90 citations · 92 across the 3 of their papers we have counts for
4 papers
Optical imaging and spectroscopy of BL Lac objects
Renato Falomo, Marie-Helene Ulrich
We present optical images and spectroscopy for a dozen of BL Lac objects. Most of these objects were not previously studied and we give for the first time the properties of their h…
The Steep Spectrum Quasar PG1404+226 with ASCA, HST and ROSAT
Marie-Helene Ulrich, Andrea Comastri, Stefanie Komossa +1
(abridged) We present and discuss our observations of the NL quasar PG1404+226 with ASCA and HST, and a re-analysis of our earlier observations with ROSAT. The soft X-ray spectrum…
30 years of multi-wavelength observations of 3C 273
M. Turler, S. Paltani, T. J. -L. Courvoisier +14
We present a wide multi-wavelength database of most observations of the quasar 3C 273 obtained during the last 30 years. This database is the most complete set of observations avai…
Multiwavelength observations of short time-scale variability in NGC 4151. IV. Analysis of multiwavelength continuum variability
R. A. Edelson et al
This paper combines data from the three preceding papers in order to analyze the multi-waveband variability and spectral energy distribution of the Seyfert~1 galaxy NGC~4151 during…