Graduate seminar on topical areas in modern astrophysics and
cosmology. Each semester a different topic of current special
interest is selected. Participants in this seminar discuss papers
given by seminar members (in rotation). Several faculty members also
participate.
Note: Participation for three semesters is required to obtain
credit for this course.
Carnegie
Observatories Astrophysics Series Volume 1: Coevolution of Black Holes
and Galaxies
A. Barth, "Black
Holes in Active Galaxies", in Carnegie Observatories Astrophysics
Series, Vol. 1: Coevolution of Black Holes and Galaxies, 2004
Gebhardt
et al. 2003, ApJ, 583, 92
Barth et al. 2001, ApJ, 555, 685
Yu & Tremaine (2002), "Observational
constraints on the growth of massive black holes"
Tremaine et al (2002), "The
Slope of the Black Hole Mass versus Velocity Dispersion
Correlation"
Silk and Reese (1998), "Quasars and galaxy formation"
Reid et al. 2004, ApJ,
616, 872
Chatterjee et al. 2002, ApJ,
572, 371
Tremaine et al. 2002, ApJ,
574, 740
Kaspi, S., Smith, P. S., Netzer, H., Maoz, D., Jannuzi, B. T., &
Giveon, U. 2000, ApJ, 533, 631
Nelson, C. H., Green, R. F., Bower, G., Gebhardt, K., & Weistrop, D.
2004, ApJ, 615, 652
Onken, C. A., Ferrarese, L., Merritt, D., Peterson, B. M., Pogge,
R. W., Vestergaard, M., & Wandel, A. 2004, ApJ, 615, 645
McHardy, I. M., Papadakis, I. E., Uttley, P., Page, M. J., & Mason,
K. O. 2004, 348, 783
Brandt and Hasinger, "Deep Extragalactic X-ray Surveys",
astro-ph/0501058.
Menci et al, "Quasar Evolution Driven by Galaxy Encounters in
Hierarchical Structures", astro-ph/0303332.
Volonteri et al, "The Assembly and Merging History of Supermassive
Black Holes in Hierarchical Models of Galaxy Formation",
astro-ph/0207276.
In my talk I examine both the observed characteristics of mergers and
the results of recent numerical simulations. I discuss both the
ability of these simulations to explain the observed trends and the
implications that these models have for our understanding of the
evolution of galaxies.
Merritt & Milosavljevic(2004) astro-ph/0410364
Escala et al.(2004) astro-ph/0406304
Hughes et al.(2004) astro-ph/0408492
Floyd et al. 2004, MNRAS, 355, 196
Sanders & Mirabel 1996, ARAA, 34, 749
Intermediate mass black holes are defined as having masses more than
about 15 and less than a millions solar masses. There is ample evidence
for the existence of both lower and higher mass BHs, but this
intermediate class if existent has so far remained undetected. The
existence of intermediate mass black holes has long been an open and
interesting question. I will review the theoretical scenarios for how
such objects could have formed and outline some of the very scarce and
uncertain observational hints for their existence.
