arXiv subjects

Jitendra Salal

Publications and source records attributed to Jitendra Salal.

3 recordsLinked to original sources

arXiv2026

SPICE: Scintillation Pipeline for Interferometric Candidate Extraction

We present Scintillation Pipeline for Interferometric Candidate Extraction (SPICE) an automated CASA-based pipeline developed to identify pulsar candidates in Giant Metrewave Radio Telescope (GMRT) and upgraded GMRT (uGMRT) data through their diffractive interstellar scintillation signatures. SPICE integrates flagging, calibration, imaging, and classification, with robust RFI excision, iterative self-calibration with dynamic reference antenna selection, source detection using PyBDSF, and classification based on our earlier development of scintillation-based visibility correlation searches. SPICE is available publicly on github and is archived on Zenodo. We applied SPICE to archival datasets from both legacy GMRT and uGMRT. The pipeline successfully recovered known pulsars such as PSR 0437-4715, PSR B0450-18, and PSR B0329+54, yielding scintillation parameters consistent with expectations. Non-detections in some scans highlight the influence of pervasive RFI, the dependence on the reference antenna, and the intrinsic variability of the scintillation properties. SPICE complements time-domain searches by enabling reproducible scintillation-based candidate identification in interferometric data. Its application to the GMRT archive opens a pathway for discovering compact variable sources and expanding pulsar searches beyond time-domain searches.

astro-ph.IM↗

arXiv2026

Prospects for identifying pulsar candidates in radio surveys using scintillation

In our previous paper, we developed a technique for identifying pulsar candidates in interferometric radio images using their distinctive scintillation signatures. Building on this technique, the present study simulates a pulsar population using the PsrPopPy Python module to investigate the technique's limitations and detection capabilities. Among pulsars detectable exclusively by this technique, 50% have duty cycles exceeding the mean value of 0.09 observed in time-domain detections. Our pulsar population simulations revealed a set of observational parameters that optimize pulsar detection. An observation frequency of ~ 1420 MHz and a channel width of ~10 kHz emerge as the optimal configuration to maximize the pulsar detection efficiency. By applying a scintillation-based technique to future radio telescopes like DSA-2000, we can detect 56% of normal pulsars and 84% of MSPs in addition to those detected using non-imaging, time-domain surveys. These detected pulsars cannot be verified by time-domain searches.

astro-ph.IM↗

arXiv2024

Identifying pulsar candidates in interferometric radio images using scintillation

Pulsars have been primarily detected by their narrow pulses or periodicity in time domain data. Interferometric surveys for pulsars are challenging due to the trade-off between beam sensitivity and beam size and the corresponding tradeoff between survey sensitivity (depth), sky coverage, and computational efforts. The detection sensitivity of time-domain searches for pulsars is affected by dispersion smearing, scattering, and rapid orbital motion of pulsars in binaries. We have developed a new technique to select pulsar candidates in interferometric radio images by identifying scintillating sources and measuring their scintillation bandwidth and timescale. Identifying likely candidates allows sensitive, focused time-domain searches, saving computational effort. Pulsar scintillation is independent of its timing properties and hence offers a different selection of pulsars compared to time-domain searches. Candidates identified from this method could allow us to find hard-to-detect pulsars, such as sub-millisecond pulsars and pulsars in very compact, highly-accelerated binary orbits. We use uGMRT observations in the fields of PSR\,B1508+55, PSR\,J0437$-$4715, and PSR\,B0031$-$07 as test cases for our technique. We demonstrate that the technique correctly differentiates between the pulsar and other non-scintillating point sources and show that the extracted dynamic spectrum of the pulsar is equivalent to that extracted from the uGMRT phased array beam. We show the results from our analysis of known pulsar fields and discuss challenges in dealing with interference and instrumental effects.

astro-ph.HE↗