Higgins, A. B.A. B.HigginsStarling, R. L. C.R. L. C.StarlingGötz, D.D.GötzMEREGHETTI, SandroSandroMEREGHETTIWiersema, K.K.WiersemaMaccarone, T.T.MaccaroneOsborne, J. P.J. P.OsborneTanvir, N. R.N. R.TanvirO'Brien, P. T.P. T.O'BrienBird, A. J.A. J.BirdRowlinson, A.A.RowlinsonGehrels, N.N.Gehrels2020-08-242020-08-2420170035-8711http://hdl.handle.net/20.500.12386/26774We 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, IGRW 151019, 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.STAMPAenArticle10.1093/mnras/stx11632-s2.0-85021803718000406842600022https://arxiv.org/abs/1709.07233https://academic.oup.com/mnras/article-abstract/470/1/314/3820928?redirectedFrom=fulltext2017MNRAS.470..314HFIS/05 - ASTRONOMIA E ASTROFISICA