2023/02/26 by Shyam Sunder, Sunder, Shyam, Jayanta Roy +9 · 1 citation
Earth and Planetary Sciences · Physics and Astronomy · #Advanced Frequency and Time Standards #FOS: Physical sciences #High Energy Astrophysical Phenomena (astro-ph.HE) #Instrumentation and Methods for Astrophysics (astro-ph.IM) #Radio Astronomy Observations and Technology #Seismic Waves and Analysis
paper · pdf · doi:10.48550/arxiv.2302.13363
openalex publication_date 2023/02/26 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The timing follow-up of newly discovered millisecond pulsars (MSPs) is hindered by the larger positional uncertainty (a few tens of arc-minutes) associated with the discovery. In this paper, we present the localization of two MSPs, discovered by the GMRT High Resolution Southern Sky (GHRSS) survey, up to arc-second accuracy using a 33~MHz offline coherently dedispersed gated correlator. This gated correlator is an upgraded version of the earlier 16~MHz design. This new development with a factor of two enhancement in the observing bandwidth offers better sensitivity in the image domain, leading to more precise localization. Aided by the precise position, we followed up these two MSPs with sensitive phased-array (PA) beams of upgraded GMRT from 300 to 1460 MHz. More sensitive observations in the PA mode for these two MSPs yield precise (∼ sub-μs) time-of-arrivals, with DM uncertainties in the range of 10-4-10-5 pc cm-3. We also report the profile evolution of the two MSPs over 300-1460 MHz. Finally, we discuss the suitability of these MSPs for the pulsar timing array experiments aimed to detect low-frequency gravitational waves.