Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Binary-driven stellar rotation evolution at the main-sequence turn-off
  in star clusters   The impact of stellar rotation on the morphology of star cluster
colour-magnitude diagrams is widely acknowledged. However, the physics driving
the distribution of the equatorial rotation velocities of main-sequence
turn-off (MSTO) stars is as yet poorly understood. Using Gaia Data Release 2
photometry and new Southern African Large Telescope medium-resolution
spectroscopy, we analyse the intermediate-age ($\sim1\,$Gyr-old) Galactic open
clusters NGC 3960, NGC 6134 and IC 4756 and develop a novel method to derive
their stellar rotation distributions based on SYCLIST stellar rotation models.
Combined with literature data for the open clusters NGC 5822 and NGC 2818, we
find a tight correlation between the number ratio of slow rotators and the
clusters' binary fractions. The blue-main-sequence stars in at least two of our
clusters are more centrally concentrated than their red-main-sequence
counterparts. The origin of the equatorial stellar rotation distribution and
its evolution remains as yet unidentified. However, the observed correlation in
our open cluster sample suggests a binary-driven formation mechanism.

27
The categories of this paper are: comp-gas
10
The categories of this paper are: q-bio
31
The categories of this paper are: ao-sci
20
The categories of this paper are: acc-phys
25
The categories of this paper are: patt-sol
34
The categories of this paper are: chem-ph
18
The categories of this paper are: econ
36
The categories of this paper are: cmp-lg
12
The categories of this paper are: nucl-th
21
The categories of this paper are: adap-org
0
The categories of this paper are: hep-ph
16
The categories of this paper are: stat
17
The categories of this paper are: q-fin
9
The categories of this paper are: nlin
28
The categories of this paper are: alg-geom
11
The categories of this paper are: hep-lat