Hostname: page-component-586b7cd67f-2brh9 Total loading time: 0 Render date: 2024-11-29T21:48:19.774Z Has data issue: false hasContentIssue false
  • English
  • Français

Star formation at low rates: impact of lacking massive stars on the evolution of dwarf galaxies

Published online by Cambridge University Press:  30 October 2019

P. Steyrleithner ,
G. Hensler ,
S. Recchi  and
S. Ploeckinger
P. Steyrleithner
Affiliation:
Department for Astrophysics, University of Vienna, Türkenschanzstrasse 17, 1180 Vienna, Austria
G. Hensler
Affiliation:
Department for Astrophysics, University of Vienna, Türkenschanzstrasse 17, 1180 Vienna, Austria
S. Recchi
Affiliation:
Department for Astrophysics, University of Vienna, Türkenschanzstrasse 17, 1180 Vienna, Austria
S. Ploeckinger
Affiliation:
Leiden Observatory, University Leiden, P. O. Box 9513, NL-2300 RA Leiden, The Netherlands
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

In recent years dedicated observations have uncovered star formation at extremely low rates in dwarf galaxies, tidal tails, ram-pressure stripped gas clouds, and the outskirts of galactic disks. At the same time, numerical simulations of galaxy evolution have advanced to higher spatial and mass resolutions, but have yet to account for the underfilling of the uppermost mass bins of stellar initial mass function (IMF) at low star-formation rates. In such situations, simulations may simply scale down the IMF, without realizing that this unrealistically results in fractions of massive stars, along with fractions of massive star feedback energy (e.g., radiation and SNII explosions). Not properly accounting for such parameters has consequences for the self-regulation of star formation, the energetics of galaxies, as well as for the evolution of chemical abundances. Here we present numerical simulations of dwarf galaxies with low star-formation rates allowing for two extreme cases of the IMF: a “filled” case with fractional massive stars vs. a truncated IMF, at which the IMF is built bottom-up until the gas reservoir allows the formation of a last single star at an uppermost mass. The aim of the study is to demonstrate the different effects on galaxy evolution with respect to self-regulation, feedback, and chemistry. The case of a stochastic sampled IMF is situated somewhere in between these extremes.

Keywords

hydrodynamicsgalaxies: dwarfgalaxies: evolutiongalaxies: star formation
Type
Contributed Papers
Information
Proceedings of the International Astronomical Union , Volume 14 , Symposium S344: Dwarf Galaxies: From the Deep Universe to the Present , August 2018 , pp. 186 - 189
Copyright
© International Astronomical Union 2019 

References

Fryxell, B., Olson, K., Ricker, P., Timmes, F. X., Zingale, M., Lamb, D. Q., MacNeice, P., Rosner, R., Truran, J. W. & Tufo, H. 2000, APJS, 131, 273–334 CrossRefGoogle Scholar
Koeppen, J., Theis, C. & Hensler, G. 1995, AAP, 296, 99 Google Scholar
Kroupa, P. 2001, MNRAS, 322, 231–246 CrossRefGoogle Scholar
Kroupa, P. & Weidner, C. 2003, APJ, 598, 1076–1078 CrossRefGoogle Scholar
Ploeckinger, S., Hensler, G., Recchi, S., Mitchell, N. & Kroupa, P. 2014, MNRAS, 437, 3980–3993 CrossRefGoogle Scholar
Recchi, S., Calura, F. & Kroupa, P. 2009, AAP, 499, 711–722 CrossRefGoogle Scholar
Recchi, S. & Hensler, G. 2013, AAP, 551, A41 CrossRefGoogle Scholar
Salpeter, E. E. 1955, APJ, 121, 161 CrossRefGoogle Scholar
Vorobyov, E. I., Recchi, S. & Hensler, G. 2012, AAP, 543, A129 CrossRefGoogle Scholar