Bibcode
Muñoz-Tuñón, C.; Elmegreen, B. G.; Sánchez Almeida, J.; Tabatabaei, F. S.; Filho, M. E.
Bibliographical reference
Monthly Notices of the Royal Astronomical Society, Volume 484, Issue 1, p.543-561
Advertised on:
3
2019
Citations
11
Refereed citations
10
Description
Correlations between the radio continuum, infrared, and CO emissions are
known to exist for several types of galaxies and across several orders
of magnitude. However, the low-mass, low-luminosity, and low-metallicity
regime of these correlations is not well known. A sample of metal-rich
and metal-poor dwarf galaxies from the literature has been assembled to
explore this extreme regime. The results demonstrate that the properties
of dwarf galaxies are not simple extensions of those of more massive
galaxies; the different correlations reflect different star-forming
conditions and different coupling between the star formation and the
various quantities. It is found that dwarfs show increasingly weaker CO
and infrared emissions for their luminosity, as expected for galaxies
with a low dust content, slower reaction rates, and a hard ionizing
radiation field. In the higher-luminosity dwarf regime [L_{1.4 GHz}
≳ 10^{27} W, where L_{1.4 GHz} ˜eq 10^{29} W for a Milky Way
star formation rate (SFR) of ≃1 M⊙ yr-1],
the total and non-thermal radio continuum emissions appear to adequately
trace the SFR. A breakdown of the dependence of the (H α-based)
thermal, non-thermal, and, hence, total radio continuum emission on SFR
occurs below L_{1.4 GHz} ˜eq 10^{27} W, resulting in a steepening
or downturn of the relations at extreme low luminosity. Below
LFIR ≃ 1036 W ≃ 3 × 109
L⊙, the infrared emission ceases to adequately trace the
SFR. A lack of a correlation between the magnetic field strength and the
SFR in low SFR dwarfs suggests a breakdown of the equipartition
assumption. As extremely metal-poor dwarfs mostly populate the low SFR
and low-luminosity regime, they stand out in their infrared, radio
continuum, and CO properties.
Related projects
Starbursts in Galaxies GEFE
Starsbursts play a key role in the cosmic evolution of galaxies, and thus in the star formation (SF) history of the universe, the production of metals, and the feedback coupling galaxies with the cosmic web. Extreme SF conditions prevail early on during the formation of the first stars and galaxies, therefore, the starburst phenomenon constitutes a
Casiana
Muñoz Tuñón