Stellar Escape from Globular Clusters. II. Clusters May Eat Their Own Tails

• DOI: 10.3847/1538-4357/ad39df
• Publication Date: 2024-05-16T09:18:14Z
• Authors: Newlin C. Weather...; Frederic A. Rasio; Sourav Chatterjee; Giacomo Fragione; Fulya Kıroğlu; Kyle Kremer
• Keywords: Velocity dispersion

Abstract We apply for the first time orbit-averaged Monte Carlo star cluster simulations to study tidal tail and stellar stream formation from globular clusters (GCs), assuming a circular orbit in time-independent spherical Galactic potential. Treating energetically unbound bodies—potential escapers (PEs)—as collisionless enables this fast but spherically symmetric method capture asymmetric extratidal phenomena with exquisite detail. Reproducing features such as epicyclic overdensities, we show how returning tails can form after fully circumnavigates Galaxy, enhancing stream's velocity dispersion by several kilometers per second our ideal case. While truly clumpy, asymmetric, evolving potential would greatly diffuse tails, they warrant scrutiny potentially excellent constraints on Galaxy’s history substructure. Reexamining escape timescale Δ t of PEs, find new behavior related chaotic scattering three-body problem; distribution sharp plateaus corresponding distinct locally smooth patches saddle separating phase-space basins escape. an cluster, finding that <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi mathvariant="normal">Δ</mml:mi> <mml:mi>t</mml:mi> <mml:mo>∼</mml:mo> <mml:mo stretchy="false">(</mml:mo> <mml:msubsup> <mml:mrow> <mml:mi>E</mml:mi> </mml:mrow> mathvariant="normal">J</mml:mi> <mml:mo>−</mml:mo> <mml:mn>0.1</mml:mn> </mml:msubsup> <mml:mo>,</mml:mo> <mml:mn>0.4</mml:mn> stretchy="false">)</mml:mo> </mml:math> PEs (low, high) Jacobi energy E J , flatter than static ( <mml:mn>2</mml:mn> ). Accounting mass loss internal evolution lowers median ∼10 Gyr ≲100 Myr. finally outline improvements intended enable large grids tail/stellar models full GC detailed comparison observations.