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.
``The American Astronomical Society Centennial collects some of the
most significant and path-breaking articles published in The
Astronomical Journal and The Astrophysical Journal, selected by
notable figures from the major sub-fields of the discipline. The
articles are accompanied by commentary that provides the
scientific-historical context essential to comprehending their
original impact. Many commentators were contemporaries of the
original authors and can provide first person accounts of papers
published in the journals - and the earliest reactions they evoked.''
Always useful is the NASA Astrophysics Data System.
This page was last updated on Thu Jan 2 20:30:01 EST 2003
Schedule for Fall'2002:
``Organizational meeting'' - Kris Stanek
0. September 18th, 2002 (in Classroom A)Abstract:
How the course is organized. Motivation for the topic. Scheduling the
talks.General reading material for the Semester:
Here is the content of the "The
Astrophysical Journal American Astronomical Society Centennial
Issue" (also as PDF).
``Gunn & Peterson: ON THE DENSITY OF NEUTRAL HYDROGEN IN INTERGALACTIC
SPACE (1965)'' - Brant
Robertson1. September 18th, 2002 (in Classroom A)Abstract:
Soon after the discovery of the distant quasar 3C9 by Schmidt (1965),
Gunn and Peterson proposed the use of its continuum spectrum blue-ward of
Lyman-alpha to constrain the density of intergalactic neutral hydrogen.
Since then, the Gunn-Peterson effect has been of interest in a variety
of observational and theoretical contexts. I will summarize work done
before Gunn and Peterson 1965, discuss the paper in some detail, and then
review the events of the last ~40 years including recent interesting
results.Reading material:
J. E. Gunn & B. A. Peterson "On
the Density of Neutral Hydrogen in Intergalactic Space" (1965,
ApJ, 142, 1633)
``Bates & Spitzer: THE DENSITY OF MOLECULES IN INTERSTELLAR SPACE (1951)'' - Scott Schnee2. September 25th, 2002 Abstract:
After the discovery of the interstellar lines CH and CH+ by Adams
(1941), Bates and Spitzer described the various formation and
destruction mechanisms for CH and CH+. This paper has been used to
determine the properties of dust in the ISM, relative isotopic
abundances, and cooling mechanisms for molecular clouds. I will
summarize the observational work done before Bates and Spitzer,
discuss their paper, and the present work done later to further
explain additional observations.Reading material:
D. R. Bates & L. Spitzer "The
Density of Molecules in Interstellar Space" (1951, ApJ, 113,
441)
``Zwicky: ON THE MASSES OF NEBULAE AND OF CLUSTERS OF NEBULAE (1937)'' - Vit Hradecky3. October 2nd, 2002 Abstract:
While there were hints for the existence of dark matter in the 1920s
and earlier, the first convincing evidence that dark matter outweighs
luminous matter was provided by Zwicky (1937). I will briefly discuss
the early studies of dark matter, summarize the contribution of
Zwicky, mention a few notable papers that followed, and conclude with
the present census of dark and luminous matter in the Universe.
Reading material:
F. Zwicky "On
the Masses of Nebulae and of Clusters of Nebulae" (1937, ApJ, 86,
217)
4. October 9th, 2002 - CANCELLED
``Abell: THE DISTRIBUTION OF RICH CLUSTERS OF GALAXIES (1958)'' - Ryan Hickox5. October 16th, 2002Abstract:
In 1958 George O. Abell published his PhD thesis, which was the first
comprehensive catalog of rich galaxy clusters. In his analysis of
this catalog Abell found the first clear evidence for structure on
scales larger than galaxy clusters. I will summarize Abell's methods
for creating and analyzing his catalog, and will look at current
developments in large-scale structure, surveys of galaxy clusters, and
uses of galaxy clusters in cosmology.
