The distance to the black hole binary GX 339-4 remains a topic of debate. We examine high-resolution optical spectra of the Na D lines resolving the velocity...

We report on the first 180 days of Rossi X-Ray Timing Explorer observations of the outburst of the black hole candidate IGR J17091-3624. This source exhibits a...

We report the detection of an orbital period decay of dot{P}=-1.83+/- 0.66 ms yr-1 in the black hole X-ray binary XTE J1118+480. This corresponds to a period...

MWC 656 is the first known Be/black hole (BH) binary system. Be/BH binaries are important in the context of binary system evolution and sources of detectable...

In this article we demonstrate that PKS J1037-2705 has a weak accretion flow luminosity, well below the Seyfert 1/QSO dividing line, weak broad emission lines...

Optical spectra were obtained of the optical counterpart of the high-latitude (b~=62deg) soft X-ray transient XTE J1118+480 near its quiescent state (R~=18.3)...

We have studied the host galaxies of a sample of radio-loud active galactic nuclei (AGNs) spanning more than 4 decades in the energy output of the nucleus. The...

While the influence of supermassive black hole (SMBH) activity on habitability has garnered attention, the specific effects of active galactic nucleus (AGN)...

We show that quasar microlensing magnification statistics induced by a population of point microlenses distributed according to a mass spectrum can be very well...