Date:
Tue, 22/12/201512:30-13:30
Location:
Kaplub building, Room No. 200
Lecturer: Dr. Ronald Läsker
Affiliation: University of Turku
Abstract:
In this talk, I will present revised scaling
relations of masses (MBH) of Supermassive
Black Holes (BHs) with galaxy and bulge
properties, focusing on bulge masses (Mbul) in
low-mass and late-type galaxies where the
bulge is only a minor component. By means of
HST/WFC3 optical and near-infrared data, we
analyzed BH host galaxies with MBH precisely
known by their nuclear Megamaser emission.
Due to the superior image quality and detailed
analysis techniques, we are able to decompose
these complex systems, to isolate and
parametrize their likely classical bulges apart
from pseudobulge and other disk-like
components. Thus we are able to test whether
BH (AGN) feedback is effective in and primarily
associated with (classical) bulges, irrespective of
BH host morphology at large. However, we do
not find a particularly tight relation between
these systems’ MBH and Mbul, questioning the
universal distinguished role of (classical) bulges
in a putative co-evolution with their BHs. We
also note an apparent offset to lower MBH on
average, when compared to the MBH - Mbul
relation of early-type systems. Finally, the log-
slope of the augmented MBH - Mbul relation is
smaller than unity, in contrast to predictions of
standard feedback scenarios. Our results
demonstrate how nuclear Megamasers are able
to significantly improve the characterization of
BH scaling relations in this otherwise hard-to-
access and undersampled regime of low masses
and late host morphologies, and highlight our
need for a more detailed and comprehensive
theory of the formation and growth of BHs.
Additional details of the upcoming Astrophysics'
seminars can be found on the following link.
האירוע הזה כולל שיחת וידאו ב-Google Hangouts.
הצטרף: https://hangouts.google.com/hangouts/_/mail.huji.ac.il/astrophysics?hceid=bWFpbC5odWppLmFjLmlsX2c0czhydDlpcmhwZzRvdGNybWIzZGFqcjdvQGdyb3VwLmNhbGVuZGFyLmdvb2dsZS5jb20.6rnppiaj3k4cbooa8m8rrqhq0s&hs=121