[5] Barger's research discoveries concern distant Universe activity and objects, including dusty galaxies, quasars and supermassive black holes.
In January 2000, the results of Barger and her colleagues' search for the origins of the cosmic X-ray background were presented at the 195th national meeting of the American Astronomical Society in Atlanta, Georgia.
[13] In 2001, she received the American Association of University Women Annie Jump Cannon Award in Astronomy for her investigation of the X-ray background, which would lead to future spectroscopic research.
[14] In 2002, she won the Newton Lacy Pierce Prize in Astronomy for outstanding achievement in observational astronomical research over the past five years.
The team captured and observed long-exposure X-ray images of black holes normally obscured by gas and dust to determine that they are between one and 12 billion light-years away from Earth.
The team discovered that the earliest black holes, which are a part of the early Universe and have at least 100 million times the mass of the Sun, quickly reach a size limit and stop accumulating matter.
[16][17][18] The researchers found that one or more systems connect a galaxy's formation of stars to its loss of cosmic materials through its black hole because the processes occur simultaneously.
[20][21] In 2013, Barger, former advisee Ryan Keenan and astronomer Lennox Cowie published the results of a study on the density of galactic matter in The Astrophysical Journal.