This page was last updated on Fri May 6 17:26:34 EDT 2005
Schedule for Spring'2005:
``Organizational meeting'' - Kris Stanek and Paul Martini
0. February 2nd, 2005Abstract:
How the course is organized. Motivation for the topic. Scheduling the
talks.General reading material and useful links for the Semester:
Always useful are the NASA Astrophysics Data
System and the astro-ph preprint
archive
``Black hole mass measurements from stellar
and gas dynamics'' - Joel Hartman1. February 2nd, 2005Abstract:
It is now suspected that most galaxies contain supermassive black
holes in their cores. The tight correlation between the masses of
these black holes and the stellar velocity dispersions of their host
galaxies suggests that the evolution of galaxies is somehow tied to
the evolution of supermassive black holes. In this talk I will review
two of the basic techniques used to measure black hole masses in the
cores of nearby galaxies. These include modelling stellar dynamics in
these galaxies and modelling the ionized gas disks or H2O masers
observed in the cores of some active galaxies. I will present these
methods, discussing the assumptions and uncertainties involved in
each.Reading material:
J. Kormendy, "The
Stellar-Dynamical Search for Supermassive Black Holes in Galactic
Nuclei", in Carnegie Observatories Astrophysics Series, Vol. 1:
Coevolution of Black Holes and Galaxies, 2004
``Black hole demographics and the M-sigma
relationship'' - Matt McQuinn2. February 9th, 2005 Abstract:
For the first part of this talk, I will compare local measurements of
the density of supermassive black holes to estimates of the density
inferred from the luminosity function of AGN and from the X-ray
background. Interestingly, these different estimates yield remarkably
similar numbers. For the rest of my talk, I will discuss various
aspects of the M-sigma relationship (the power-law relationship
between the nuclear black hole mass and the stellar velocity
dispersion in galaxies). I will discuss the brief history of this
relationship, its applicability to different mass black holes and to
different galactic types, and other pertinent details. I will
conclude by discussing two simple analytic theories for the physical
origin of this relationship: one which utilizes ballistic infall onto
a seed black hole, and another that invokes AGN feedback.Reading material:
Richstone (2004), "Supermassive
Black Holes: Demographics and Implications"
``The black hole in the Milky Way'' - Alexandre Tchekhovskoi 3. February 16th, 2005 Abstract:
In the first part of my talk, I will review the modern techniques used
for accurately determining and localizing the mass at the center of the
Milky Way by measuring the motions of stars near it. Further, I will
discuss the proposed alternatives to the case of having a galactic black
hole and explain why recent observations make these alternatives highly
unlikely. Then I will continue with the discussion of whether the
observed motion of the black hole candidate -- the unusual radio source
SgrA* -- is consistent with the mass of 3 - 4 millions of solar masses
attributed to it. Finally, I will conclude with the discussion of how
the new black hole mass estimates affect the M-sigma relation that was
discussed last week.Reading material:
Ghez 2004, The
Supermassive Black Hole at the Center of the Milky Way
``The Black Hole Mass Ladder: Reverberation Mapping and Other
Secondary Black Hole Mass Measurements'' - Jenny Greene4. February 23rd, 2005 Abstract:
We have seen in previous talks that a) every galaxy with a bulge
contains a black hole (BH) and b) the BH mass is correlated with the
bulge velocity dispersion (the M-sigma relation). Apparently the
growth of the BH is intimately related to the evolution of its galaxy
host. In order to fully explore the origins and evolution of the
M-sigma relation we need a census of BH mass density with cosmic time.
The techniques we have discussed thus far, including stellar and gas
dynamics and stellar velocity dispersions, are limited to local
quiescent galaxies. Active galaxies, though, are far brighter and
trace the growth phase of the BH. There are a series of indirect
techniques for estimating BH masses in actively accreting systems,
based on reverberation mapping. I will discuss these techniques and
their respective limitations. I will end with the prospects for
measuring redshift evolution in the M-sigma relation.Reading material:
Peterson, B. M. 1993, PASP, 105, 274
``Evolution of the AGN space density'' -
Loren Hoffman5. March 2nd, 2005 Abstract:
First I will present an overview of the observed evolution of the AGN
luminosity function at various wavelengths and the inferred evolution
of the AGN space density, focusing on the optical 2dF and SDSS
surveys, and Chandra and XMM-Newton in x-rays. I will then outline
the mainstream interpretation of the observed AGN evolution and
present two merger-tree studies that roughly reproduce this evolution
starting from small seed black holes at high redshift and using a
simple prescription for black hole accretion accompanying merger
events.Reading material:
Osmer, P.S., "The Evolution of Quasars" in "Coevolution of black holes
and Galaxies" 2004.
``The Formation of the First Structures in the
Universe'' - Jaime Pineda6. March 9th, 2005 Abstract:
After the universe gets recombined the first structures can form.
