3 papers
astro-ph.HE2026
X-ray spectral and temporal evolution of atoll source 4U 1820-30 with AstroSat: detection of high frequency quasi-periodic oscillation
Subhasish Das, Vivek Kumar Agrawal, Parijat Thakur +4
AstroSat/LAXPC and SXT observed the persistent neutron star low-mass X-ray binary 4U 1820-30 between 2016 and 2022. During these observations, the hardness-intensity diagram (HID)…
astro-ph.HE2025
Accretion Geometry of the New Galactic Black Hole Candidate AT2019wey in the Hard State
Pragati Sahu, Swadesh Chand, Gulab C. Dewangan +3
We perform broadband spectral and timing studies of the Galactic low-mass black hole candidate AT2019wey using quasi-simultaneous NICER, Swift, and NuSTAR observations obtained in…
astro-ph.EP2025
Transit Timing Variations of the Sub-Saturn Exoplanet HAT-P-12b
Kaviya Parthasarathy, Hsin-Min Liu, Ing-Guey Jiang +12
We present Transit Timing Variations (TTVs) of HAT-P-12b, a low-density sub-Saturn mass planet orbiting a metal-poor K4 dwarf star. Using 14 years of observational data (2009-2022)…