Criteria for Sample Selection to Maximize Planet Sensitivity and Yield from Space-Based Microlens Parallax Surveys

TL;DR

This paper establishes objective criteria and procedures for selecting microlensing events in space-based surveys to maximize planet detection sensitivity while minimizing biases, ensuring a controlled and unbiased sample for studying exoplanet populations.

Contribution

It introduces specific objective and subjective selection procedures and conflict resolution methods to optimize planet sensitivity in space-based microlensing surveys.

Findings

Defined objective criteria for event selection and cadence

Established procedures to separate subjective and objective decisions

Maximized planet sensitivity through optimized selection protocols

Abstract

Space-based microlens parallax measurements are a powerful tool for understanding planet populations, especially their distribution throughout the Galaxy. However, if space-based observations of the microlensing events must be specifically targeted, it is crucial that microlensing events enter the parallax sample without reference to the known presence or absence of planets. Hence, it is vital to define objective criteria for selecting events where possible and to carefully consider and minimize the selection biases where not possible so that the final sample represents a controlled experiment. We present objective criteria for initiating observations and determining their cadence for a subset of events, and we define procedures for isolating subjective decision making from information about detected planets for the remainder of events. We also define procedures to resolve conflicts between subjective and objective selections. These procedures maximize planet sensitivity of the sample as a whole by allowing for planet detections even if they occur before satellite observations for objectively-selected events and by helping to trigger fruitful follow-up observations for subjectively-chosen events. This paper represents our public commitment to these procedures, which is a necessary component of enforcing objectivity on the experimental protocol.