"DQ White Dwarfs"
Tommi VORNANEN (University of Turku)

Abstract Black on White DQ white dwarfs (WDs) are a class of WDs characterized by carbon spectral lines. In these objects carbon can be seen as neutral or ionized atomic lines or molecules of C_2 or CH. The class can be divided into to three sub-classes: hot, cool and peculiar DQs. The evolution of these objects is discussed and how the subclasses fit together in the bigger picture. Special attention needs to be given to the recently discovered hot DQs as their connection with the other two subclasses is less obvious. The purpose of the observations at the VLT is also explained and the overall reason for studies of the magnetic fields in these objects in the context of evolution is discussed.

"Introduction to astrobiology"
Dainis DRAVINS (Lund University)

Abstract Since times immemorial, humans have speculated about the possibilities for life outside Earth but only recently has astrobiology grown into a frontier natural science. The developments are equally astronomical and biological: On Earth, "extremophile" life forms have been found in "unlikely" places such as deep below ground, in very hot, acidic, or radioactive media, widening the understanding of the environmental limits to life. Plausibly habitable locations within the solar system are now studied from spacecraft, and numerous exoplanets are becoming accessible to search for chemical signatures, including biomarkers. A possible discovery of extraterrestrial life could have impacts far beyond the natural sciences in addressing fundamental existentialistic, philosophical and ethical questions.

"QSO host galaxies"
Roberto DE CARLI (MPIA)

Abstract QSOs are used as a tool to investigate how galaxies and supermassive black holes formed, their (co-)evolvution, the mechanisms responsible for igniting nuclear activity, and the effects of AGN feedback on the galaxy. In this talk, I will present our studies of the black hole mass -- host galaxy mass relation in QSOs up to z=3, focusing on the global evolution of the relation, its slope, the properties of QSO host galaxies (in particular, their colors, morphology and stellar mass) and their dependence on the black hole mass. Finally, I will present some preliminary results on the properties of QSO host galaxies at very high redshift (z › 6, when the Universe was ‹ 1 Gyr old).

"Warm CO gas in the planet-forming regions of flaring proto-planetary disks"
Rosina HEIN BERTELSEN (Groningen, The Netherlands)

Abstract CRIRES observations of a small sample of Herbig Ae/Be stars ( Plas et al. 2009, 2011) readily show detections of infrared emission from CO (ro-vibrational transitions) in the inner 50 AU of flat disks, thus making this a powerful tool to understand the physical structure of planet forming regions. Contrary to model expectations and observations of other gas tracers, the CO emission in three flaring Herbig disks is seen to originate further out than seen for flat disks. However, the small number of observed flaring disks hampers our ability to understand this apparent difference and use CO as a general tracer of the inner disk. We propose CRIRES observations of an additional 12 flaring disks as a rigorous test for our hypothesis that ro-vibrational CO emission is only present in the outer parts of flaring disks around Herbig Ae/Be stars. If confirmed, this new correlation could provide first direct evidence for an evolutionary difference between flared and flat disks.

"Optical imaging with submilliarcsecond resolution: Intensity interferometry with Cherenkov telescopes"
Dainis DRAVINS(Lund University)

Abstract Although we do observe starlight, we are still unable – with few exceptions – to observe the stars themselves, i.e., to resolve their disks or view structures across and outside their surfaces. Bright stars have typical sizes of some milliarcsecond(s), and kilometer-scale optical baselines are required for their imaging. However, such phase/amplitude interferometry is hindered by atmospheric turbulence while space interferometry is too complex. Atmospheric effects can be circumvented by intensity interferometry, a technique (once pioneered by Hanbury Brown and Twiss) for measuring the second-order coherence of light. The required large flux collectors are now becoming available as the arrays primarily erected to measure atmospheric Cherenkov light induced by gamma rays. Planned facilities such as CTA, Cherenkov Telescope Array (www.cta-observatory.org ), envision many tens of telescopes distributed over a few square km. Digital signal handling enables very many baselines to be simultaneously synthesized between many pairs of telescopes, while stars may be tracked across the sky with electronic time delays, in effect synthesizing an optical interferometer in software, enabling two-dimensional imaging with angular resolutions around 30 microarcseconds.