The workshop on Massive Black Holes at the Kavli Institute for Theoretical Physics continues with today’s session on “Co-evolution of black holes and their host galaxies”.
I continue a semi-liveblog of the proceedings.
As before, talks are online here – podcast, audio and video options; pdfs of talk slides added as speakers get them in.
First up is Yohan Dubois (IAP / Oxford Univ.) – on “AGN feedback in adaptive mesh refinement cosmological simulations” – high res AMR simulations of massive gas rich halos at z ~ 5-6
make some assumptions about SMBH formation and accretion efficiency on small (unresolved) scales and couple energy/momentum back into gas locally.
Include prescription for SMBH spin evolution.
Hot gas bubbles out.
Need efficient accretion flows, implies high spin black holes, sustained Eddington accretion for many Salpeter times.
Interesting discussion on systematic differences between AMR and SPH sims at same resolution – definitely some numerics there.
Next up Andrea Merloni (MPE) – “Cosmological evolution of supermassive black holes: clues about AGN feedback from multi-wavelength surveys”
Interesting step back to look at the big picture of why feedbacks are such a concern and all the issues they try to address
one of these talks where you really should listen to the talk and not just read the slides.
Interesting statistics on “specific accretion rate” – similar dot-M/dot-M_Edd prob distributions (~ 1/L ) but amplitude systematically higher with z
some evidence for cut-off at dot-M=dotM_Edd which would be nicely physical if it holds
Last before break: Alison Coil (UC San Diego) on “The host galaxies of AGN at 0.2
found in all galaxy types
no dependence on stellar mass
little dependence on star formation rate (at fixed z? I presume - the is z dependence and global SFR is z dependent)
see Aird et al 2012 “PRIMUS: The dependence of AGN accretion on host stellar mass and color”
ok, this is an interesting way to look at things, but I’m not sure it is telling us anything deep – good way to remind people of the biases – it is easier to see the big bright things
back from break
Brendon Kelly (UC Santa Barbara) “Investigating the growth of black holes with the quasar black hole mass function”
Daniel Angles-Alcazar (Univ. of Arizona) “Is black hole growth in galaxies self-regulated”
Akos Bogdan (CfA) “The asynchronous evolution of bulges and supermassive black holes in NGC4342 and NGC4291″
Something interesting going on here.
you’re gonna have to go to the web for these, kinda busy, can’t do even partial blog on them
back after lunch
and we are back from lunch:
Kayhan Gultekin (Univ. of Michigan) “Probing the black hole-galaxy scaling relations: present and past”
cf “The M-σ and M-L Relations in Galactic Bulges and Determinations of their Intrinsic Scatter” – Gültekin et al 2009
still surprisingly low scatter in M-σ relation
some funky SMBH hosts out there
megamaser masses coming in systematically low – systematic effect somewhere but in which sample
uncalibrates M_BH estimates for low mass SMBH in Sloan seem to show tail down at low masses, but that could be selection effect
Tiziana Di Matteo (Carnegie Mellon) “Supermassive black holes in cosmic structure formation”
efficient AGN feedback can in principle affect structure on the few Mpc scale and therefore bias power spectrum on small angular scales – need to know for near future surveys
so need to know struture with and without feedback, up to some sort of maximum plausible feedback
caveat radiation and accretion efficiencies
MB and MBII simulations
BHCosmo sims with pretty pics and movies
and we are back from break
some rapid fire short talks:
Tommaso Treu (UC Santa Barbara) “The co-evolution of galaxies and black holes in the past ten billion years”
Marianne Vestergaard (Niels Bohr Instit.) “Black hole demographics and mass estimates of high-redshift AGN and quasars”
Remco van den Bosch (MPA) “Supermassive black holes in compact galaxies”
Weird. Very weird.
Gregory Shields (Univ. of Texas at Austin) “A captured runaway black hole in NGC 1277″
Is the SMBH in 1277 ejected from 1275 and recaptured.
Worth thinking about though.
Roger Blandford (KIPAC) “Massive black holes: Open questions”
Roger giving a colloquium – not quite conference summary.
Intent to cover topics we didn’t address to some extent.
Ought to be good.
Quick plug for Event Horizon Telescope concept and sub-mm interferometry;
then onto BH bombs and energy extraction from rotation.
I wonder if any of them young grad students still read “The Membrane Paradigm” – is it even in print?
some nice GR-MHD sims of massive disk with strong B-field around SMBH
(McKinney + Tchekhoskoy et al)
helical instability at ΩBH/4
A: “why so can I, so can any man. But if you call them will the come?” – paraphrasing
Where does helicity go…?
Principle of Least Pessimism… is inferred GW background at low frequencies too optimistic? Requires high energy density in GW
Can GW energy density be over 1% of EM background – at the low frequencies?
and we are done