KMT-2022-BLG-0475Lb and KMT-2022-BLG-1480Lb: Microlensing ice giants detected via non-caustic-crossing channel

Abstract

We investigate the microlensing data collected in the 2022 season from the high-cadence microlensing surveys in order to find weak signals produced by planetary companions to lenses. From these searches, we find that two lensing events KMT-2022-BLG-0475 and KMT-2022-BLG-1480 exhibit weak short-term anomalies. From the detailed modeling of the lensing light curves, we identify that the anomalies are produced by planetary companions with a mass ratio to the primary of $q\sim 1.8\times 10^{-4}$ for KMT-2022-BLG-0475L and a ratio $q\sim 4.3\times 10^{-4}$ for KMT-2022-BLG-1480L. It is estimated that the host and planet masses and the projected planet-host separation are $(M_{\rm h}/M_\odot, M_{\rm p}/M_{\rm U}, a_\perp/{\rm au}) = (0.43^{+0.35}_{-0.23}, 1.73^{+1.42}_{-0.92}, 2.03^{+0.25}_{-0.38})$ for KMT-2022-BLG-0475L, and $(0.18^{+0.16}_{-0.09}, 1.82^{+1.60}_{-0.92}, 1.22^{+0.15}_{-0.14})$ for KMT-2022-BLG-1480L, where $M_{\rm U}$ denotes the mass of Uranus. Both planetary systems share common characteristics that the primaries of the lenses are early-mid M dwarfs lying in the Galactic bulge and the companions are ice giants lying beyond the snow lines of the planetary systems.