Detection of a potential persistent radio source associated with FRB 20240114A

ATel #16820; Yash Bhusare (NCRA - TIFR), Yogesh Maan (NCRA - TIFR), Ajay Kumar (NCRA - TIFR)
on 19 Sep 2024; 12:44 UT
Credential Certification: Yogesh Maan (maan@astron.nl)

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In January 2024, the CHIME/FRB Collaboration discovered a repeating FRB 20240114A (ATel #16420). Based on observations from MeerKAT (ATel #16446) and the European Very Long Baseline Interferometry Network (EVN; ATel #16542), FRB 20240114A is localized in the galaxy J212739.84+041945.8 with a redshift of z=0.13 (ATel #16613). The precise localization has helped in detecting extreme burst activity from FRB 20240114A, with bursts detected in a wide frequency range from 300 MHz to 6 GHz using various telescopes (e.g., ATel #16432 , ATel #16452 , ATel #16494 , ATel #16505 , ATel #16597 , ATel #16620), and potentially even with hints of chromaticity (Kumar et al. 2024).

Many studies were conducted to search for any co-located continuum radio emission (e.g., Kumar et al. 2024 and Panda et al. 2024). Recently, Zhang et al. 2024 (Atel #16695) detected a radio continuum source at L-band using MeerKAT, potentially a persistent radio source (PRS). Here, we report an 8-sigma detection of this potential PRS associated with FRB 20240114A at 650 MHz using uGMRT. We combined observations from 4 epochs between 14 June and 22 August 2024 amounting to a total on-source time of 10 hours. The imaging was performed using the CAPTURE pipeline (Kale et al. 2021). We detected a point source with a peak flux density of 65.6+/-8.1 micro-Jy. The location of this point source coincides with the location of the FRB. The estimated spectral luminosity is (2.83+/-0.35) x 10^28 erg/s/Hz, which is an order of magnitude fainter when compared to that of the PRSs associated with FRB 20121102A and FRB 20190520B. Our flux density measurement at 650 MHz combined with that at L-band from ATel #16695 , suggests a flat spectral index. A deep VLBI observation would help in constraining the compactness and confirming whether the emission is indeed due to an underlying PRS associated with FRB 20240114A.

We thank the staff of the GMRT for their support and assistance with these observations. We acknowledge the prompt approval and scheduling of the DDT observations allowing us to do this study. The GMRT is run by the National Centre for Radio Astrophysics of the Tata Institute of Fundamental Research.

References:
Kumar, A., Maan, Y., and Bhusare, Y. 2024, arXiv e-prints, arXiv:2406.12804, doi: 10.48550/arXiv.2406.12804
Panda, U., Roy, J., Bhattacharyya, S., Dudeja, C., and Kudale, S. 2024b, arXiv e-prints, arXiv:2405.09749, doi: 10.48550/arXiv.2405.09749
Kale, R., and Ishwara-Chandra, C. H. 2021, Experimental Astronomy, 51, 95, doi: 10.1007/s10686-020-09677-6