Mass Production of 2023 KMTNet Microlensing Planets. III: Three Planets from the Subprime Field

TL;DR

This paper analyzes six microlensing events from the 2023 KMTNet subprime field, confirming three as planets and exploring degeneracies in the others, contributing to the understanding of planetary distributions.

Contribution

It presents the analysis of six microlensing events, confirming three as planets and examining degeneracies, expanding the planetary sample and distribution understanding.

Findings

Three events are securely confirmed as planetary.

Degeneracies exist between binary-lens/single-source and single-lens/binary-source models.

The planetary mass-ratio distribution aligns with previous KMTNet samples.

Abstract

To complete the analysis of the 2023 KMTNet subprime-field microlensing planetary events identified by its AlertFinder system, we present the analysis of six events, KMT-2023-BLG-(1810, 0084, 1118, 0584, 1697, 2218). We find that the first three events are securely confirmed as planetary, with inferred mass ratios of $\log q \sim -1.9$, $-2.0$, and $-2.6$, respectively. The remaining three events exhibit the well-known degeneracy between binary-lens/single-source (2L1S) and single-lens/binary-source (1L2S) models, and two of these also admit viable stellar binary solutions. A Bayesian analysis indicates that the companions in the confirmed planetary events are likely either super-Jupiters orbiting beyond the snow line of M- or K-dwarf hosts or, for two degenerate solutions of KMT-2023-BLG-1118, Saturn-mass planets orbiting late-type M dwarfs. To date, the 2023 KMTNet sample contains 25 unambiguous planetary events, and its mass-ratio distribution is consistent with that of the KMTNet planetary sample from 2016--2019.