Dust-poor galaxies at early times

Dust Formation In Early Galaxies

We investigate the sources and amount of dust in early galaxies. We discuss dust nucleation in stellar atmospheres using published extended atmosphere models, stellar evolution tracks and nucleation conditions. The Thermally Pulsating Asymptotic Giant Branch (TPAGB) phase of intermediate mass stars is likely to be the most promising site for dust formation in stellar winds. We present an elemen...

Gamma-Ray Burst Dust Echoes Revisited: Expectations at Early Times

Gamma-ray burst (GRB) dust echoes were first proposed as an alternative explanation for the supernova-like (SN-like) components to the afterglows of GRB 980326 and GRB 970228. However, the spectroscopic identification of Type Ic SN 2003dh associated with GRB 030329, as well as the identification of SN-like components to the afterglows of other GRBs, appears to have confirmed the GRB/SN paradigm...

Properties of dust in early-type galaxies

We report optical extinction properties of dust for a sample of 26 early-type galaxies based on the analysis of their multicolour CCD observations. The wavelength dependence of dust extinction for these galaxies is determined and the extinction curves are found to run parallel to the Galactic extinction curve, which implies that the properties of dust in the extragalactic environment are quite ...

Dust emission in early - type galaxies : The mid - infrared view . ⋆

We present mid-infrared (MIR) maps for a sample of 18 early-type galaxies observed at 4.5, 6.7 and 15 μm with the ISOCAM instrument on board the ISO satellite with a 6” spatial resolution. We model the Spectral Energy Distribution (SED) of these galaxies using the stellar evolutionary synthesis model PÉGASE and we derive the MIR excess over the stellar component. We then explore the nature of t...

Luminous Infrared Galaxies Early starbusts and dust-enshrouded AGNs