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Alex Markowitz

Associate Research Scientist, CASS

Office: SERF 438 (4th floor visitor office)

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Dr. Markowitz received his A.B. in Astrophysics at the University of California, Berkeley in 1996, then spent two years as a Data Analyst with the National Radio Astronomy Observatory in Socorro, New Mexico. He earned his PhD in Astronomy from the University of California, Los Angeles, in 2003, studying long-term X-ray variability properties of Active Galactic Nuclei. He worked as a National Research Council/NASA Postdoc Fellowship at NASA Goddard Space Flight Center from 2004 to 2007 before joining the staff at CASS, first as an Assistant Project Scientist for the RXTE project, then as an Assistant Research Scientist since 2011. These days, he splits his time between CASS and the Dr. Karl Remeis Observatory in Bamberg, Germany, where he is an Alexander von Humboldt Fellow.

Research Interests

Exploring accretion mechanisms in Active Galactic Nuclei (AGN), mainly via X-ray spectroscopy and variability. Exploring the geometry and accretion behavior of circumnuclear material around supermassive black holes across a range of length scales, from the region of extreme gravity to parsec scales. Connections between AGN and stellar-mass accreting compact objects. Links between black hole mass, luminosity, and continuum variability. Links between accretion disks and relativistic jets.


X-ray spectroscopy and multi-timescale spectral variability of AGN with X-ray observatories such as the Rossi X-ray Timing Explorer, Suzaku, and XMM-Newton. Spectroscopic monitoring to probe variable absorption and test "clumpy-torus" models. Fe K bandpass spectroscopic studies to probe accretion disk properties and black hole spin. Continuum variability in AGN, including X-ray power density spectra. Ionized outflows from AGN, probed via X-ray absorption features. Observations of Galactic pulsars and Black Hole X-ray Binary systems.

Select Publications

Full Spectral Survey of Active Galactic Nuclei in the Rossi X-ray Timing Explorer Archive Rivers, E.S., Markowitz, A., & Rothschild, R.E., 2013, ApJ 772, 114

A Suzaku Survey of Fe K Lines in Seyfert 1 Active Galactic Nuclei Patrick, A.R., Reeves, J.N., Porquet, D., Markowitz, A., Braito, V., Lobban, A.P., 2012, MNRAS 426, 2522

An Occultation Event in Centaurus A and the Clumpy Torus Model Rivers, E.S., Markowitz, A., & Rothschild, R.E., 2011, ApJ 742, L29

The X-ray Power Spectral Density Function of the Seyfert Active Galactic Nucleus NGC 7469 Markowitz, A., 2010, ApJ 724, 26

A Suzaku Observation of NGC 4593: Illuminating the Truncated Disk Markowitz, A. & Reeves, J.N., 2009, ApJ 705, 496

The Suzaku Observation of the Nucleus of the Radio-loud Active Galaxy Centaurus A: Constraints on Abundances of the Accreting Material Markowitz, A., et al., 2007, ApJ 665, 209

An Expanded Rossi X-Ray Timing Explorer Survey of X-Ray Variability in Seyfert 1 Galaxies Markowitz, A. & Edelson, R., 2004, ApJ 617, 939

Long-Term X-Ray Spectral Variability in Seyfert 1 Galaxies Markowitz, A., Edelson, R., & Vaughan, S., 2003, ApJ 598, 935

X-Ray Fluctuation Power Spectral Densities of Seyfert 1 Galaxies Markowitz, A., et al., 2003, ApJ 593, 96