Blazar Research at Boston University

Institute for Astrophysical Research

                                                                              People in the Blazar Research Group

Movie of gamma-ray bright quasar 1222+216, made from VLBA images    1222+216 on kpc scales    1222+216 light curves
Above left: Movie of the jet of gamma-ray bright quasar 1222+216 (or 4C21.35), at a redshift of 0.435 (distance of 3.8 billion light-years), so that 0.5 mas (milli-arcseconds) corresponds to 9.2 light-years. The images used to make the movie are from the Very Long Baseline Array. Colors indicate brightness. Although we think that the jet flows continously from near the black hole (which is invisible and located near the bottom of the frame), "blobs" of brightness appear and move down the jet (at speeds that appear to be faster than light - just an illusion) as the jet becomes bright in gamma rays (as observed by NASA's Fermi Gamma-ray Space Telescope) and at other frequencies.
Above middle: The same quasar but on scales of tens of thousands of light-years, showing how the jet twists.We think that the jet is really coming almost right at us, so the bends appear more dramatic than they are in 3D. False color: X-ray image from NASA's Chandra X-ray Observatory; contours: 1.4 GHz radio image from the Very Large Array. The Very Long Baseline Array and the Very Large Array are instrumenst of the National Radio Astronomy Observatory, which is a facility of the National Science Foundation operated by Associated Universities, Inc.
Above right: Brightness vs. time. Top panel: Gamma-ray (blue: Fermi; yellow: MAGIC and VERITAS); bottom panel: visible light. Red vertical dashed lines mark times when a new blob first appears in the jet.

Project VLBA-BU-BLAZAR: Roughly Monthly VLBA Images of Gamma-Ray Bright Blazars at 43 GHz with Data Files and Graphs of Gamma-ray and Visible-light Brightness Plus Visible-light Polarization vs. Time

General Description of Our Research on Blazars    

TEMZ computer model for variability of flux, polarization, and spectral energy distribution of blazars            

Prof. Alan Marscher's textbook on cosmology for non-science majors: From Nothing to Everything: The Story of Our Universe

Prof. Alan Marscher's presentation on Jets from Black Holes in Quasars at the Northeast Astronomy Forum on Saturday April 18, 2009 (for anyone interested in black holes & quasars)

Original Science Songs by Cosmos II (including international hit "Superluminal Lover"), aka Alan Marscher

Press Release: Graduate student Nicholas MacDonald won the prize for best student talk at the May 2015 meeting of the Canadian Astronomical Society in Hamilton, Ontario. His talk on his model for "orphan" gamma-ray flares from a blob of plasma passing through a region of strong emission in the sheath of a blazar jet was accompanied by a press release.

Dr. Alan Marscher                                      Dr. Svetlana Jorstad

Professor of Astronomy                                       Senior Research Scientist



Dr. Manasvita Joshi, Research Scientist Dr. Monasvita Joshi photo


                           Nick MacDonald Dr. Mahito Sasada, Postdoctoral Fellow


                                 Nick MacDonald Dr. Nicholas MacDonald, Instructor


        Mason Keck        

Mr. Mason Keck, Graduate Student


                                 Karen Williamson Ms. Karen Williamson, Research Technician


            Mr. Muhammad Zain Mobeen, 3rd-year Undergraduate Student


Mr. John Hunter, 2nd-Year Undergraduate Student

        Karen Williamson

            Ms. Katya Leidig, 1st-year Undergraduate Student



If you have any questions about the BU Blazar Research Group, please send e-mail to Prof. Marscher.