| Abstract: |
During the Chandra campaign to extend the Chandra Deep Field-South (CDF-S) from 4Ms to 7Ms, a fast X-ray transient was discovered. The wealth of ancillary data, plus subsequent optical/NIR limits, put interesting constraints on its origin, effectively ruling out a Galactic transient, as well as all known supernovae and the vast majority of gamma-ray bursts (GRBs) and tidal disruption events (TDEs). The remaining possibilities include a low-luminosity off-axis short GRB or a beamed TDE involving an intermediate-mass black hole and a white dwarf, although neither explains all of the observed properties. The event rate is low, but comparable to the intrinsic GRBs rate at z>1. I will discuss the potential for finding more examples from this intriguing population. |
