The mathematical simplicity of black holes, combined with their links to some of the most
energetic events in the universe, means that black holes are key objects for fundamental …

We have found compact X-ray sources in the center of 21 (54%) of 39 nearby face-on spiral
and elliptical galaxies with available ROSAT HRI data. ROSAT X-ray luminosities (0.2–2.4 …

The recent development of unified theories of active galactic nuclei (AGN) has indicated that
there are two physically distinct classes of these objects - radio-loud and radio-quiet. The …

We have analyzed Chandra ACIS observations of 32 nearby spiral and elliptical galaxies
and present the results of 1441 X-ray point sources that were detected in these galaxies. The …

ROSAT, and now Chandra, X-ray images allow studies of extranuclear X-ray point sources
in galaxies other than our own. X-ray observations of normal galaxies with ROSAT and …

We present arcsecond resolution Chandra X-ray and ground-based optical H α imaging of a
sample of 10 edge-on star-forming disk galaxies (seven starburst and three" normal" spiral …

We investigate how the empirical properties of hot X-ray-emitting gas in a sample of seven
starburst and three normal edge-on spiral galaxies (a sample that covers the full range of star …

We present deep images of the kpc-scale radio continuum emission in 14 edge-on galaxies
(ten Seyfert and four starburst galaxies). Observations were taken with the VLA at 4.9~GHz (…

Today's IoT systems include event-driven smart applications (apps) that interact with sensors
and actuators. A problem specific to IoT systems is that buggy apps, unforeseen bad app …

… Colbert leads research on methods for defending Army SCADA and ICS systems. Before
working at ARL, Dr. Colbert performed telecommunications research for the Department of …