PSF-based Analysis for Detecting Unresolved Wide Binaries

Abstract

Wide binaries play a crucial role in analyzing the birth environment of stars and the dynamical evolution of clusters. When wide binaries are located at greater distances, their companions may overlap in the observed images, becoming indistinguishable and resulting in unresolved wide binaries, which are difficult to detect using traditional methods. Utilizing deep learning, we present a method to identify unresolved wide binaries by analyzing the point-spread function (PSF) morphology of telescopes. Our trained model demonstrates exceptional performance in differentiating between single stars and unresolved binaries with separations ranging from 0.1 to 2 physical pixels, where the PSF FWHM is ~2 pixels, achieving an accuracy of 97.2% for simulated data from the Chinese Space Station Telescope. We subsequently tested our method on photometric data of NGC 6121 observed by the Hubble Space Telescope. The trained model attained an accuracy of 96.5% and identified 18 wide binary candidates with separations between 7 and 140 au. The majority of these wide binary candidates are situated outside the core radius of NGC 6121, suggesting that they are likely first-generation stars, which is in general agreement with the results of Monte Carlo simulations. Our PSF-based method shows great promise in detecting unresolved wide binaries and is well suited for observations from space-based telescopes with stable PSF. In the future, we aim to apply our PSF-based method to next-generation surveys such as the China Space Station Optical Survey, where a larger-field-of-view telescope will be capable of identifying a greater number of such wide binaries.

17 pages, 12 figures. Accepted for publication in ApJS

References in corpus (16)

• The Effectiveness of Data Augmentation in Image Classification using Deep Learning
• Formation and Dynamical Evolution of Multiple Stellar Generations in Globular Clusters
• Captum: A unified and generic model interpretability library for PyTorch
• The Hubble Space Telescope UV Legacy Survey of Galactic Globular Clusters. IX. The Atlas of Multiple Stellar Populations
• A million binaries from Gaia eDR3: sample selection and validation of Gaia parallax uncertainties
• Spectroscopic and Photometric evidence of two stellar populations in the Galactic Globular Cluster NGC6121 (M4)
• The fraction of binary systems in the core of thirteen low-density Galactic globular clusters
• Deep FORS1 observations of the double Main Sequence of omega Centauri
• Identical or fraternal twins? : The chemical homogeneity of wide binaries from Gaia DR2
• The initial-final mass relationship from white dwarfs in common proper motion pairs
• Wide binaries are rare in open clusters
• Wide Binaries in Tycho-Gaia II: Metallicities, Abundances, and Prospects for Chemical Tagging
• Evolution of Binary Stars in Multiple-Population Globular Clusters
• The Hubble Space Telescope UV Legacy Survey of Galactic Globular Clusters. XXI. Binaries among multiple stellar populations
• Mass loss of different stellar populations in Globular Clusters: the case of M4
• Monte Carlo simulations of multiple populations in globular clusters: constraints on the initial size of the second generation from binary stars