Quantifying the Contamination From Nearby Stellar Companions in Gaia DR3 Photometry

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Sullivan, Kendall, Kraus, Adam L., Berger, Travis A., Huber, Daniel
Format: Preprint
Published: 2024
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866909379369893888
author Sullivan, Kendall
Kraus, Adam L.
Berger, Travis A.
Huber, Daniel
author_facet Sullivan, Kendall
Kraus, Adam L.
Berger, Travis A.
Huber, Daniel
contents Identifying and removing binary stars from stellar samples is a crucial but complicated task. Regardless of how carefully a sample is selected, some binaries will remain and complicate interpretation of results, especially via flux contamination of survey photometry. One such sample is the data from the Gaia spacecraft, which is collecting photometry and astrometry of more than $10^{9}$ stars. To quantify the impact of binaries on Gaia photometry, we assembled a sample of known binary stars observed with adaptive optics and with accurately measured parameters, which we used to predict Gaia photometry for each stellar component. We compared the predicted photometry to the actual Gaia photometry for each system, and found that the contamination of Gaia photometry because of multiplicity decreases non-linearly from near-complete contamination ($ρ\leq 0''.15$) to no contamination (binary projected separation, or $ρ> 0''.3$). We provide an analytic relation to analytically correct photometric bias in a sample of Gaia stars using the binary separation. This correction is necessary because the Gaia PSF photometry extraction does not fully remove the secondary star flux for binaries with separations with $ρ\lesssim 0''.3$. We also evaluated the utility of various Gaia quality-of-fit metrics for identifying binary stars and found that RUWE remains the best indicator for unresolved binaries, but multi-peak image fraction probes a separation regime not currently accessible to RUWE.
format Preprint
id arxiv_https___arxiv_org_abs_2411_04196
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Quantifying the Contamination From Nearby Stellar Companions in Gaia DR3 Photometry
Sullivan, Kendall
Kraus, Adam L.
Berger, Travis A.
Huber, Daniel
Instrumentation and Methods for Astrophysics
Solar and Stellar Astrophysics
Identifying and removing binary stars from stellar samples is a crucial but complicated task. Regardless of how carefully a sample is selected, some binaries will remain and complicate interpretation of results, especially via flux contamination of survey photometry. One such sample is the data from the Gaia spacecraft, which is collecting photometry and astrometry of more than $10^{9}$ stars. To quantify the impact of binaries on Gaia photometry, we assembled a sample of known binary stars observed with adaptive optics and with accurately measured parameters, which we used to predict Gaia photometry for each stellar component. We compared the predicted photometry to the actual Gaia photometry for each system, and found that the contamination of Gaia photometry because of multiplicity decreases non-linearly from near-complete contamination ($ρ\leq 0''.15$) to no contamination (binary projected separation, or $ρ> 0''.3$). We provide an analytic relation to analytically correct photometric bias in a sample of Gaia stars using the binary separation. This correction is necessary because the Gaia PSF photometry extraction does not fully remove the secondary star flux for binaries with separations with $ρ\lesssim 0''.3$. We also evaluated the utility of various Gaia quality-of-fit metrics for identifying binary stars and found that RUWE remains the best indicator for unresolved binaries, but multi-peak image fraction probes a separation regime not currently accessible to RUWE.
title Quantifying the Contamination From Nearby Stellar Companions in Gaia DR3 Photometry
topic Instrumentation and Methods for Astrophysics
Solar and Stellar Astrophysics
url https://arxiv.org/abs/2411.04196