The dust SED of dwarf galaxies

Modeling the Dust Spectral Energy Distributions of Dwarf Galaxies

Recent efforts on the modeling of the infrared spectral energy distributions (SEDs) of dwarf galaxies are summarised here. The characterisation of the dust properties in these low metallicity environments is just unfolding, as a result of recently available mid-infrared to millimetre observations. From the limited cases we know to date, it appears that the hard radiation fields that are present...

Dust-to-gas Ratio and Metal Abundance in Dwarf Galaxies

We have compared the metallicity (represented by oxygen abundance), Xo, and the dust-to-gas ratio, D, in a sample of dwarf galaxies. For dwarf irregulars (dIrrs) we find a good correlation between the two quantities, with a power-law index 0.52± 0.25. Blue Compact Dwarf (BCD) galaxies do not show such a good correlation; in addition both the dust-to-gas ratio and the metallicity tend to be high...

Panchromatic SED Models of Simulated Galaxies

High Redshift Dust Obscured Galaxies, a Morphology-sed Connection Revealed by Keck Adaptive Optics

A simple optical to mid-IR color selection, R − [24] > 14, i.e. fν(24 μm)/fν(R) & 1000, identifies highly dust obscured galaxies (DOGs) with typical redshifts of z ∼ 2±0.5. Extreme mid-IR luminosities (LIR > 10 ) suggest that DOGs are powered by a combination of AGN and star formation, possibly driven by mergers. In an effort to compare their photometric properties with their rest frame optical...

Giant Halos in Dwarf Irregular Galaxies vs. Dwarf Elliptical Galaxies

We present a discovery of a giant stellar halo in NGC 6822, a dwarf irregular galaxy in the Local Group. This halo is mostly made of old red giants, showing striking features: 1) it is several times larger than the main body of the galaxy seen in the optical images, and 2) it is elongated in the direction almost perpendicular to the HI disk of NGC 6822. The structure of this stellar halo looks ...