All meetings and special seminars are on Thursday at 3:30 PM in Dearborn Observatory Room 23. Please contact Fred Rasio if you would like to volunteer to present something or suggest a topic for discussion. We can accommodate any format, from short informal talks on recent research results to journal-club style discussions and special seminars by visitors.

June 10, 2003

Special Theoretical Astrophysics Seminar
Prof. Andrew King (Leicester)
Title: "Outflows from Quasars and Ultraluminous X-Ray Sources"

This is our last meeting for this academic year!

June 5, 2003

This week we will have two journal-club style presentations:

Chris Belczynski will discuss the paper on "A New Evolutionary Channel for Type Ia Supernovae" by Andrew King et al. (incidentally, Andrew King will be visiting us from this Sunday, June 8, until Wednesday, June 11).

Philippe Grandclément will talk about the "Lazarus Project" on mergers of binary black holes and their latest paper, "The final plunge of spinning binary black holes".

May 29, 2003

This week Genya Takeda will talk about a recent paper by Man Hoi Lee and Stan Peale on "Secular Evolution of Hierarchical Planetary Systems."

Also this week Natasha Ivanova and Ron Taam will summarize some of the new results presented at recent conferences they attended:

International School on "Black Holes in the Universe" CargËse, Corsica, May 12-24
Workshop on "Thermonuclear Bursts on Neutron Stars" IAS, Princeton, May 11-13

May 22, 2003

Special Theoretical Astrophysics Seminar
Dr. Milos Milosavljevic (Caltech)
Title: "Stellar Dynamics at the Galactic Center"

May 8, 2003

Three of our undergraduate students were selected to give talks at Northwestern's 2003 Undergraduate Research Symposium, which is intended to showcase creative and scholarly work by Northwestern undergraduates in all fields.

As part of their preparation for this symposium they will give their talks to the group on Thursday:

Mike Henninger: "Ultra-Luminous X-Ray Sources: A New Class of Black Holes?"

Phil Nutzman: "Detection of Gravitational Waves from Nearby Galaxies" Ken Yu: "Chaos and Dynamical Instabilities in Extrasolar Planetary Systems"

Each talk will be 15 mins (12 mins plus questions).

In addition, Walter Lewin is visiting us this week from MIT and we will be discussing some of his latest results on Chandra observations of globular clusters, summarized in the recent preprint by Pooley et al. on [astro-ph/0305003].

May 1, 2003

his Thursday Josh Faber will give a tutorial on how to use our computer cluster Typhoon. All students who plan to use Typhoon in their projects should make an effort to attend!

Josh Faber and Chunglee Kim will also jointly summarize some of the results presented at the conference they attended last week on "The Astrophysics of Gravitational Wave Sources" at the University of Maryland.

April 17, 2003

This week Ron Taam will lead a discussion of the new paper by Podsiadlowski, "On the Evolution and Appearance of a Surviving Companion after a Type Ia Supernova Explosion".

Josh Faber will also give us a very brief update on our parallel computing cluster Typhoon.

Also of interest this week:

Casey Law will give a talk on the Chandra X-ray observatory at the departmental lunch seminar on Wednesday (noon in Tech F235).

Lyman Page from Princeton is giving the departmental colloquium on the WMAP results Friday at 4 PM. Do not miss this one!

April 10, 2003

First group meeting of the Spring quarter!
Chunglee Kim will talk about new developments in gravitational wave astronomy from the 2nd LIGO science run and from the APS meeting.

Fred Rasio will talk about tidal dissipation and orbital decay of "hot jupiters" based on the recent ApJ Letter by D. Sasselov [astro-ph/0303403].

March 10, 2003

Chris Belczynski will lead a discussion on ultracompact binaries (ultracompact LMXBs and RS CVn binaries).

February 24, 2003

Today we have two visitors:

Alex Heger from the University of Chicago will talk to us about massive star evolution and the formation of neutron stars and black holes (following up on his astrophysics seminar this week).

Andreas Zezas from the Harvard-Smithsonian Center for Astrophysics will tell us about some recent Chandra observations of extragalactic X-ray sources.

February 17, 2003

We will discuss two recent news items:

A measurement of the "speed of gravity" announced at the AAS meeting last month. (See, e.g., Nature; the most relevant preprint by Kopeikin appears to be gr-qc/0212121) - discussion led by Josh Faber and Philippe Grandclément.