Since the first stars (Pop III) are formed in a metal-free environment
they were very massive, producing a strong radiation field that could
have incidence in the evolution of the of the Universe, producing a
re-ionization of the Inter Galactic Medium (IGM) and the production of
Intermediate Mass Black Holes. The Super Massive Black Holes found in
high z galaxy (z~6) place a tight constraint over the Black Hole
growing process. On the other hand, WMAP result provides information
about the re-ionization epoch. I will review how these stars and the
first quasars are formed and some possibilities about how to produce
those SMBH.Reading material:
``Gas-rich galaxy mergers'' - Heather Knutson7. March 16th, 2005 Abstract:
Gas-rich galaxy mergers appear to be a relatively common phenomenon in
the history of our universe, and yet they are still not very well
understood. Historically, it was thought that galaxy mergers produced
elliptical galaxies, which evolved into disks over time. Recent
simulations, however, have demonstrated that mergers between gas-rich
galaxies can sometimes produce disk-like structures. Black holes also
appear to play an important role in the merger process, as feedback
from an AGN may dramatically decrease the rate of star formation in a
newly-formed merger remnant. This process of AGN feedback has been
invoked to explain both the intrinsic lifetimes of quasars and the
development of the M-sigma relation.Reading material:
``Merging binary black holes'' - Cesar Fuentes8. March 23rd, 2005 Abstract:
Galaxy mergers are supposed to be important in galaxy evolution and
formation. The M-sigma relation hints that most galaxies have a
massive B-H in their cores. As a result, super-massive black holes
(SBH) merging is a picture that must be elucidated to fully understand
the picture of merging evolution for galaxies. Coalescence of SBH
should be the most important source of gravitational waves detectable
with LISA. A set of related phenomena can be used to constrain
theoretical scenarios. I will focus the discussion on our physical
understanding of these objects and how this matches current
observations.Reading material:
Merritt, ''Single and Binary Black Holes and their Influence on Nuclear
Structure'' , in Carnegie Observatories Astrophysics Series, Vol. 1:
Coevolution of Black Holes and Galaxies, 2004
Spring Break
``Quasar host galaxies'' - Philip Hopkins9. April 6th, 2005 Abstract:
Understanding the host galaxies of quasars is critical to inform
theories of quasar formation and evolution, and to constrain mechanisms
by which quasars are fueled. With the discovery of the M-sigma relation
and the awareness that essentially all spheroids host supermassive
black holes at their center, this subject has moved from a peculiar
interest of quasar observers and theorists to a crucial ingredient in
understanding galaxy evolution. Theories of the fueling of quasars
often invoke galaxy mergers as a means to drive gas to the nuclear
regions, which should be observable in the morphological properties of
quasar hosts. Furthermore, observations and theories of galaxy
formation suggest a correlation and perhaps an evolutionary link
between luminous infrared or starburst galaxies, mergers, and quasar
activity. I will review the methods and results of morphological
observations of quasar hosts, and the current status of observational
evidence for and against these theories.Reading material:
Dunlop, "Quasar Hosts and the Black Hole-Spheroid Connection,"
Coevolution of Black Holes and Galaxies
``Sub-mm sources and the cosmic star formation rate'' - Cullen H. Blake10. April 13th, 2005 Abstract:
Reading material:
``Reionization of Hydrogen and Helium'' - Heng Hao11. April 20th, 2005 Abstract:
The process of reionization of the intergalactic medium at high
redshift has been discussed for the past several years, and current
observations are at the threshold of probing the reionization epoch of
hydrogen and helium. Many exciting results come out and change our
understanding of the reionization history. In this talk, I will begin
with a brief introduction of the history of the universe by giving the
milestones at different epochs. Then I will focus on discussing when
and how the reionization of hydrogen happens, based on the theoretical
model and various observation probes such as polarization of CMB
anisotropies, QSO constraints, 21cm probes etc. Then I will go on
discussing possible ionization sources such as miniquasars. Finally, I
will briefly introduce the theory and recent observational evidence of
the reionization history of helium.
Reading material:
``AGN feedback on galaxy formation'' - Philip Nutzman
12. April 27th, 2005 Abstract:
We have learned that ~10% of the mass accreted on to a black hole is
released as energy, and also that black holes at the center of
galaxies have accreted on order millions of solar masses of material.
Only a small fraction of the total released energy needs to interact
with the surrounding environment in order to cause profound feedback.
I discuss the different types of energy injection, which not only
include radiative feedback, but also feedback through winds and
jets. Feedback from AGNs may resolve some mysteries involved in galaxy
formation including the observed bimodal color distribution in local
galaxies, and the population of massive, very red galaxies at high
redshift. Observations of x-rays from clusters of galaxies may begin
to shed light on aspects of AGN feedback.Reading material:
``Intermediate mass black holes'' - Kaloyan Penev
13. May 4th, 2005 Abstract:
Reading material:
Questions or Comments? Send an
e-mail to kstanek@cfa.harvard.edu.