Work

The formation of ultra compact dwarf galaxies and massive globular clusters

Year: 2017

Type: article

Abstract: The stellar initial mass function (IMF) has been described as being invariant, bottom-heavy, or top-heavy in extremely dense star-burst conditions. To provide usable observable diagnostics, we calculate redshift dependent spectral energy distributions of stellar populations in extreme star-burst clusters, which are likely to have been the precursors of present day massive globular clusters (GCs) and of ultra compact dwarf galaxies (UCDs). The retention fraction of stellar remnants is taken into account to assess the mass to light ratios of the ageing star-burst. Their redshift dependent photometric properties are calculated as predictions for James Webb Space Telescope (JWST) observations. While the present day GCs and UCDs are largely degenerate concerning bottom-heavy or top-heavy IMFs, a metallicity- and density-dependent top-heavy IMF implies the most massive UCDs, at ages < 100 Myr, to appear as objects with quasar-like luminosities with a 0.1−10% variability on a monthly timescale due to core collapse supernovae.

Source: Astronomy and Astrophysics

DOI: 10.1051/0004-6361/201731240

Authors: T. Jeřábková, P. Kroupa, J. Dabringhausen, M. Hilker, K. Bekki

Institutions: University of Bonn, Charles University, European Southern Observatory, The University of Western Australia, International Centre for Radio Astronomy Research

Language: English

Topic: Galaxies: Formation, Evolution, Phenomena

Subfield: Astronomy and Astrophysics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: bronze

Funders: Univerzita Karlova v Praze, Deutscher Akademischer Austauschdienst, Rheinische Friedrich-Wilhelms-Universität Bonn

Awards: G2199890687, G7159984209, G8993780391