Америкалық астроном Эми Дж. Баргер және галактикалар зерттеуі

American astronomer

Amy J. Barger (born January 18, 1971) is an American astronomer and Henrietta Leavitt Professor of Astronomy at the University of Wisconsin–Madison. She is considered a pioneer in combining data from multiple telescopes to monitor multiple wavelengths and in discovering distant galaxies and supermassive black holes, which are outside of the visible spectrum. Barger is an active member of the International Astronomical Union.

Barger earned a Bachelor of Arts in astronomy physics in 1993 from the University of Wisconsin Madison. She was a Marshall scholar at King's College, University of Cambridge and received a doctor of philosophy in astronomy from the university in 1997. Barger holds positions as a Henrietta Leavitt Professor of Astronomy at the University of Wisconsin Madison and as an affiliate graduate faculty member in the University of Hawaii Department of Physics and Astronomy. During this time, she was a part of the MORPHS collaboration, a research group that studied the formation and morphologies of distant galaxies. Based on the data they retrieved from Hubble Space Telescope Wide Field and Planetary Camera 2 images, photometry and spectroscopy, the group was able to analyze and catalogue approximately 2,000 distant galaxies in 10 clusters and conclude that the spectral and morphological transformation of the galaxies were affected by two different timescales and/or physical processes. Barger also used the Submillimetre Common User Bolometer Array (SCUBA), a far infrared camera, to discover new quasars, and as a 1999 Hubble Fellow and Chandra Fellow at large, she was granted access to NASA's Chandra X Ray Observatory (CXO). 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. With the data they gathered from their research in the CXO, the team furthered previous research in finding that about one third of the origins of the X ray background are active galactic nuclei (AGNs) that emit light not on the visible spectrum. The AGNs contain a massive black hole that produces X rays as gas is pulled toward them at virtually the speed of light. The team also found that ultra faint galaxies are a source of another third of the X ray background. The ultra faint galaxies emit little to no visible light due to dust formation around them or due to the absorption of visible light by cool gas. The team concluded that more optical observations with more powerful telescopes, such as the Next Generation Space Telescope and Constellation X, were required to gain more insight into the two types of far distant objects they observed. As a follow up to the research presented in January, Barger lead a team in surveying black holes. The team used a Keck 10 meter telescope, James Clerk Maxwell Telescope and the Very Large Array of the National Radio Astronomy Observatory to study the time intervals for black hole growth and found that the activity of an abundance of black holes in nearby galaxies was greater and more recent than once thought. The team concluded that, contrary to widespread belief, not all black holes formed when galaxies did. Rather, there are black holes currently growing slowly, taking more than one billion years to form. In December 2000, Barger led the presentation of the findings at a press conference at the 20th Texas Symposium on Relativistic Astrophysics, in Austin, Texas.