Reading material:
G. O. Abell "The
Distribution of Rich Clusters of Galaxies" (1958, ApJS, 3, 211)
``Clayton, Colgate, & Fishman: GAMMA-RAY LINES FROM YOUNG SUPERNOVA
REMNANTS (1969)'' - Jonathan
Jenkins6. October 23rd, 2002 (2:30-3:30 p.m.)Abstract:
Clayton, Colgate, and Fishman (1969) predicted observable gamma-ray
lines from the decay of Ni-56 and Co-56 in young supernova remnants. I
will discuss how this prediction grew out of the pioneering
theoretical work of Burbidge, Fowler, and Hoyle in understanding
nucleosynthesis, and how the prediction was eventually realized in
observations of SN 1987A. One of the driving goals of the Compton
Gamma-Ray Observatory was the detection of gamma-ray lines from SNRs,
and in the next few years the INTEGRAL mission will follow up with
significantly better energy resolution. There are a number of
experiments under development (two based at the CfA) which will
continue to improve sensitivity and resolution over the next decade,
with the twin goals of finding new supernova remnants and better
understanding where and when nucleosynthesis occurs in supernovae.
Reading material:
D. D. Clayton, S. A. Colgate, & G. J. Fishman "Gamma-Ray
Lines from Young Supernova Remnants" (1969, ApJ, 155, 75)
``Penzias & Wilson: A MEASUREMENT OF EXCESS ANTENNA TEMPERATURE AT
4080 Mc/s (1965)'' - Paul Kondratko7. October 30th, 2002 Abstract:
In 1965, two radio astronomers at Bell Laboratories, Arno Penzias and
Robert Wilson, reported the detection of a cosmic microwave background
radiation. The discovery has had a profound impact on cosmology and
astronomy in general. I will describe the history and the details of
the discovery as well as current developments in this rapidly evolving
area of observational cosmology.
Reading material:
A. A. Penzias & R. W. Wilson "A
Measurement of Excess Antenna Temperature at 4080 Mc/s" (1965,
ApJ, 142, 419)
``Schreier et al.: EVIDENCE FOR THE BINARY NATURE OF CENTAURUS X-3 FROM
UHURU X-RAY OBSERVATIONS (1972)'' - Slavko Bogdanov8. November 6th, 2002 Abstract:
In their landmark 1972 paper, Schreier et al. used observations from
the UHURU X-ray satellite to show beyond doubt that the X-ray source
Centaurus X-3 was part of a binary system. This was the discovery that
revealed the true nature of a particular class of Galactic X-ray
sources: X-ray binaries. This paper represents a milestone in the
development of X-ray astronomy. I will discuss the history of X-ray
astronomy prior to 1972, the contents of the Schreier et al. paper,
and what we presently know about Cen X-3 and similar objects.
Reading material:
E. Schreier et al. "Evidence
for the Binary Nature of Centaurus X-3 from UHURU X-Ray
Observations" (1972, ApJ, 172, L79)
``Baade & Minkowski: ON THE IDENTIFICATION OF RADIO SOURCES (1954)'' -
Maryam Modjaz9. November 13th, 2002 Abstract:
In their 1954 paper, Baade and Minkowski at Palomar Observatories
identified the optical counterparts of the strongest radio
sources. Their most important discovery was that Cygnus A was an
extragalactic object, a discovery which marked the beginning of
research on radio galaxies (belonging to the general class of AGNs). I
will discuss the paper, summarize what we know today about Cygnus A
and similar objects and outline the most recent developments in AGN
research.
Reading material:
W. Baade & R. Minkowski "On
the Indentification of Radio Sources" (1954, ApJ, 119, 21)
``Ostriker, Peebles, & Yahil: THE SIZE AND MASS OF GALAXIES, AND THE
MASS OF THE UNIVERSE (1974)'' - Shinae
Park10. November 20th, 2002 (in Classroom A) Abstract:
In their 1974 paper, Ostriker, Peebles, & Yahil give evidence that M/L
ratios of galaxies increase with increasing radius, and that dark
matter is present in cosmologically significant amounts. I will
discuss five methods of measuring galaxy masses as summarized in the
paper, explain the cosmological importance of the results, and
summarize the progress made in the field since the paper was written.
