Aims:To check whether the polar angle distribution of QSOs around nearby spiral galaxies is isotropic or not. Methods: A statistical analysis of the polar angle distribution of large samples of QSOs from the SDSS survey and Monte Carlo simulations to calculate their significance are carried out. Results: There is a clear excess of QSOs near the

Due to an error at the Press, the header to column (8) of Table 1 is incorrect. This column head should read log([O I/Hα), not log([O III/Hα). The Press sincerely regrets this error.

In 2005 and 2006, the MAGIC telescope observed very high energy gamma-ray emission from the distant BL Lac object PG 1553+113. The overall significance of the signal was 8.8 σ for 18.8 hr of observation time. The light curve shows no significant flux variations on a daily timescale; the flux level during 2005 was, however, significantly higher

We present results from a series of follow-up observations of a subsample of the representative SAURON survey elliptical (E) and lenticular (S0) galaxies using the OASIS integral-field spectrograph. These observations focus on the central 10 " x 10 ", with roughly double the spatial resolution of the SAURON observations. This increased spatial

We study X-ray fluorescent emission and monochromatic scattering from the surfaces of asteroids and other atmosphereless solar-system objects using numerical Monte Carlo simulations. X-ray observations allow the assessment of the elemental composition and structure of the surface. We assume that the model regolith consists of close-packed spherical

Velocity oscillations measured simultaneously at the photosphere and the chromosphere of different solar magnetic features (sunspots, pores and facular regions) allow us to study the properties of wave propagation as a function of the magnetic flux of the structure. While photospheric oscillations are similar everywhere, oscillations measured at