arXiv subjects

Prapti Mittal

Publications and source records attributed to Prapti Mittal.

3 recordsLinked to original sources

arXiv2026

HEL1OS on Aditya-L1 Mission: Operations, Data Processing and Monitoring of Sun in Hard X-rays

HEL1OS (High Energy L1 Orbiting X-ray Spectrometer) is the hard X-ray spectrometer on-board Aditya-L1 solar mission, monitoring the Sun continuously in the hard X-ray band of 8 keV to 150 keV from the vantage observation platform around the Sun-Earth Lagragian Point 1 (L1). HEL1OS was commissioned in end of October, 2023 and the final instrument configuration was set by end of June, 2024 after all the performance verifications. The instrument always operates in the event mode, and the down-linked data is processed in an automated pipeline to generate Science-ready products comprising mainly of solar spectra in 8 keV to 150 keV energy band. The data products of observations since December, 2023 are hosted on the internet with open access. This includes data from the performance verification phase of the payload operations. In this paper, the details of the commissioning and performance verification phases, all the stages of the fully automated data pipeline, and the data products of HEL1OS are discussed. Also a few scientific results are discussed to illustrate the timing and spectral capabilities of the instrument in monitoring Sun in the X-ray energy bands.

astro-ph.IM↗

arXiv2026

Importance and Science Outcomes from the first XSPECT/XPoSat Workshop

This paper summarizes the science outcomes of the first Workshop on Data Analysis using observations from the XSPECT payload onboard the XPoSat, which brought together early-career researchers and experts to explore the instrument's scientific capabilities through lectures and hands-on analyses. Participants performed end-to-end data analysis, including calibration, spectral modeling, and timing studies, on seven sources comprising Neutron Star Low-Mass X-ray Binaries, pulsars, and Black Hole X-ray Binaries, demonstrating the instrument's scientific potential. The observations, obtained during the first year of XSPECT operations, together with in-house developed software, were provided to the participants, making them the first users outside the instrument team to analyze XSPECT data. For NS-LMXBs, Aql X-1 exhibited a classical Type-I X-ray burst, enabling constraints on the stellar radius through spectral fitting. Sco X-1, observed across its complete Z-track, revealed systematic spectral evolution driven by accretion-rate fluctuations and disk-corona coupling, while Cir X-1 displayed orbital phase-dependent transitions between hard and soft states, reflecting changes in accretion geometry. Among accretion-powered pulsars, GX 301-2 showed a double-peaked, energy-dependent pulse profile and strong iron fluorescence lines due to stellar wind reprocessing, whereas Vela X-1 exhibited orbital phase-dependent absorption and steady coronal temperatures. Among BH-XRBs, Cyg X-1 transitioned from a hard to soft-intermediate state with increasing disk contribution and spectral softening, while Cyg X-3 remained in the intermediate state with multiple emission lines originating from a clumpy stellar wind. The workshop outcomes highlight the scientific promise of XSPECT and the importance of collaborative training in maximizing the science from XSPECT and future Indian space astronomy missions.

astro-ph.HE↗

arXiv2025

Unraveling the Secrets of the lower Solar Atmosphere: One year of Operation of the Solar Ultraviolet Imaging Telescope (SUIT) on board Aditya-L1

The Solar Ultraviolet Imaging Telescope (SUIT) is an instrument onboard Aditya--L1, the first solar space observatory of the Indian Space Research Organization (ISRO), India, launched on September 2, 2023. SUIT is designed to image the Sun in the 200--400 nm wavelength band in eight narrowband and three broadband filters. SUIT's science goals start with observing the solar atmosphere and large-scale continuum variations, the physics of solar flares in the NUV region, and many more. The paper elucidates the functioning of the instrument, software packages developed for easier calibration, analysis, and feedback, calibration routines, and the regular maintenance activity of SUIT during the first year of its operation. The paper also presents the various operations undergone by, numerous program sequences orchestrated to achieve the science requirements, and highlights some remarkable observations made during the first year of observations with SUIT.

astro-ph.SR↗