Luminous Fast Blue Optical Transients in the 2040s
A. A. Chrimes, N. Sarin, D. Coppejans, P. J. Groot, A. Inkenhaag, P. G. Jonker, T. L. Killestein, D. A. Perley, M. Pursiainen
TL;DR
The study addresses the enigmatic Luminous Fast Blue Optical Transients (LFBOTs), a class whose origins remain uncertain but are linked to extreme black hole physics and transient-host interactions. It argues for a 2040s observational framework featuring deep, high-cadence, wide-field surveys, along with rapid, automated photometric and spectroscopic classification and multi-wavelength follow-up, to build a large, uniform sample. By synthesizing current observations (e.g., AT2018cow) and proposed progenitor scenarios (including IMBH TDEs, failed SNe, and BH–star mergers), the paper outlines concrete capabilities needed to reveal the central engines, accretion physics, and host-galaxy impact of LFBOTs. Achieving these capabilities would transform LFBOTs into powerful probes of BH formation/growth across cosmic history and the physics of extreme transient outflows.
Abstract
Luminous Fast Blue Optical Transients (LFBOTs) are a class of extragalactic transient of uncertain origin. Several hypotheses have been put forward which could feasibly be consistent with the sample number of events discovered thus far, including tidal disruption events around intermediate mass black holes, failed supernovae and mergers of stars with black holes. Whatever their origin, it is clear that better understanding LFBOTs will provide unique insight into the black hole formation/growth, central engine physics and transient-host galaxy interactions - themes which are expected to drive research in transient astronomy over the coming decades. The vast majority of LFBOTs are missed by current photometric surveys, or not efficiently selected for detailed follow-up. This white paper outlines the observing capabilities required on a 2040 timescale to maximise the discovery potential from these enigmatic events.