Gaia Assorted Mass Binaries Long Excluded from SLoWPoKES (GAMBLES): Identifying Ultra-Wide Binary Pairs with Components of Diverse Mass

TL;DR

This paper extends previous catalogs to include diverse mass wide binary star pairs, identifying 8,660 significant systems with long dissipation timescales, revealing bimodal separation distributions and insights into binary formation and longevity.

Contribution

It introduces the GAMBLES catalog, expanding the scope of wide binary systems to a broader mass range and providing a comprehensive online database for further research.

Findings

Identified 8,660 wide binary pairs with high statistical significance.

Discovered a bimodal distribution of binary separations.

Found over 76% of long-lived binaries have large binding energies.

Abstract

The formation and evolution of binary star systems still remain key questions in modern astronomy. Wide binary pairs (separations $>10^3$ AU) are particularly intriguing because their low binding energies make it difficult for the stars to stay gravitationally bound over extended timescales,and thus probe the dynamics of binary formation and dissolution. Our previous SLoWPoKES I \& II catalogs provided the largest and most complete sample of wide binary pairs of low masses. Here we present an extension of these catalogs to a broad range of stellar masses: the Gaia Assorted Mass Binaries Long Excluded from SloWPoKES (GAMBLES), comprising 8,660 statistically significant wide pairs that we make available in a living online database. Within this catalog we identify a subset of 543 long-lived (dissipation timescale $>$1.5 Gyr) candidate binary pairs, of assorted mass, with typical separations between $10^3-10^{5.5}$ AU ($0.002-1.5$ pc), using the published distances and proper motions from the Tycho-Gaia Astrometric Solution and Sloan Digital Sky Survey photometry. Each pair has at most a false positive probability of 0.05; the total expectation is 2.44 false binaries in our sample. Among these, we find 22 systems with 3 components, 1 system with 4 components, and 15 pairs consisting of at least 1 possible red giant. We find the largest long-lived binary separation to be nearly 3.2 pc; even so, $>76\%$ of GAMBLES long-lived binaries have large binding energies and dissipation lifetimes longer than 1.5 Gyr. Finally, we find the distribution of binary separations is clearly bimodal, corroborating the finding from SloWPoKES and suggesting multiple pathways for the formation and dissipation of the widest binaries in the Galaxy.