|3rd of November 2016|
|Radio light curve of the galaxy possibly associated with FRB150418|
|by Simon Johnston (CASS)|
Johnston et al. present
observations made with the Australia Telescope Compact Array (ATCA), the Jansky Very Large Array (JVLA) and the Giant Metre-Wave Telescope of the radio source within the galaxy WISE~J071634.59-190039.2, claimed to be host of FRB~150418 by Keane et al. (2016). At a frequency of 5.5 GHz, the source has a mean flux density of 140~uJy and is variable on short timescales with a modulation index of 0.36. Statistical analysis of the flux densities shows that the variations seen are consistent with refractive interstellar scintillation of the weak active galactic nucleus at the centre of the galaxy. It may therefore be the case that the FRB and the galaxy are not associated. However, taking into account the rarity of highly variable sources in the radio sky, and our lack of knowledge of the progenitors of FRBs as a class, the association between WISE~J071634.59-190039.2 and FRB~150418 remains a possibility. |
Figure caption: Left panel: Radio light curve at 5.5 GHz. Black crosses denote ATCA observations, blue triangles JVLA observations, and red squares VLBA, e-MERLIN and EVN. Right panel: Radio light curve from the ATCA data at 5.5 GHz (black crosses) and 7.5 GHz (red squares).
These results will be presented today at the First Pietro Baracchi Conference in Perth.