Abstract
We have analyzed populations of blue straggler stars (BSSs) in 24 Magellanic Cloud (MC) star clusters using multi-passband Hubble Space Telescope images. We compiled a homogeneous BSS database, containing both traditional and evolved BSSs. We uncovered a sublinear correlation between the number of BSSs in the cluster cores and the clusters' core masses, characterized by a power-law index of 0.51 0.07. For low stellar collision rates, the mass-normalized number of BSSs depends only weakly (or perhaps not at all) on the collision rate, implying that the binary-driven BSS formation channel dominates. Comparison with simulations suggests that stellar collisions contribute less than 20% to the total number of BSSs formed. Further tests, including the analysis of the BSS-specific frequencies and their population numbers at larger cluster radii, suggest that binary interactions may be their main formation channel, hinting at an anti-correlation between a cluster's binary fraction and its core mass.
| Original language | English |
|---|---|
| Article number | 133 |
| Pages (from-to) | 1-11 |
| Number of pages | 11 |
| Journal | Astrophysical Journal |
| Volume | 862 |
| Issue number | 2 |
| DOIs | |
| Publication status | Published - 1 Aug 2018 |
Bibliographical note
Copyright 2018 The American Astronomical Society. First published in the Astrophysical journal, 862(2), 133, 2018, published by IOP Publishing. The original publication is available at http://www.doi.org/10.3847/1538-4357/aacc6b. Version archived for private and non-commercial use with the permission of the author/s and according to publisher conditions. For further rights please contact the publisher.Keywords
- blue stragglers
- galaxies: star clusters: general
- Magellanic Clouds