Renee Ludlam

Renee Ludlam

Assistant Professor

 Physics 333

Curriculum vitae


Renee Ludlam


 Physics and Astronomy

Research interest(s)/area of expertise

- X-ray binaries (neutron stars or black holes)

- Accretion physics

- Cross-calibration of X-ray missions 

- Equation of State of ultra-dense cold matter 


My research focusses on utilizing X-ray observations of compact objects in low-mass X-ray binary systems (where the stellar companion is roughly the size of the Sun). Material is stripped from the stellar companion and forms an accretion disk around the compact object (which is either a black hole or neutron star). The accretion disk can reprocess emission in these systems that can then be used to ascertain valuable information about the properties of the compact object. In the case where the system has a black hole, limits can be obtained for its spin parameter (which is one of three properties needed to fully describe a black hole). For neutron stars, the disk emission can be used to place limits on the radial extent or magnetic field strength. Limits on neutron star radius have important implications regarding the composition of the object. Neutron stars are the densest objects with a surface in the Universe with a mass that is roughly twice the Sun compressed into the size of a city. The matter within exists in an ultra-dense, cold state that cannot be replicated in terrestrial laboratories. Hence, we can only use observations of these objects to determine how matter exists under such conditions. Since our ability to infer information through observations hinges upon our understanding of the instrumentation being used, I am also interested in the cross-calibration between X-ray missions and supporting the future of X-ray astronomy. 


PhD - Astronomy and Astrophysics, University of Michigan (2019)

Awards and grants

- NASA Hubble Fellowship Program - Einstein Fellow (2019-2022)

- American Astronomical Society High-Energy Astrophysics Division Dissertation Prize (2021)

Currently teaching

 PHY/AST 5010: Astrophysics and Stellar Astronomy

Citation index

Over 2500 citations

H-index: 20