He serves on the editorial board of the journal “Universe”, and is the member of International Astronomical Union’s Executive Committee on Astronomy for Equity and Inclusion.

[7] Following his doctoral degree, Seigar held concurrent appointments as a postdoctoral research fellow at the University of Ghent, and as a visiting astronomer at the Space Telescope Science Institute until 2001.

From 2004 to 2007, he served as an assistant project scientist at the University of California, Irvine, and as visiting astronomer at the observatories of the Carnegie Institution for Science.

He was appointed as head of the Department of Physics and Astronomy at the University of Minnesota Duluth from 2014 until 2017, and as associate dean at Swenson College of Science and Engineering from 2017 until 2020.

[15] He, along with his team, also demonstrated the relationship between spiral arm pitch angle and the mass of supermassive black holes (BHs) in the context of the nuclei of disk galaxies.

Since 2021, he has focused his research towards finding the evidences regarding the existence of Intermediate-Mass Black Holes (IMBHs) using X-ray and optical images of galaxies.

[17] Seigar provided a cosmologically motivated description of the dark matter halo profile for the low surface brightness galaxy, Malin 1.

His research work shows that the rotation curve of Andromeda Galaxy (M31) can only be produced with a mass model that includes a halo that has contracted adiabatically.