Richard Plotkin: Jets from intermediate mass black holes

Richard Plotkin

Jets from Intermediate Mass Black Holes


Richard Plotkin



Bio sketch

My research uses multiwavelength space- and ground-based observations to study a wide variety of phenomena related to accreting black holes, over the full range of black hole masses and accretion rates. My main research goal is to better understand the structure/geometry of accretion flows and outflows in different accretion regimes, in order to more effectively use radiation as a probe of Galactic and extragalactic black hole populations, and to learn how black holes may impact their large-scale environments.

My interests include: quiescent black hole X-ray binaries, low-luminosity active galactic nuclei quasars, relativistic jets, and X-ray populations in nearby galaxies.

I often use the following telescopes: Chandra X-ray Telescope (NASA; X-ray), Hubble Space Telescope (NASA; optical/ultraviolet), Very Large Array (National Radio Astronomy Observatory; radio), and the Great Basin Observatory (0.7 m robotic optical telescope in Great Basin National Park)

Project overview

Lurking at the center of every large galaxy is a supermassive black hole, which can have a mass up to a few billion times that of our Sun. Creating such massive black holes requires the Universe to first form smaller black holes, which grow over cosmic time by merging into larger ones, and/or by accreting nearby matter. One way to learn how black holes grow over time is to search inside smaller galaxies for black holes in the so-called "intermediate mass range" (weighing between a few hundred to a few million Suns), which provide a window into what black holes might have looked like before they grew to supermassive sizes.

For this project, we will search for intermediate mass black holes in nearby galaxies.  When matter falls into a black hole it releases large amounts of X-ray radiation.  In some cases, accreting black holes also launch jets of plasma moving away from the black hole at close to the speed of light, which emit copious amounts of radio waves.  By comparing data from X-ray satellites operated by NASA to observations taken with radio telescopes on Earth, we will search for X-ray and radio signatures of accreting intermediate mass black holes, with a focus on finding outflowing jets. Identification of new intermediate mass black holes will help us to understand (a) how black holes formed and (b) how accretion and jet physics operate in this intermediate mass range.