The mass-to-light ratio of rich star clusters
(2009) In Astrophysics and Space Science 324(2-4). p.265-269- Abstract
- We point out a strong time evolution of the mass-to-light conversion factor, η, commonly used to estimate masses of unresolved star clusters from observed cluster spectrophotometric measures. We present a series of gas-dynamical models, coupled with the Cambridge stellar evolution tracks, to compute line-of-sight velocity dispersions and half-light radii weighted by the luminosity. We explore a range of initial conditions, varying in turn the cluster mass and/or density, and the stellar population’s initial mass function. We find that η, and hence the estimated cluster mass, may increase by as much as a factor of three over time-scales of 50 million yr. We apply these results to an hypothetic cluster mass distribution function (d.f.), and... (More)
- We point out a strong time evolution of the mass-to-light conversion factor, η, commonly used to estimate masses of unresolved star clusters from observed cluster spectrophotometric measures. We present a series of gas-dynamical models, coupled with the Cambridge stellar evolution tracks, to compute line-of-sight velocity dispersions and half-light radii weighted by the luminosity. We explore a range of initial conditions, varying in turn the cluster mass and/or density, and the stellar population’s initial mass function. We find that η, and hence the estimated cluster mass, may increase by as much as a factor of three over time-scales of 50 million yr. We apply these results to an hypothetic cluster mass distribution function (d.f.), and show that the d.f. shape may be strongly affected at the low-mass end by this effect. Fitting truncated isothermal (Michie–King) models to the projected light profile leads to over-estimates of the concentration parameter, c, of δ c≈0.3 compared to the same functional fit applied to the projected mass density. (Less)
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https://lup.lub.lu.se/record/157de64d-644e-458f-b617-5b7092636dfe
- author
- Boily, Christian M. ; Fleck, Jean-Julien ; Lançon, Ariane and Renaud, Florent LU
- publishing date
- 2009-12-01
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Stellar dynamics, Stars: evolution, Astrophysics - Cosmology and Nongalactic Astrophysics
- in
- Astrophysics and Space Science
- volume
- 324
- issue
- 2-4
- pages
- 5 pages
- publisher
- Springer
- external identifiers
-
- scopus:84895911173
- ISSN
- 0004-640X
- DOI
- 10.1007/s10509-009-0118-3
- language
- English
- LU publication?
- no
- id
- 157de64d-644e-458f-b617-5b7092636dfe
- date added to LUP
- 2019-05-21 15:24:45
- date last changed
- 2022-06-21 14:32:12
@article{157de64d-644e-458f-b617-5b7092636dfe, abstract = {{We point out a strong time evolution of the mass-to-light conversion factor, η, commonly used to estimate masses of unresolved star clusters from observed cluster spectrophotometric measures. We present a series of gas-dynamical models, coupled with the Cambridge stellar evolution tracks, to compute line-of-sight velocity dispersions and half-light radii weighted by the luminosity. We explore a range of initial conditions, varying in turn the cluster mass and/or density, and the stellar population’s initial mass function. We find that η, and hence the estimated cluster mass, may increase by as much as a factor of three over time-scales of 50 million yr. We apply these results to an hypothetic cluster mass distribution function (d.f.), and show that the d.f. shape may be strongly affected at the low-mass end by this effect. Fitting truncated isothermal (Michie–King) models to the projected light profile leads to over-estimates of the concentration parameter, c, of δ c≈0.3 compared to the same functional fit applied to the projected mass density.}}, author = {{Boily, Christian M. and Fleck, Jean-Julien and Lançon, Ariane and Renaud, Florent}}, issn = {{0004-640X}}, keywords = {{Stellar dynamics, Stars: evolution, Astrophysics - Cosmology and Nongalactic Astrophysics}}, language = {{eng}}, month = {{12}}, number = {{2-4}}, pages = {{265--269}}, publisher = {{Springer}}, series = {{Astrophysics and Space Science}}, title = {{The mass-to-light ratio of rich star clusters}}, url = {{http://dx.doi.org/10.1007/s10509-009-0118-3}}, doi = {{10.1007/s10509-009-0118-3}}, volume = {{324}}, year = {{2009}}, }