Ephemeral Flaring Transients Following Supernova Explosions in Black-Hole Binary Systems
Davide Lazzati, Rosalba Perna, Taeho Ryu
arXiv:2403.18911v1 Announce Type: new
Abstract: The majority of massive stars are members of binary systems, a fraction of which is expected to remain bound after the first star goes off as a supernova. When the second star also explodes, the SN ejecta are bound to interact with the compact object companion. We explore the consequences of this interaction in the case of a black hole (BH) companion. We show that accretion of the SN ejecta by the BH generally occurs with highly super-Eddington rates, which can be strongly modulated if the ejecta are clumpy, as typically observed in supernova remnants. This late accretion produces transient flaring activity with a time delay from the SN explosion of days to months, depending on the orbital separation and the velocity of the ejecta. The flares are expected to have a non-thermal, broad band spectrum, but their high-frequency emission (UV and X-rays) would be absorbed within the remnant. Observed flares should therefore be in the optical and near-infrared. We propose this model as an explanation to the late-time flaring activity observed in the fast blue optical transient AT2022tsd.arXiv:2403.18911v1 Announce Type: new
Abstract: The majority of massive stars are members of binary systems, a fraction of which is expected to remain bound after the first star goes off as a supernova. When the second star also explodes, the SN ejecta are bound to interact with the compact object companion. We explore the consequences of this interaction in the case of a black hole (BH) companion. We show that accretion of the SN ejecta by the BH generally occurs with highly super-Eddington rates, which can be strongly modulated if the ejecta are clumpy, as typically observed in supernova remnants. This late accretion produces transient flaring activity with a time delay from the SN explosion of days to months, depending on the orbital separation and the velocity of the ejecta. The flares are expected to have a non-thermal, broad band spectrum, but their high-frequency emission (UV and X-rays) would be absorbed within the remnant. Observed flares should therefore be in the optical and near-infrared. We propose this model as an explanation to the late-time flaring activity observed in the fast blue optical transient AT2022tsd.