Speaker: Dr. Sera Markoff, MIT Center for Space Research

Title: "Common weaknesses:  similarities between low-luminosity black
holes from the stellar to the supermassive"

Abstract: This seminar is related to my colloquium, but goes into more
details about the analysis, with less background. General relativity
states that black holes can be defined by three parameters: mass, spin
and charge.  One possible consequence of this would be that accreting
black holes experience similar accretion physics, but with timescales
that vary according to the mass difference.  In other words, we see
time-dependent "states" in stellar black holes in X-ray binaries (XRBs)
lasting days to weeks that we might naively predict would correspond to
states in active galactic nuclei (AGN) lasting hundreds to thousands of
years or more. If true, this would obviously impact our understanding of
the various observed AGN classes, which may in fact be unified further,
beyond orientation effects.  I will present the best evidence so far for
this kind of "state mapping", which exists between the weakest states in
both classes of black hole sources, the "hard state" in XRBs and the
class of Low-Luminosity AGN (LLAGN). I will also discuss how we are
using this mapping to make new constraints on the physics of accretion,
and in particular for my research, jet formation.