Highly Extinguished Host Galaxy of the Dark GRB 020819
  We analyse the properties of the host galaxy of the optically dark gamma-ray
burst (GRB) 020819 (z = 0.41) and discuss the possible implications in the
context of "dark" GRBs. We present g'r'i'z'JHK photometry of the host galaxy
and fit the broad spectral energy distribution including the public Spitzer
IRAC data using stellar population models. The broad spectral energy
distribution (SED) indicates a high extinction, A_V ~ 1.8 - 2.6 mag, for this
relatively massive galaxy. This is the highest global extinction for a GRB host
galaxy with a robust spectroscopic redshift. The properties of the host galaxy
are indicative of dusty, intense star-formation, which differ from those of the
current sample of GRB hosts. This implies that the dust extinction is one of
the main reasons for the darkness of low-redshift bursts and that the long GRB
host population is far more diverse than previously anticipated.
