966).

Two waiting-mode KW events were detected during ~18-hour (~0.74 days)
interval before T0. The burst localizations are inconsistent with 
the ZTF20aajnksq.

For the interval excluding the KW events, we estimate
an upper limit (90% conf.) on the 20 - 1500 keV fluence to
6.1x10^-7 erg/cm^2 for a burst lasting less than 2.944 s and having a
typical KW short GRB spectrum (an exponentially cut off power law with
alpha =-0.5 and Ep=500 keV). For a typical long GRB spectrum (the Band
function with alpha=-1, beta=-2.5, and Ep=300 keV), the corresponding
limiting peak flux is 1.7x10^-7 erg/cm^2/s (20 - 1500 keV, 2.944 s 
scale).

All the quoted values are preliminary.