TY - JOUR
T1 - Investigating the nature of the INTEGRAL gamma-ray bursts and sub-threshold triggers with Swift follow-up
AU - Higgins, A. B.
AU - Starling, R. L.C.
AU - Götz, D.
AU - Mereghetti, S.
AU - Wiersema, K.
AU - Maccarone, T.
AU - Osborne, J. P.
AU - Tanvir, N. R.
AU - O'Brien, P. T.
AU - Bird, A. J.
AU - Rowlinson, A.
AU - Gehrels, N.
N1 - Publisher Copyright:
© 2017 The Author. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved.
PY - 2017/9/1
Y1 - 2017/9/1
N2 - We explore the potential of the INTErnational Gamma-Ray Astrophysics Laboratory (INTEGRAL) to improve our understanding of the low-fluence regime for explosive transients, such as Gamma-ray Bursts (GRBs). We probe the nature of the so-called 'WEAK' INTEGRAL triggers, when the gamma-ray instruments record intensity spikes that are below the usual STRONG significance thresholds. In a targeted Swift follow-up campaign, we observed 15 WEAK triggers.We find six of these can be classified as GRBs. This includes GRB 150305A, a GRB discovered from our campaign alone. We also identified a source coincident with one trigger, IGRW151019, as a candidate active galactic nucleus.We show that real events such as GRBs exist within the INTEGRAL Burst Alert System (IBAS) WEAK trigger population. A comparison of the fluence distributions of the full INTEGRAL IBAS and Swift-BAT GRB samples showed that the two are similar.We also find correlations between the prompt gamma-ray and X-ray properties of the two samples, supporting previous investigations.We find that both satellites reach similar, low fluence levels regularly, although Swift is more sensitive to short, low-fluence GRBs.
AB - We explore the potential of the INTErnational Gamma-Ray Astrophysics Laboratory (INTEGRAL) to improve our understanding of the low-fluence regime for explosive transients, such as Gamma-ray Bursts (GRBs). We probe the nature of the so-called 'WEAK' INTEGRAL triggers, when the gamma-ray instruments record intensity spikes that are below the usual STRONG significance thresholds. In a targeted Swift follow-up campaign, we observed 15 WEAK triggers.We find six of these can be classified as GRBs. This includes GRB 150305A, a GRB discovered from our campaign alone. We also identified a source coincident with one trigger, IGRW151019, as a candidate active galactic nucleus.We show that real events such as GRBs exist within the INTEGRAL Burst Alert System (IBAS) WEAK trigger population. A comparison of the fluence distributions of the full INTEGRAL IBAS and Swift-BAT GRB samples showed that the two are similar.We also find correlations between the prompt gamma-ray and X-ray properties of the two samples, supporting previous investigations.We find that both satellites reach similar, low fluence levels regularly, although Swift is more sensitive to short, low-fluence GRBs.
KW - Gamma-ray burst: general
UR - http://www.scopus.com/inward/record.url?scp=85021803718&partnerID=8YFLogxK
U2 - 10.1093/mnras/stx1163
DO - 10.1093/mnras/stx1163
M3 - Article
AN - SCOPUS:85021803718
VL - 470
SP - 314
EP - 323
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
SN - 0035-8711
IS - 1
ER -