Abstract
We develop a dust efflux model of radiation pressure acting on dust
grains which successfully reproduces the relation between stellar mass,
dust opacity and star formation rate observed in local star-forming
galaxies. The dust content of local star-forming galaxies is set by the
competition between the physical processes of dust production and dust
loss in our model. The dust loss rate is proportional to the dust
opacity and star formation rate. Observations of the relation between
stellar mass and star formation rate at several epochs imply that the
majority of local star-forming galaxies are best characterized as having
continuous star formation histories. Dust loss is a consequence of
sustained interaction of dust with the radiation field generated by
continuous star formation. Dust efflux driven by radiation pressure
rather than dust destruction offers a more consistent physical
interpretation of the dust loss mechanism. By comparing our model
results with the observed relation between stellar mass, dust extinction
and star formation rate in local star-forming galaxies, we are able to
constrain the time-scale and magnitude of dust loss. The time-scale of
dust loss is long and therefore dust is effluxed in a `slow flow'. Dust
loss is modest in low-mass galaxies but massive galaxies may lose up to
70-80 per cent of their dust over their lifetime. Our slow flow model
shows that mass-loss driven by dust opacity and star formation may be an
important physical process for understanding normal star-forming galaxy
evolution.
Original language | English |
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Pages (from-to) | 1852-1866 |
Journal | Monthly Notices of the Royal Astronomical Society |
Volume | 436 |
Issue number | 2 |
DOIs | |
Publication status | Published - 4 Oct 2013 |
Keywords / Materials (for Non-textual outputs)
- galaxies: evolution
- galaxies: ISM
- galaxies: star-formation