What is DAGAL

DAGAL (Detailed Anatomy of GALaxies) is a EU-funded training network between the academic nodes Instituto de Astrofisica de Canarias in Tenerife, Spain (coordinator), Universidad Complutense de Madrid, Spain, the Max Planck Institute for Astronomy in Heidelberg, Germany, the Laboratoire d'Astrophysique de Marseille, France, the University of Groningen, the Netherlands, and the University of Oulu, Finland, and with associated private sector partners Springer, FRACTAL, and Specim. Altogether the network has 8 PhD and 2 postdoc-positions, related to observational and numerical research of galaxy evolution in the nearby Universe. DAGAL collaborates closely with the Spitzer Survey of Stellar Structure in Galaxies (S4G) .

Oulu node

Oulu university DAGAL node hosts 2 PhD-training positions (ESRs in EU-terminology). The funding period is 36 months, starting in September 2012. The salary is according to EU guidelines, which is considerably higher than the normal University doctoral student salary.

Structure analysis of S4G sample (ESR6 - position filled)

The S4G mid-IR images provide an ideal database to study galaxy morphology and how it is related to secular evolution of galaxies. In this project the origin of early-type disk galaxies is studied. When the PhD projects starts, detailed morphological classifications will be available, at a similar level of detail as in Laurikainen et al. (2011, MNRAS 418, 1452). The S4G data analysis pipelines offer bulge/disk/bar decompositions which, together with the classifications, are used as a starting point for in-depth analysis of the structure components. The analysis methods include the Fourier amplitude and force calculation methods developed and extensively used by our group. The morphological properties are connected to stellar populations and kinematics of structures, in collaboration with IAC (where the student will spend an extended time period), and with Max Planck institute (MPIA). The scientific questions to be addressed are: (1) what are the possible progenitors of S0s (from dwarf S0s to bright SOs) in the nearby Universe,(2) to test the various bulge formation scenarios of S0s.

Signatures of secular evolution (ESR7 -position filled)

The main goal of ESR7 is to search observational evidence (or lack of it) for the theoretically predicted slow-down of bars due to flow of angular momentum to dark halo components. This prediction is not easy to reconcile with the fact that most stellar absorption line measurements with Tremaine-Weinberg method imply fast bars. However, these direct measurement are limited to early type galaxies, and there is evidence that late-type galaxies might harbor also slower bars. For example, we use sticky-particle simulations to model the morphological and kinematic response to a bar perturbation, searching through different assumed bar pattern-speeds and halo contributions. The gravity potentials are calculated from the Spitzer S4G 3.6 micron data, which provides the sofar largest uniform high quality dataset for such modeling, spanning through large variety of galaxy properties and environments. Other aspects of bars are also studied, including their role to spiral structure.
The ESR7 position involves also collaboration with the DAGAL Marseille node, using full N-body simulations (Lia Athanassoula), with an option for a joint Oulu-Marseille PhD-degree.

Background of the Oulu Group

The dynamics group in Oulu consists of four senior level researchers, one postdoc, two PhD and two MSc students, dealing both with galactic dynamics and the dynamics of planetary rings. Our group members belong to the S4G core data analysis team, and lead the 2D-decomposition pipeline of the S4G project.

Our other extragalactic interests include e.g. the generation of spiral structure in tidal interactions (see Fig. 6.26 in Binney and Tremaine 2008-edition; also see our M51 models in Salo & Laurikainen 2000 MNRAS 319, 377; 393), the role of bars in inducing spiral structure (eg. Salo & Laurikainen & Buta & Knapen 2010 ApJL 715, L56), and the formation and evolution of S0-galaxies (NIRS0S S0-galaxy Survey: a review of our results can be found in Laurikainen et al. 2012, Advances in Astronomy in press, astro-ph 1111.6447). See also the NIRS0S webpage. .

In the study of planetary rings (conceptually not as distinct from extragalactic research as it may seem) we employ both N-body simulations and hydrodynamical analysis to model the ring fine-structure induced by gravitational and viscous mechanisms.

The dynamics group is one of the three Astronomy subunits at the Department of Physics , which has a centre of Excellence in Research status in the Oulu University.

PhD-study system in Oulu

All PhD-students in the university of Oulu are enrolled to the Oulu University Graduate School. The nominal duration of PhD studies is 4 years. Since this is longer than the EU-funded 3 year period, Oulu university will cover the last year's salary of a succesful DAGAL ESR. However, in principle it is possible to finish the thesis also in 3 years.

Oulu University

Oulu University is 5th largest University in Finland, with about 14, 000 MSc and PhD students. It has a large number of foreign students, so that many of the advance-level coures etc. are lectured in English. The university International relations office organizes many type of activities for foreign students, including concise 'survival courses' in Finnish language. See also their guide for Internaltional students .

Worried about the winters ?

Looking at the map, the location of Oulu at 65 North latitude can appear horrifying (there is only tundra /permafrost on similar latitudes in Alaska and Canada), but the map is deceiving. Due to the warm Gulf Stream, Oulu, like most of Scandinavia, belongs to the boreal forest zone with cool but not excessively cold climate (no reported polar bear sightings for the last 10,000 yrs).

The survival rate of foreign students through Finnish winters is full 100%. Eventhough the typical December- February temperatures are around -10^oC (and for some weeks may go down to -25^oC), the air is dry and there is no cold wind. This makes it easily tolerable - and in fact quit refreshing after a while. The houses/apartments are designed to keep warm also in these low temperatures (3 or 4 -layer windows etc.), so that the chance of freezing indoors is much less than in most 'warm' countries. And of course heating saunas helps (and can become an addictive habit). During summer the typical temperatures are around 20C (over 25C is considerd as a heatwave! All time record from, 33C is from 2010)

Worried about long summer days ?

Located just 200 km south of the Arctic Circle, the annual variation in the length of day is 'easily' noticeable in Oulu: during Summer Solstice the sun stays above horizon for over 22 hours, while the shortest days at Xmas time are barely 4 hours (horizontal refraction makes miracles). In fact, there is no dark time at all from mid-May to the end of July: during this period the evening and morning twilights blend together. The Finns usually make a lot out of this time, spending time on outdoor activities etc (or in PhD studies), though a small minority of foreigners find it hard to get adjusted at first (but in the end they will miss it if leaving Oulu). The darkest time is in fact in November, before the snow covers the ground (typically at mid-November). In March (snow melts in early April), the reflection of sun from snow is already so strong that sun glasses are a must when skiing to work at the university.