Radio observations of FRB20201124a at 4-8 GHz with the 100-m Effelsberg Radio Telescope
ATel #14537; Laura Spitler (MPIfR), Henning Hilmarsson (MPIfR)
on 9 Apr 2021; 13:45 UT
Credential Certification: Laura Spitler (lspitler@mpifr-bonn.mpg.de)
Subjects: Radio, Fast Radio Burst
We report observations with the 100-m Effelsberg radio telescope at 4-8 GHz of FRB20201124a (ATel #14497). The observations began at 15:32:36 UTC on 7 April 2021 (MJD 58946) and continued for a total of 21600 s. The telescope was pointed at the interferometrically determined source position from ASKAP (ATel #14515). Total intensity filterbank data were recorded in two adjacent 2 GHz bands with 2048 channels each and a time resolution of 131 us.
The data were searched for single pulses using HEIMDALL and PRESTO with a S/N threshold of 8 over a DM range between 400 and 430 pc/cc. Candidates were classified using FETCH as well as being visually inspected. No single pulses were found in the data.
We place a fluence upper limit of 0.07 Jy ms, assuming a minimum S/N threshold of 8, 4 GHz of bandwidth, and a fiducial burst duration of 1 ms. Previous observations placed a fluence limit of 5.4 Jy ms at 2.26 GHz (ATel #14519). Our observations significantly deepen the fluence limit on emission at higher radio frequencies and suggest that bursts with fluences greater than roughly 0.1 Jy ms in the 4-8 GHz band are rare. Therefore, we recommend that future observations searching for bursts will be more fruitful at lower radio frequencies.
