A search for optical bursts from RRAT J1819-1458: II. Simultaneous ULTRACAM-Lovell Telescope observations

TL;DR

This study conducted simultaneous optical and radio observations of RRAT J1819-1458 using ULTRACAM and the Lovell Telescope, aiming to detect optical bursts associated with radio bursts, but found no optical emission brighter than magnitude i'=19.3.

Contribution

First simultaneous high-speed optical and radio observations of RRAT J1819-1458, setting new deeper limits on optical burst brightness.

Findings

No optical bursts detected brighter than i'=19.3 magnitude.

Optical burst detection sensitivity improved by nearly 3 magnitudes over previous limits.

Results constrain models of optical emission from RRATs.

Abstract

The Rotating RAdio Transient (RRAT) J1819-1458 exhibits ~3 ms bursts in the radio every ~3 min, implying that it is visible for only ~1 per day. Assuming that the optical light behaves in a similar manner, long exposures of the field would be relatively insensitive due to the accumulation of sky photons. A much better way of detecting optical emission from J1819-1458 would then be to observe with a high-speed optical camera simultaneously with radio observations, and co-add only those optical frames coincident with the dispersion-corrected radio bursts. We present the results of such a search, using simultaneous ULTRACAM and Lovell Telescope observations. We find no evidence for optical bursts in J1819-1458 at magnitudes brighter than i'=19.3 (5-sigma limit). This is nearly 3 magnitudes fainter than the previous burst limit, which had no simultaneous radio observations.