Upper limits to low energy (v)over-bar(e) flux from GRB 990705

Citation
M. Aglietta et al., Upper limits to low energy (v)over-bar(e) flux from GRB 990705, ASTRON ASTR, 366(2), 2001, pp. 573-577
Citations number
18
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Space Sciences
Journal title
ASTRONOMY AND ASTROPHYSICS
ISSN journal
0004-6361 → ACNP
Volume
366
Issue
2
Year of publication
2001
Pages
573 - 577
Database
ISI
SICI code
0004-6361(200102)366:2<573:ULTLE(>2.0.ZU;2-Z
Abstract
The detection of Gamma Ray Burst GRB 990705 on 1999, July 5.66765 UT, point ing to the Large Magellanic Clouds, suggested the search for a possible neu trino counterpart, both in coincidence with and slightly before (or after) the photon burst. We exploited such a possibility by means of the LVD neutr ino telescope (National Gran Sasso Laboratory, Italy), which has the capabi lity to study low-energy cosmic neutrinos. No evidence for any neutrino sig nal, over a wide range of time durations, has been found, at the occurrence of GRB 990705. Due to the lack of information about both the source distan ce and its emission spectrum, the results of the search are expressed in te rms of upper limits, at the Earth, to the nu (e) flux cross-section, integr ated over different time durations, integral integral Phi nu (e)sigma dEdt. Moreover, assuming thermal nu (e) spectra at the source, upper limits to t he nu (e) flux, integrated over time duration, for different spectral tempe ratures, are obtained. Based on these limits and on the expectations for nu emission from collapsing astrophysical objects, the occurrence of a gravit ational stellar collapse can be excluded up to a distance r approximate to 50 kpc, in the case of time coincidence with GRB 990705, and r approximate to 20 kpc, for the 24 hours preceding it.