On the initial binary population for star cluster simulations
Belloni, Diogo ; Askar, Abbas LU
; Giersz, Mirek
; Kroupa, Pavel
and Rocha-Pinto, Helio J.
(2017)
In Monthly Notices of the Royal Astronomical Society
471(3).
p.2812-2828
- Abstract
- Colour–magnitude diagrams (CMDs) are powerful tools that might be used to infer stellar properties in globular clusters (GCs), for example, the binary fraction and their mass ratio (q) distribution. In the past few years, observations have revealed that q distributions of GC main-sequence binaries are generally flat, and a distribution characterized by a strong increase towards q ≈ 1 is not typical in GCs. In numerical simulations of GC evolution with the initial binary population (IBP) described by Kroupa, synthetic CMD colour distributions exhibit a peak associated with binaries that have q ≈ 1. While the Kroupa IBP reproduces binary properties in star-forming regions, clusters and the Galactic field, the peak in the q distribution... (More)
- Colour–magnitude diagrams (CMDs) are powerful tools that might be used to infer stellar properties in globular clusters (GCs), for example, the binary fraction and their mass ratio (q) distribution. In the past few years, observations have revealed that q distributions of GC main-sequence binaries are generally flat, and a distribution characterized by a strong increase towards q ≈ 1 is not typical in GCs. In numerical simulations of GC evolution with the initial binary population (IBP) described by Kroupa, synthetic CMD colour distributions exhibit a peak associated with binaries that have q ≈ 1. While the Kroupa IBP reproduces binary properties in star-forming regions, clusters and the Galactic field, the peak in the q distribution towards q ≈ 1 observed for GC simulations is not consistent with distributions derived from observations. The objective of this paper is to refine and further improve the physical formulation of pre-main-sequence eigenevolution proposed by Kroupa in order to achieve CMD colour distributions of simulated GC models similar to those observed in real GCs, and to get a similarly good agreement with binary properties for late-type binaries in the Galactic field. We present in this paper a modified Kroupa IBP, in which early-type stars follow observational distributions, and late-type stars are generated according to slightly modified pre-main-sequence eigenevolution prescriptions. Our modifications not only lead to a qualitatively good agreement with respect to long-term observations of late-type binaries in the Galactic field but also resolve the above-mentioned problem related to binary distributions in GC models. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/c0250157-d4a5-46f6-ad75-5fef06d10dc1
- author
- Belloni, Diogo
; Askar, Abbas
LU
; Giersz, Mirek
; Kroupa, Pavel
and Rocha-Pinto, Helio J.
- publishing date
- 2017-07-01
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Monthly Notices of the Royal Astronomical Society
- volume
- 471
- issue
- 3
- pages
- 17 pages
- publisher
- Oxford University Press
- external identifiers
-
- scopus:85045561261
- ISSN
- 1365-2966
- DOI
- 10.1093/mnras/stx1763
- language
- English
- LU publication?
- no
- id
- c0250157-d4a5-46f6-ad75-5fef06d10dc1
- date added to LUP
- 2018-10-30 17:57:14
- date last changed
- 2022-04-25 18:30:58
@article{c0250157-d4a5-46f6-ad75-5fef06d10dc1,
abstract = {{Colour–magnitude diagrams (CMDs) are powerful tools that might be used to infer stellar properties in globular clusters (GCs), for example, the binary fraction and their mass ratio (q) distribution. In the past few years, observations have revealed that q distributions of GC main-sequence binaries are generally flat, and a distribution characterized by a strong increase towards q ≈ 1 is not typical in GCs. In numerical simulations of GC evolution with the initial binary population (IBP) described by Kroupa, synthetic CMD colour distributions exhibit a peak associated with binaries that have q ≈ 1. While the Kroupa IBP reproduces binary properties in star-forming regions, clusters and the Galactic field, the peak in the q distribution towards q ≈ 1 observed for GC simulations is not consistent with distributions derived from observations. The objective of this paper is to refine and further improve the physical formulation of pre-main-sequence eigenevolution proposed by Kroupa in order to achieve CMD colour distributions of simulated GC models similar to those observed in real GCs, and to get a similarly good agreement with binary properties for late-type binaries in the Galactic field. We present in this paper a modified Kroupa IBP, in which early-type stars follow observational distributions, and late-type stars are generated according to slightly modified pre-main-sequence eigenevolution prescriptions. Our modifications not only lead to a qualitatively good agreement with respect to long-term observations of late-type binaries in the Galactic field but also resolve the above-mentioned problem related to binary distributions in GC models.}},
author = {{Belloni, Diogo and Askar, Abbas and Giersz, Mirek and Kroupa, Pavel and Rocha-Pinto, Helio J.}},
issn = {{1365-2966}},
language = {{eng}},
month = {{07}},
number = {{3}},
pages = {{2812--2828}},
publisher = {{Oxford University Press}},
series = {{Monthly Notices of the Royal Astronomical Society}},
title = {{On the initial binary population for star cluster simulations}},
url = {{http://dx.doi.org/10.1093/mnras/stx1763}},
doi = {{10.1093/mnras/stx1763}},
volume = {{471}},
year = {{2017}},
}