Microvariability detection in quasars: An astrostatistical problem
Microvariations probe the physics and internal structure of quasars. Unpredictability and small flux variations make this phenomenon elusive and difficult to...
Mid-infrared sources in the ELAIS Deep X-ray Survey
We present a cross-correlation of the European Large Area Infrared Space Observatory (ISO) survey (ELAIS) with the ELAIS Deep X-ray Survey of the N1 and N2...
Mid-infrared spectroscopy of infrared-luminous galaxies at z ~ 0.5-3
We present results on low-resolution mid-infrared (MIR) spectra of 70 IR-luminous galaxies obtained with the infrared spectrograph (IRS) onboard Spitzer. We...
MiNDSTEp differential photometry of the gravitationally lensed quasars WFI 2033-4723 and HE 0047-1756: microlensing and a new time delay
Aims: We present V and R photometry of the gravitationally lensed quasars WFI 2033-4723 and HE 0047-1756. The data were taken by the MiNDSTEp collaboration with...
Monitoring of active galactic nuclei. I - The quasars 1302 - 102 and 1217 + 023
We present the results of a five-month spectroscopic monitoring campaign of two radio loud quasars, PKS 1217 + 023 and PKS 1302 - 102. There is a pronounced...
Monitoring of active galactic nuclei. VI. The quasar MKN 876.
We present the results of a 6 month monitoring campaign of Mkn 876, a low luminosity quasar with M_abs_=~-24. High resolution spectroscopy and direct imaging in...
Most Hard-X-Ray-Selected Quasars in the Chandra Deep Fields are Obscured
Measuring the population of obscured quasars is one of the key issues in understanding the evolution of active galactic nuclei (AGNs). With a redshift...
Multiband optical variability of the TeV blazar PG 1553 + 113 in 2019
We report the flux and spectral variability of PG 1553 + 113 on intra-night (IDV) to short-term time-scales using BVRI data collected over 91 nights from 28...