The idea that most, perhaps all, LMXBs in the Galaxy were formed in globular clusters. (see the Press Release and the article by Mirabel & Rodrigues) - discussion led by Vicky Kalogera.

February 10, 2003

Many of us have been traveling to various conferences over the past two weeks and today will report on what we have learned (KITP conferences on Globular Clusters and on Ultracompact Binaries, and Aspen workshop on Advanced Gravitational Wave Detectors).

In addition, Atakan Gürkan will give his Wednesday-lunch talk on "Globular Clusters and Intermediate-Mass Black Holes" as practice talk to the group.

February 3, 2003

Josh Faber will be presenting his new animations of compact binary mergers, and he will talk about the facilities available at the Northwestern VisLab .

January 20, 2003

Special Theoretical Astrophysics Seminar
Dr. Philipp Podsiadlowski (Oxford)
Title: "Formation and Evolution of Black-Hole X-ray Binaries"

January 13, 2003

First group meeting of the Winter quarter!

Ken Yu will talk about recent detections of new extrasolar planets, and Natasha Ivanova will present a summary of discussions at the MODEST - 2 workshop in Amsterdam last month.

Here are a few relevant papers:
A New Transiting Extrasolar Giant Planet, by Konacki et al., to appear in Nature Jan 30, 2003.
A Mass for the Extrasolar Planet Gl 876b ..., by Benedict et al. (ApJ Letters, Dec 20, 2002).
MODEST-1: Integrating Stellar Evolution and Stellar Dynamics, by Hut et al., to appear in New Astronomy.

December 16, 2002

Special Theoretical Astrophysics Seminar
Dr. Mike Muno (MIT)
Title: "Chandra Observations of the Galactic Center Region"

December 9, 2002

Casey Law will present "An Introduction to the Chandra X-ray Observatory."
Background material at the Chandra Web Site.

December 2, 2002

Special Theoretical Astrophysics Seminar
Philippe Grandclément (Northwestern)
Title: "A New Detection Strategy for Gravitational Waves from Precessing Compact Binaries"

November 25, 2002

Phil Nutzman will present the results from his recent work on coalescence rates of compact binaries in other galaxies. This will be his practice talk for next week's workshop on Stellar Populations and Gravitational Wave Observations at Penn State.

Philippe Grandclément will give an overview of the new Chandra observations of a binary supermassive black hole. Read the press release!

November 18, 2002

There will be two short presentations:

"Update on Neutron Star Equations of State" by Josh Faber.

"Evidence for Large Natal Kick Velocities of Black Holes" by Vicky Kalogera, based in part on a new paper by Mirabel et al. on GRO J1655-40, press embargoed until Monday... (It's out! See, eg, the CNN story)

November 11, 2002

David Lin will present an update on measurements of M/R for neutron stars, based on the recent Nature paper by Cottam et al..

Everyone should at least read the short "news and views" article on this by Cole Miller.

November 4, 2002

Fred Rasio will present an overview of recent observational evidence and possible formation processes for massive black holes at the centers of dense star clusters, based in part on talks presented at the Carnegie Centennial Symposium (Pasadena, CA, Oct 21-25).

October 28, 2002

Mike Henninger and Ron Taam will lead a discussion on ultra luminous X-ray sources in galaxies in the framework of binary systems containing a black hole and a non compact companion and their transient accretion disks.

October 21, 2002

Natasha Ivanova and Ron Taam will lead a discussion on the evolution of binaries with white dwarf companions in relation to the formation of cataclysmic variables, supersoft sources and as progenitors for Type Ia supernovae.

October 14, 2002

Special Theoretical Astrophysics Seminar
Natasha Ivanova (Northwestern)
Title: "The Evolution of Helium Stars and the Formation of Binary Neutron Stars"

September 30, 2002

Marc Freitag will lead a discussion of the recent papers on the evidence for central massive black holes in globular clusters: Gerssen et al. on M15 and Gebhardt et al. on G1.

September 23, 2002

Special Theoretical Astrophysics Seminar
Dr. Scott Hughes (UCSB/MIT)
Title: "Tuning Gravitational-Wave Detector Networks to Measure Compact Binary Mergers"