EMail Print



Galaxy interactions and mergers across cosmic time
11.03.2018 - 16.03.2018
Sport & Kurhotel at Bad Moos - Via Val Fiscalina 27, 39030, Sexten
Conferences 2018


Collisions between galaxies have long been thought to play a key role in galaxy evolution. In addition to assembling the most massive galaxies, mergers also represent the main mechanism to increase the dispersion in stellar orbits and form bulges. However, recent numerical simulations and observations support the idea that the evolution of z>2 galaxies are primarily driven by local disk instabilities, rather than mergers. Consequently, the relative importance of mergers and disk instabilities in shaping the early lives of massive galaxies remain debated. In the proposed workshop, we plan to discuss open questions relevant to the role of mergers in galaxy evolution, both near and far.

Firstly, we will discuss how to best identify a merger, both observationally and in cosmological simulations. Galaxy surveys have provided us with rich data, such as broadband imaging, spectroscopic surveys, and resolved ionized and molecular gas kinematics. However, there remain discrepancies among the various selection methods: different physical components of galaxies are traced at different wavelengths, and display merger signatures differently as the interaction proceeds. How do we ensure a fair comparison across observations, as well as with simulations? Reaching a consensus on this is fundamental to determining the role of mergers in galaxy evolution, and therefore forms the basis of the workshop.

Next, quantifying the impact of interactions on galaxy star formation histories is key to understand how massive galaxies were assembled. This subject is currently intensively investigated, thanks to new numerical simulations with unprecedented high spatial resolution that reveal the importance of the interaction-induced tidal field and interstellar medium (ISM) turbulence on star formation. Do mergers enhance star formation, in the local Universe and at high redshift?

Finally, we would like to discuss the connection between mergers and nuclear activity, which can potentially lead to the quenching of star formation. Simulations have successfully shown that galaxy collisions can trigger gas inflows that can feed a central active galactic nucleus (AGN) and starburst. However, it remains controversial whether mergers are causally linked to AGN, both locally and at high redshift. What can we learn about the triggering mechanism of AGN? Namely, do mergers necessarily trigger AGN, and are all AGN triggered only by mergers?

We live in a crucial moment, when many of these questions can finally be tackled. On the one hand, galaxy simulations are starting to resolve gravitational instabilities in the ISM down to parsec-scales. On the other hand, new and upcoming facilities such as ALMA, JWST and ELT will reveal how gas and stars reorganize when galaxies collide out to high redshift. The goal of this workshop is to catalyze discussions among experts working on different redshifts, techniques and wavelengths, and to foster synergies between observers and theorists. This will help build a complete picture of this fundamental phenomenon, and to identify the most fruitful instrumental avenues to explore in the near future.

Confirmed invited speakers (click to open)

Programme and logistics

Click here for the scientific program

- The workshop will begin on Monday morning and finish by lunchtime on Friday.

- Transportation between Venice airport and Sexten:

- The drive is around 3 hours

- We will organize shuttle buses from Venice airport to Sexten on Sunday 11th March (leaving 15:30h and 19:30h)

- We will organize shuttle buses from Sexten to Venice airport on 16th March (Friday) around 13:00h, and early morning on 17th March (Saturday)

- These shuttle buses cost 50€ extra per way (including taxes).

- For other transport options, please refer to this page:

- There will be a cocktail reception at 18:30h for those arriving with the first bus.

- The conference dinner will take place at Hotel Bad Moos. For those staying at Hotel Bad Moos on full board (20% discount for workshop participants), the conference dinner is free; people who opt for other accommodation options can still attend the conference dinner at a cost of 45€ per person.


Workshop leaders:
Allison Man (1),
Miguel Querejeta (1),
Jérémy Fensch (2),
Chian-Chou Chen (1) 
Federico Lelli (1)

1. European Southern Observatory, Garching, Germany 2. Laboratoire AIM Paris-Saclay, France

Email addresses: - This e-mail address is being protected from spambots. You need JavaScript enabled to view it - This e-mail address is being protected from spambots. You need JavaScript enabled to view it - This e-mail address is being protected from spambots. You need JavaScript enabled to view it - This e-mail address is being protected from spambots. You need JavaScript enabled to view it  

This event has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 730562 [RadioNet]

Due to space limitations, we can only host up to 50 people. At this stage, registration is primarily for invited participants. If you did not get an invitation but are interested in the workshop, please, send us an email and we will consider your name if we still have space left. Email:  This e-mail address is being protected from spambots. You need JavaScript enabled to view it
EU flag


Sport & Kurhotel at Bad Moos   -   Website

3  infn logo 340x238 Logo ASI    4   Consorzio  Logo-Unife_color