Upper limits on radio afterglow emission and previous outbursts for the very bright FRB180309 from observations with the Lovell Telescope
ATel #11606; Mitchell B. Mickaliger (University of Manchester), Fabian Jankowski (University of Manchester), Kaustubh Rajwade (University of Manchester), Karel Adamek (Oxford University), Wes Armour (Oxford University), Cees Bassa (ASTRON), Rene P. Breton (University of Manchester), Manisha Caleb (University of Manchester), Laura Driessen (University of Manchester), Aris Karastergiou (Oxford University), Michael Kramer (MPIfR, University of Manchester), Vincent Morello (University of Manchester), Sotiris Sanidas (University of Manchester), Ben Stappers (University of Manchester), Charles Walker (University of Manchester)
on 4 May 2018; 11:25 UT
Credential Certification: Mitchell Mickaliger (mitchell.mickaliger@manchester.ac.uk)
Subjects: Radio, Fast Radio Burst
As part of a search programme for fast radio transients that is running at the Lovell Telescope at Jodrell Bank Observatory, we have followed up the very bright FRB180309 (ATel #11387). Follow-up observations started less than 7 hours after the event, on 2018-03-09 at 09:34:51 UTC, pointing at the reported position centered at RA = 21:24:43.8, Dec = -33:58:44.5 (J2000), close to PSR J2124-3358. Two hours of data were recorded. The observations were conducted using the L-band receiver, with the Apollo backend sampling a bandwidth of 336 MHz, centred at 1564 MHz, with 0.5 MHz channel bandwidth. 8-bit filterbank files were produced with a sampling time of 256 us.
We analysed the data using two single-pulse search pipelines. One pipeline is based on the Heimdall algorithm (Barsdell et al. 2011). For the second pipeline, we used algorithms from Astro-Accelerate (https://github.com/AstroAccelerateOrg/astro-accelerate) that is part of the ongoing development of highly optimized fast transient search software for upcoming facilities like MeerKAT and the Square Kilometre Array. Our preliminary analyses using both pipelines show no events above a signal-to-noise ratio (S/N) of 8 for widths between 0.256 - 655.36 ms (0.256 - 500 ms for AA) and dispersion measures (DMs) 0 - 5000 pc cm^-3 (0 - 750 pc cm^-3 for AA). The non-detection places an upper-limit on potential radio afterglow emission of 0.6 Jy ms for events of 1 ms duration. The limit takes into account the fraction of data corrupted by radio-frequency interference (RFI) and the contribution to the system temperature from ground spill-over caused by the low elevation of the field for the telescope.
Additionally, we reprocessed about 4 hours of archival data of the field that were obtained during regular observations as part of the Jodrell Bank pulsar timing programme of PSR J2124-3358. These typically 15 minute long observations span the period from 2013-11-22 to a few days before the event (2018-03-05). Again, our preliminary analyses indicate no single-pulse events above a S/N of 8 (0.256 <= width <= 655.36 ms, 0 <= DM <= 5000 pc cm^-3), placing an upper-limit on previous outbursts of 0.6 Jy ms for events of 1 ms duration. This includes the same additional contributions as above.
Follow-up observations of the field and further data analysis are ongoing. Part of this research was made possible by the ERC funded MeerTRAP project (grant no. 694745).
