EVN measurement of the FRB 150418 host galaxy candidate and its stability on VLBI scales
ATel #8959; B. Marcote (JIVE), M. Giroletti (INAF), M. Garrett (ASTRON), J. Yang (OSO), Z. Paragi (JIVE), K. Hada (NAOJ), C. C. Cheung (NRL)
on 16 Apr 2016; 08:13 UT
Credential Certification: Benito Marcote (marcote@jive.eu)
Subjects: Radio, AGN, Transient
From Very Large Baseline Array (VLBA) and e-MERLIN observations at 5 GHz, Bassa et al. (ATel #8938) reported a milliarcsecond-scale compact radio source coincident with the center of WISE J071634.59-190039.2, the proposed galaxy counterpart of the Fast Radio Burst FRB 150418 (Keane et al. 2016, Nature 530 453).
At the provided VLBI position, our EVN data (ATel #8865) shows a radio source with a peak brightness of 129 ± 27 μJy/beam (4.8-σ confidence level), consistent with our previously reported compact radio source upper-limit of 170 μJy/beam at a 6-σ noise level in the 2 x 2 arcsec2 field.
As a summary, the 5 GHz peak surface brightnesses inferred from the high angular resolution observations are (quoted errors are image rms noise, and MJD at the middle of the observation):
| MJD | peak (μJy/beam) | Array |
| 57455.15 | 130 ± 14 | VLBA |
| 57463.80 | 129 ± 27 | EVN |
| 57469.81 | 144 ± 25 | e-MERLIN |
which can be compared with the JVLA and ATCA data (see Williams & Berger 2016, ApJL, in press,
arXiv:1602.08434; ATels #
8752,#
8946; and Vedantham et al. 2016,
arXiv:1603.04421).
The three epoch VLBI results spanning 14 days are consistent within the errors, indicating a steady compact source. Further very high resolution observations with the EVN are planned to clarify if significant variability is observed at these scales.
