Investigation of the WR 11 field at decimeter wavelengths
  The massive binary system WR11 has been recently proposed as the counterpart
of a Fermi source. If correct, it would be the second colliding wind binary
detected in GeV gamma-rays. However, the reported flux measurements from 1.4 to
8.64GHz fail to establish the presence of non-thermal (synchrotron) emission
from this source. Moreover, WR11 is not the only radio source within the Fermi
detection box. Other possible counterparts have been identified in archival
data, some of which present strong non-thermal radio emission. We conducted
"-resolution observations towards WR11 at very low frequencies (150 to
1400~MHz) where the NT emission is expected to dominate, and present a catalog
of more than 400 radio-emitters, among which a significant part is detected at
more than one frequency, including limited spectral index information. A search
for counterparts for this last group pointed at MOST0808-471, a source 2' away
from WR11, as a promising candidate for high-energy emission, with resolved
structure along 325 - 1390 MHz. For it, we reprocessed archive interferometric
data up to 22.3 GHz and obtained a non-thermal radio spectral index of -0.97 +-
0.09. However, multiwavelength observations of this source are required to
establish its nature and to assess whether it can produce (part of) the
observed gamma-rays. WR11 spectrum follows a spectral index of 0.74 +- 0.03
from 150 to 230 GHz, consistent with thermal emission. We interpret that any
putative synchrotron radiation from the colliding-wind region of this
relatively short-period system is absorbed in the photospheres of the
individual components. Notwithstanding, the new radio data allowed to derive a
mass loss rate of 0.000025 Mo/yr, which, according to the latest models for
gamma-ray emission in WR 11, would suffice to provide the required kinetic
power to feed non-thermal radiation processes.