Reading material:
J. P. Ostriker, P. J. E. Peebles & A. Yahil "The
size and mass of galaxies, and the mass of the universe" (1974,
ApJ, 193, L1)
``Baade & Swope: VARIABLE STAR FIELD 96' SOUTH PRECEDING THE NUCLEUS
OF THE ANDROMEDA GALAXY (1963)" - Alceste Bonanos
11. November 27th, 2002 Abstract:
In their 1963 paper, Baade and Swope derive the distance to M31 using
the Cepheid P-L relation. Baade's 1952-54 observations of field IV
with the 200 inch Palomar telescope led to the discovery of 20
Cepheids and Swope's careful analysis to an accurate distance. This is
the same data Baade used to double the cosmic distance scale in 1952.
I will present their work after placing it in historical context and
will discuss current developments in the field.
Reading material:
W. Baade & H. H. Swope "Variable star field 96' south preceeding the nucleous oftheAnd galaxy" (1963, AJ, 68, 435)
``Peebles: PRIMORDIAL HELIUM ABUNDANCE AND THEPRIMORDIAL FIREBALL. II. (1966)'' - Andrew Friedman
12. December 4th, 2002 Abstract:
In 1966, a year after the discovery of the Cosmic Microwave Background
Radiation, P.J.E. Peebles of Princeton performed some of the first
detailed Big Bang Nucleosynthesis (BBN) calculations of the primordial
Helium abundance Y_p, finding Y_p ~ 26-28%, which is remarkably close
to the modern value of Y_p ~ 24%. In this talk, I will discuss the
history of BBN prior to the paper, I will go in detail through
Peebles' actual calculation, and finish by reviewing what we know
today about Y_p from improved theoretical calculations and
observations of the Helium abundance in the universe. The Peebles
paper was an important step for astrophysics and cosmology, as it
solidified the predictions of BBN, which along with the CMB, and the
Hubble expansion of the universe, now form the three major pillars of
Big Bang Theory.
Reading material:
P. J. E. Peebles "Primordial
Helium Abundance and the Primordial Fireball. II" (1966, ApJ, 146,
542)
``Fabricant, Lecar, & Gorenstein: X-RAY MEASUREMENTS OF THE MASS OF
M87 (1980)'' - Ming
Sun13. December 11th, 2002 Abstract:
I will review the paper and our understanding of X-rays from M87
before and after FLG80. X-ray observations serve as an important way
to derive the mass of galaxies and clusters. This paper is the very
first one to demonstrate the power of X-ray imaging on determining the
mass of dark matter halo around galaxies. Currently, this method has
been applied to many other galaxies, groups and clusters.
Reading material:
D. Fabricant, M. Lecar & P. Gorenstein "X-ray
measurements of the mass of M87" (1980, ApJ, 241, 552)
``Klebesadel, Strong, & Olson: OBSERVATIONS OF GAMMA-RAY BURSTS OF
COSMIC ORIGIN (1973)'' -
Steven Furlanetto14. December 18th, 2002 Abstract:
In June 1973, Klebesadel, Strong, & Olson achieved the rare feat of
shocking both astronomers (with their announcement of the discovery of
bright, mysterious gamma-ray bursts, or GRBs) and readers of the
"National Enquirer" (with news of nuclear war between
extraterrestrials). I will briefly review the observations described
in their paper with special reference to the role of the
military-industrial complex in fundamental science. I will then
summarize our present theoretical understanding of GRBs and their
afterglows in the context of the fireball model (more accurately
described as the "relativistic flying pancake model"). I will
conclude with a discussion of the future challenges in GRB research
and of their potential role in studies of other problems in
astrophysics.
Reading material:
R. W. Klebesadel, I. B. Strong & R. A. Olson "Observations
of Gamma-Ray Bursts of Cosmic Origin" (1973, ApJ, 182, L85)
Questions or Comments? Send an
e-mail to kstanek@cfa.harvard.edu.