Low frequency view of profile change event in PSR J1713+0747 with the uGMRT

ATel #14667; Jaikhomba Singha (IIT Roorkee), Bhal Chandra Joshi (NCRA-TIFR, Pune), Yogesh Maan (ASTRON-NIRA), Yashwant Gupta (NCRA-TIFR, Pune), Nikita Agarwal (MIT, Manipal), Manjari Bagchi (IMSc, Chennai), Neelam Dhanda Batra(IIT Delhi), Avishek Basu(JBCA, Manchester), Suryarao Bethapudi (UTRG, USA), Arpita Choudhary (IMSc, Chennai), Subhajit Dandapat (TIFR, Mumbai), Shantanu Desai (IIT Hyderabad), Kishalay De (Caltech, USA), Lankeswar Dey (TIFR, Mumbai), A. Gopakumar (TIFR, Mumbai), Raghav Girgaonkar (IIT Hyderabad), M. A. Krishnakumar (Uni-Bielfield, Germany), P. K. Manoharan (University of Central Florida), Arun Kumar Naidu (University of Oxford), K. Nobleson (BITS, Hyderabad), Ashwin Pandey (IIT Hyderabad), Dhruv Pathak(IMsc, Chennai), T. Prabu (RRI, Bengaluru), Mayuresh P. Surnis (JBCA, Manchester), Sai Chaitanya Susarla (IISER, Thiruvananthapuram), Abhimanyu Susobhanan (TIFR Mumbai)
on 28 May 2021; 10:46 UT
Credential Certification: Bhal Chandra Joshi (bcj@ncra.tifr.res.in)

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We report observations at Band 3 (300-500 MHz) and Band 5 (1260-1460 MHz) of PSR J1713+0747 before and after a recently reported profile change event (ATELs #14642 and #14652). This pulsar is observed once every fortnight with the uGMRT as a part of Indian Pulsar Timing Array (InPTA) experiment. As the uGMRT was down for annual maintenance between April 5 and May 6, 2021, the nearest observations to the reported epoch of change were carried out on April 5 and May 15, 2021. These were simultaneous observations at Band 3 and Band 5 with 10 and 14 antenna phased array. The data at Band 3 were coherently dedispersed over 200 MHz band with a sampling time of 10/5 us, whereas the data at Band 5 were incoherently dedispersed with a sampling time of 40 us.

We confirm a clear change in the profile in both the bands in observations before and after the reported epoch of change (April 16, 2021). The summary observations are shown in Figures 1-4.

Profiles in Band 3 and Band 5 before and after April 16, 2021

While there appear to be two components present in both before and after observations in Band 3, the trailing component is distinct and fainter than the main peak on MJD 59348 compared to that in the profile before the change (MJD 59309) and a detailed analysis is required to determine if a scattering event accompanied the profile change. The after observations of MJD 59348 show a prominent trailing component at Band 5 similar to L band profile reported in ATEL #14642 as opposed to absence of this component in before observations of MJD 59309. A sustained change in profile was also noticed in more recent observations on May 26, 2021 (MJD 59359).

Further higher cadence observations are planned to investigate the evolution of this event with time.

We thank the staff of the GMRT who made our observations possible. GMRT is run by the National Centre for Radio Astrophysics of the Tata Institute of Fundamental Research.

Profiles in Band 3 and Band 5 before and after April 16, 2021