Extragalactic Astronomy and Cosmology

Example of high-resolution re-simulations. The upper-left panel shows the projection of a region of 30 Mpc/$h$ side around a massive ( $2.3\times 10^{15}$ M$_\odot/h$) dark matter halo, obtained in the VLS cosmological N-body simulations carried out by the Virgo Consortium (Yoshida et al. 2001). The upper-right panel is a zoom in the 2 r$_{\rm vir}$ ($5.4$ Mpc/$h$) region centered on the main halo; the mass resolution is $m_p=6.68\times 10^{10}$ M$_\odot/h$, and about $3\times10^{4}$ particles are shown in the image. The lower panels are the corresponding images in the high-resolution re-simulations: the mass resolution is now $m_p=2\times10^{9}$ M$_\odot/h$, and more than $10^6$ particles are contained within the virial radius of the re-simulated halo. Credit: B. Lanzoni, G. Tormen, V. Springel, G. Mamon, S.D. White.

People involved at OAB:

• Scientific staff: S. Bardelli, A. Cappi, P. Ciliegi, A. Comastri, H. de Ruiter, C. Gruppioni, R. Merighi, M. Mignoli, L. Origlia, L. Pozzetti, R. Sancisi, G. Stirpe, G. Zamorani, V. Zitelli, E. Zucca;

• Fellows: E. Calabrese, S. Giacintucci, B. Lanzoni, F. Marini, H. McCracken, F. Pozzi, C. Vignali.

Observational extragalactic astronomy has traditionally been one of the main themes of research at the Bologna Observatory. It includes a wide range of subjects, from the structure and evolution of ``normal" galaxies, to the physical properties of active galactic nuclei (AGNs) to observational cosmology.
The extragalactic research at the Bologna Observatory is characterized by a multiwavelength approach: while optical astronomy is the main field at the Observatory, some of the scientific staff specialize in X-ray observations of AGNs, and others find their main interest in radio studies of galaxies and quasars.
Much of this research is based on an intensive use of the most advanced instruments available today: the X-ray satellites Chandra and XMM-Newton, the ESO optical/NIR telescopes (including VLT), the Westerbork, VLA and ATCA radiotelescopes.