Binary properties of the globular cluster 47 Tuc (NGC 104). A dearth of short-period binaries

Fuente: arXiv
Salvato in:
Dettagli Bibliografici
Autori principali: Müller-Horn, Johanna, Göttgens, Fabian, Dreizler, Stefan, Kamann, Sebastian, Martens, Sven, Saracino, Sara, Ye, Claire S.
Natura: Preprint
Pubblicazione: 2024
Soggetti:
Accesso online:
Tags: Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
_version_ 1866915102934958080
author Müller-Horn, Johanna
Göttgens, Fabian
Dreizler, Stefan
Kamann, Sebastian
Martens, Sven
Saracino, Sara
Ye, Claire S.
author_facet Müller-Horn, Johanna
Göttgens, Fabian
Dreizler, Stefan
Kamann, Sebastian
Martens, Sven
Saracino, Sara
Ye, Claire S.
contents Spectroscopic observations of binary stars in globular clusters are essential to shed light on the poorly constrained period, eccentricity, and mass ratio distributions and to develop an understanding of the formation of peculiar stellar objects. 47 Tuc (NGC 104) is one of the most massive Galactic globular clusters, with a large population of blue stragglers and with many predicted but as-yet elusive stellar-mass black holes. This makes it an exciting candidate for binary searches. We present a multi-epoch spectroscopic survey of 47 Tuc with the VLT/MUSE integral field spectrograph to determine radial velocity variations for 21,699 stars. We find a total binary fraction in the cluster of $(2.4\pm1.0)\%$, consistent with previous photometric estimates, and an increased binary fraction among blue straggler stars, approximately three times higher than the cluster average. We find very few binaries with periods below three days, and none with massive dark companions. A comparison with predictions from state-of-the-art models shows that the absence of such short-period binaries and of binaries with massive companions is surprising, highlighting the need to improve our understanding of stellar and dynamical evolution in binary systems.
format Preprint
id arxiv_https___arxiv_org_abs_2412_13189
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Binary properties of the globular cluster 47 Tuc (NGC 104). A dearth of short-period binaries
Müller-Horn, Johanna
Göttgens, Fabian
Dreizler, Stefan
Kamann, Sebastian
Martens, Sven
Saracino, Sara
Ye, Claire S.
Solar and Stellar Astrophysics
Astrophysics of Galaxies
Spectroscopic observations of binary stars in globular clusters are essential to shed light on the poorly constrained period, eccentricity, and mass ratio distributions and to develop an understanding of the formation of peculiar stellar objects. 47 Tuc (NGC 104) is one of the most massive Galactic globular clusters, with a large population of blue stragglers and with many predicted but as-yet elusive stellar-mass black holes. This makes it an exciting candidate for binary searches. We present a multi-epoch spectroscopic survey of 47 Tuc with the VLT/MUSE integral field spectrograph to determine radial velocity variations for 21,699 stars. We find a total binary fraction in the cluster of $(2.4\pm1.0)\%$, consistent with previous photometric estimates, and an increased binary fraction among blue straggler stars, approximately three times higher than the cluster average. We find very few binaries with periods below three days, and none with massive dark companions. A comparison with predictions from state-of-the-art models shows that the absence of such short-period binaries and of binaries with massive companions is surprising, highlighting the need to improve our understanding of stellar and dynamical evolution in binary systems.
title Binary properties of the globular cluster 47 Tuc (NGC 104). A dearth of short-period binaries
topic Solar and Stellar Astrophysics
Astrophysics of Galaxies
url https://arxiv.org/abs/2412.13189