uGMRT detection of a persistent radio source coincident with FRB20201124A
ATel #14529; Robert Wharton (MPIfR), Suryarao Bethapudi (MPIfR), Tasha Gautam (MPIfR), Dongzi Li (Caltech), Hsiu-Hsien Lin (CITA), Robert Main (MPIfR), Viswesh Marthi (NCRA), Laura Spitler (MPIfR), Ue-Li Pen (CITA)
on 8 Apr 2021; 14:39 UT
Credential Certification: Robert Wharton (wharton@mpifr-bonn.mpg.de)
Subjects: Radio, Fast Radio Burst
Based on the initial ASKAP localization of the newly active repeater FRB20201124A (ATels #14497, #14508), we conducted observations with the upgraded Giant Metrewave Radio Telescope (uGMRT) at 550-750 MHz between UTC 2021-04-05T12:30:00 and 2021-04-05T16:45:00 with a total on-source exposure of 3.0 hr. We have analyzed 40 min of data starting from UTC 2021-04-05T13:46:33.2. An unresolved persistent radio source with a 650 MHz flux density of 0.7 +/- 0.1 mJy is found at a position (epoch J2000) of (RA, Dec) = (05:08:03.43, +26:03:38.5) with a 5 sigma positional uncertainty of about 0.9 arcsec. This persistent radio source is coincident with both the VLA/realfast burst position (ATel #14526) and the location of the galaxy SDSS J050803.48+260338.0 (ATel #14516), but offset by about 3.5 arcsec from the latest ASKAP burst position (ATel #14515). Since the source was not detected at 1400 MHz in the VLA/realfast image (3 sigma upper limit of 0.5 mJy), the spectral index of the source must be steeper than -0.4. We encourage higher resolution interferometric observations of this source to better determine its relationship to the bursts and the SDSS galaxy.
In addition to standard interferometric visibilities, we also recorded channelized time series data from the incoherently summed array to search for bursts. The incoherent beam data from this observation yielded many (>30) burst detections. Analysis of the localization, TOAs, and fluences of these bursts is in progress.
Below is a link to our 650 MHz map showing the persistent radio source with the 5 sigma source position uncertainty (black), the ASKAP (green) and VLA/realfast (cyan) burst localizations, the location of SDSS J050803.48+260338.0 (blue cross), and the uGMRT synthesized beam shape (white).
Image of Persistent Source
