Neutron Stars | Accreting Systems | Supermassive Black Holes and Active Galactic Nuclei

 

The MSU Astronomy and Astrophysics Group is committed to undergraduate and graduate education, public outreach, and research supported by NASA and the NSF.  We do basic research in the following areas:

Neutron Stars

Neutron stars contain the densest known matter in the Universe and the strongest magnetic fields; a cubic centimeter of neutron-star matter has a mass of one hundred million metric tons, while magnetic fields are as large as 1015 G (1011 T). The Astronomy and Astrophysics Group studies neutron-star rotational dynamics, thermal evolution, and explosive phenomena to deduce the properties and dynamics of the stellar interior.

The Neutron Star Internal Composition Explorer (NICER) was launched on June 1, 2017. During its nominal lifetime of 17 months, this x-ray observatory will study high-energy phenomena in neutron stars with the goal of learning about the composition of these objects at such high densities that neutrons could dissolve into their constituent quarks, and other particles such as kaons could appear. 

Neutron Star

Accreting Systems

Most galaxies, including the Milky Way, contain supermassive black holes at their centers. These giant black holes have masses of more than a billion times the of our Sun. If matter falls into the black hole it is heated and compressed, emitting intense radiation before passing through the event horizon. Jets of material traveling at nearly the speed of light can be driven away from the black hole. Our group studies how matter falls into a supermassive black hole, the formation of jets, radiative properties near the event horizon, the formation of supermassive stars, and gravitational wave emission from merging black holes that could be detectable by LISA.   accretion disk

 

Supermassive Black Holes and Active Galactic Nuclei

Essentially every massive galaxy, including our own Milky Way, harbors a supermassive black hole at its center. These giant black holes can grow to have masses more than a billion times the mass of our Sun.  When matter falls onto a black hole, it is heated and emits intense radiation before passing through the event horizon.  Jets of material traveling at nearly the speed of light can be driven away from the black hole.  In addition to using observations to help reveal how the first “seeds” of supermassive black holes formed and grew in the early Universe, our group studies how matter falls onto supermassive black holes, the formation of jets, radiative properties near the event horizon, the formation of supermassive stars, and gravitational wave emission from merging black holes that could be detectable by LISA.   black holes

 

Extreme Star Formation

Super star clusters are the product of the most intense bursts of star formation in the local Universe.  Packed with thousands of young massive stars, these dense stellar clusters can have a major impact on the energetics and evolution of galaxies. We study these massive clusters and nearby dwarf starburst galaxies to provide a template for interpreting observations of infant galaxies at the edge of the observable Universe undergoing extreme star formation.  

 

Galactic Structure and Chemical Evolution

Galaxies form and grow hierarchically over cosmic time. Small galaxies formed first in the early Universe and through continual mergers built up larger galaxies like our own Milky Way. This produces remnant pieces of the aggregated small galaxies that litter the outskirts of large galaxies. This graveyard can be harnessed as a probe of a galaxy’s merger history by means of “galactic archaeology”.  We study the the structure, formation and chemical evolution of the Milky Way and its satellite galaxies using large astronomical surveys.