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Award Detail

Awardee:MICHIGAN STATE UNIVERSITY
Doing Business As Name:Michigan State University
PD/PI:
  • Stephen E Zepf
  • (517) 884-5617
  • zepf@pa.msu.edu
Award Date:05/22/2008
Estimated Total Award Amount: $ 170,137
Funds Obligated to Date: $ 170,137
  • FY 2009=$85,121
  • FY 2008=$85,016
Award Start Date:08/01/2008
Award Expiration Date:07/31/2012
Transaction Type:Grant
Agency:NSF
Awarding Agency Code:4900
Funding Agency Code:4900
CFDA Number:47.049
Primary Program Source:490100 NSF RESEARCH & RELATED ACTIVIT
Award Title or Description:Emission Lines and Black-Hole Acitivity in Extragalactic Globular Clusters
Federal Award ID Number:0807557
DUNS ID:193247145
Parent DUNS ID:053343976
Program:EXTRAGALACTIC ASTRON & COSMOLO
Program Officer:
  • Thomas S. Statler
  • (703) 292-4910
  • tstatler@nsf.gov

Awardee Location

Street:CONTRACT AND GRANT ADMINISTRATIO
City:EAST LANSING
State:MI
ZIP:48824-1046
County:East Lansing
Country:US
Awardee Cong. District:08

Primary Place of Performance

Organization Name:Michigan State University
Street:CONTRACT AND GRANT ADMINISTRATIO
City:EAST LANSING
State:MI
ZIP:48824-1046
County:East Lansing
Country:US
Cong. District:08

Abstract at Time of Award

Dr. Zepf will follow up his serendipitous discovery of a violently variable X-ray source and a very broad optical emission line in the spectrum of a globular star cluster in elliptical galaxy in the Virgo Cluster of galaxies. It is difficult to interpret these two observations other than as signatures of a black hole into which gas is falling. The group will obtain wider spectral coverage to determine line ratios and hence whether the emitting gas is likely to be photo-ionized or shock-ionized. This bears on the mass of the likely black hole: a stellar-mass black hole is likely to produce shock-ionization, while a more massive black hole would photo-ionize the gas. Other globular star clusters would be searched for similar signatures.

This work is potentially transformative, as it could provide the most solid evidence yet for intermediate-mass black holes: these objects are so massive that the explosion of a single dying star cannot make them. If intermediate-mass black holes are found to form in globular clusters, this will open a new area of research. Students will be trained as they participate in this research. Dr. Zepf will give public lectures on his work, and incorporate the results into his teaching of introductory survey classes.

Publications Produced as a Result of this Research

Gnedin, OY; Maccarone, TJ; Psaltis, D; Zepf, SE "SHRINKING THE BRANEWORLD: BLACK HOLE IN A GLOBULAR CLUSTER" ASTROPHYSICAL JOURNAL LETTERS, v.705, 2009, p.L168 View record at Web of Science

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