At its core, three key overarching themes govern my research: (1) through targeted (multi-waveband) studies of individual efficient accretion systems associated with neutron stars and stellar and supermassive black holes, I focus on understanding the physics and dynamics driving the hottest regions most central to the compact object to get at solutions to BH spin and/or the sensitive relationship between accretion disk behavior and jet over many magnitude differences in  mass scales.  (2) In parallel, these systems can be used as illumination sources for high opacity material along the line-of-sight to enable a better understanding of the distribution of material (gas and dust) in the interstellar and intergalactic medium.  (3) In the course of the aforementioned studies, I  discovered interesting spectral features (atomic lines and edge structures) that has motivated me to develop an X-ray based laboratory and space program, based in condensed matter theory and practices,  as a major new thrust in astrophysics research for studying cosmic dust properties.  

Condensed Matter Astrophysics: X-ray Studies of Cosmic Dust

Cosmic dust plays a major role in the chemical evolution of stars, planets, life, and the energy balance of the Universe. X-rays, with its ability to penetrate through atoms, enables the only single-wavelength approach to simultaneously probe gas and (< 10-micron) dust. Capitalizing on this, we have a combined lab and space experimental program based in condensed matter theory and experimental practices to determine the quantity and composition of dust through absorption studies, and its distribution through studies of the dust scattering halo.

Relevant (Lab and Space Dust) Publications 

X-ray Binaries: Galactic BHs and Neutron Stars

Micro-quasars, stellar mass black holes (BH) or neutron stars (NS) which mimic the behavior of their supermassive active galactic nuclei (AGN) counterparts are the ideal nearby laboratories for studying the complex symbiosis between accretion and jet phenomena in BH systems, and disk instabilities.  Topics related to energetic accretion processes in X-ray binaries are actively researched through X-ray and IR spectroscopy and photometry with most of the available top ground and space instruments. These are supplemented with radio observations when available.

Relevant XRB Publications

Supermassive Black Holes

In concert with research on X-ray binaries (XRBs), active research is on-going within my group to study the jet-launching behaviour in radio-loud active galactic nuclei (AGNs) to compare against the galaxy environments hosting the less energetic Seyfert galaxies. We explore these topics primarily through multi-wavelength (radio, IR, optical, UV, X-ray) high resolution spectroscopic studies.

Relevant SMBH Publications

Plasma Theory

We have been engaged in theory work in support of our black hole and neutron star studies. We have been focusing particularly on studying thermodynamic stability conditions that may affect wind conditions in stellar and supermassive black hole systems. 

Relevant Plasma Theory Publications

Cosmology: IGM & DE

In the past, I was heavily engaged in Cosmology topics associated with (X-ray) searches for the hotter baryonic component of the intergalactic medium, as well as supernovae studies which ultimately led to the discovery of an accelerating force, now known as dark energy. The supernovae work, led by Saul Perlmutter, on which I am a co-author was awarded the 2011 Nobel Prize in Physics. 

Relevant Publications: IGM, Dark Energy