Microlensing Discovery and Characterization Efficiency in the Vera C. Rubin Legacy Survey of Space and Time
Abstract The Vera C. Rubin Legacy Survey of Space and Time will discover thousands of microlensing events across the Milky Way, allowing for the study of populations of exoplanets, stars, and compact objects. We evaluate numerous survey strategies simulated in the Rubin Operation Simulations to assess the discovery and characterization efficiencies of microlensing events. We have implemented three metrics in the Rubin Metric Analysis Framework: a discovery metric and two characterization metrics, where one estimates how well the light curve is covered and the other quantifies how precisely event parameters can be determined. We also assess the characterizability of microlensing parallax, critical for detection of free-floating black hole lenses. We find that, given Rubin’s baseline cadence, the discovery and characterization efficiency will be higher for longer-duration and larger-parallax events. Microlensing discovery efficiency is dominated by the observing footprint, where more time spent looking at regions of high stellar density, including the Galactic bulge, Galactic plane, and Magellanic Clouds, leads to higher discovery and characterization rates. However, if the observations are stretched over too wide an area, including low-priority areas of the Galactic plane with fewer stars and higher extinction, event characterization suffers by >10%. This could impact exoplanet, binary star, and compact object events alike. We find that some rolling strategies (where Rubin focuses on a fraction of the sky in alternating years) in the Galactic bulge can lead to a 15%–20% decrease in microlensing parallax characterization, so rolling strategies should be chosen carefully to minimize losses.
Authors
- M. Rabus (ORCID: https://orcid.org/0000-0003-2935-7196)
- M. Hundertmark (ORCID: https://orcid.org/0000-0003-0961-5231)
- Natasha S. Abrams (ORCID: https://orcid.org/0000-0002-0287-3783)
- Somayeh Khakpash (ORCID: https://orcid.org/0000-0002-1910-7065)
- R. A. Street (ORCID: https://orcid.org/0000-0001-6279-0552)
- Lynne Jones (ORCID: https://orcid.org/0000-0001-5916-0031)
- R. Di Stefano (ORCID: https://orcid.org/0000-0003-0972-1376)
- Martı́n Makler (ORCID: https://orcid.org/0000-0003-2206-2651)
- M. Moniez (ORCID: https://orcid.org/0000-0001-8716-6561)
- Y. Tsapras (ORCID: https://orcid.org/0000-0001-8411-351X)
- E. Bachelet (ORCID: https://orcid.org/0000-0002-6578-5078)
- Jessica R. Lu (ORCID: https://orcid.org/0000-0001-9611-0009)
- Tristan Blaineau
- Anibal Varela
Institutions
- Rutgers, The State University of New Jersey (US)
- California Institute of Technology (US)
- Las Cumbres Observatory Global Telescope Network (US)
- Centre National de la Recherche Scientifique (FR)
- Consejo Nacional de Investigaciones Científicas y Técnicas (AR)
- Heidelberg University (DE)
- National University of General San Martín (AR)
- Université Paris-Saclay (FR)
- Universidad Católica de la Santísima Concepción (CL)
- Center for Astrophysics Harvard & Smithsonian (US)
- Centro Brasileiro de Pesquisas Físicas (BR)
- Institut National de Physique Nucléaire et de Physique des Particules (FR)
- Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (FR)
- International Center for Advanced Studies (AR)
- Infrared Processing and Analysis Center (US)
- University of California, Berkeley (US)
Publication Details
- Journal
- The Astrophysical Journal Supplement Series
- Published
- 2024-12-24
- DOI
- https://doi.org/10.3847/1538-4365/ad91b0
- Citations
- 12
- Primary Topic
- Stellar, planetary, and galactic studies
- Type
- article
- Field-Weighted Citation Impact
- 3.98
Funders
- National Science Foundation
- U.S. Department of Energy
- Heising-Simons Foundation
- National Energy Research Scientific Computing Center
- Deutsche Forschungsgemeinschaft
- Universidad Católica de la Santísima Concepción
- Office of Science
- Lawrence Berkeley National Laboratory