Star-Forming Clumps and Clustered Starbursts across Cosmic Time

5 - 30 October 2020

Anita Zanella, Daniela Calzetti, Bruce Elmegreen, Michael Hilker, Florent Renaud

This workshop addresses the questions of how starbursting complexes, gaseous high-redshift clumps, giant molecular clouds, and young massive star clusters are formed, what are their physical properties, and what is their fate. Current observations and simulations allow us to directly compare how star formation proceeds at low and high redshift, down to the small spatial scales of star clusters (from ~ 1 pc to 1 kpc). They have shown that local galaxies have modest star formation rates and form the bulk of their stars in giant molecular clouds (gaseous star-forming regions with masses ~ 105 – 107 M☉), producing star complexes in a self-similar hierarchy from individual stars to young massive star clusters. In comparison, in the early Universe galaxies have high star formation rates and host large star-forming regions, dubbed “clumps”, with typical stellar masses ~ 108 – 109 M☉, 10 – 1000 times larger, brighter, and more massive than local giant molecular clouds, although recent observations suggest that giant clumps may be formed of sub-clumps. An additional piece of the puzzle is represented by globular clusters, conglomerates of stars with typical masses ~ 104 – 106 M☉, and a wide diversity of metallicities. Connecting the origins and physical properties of local giant molecular clouds, young massive star clusters, high-redshift clumps, and globular clusters is paramount to make a step forward in our

understanding of clustered star formation in the context of galaxy evolution. To bridge these topics and spark the discussion among experts with different backgrounds, this workshop will focus on four pillars that are common to all the communities.

• The formation of dense stellar systems: how do giant molecular clouds and young massive clusters form, and can we learn from them, extrapolating to high-redshift clumps? Are the metal-rich and metalpoor globular clusters formed through different physical channels, in separate environments and epochs? What are the main simulations' ingredients determining the formation scenariosof clumps and globular clusters?

• Their scaling relations: are giant cloud complexes and young stellar associations in local galaxies scaled down versions of star-forming clumps at high redshift? Are there scaling relations linking these populations and how can simulations consistently investigate this? Do these scaling relations apply to clustered star formation as well, including the formation of globular clusters?

• Their fate: are high-redshift clumps disrupted by stellar feedback or are they long-lived? What is the evidence that individual clumps migrate to a galaxy center to contribute to the bulge? What are the processes determining clusters survival and what is the relevance of these mechanisms to the lifetime of giant molecular clouds? Can surviving or “kicked-out” sub-clumps explain the spatial distribution of bulge/spheroid globular clusters in local galaxies?

• Future perspectives: what are the key observables needed to proceed further in our understanding of clustered star formation? What are the main theoretical predictions that can be tested with JWST and the ELTs? How can simulations span the required range of spatial scales to capture both galaxyformation and star formation?

Register here


(Deadline: 7 January 2020)

Technische Universitaet Muenchen
Exzellenzcluster Universe

Boltzmannstr. 2
D-85748 Garching

Tel. + 49 89 35831 - 7100
Fax + 49 89 3299 - 4002