The extremely red host galaxy of GRB 080207

Understand

We present optical, near-infrared, and Spitzer IRAC and MIPS observations of the host galaxy of the dark gamma-ray burst GRB 080207.

• The host is faint, with extremely red optical-infrared colors ($R-K\,=\,6.3$, 24\micron/$R-$band flux $\sim1000$) making it an extremely red object (ERO) and a dust-obscured galaxy (DOG).
• The spectral energy distribution (SED) shows the clear signature of the 1.6 micron photometric "bump", typical of evolved stellar populations.
• We use this bump to establish the photometric redshift $z_{\rm phot}$ as 2.2$^{+0.2}_{-0.3}$, using a vast library of SED templates, including M 82.