On Finding Black Holes in Photometric Microlensing Surveys

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Kaczmarek, Zofia, McGill, Peter, Perkins, Scott E., Dawson, William A., Huston, Macy, Ho, Ming-Feng, Abrams, Natasha S., Lu, Jessica R.
Format: Preprint
Published: 2024
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866913552976052224
author Kaczmarek, Zofia
McGill, Peter
Perkins, Scott E.
Dawson, William A.
Huston, Macy
Ho, Ming-Feng
Abrams, Natasha S.
Lu, Jessica R.
author_facet Kaczmarek, Zofia
McGill, Peter
Perkins, Scott E.
Dawson, William A.
Huston, Macy
Ho, Ming-Feng
Abrams, Natasha S.
Lu, Jessica R.
contents There are expected to be millions of isolated black holes in the Galaxy resulting from the death of massive stars. Measuring the abundance and properties of this remnant population would shed light on the end stages of stellar evolution and the evolution paths of black hole systems. Detecting isolated black holes is currently only possible via gravitational microlensing which has so far yielded one definitive detection. The difficulty in finding microlensing black holes lies in having to choose a small subset of events based on characteristics of their lightcurves to allocate expensive and scarce follow-up resources to confirm the identity of the lens. Current methods either rely on simple cuts in parameter space without using the full distribution information or are only effective on a small subsets of events. In this paper we present a new lens classification method. The classifier takes in posterior constraints on lightcurve parameters and combines them with a Galactic simulation to estimate the lens class probability. This method is flexible and can be used with any set of microlensing lightcurve parameters making it applicable to large samples of events. We make this classification framework available via the popclass python package. We apply the classifier to $\sim10,000$ microlensing events from the OGLE survey and find $23$ high-probability black hole candidates. Our classifier also suggests that the only known isolated black hole is an observational outlier according to current Galactic models and allocation of astrometric follow-up on this event was a high-risk strategy.
format Preprint
id arxiv_https___arxiv_org_abs_2410_14098
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle On Finding Black Holes in Photometric Microlensing Surveys
Kaczmarek, Zofia
McGill, Peter
Perkins, Scott E.
Dawson, William A.
Huston, Macy
Ho, Ming-Feng
Abrams, Natasha S.
Lu, Jessica R.
Solar and Stellar Astrophysics
Astrophysics of Galaxies
High Energy Astrophysical Phenomena
Instrumentation and Methods for Astrophysics
There are expected to be millions of isolated black holes in the Galaxy resulting from the death of massive stars. Measuring the abundance and properties of this remnant population would shed light on the end stages of stellar evolution and the evolution paths of black hole systems. Detecting isolated black holes is currently only possible via gravitational microlensing which has so far yielded one definitive detection. The difficulty in finding microlensing black holes lies in having to choose a small subset of events based on characteristics of their lightcurves to allocate expensive and scarce follow-up resources to confirm the identity of the lens. Current methods either rely on simple cuts in parameter space without using the full distribution information or are only effective on a small subsets of events. In this paper we present a new lens classification method. The classifier takes in posterior constraints on lightcurve parameters and combines them with a Galactic simulation to estimate the lens class probability. This method is flexible and can be used with any set of microlensing lightcurve parameters making it applicable to large samples of events. We make this classification framework available via the popclass python package. We apply the classifier to $\sim10,000$ microlensing events from the OGLE survey and find $23$ high-probability black hole candidates. Our classifier also suggests that the only known isolated black hole is an observational outlier according to current Galactic models and allocation of astrometric follow-up on this event was a high-risk strategy.
title On Finding Black Holes in Photometric Microlensing Surveys
topic Solar and Stellar Astrophysics
Astrophysics of Galaxies
High Energy Astrophysical Phenomena
Instrumentation and Methods for Astrophysics
url https://arxiv.org/abs/2410.14098