Faint stars in the Ursa Minor dwarf spheroidal galaxy: implications for the low-mass stellar initial mass function at high redshift
Wyse, RFG ; Gilmore, G ; Houdashelt, ML ; Feltzing, Sofia LU
; Hebb, L
; Gallagher, JS
and Smecker-Hane, TA
(2002)
In New Astronomy
7(7).
p.395-433
- Abstract
- The stellar initial mass function at high redshift is an important defining property of the first stellar systems to form and may also play a role in various dark matter problems. We here determine the faint stellar luminosity function in an apparently dark-matter-dominated external galaxy in which the stars formed at high redshift. The Ursa Minor dwarf spheroidal galaxy is a system with a particularly simple stellar population-all of the stars being old and metal-poor-similar to that of a classical halo globular cluster. A direct comparison of the faint luminosity functions of the UMi dSph and of similar metallicity, old globular clusters is equivalent to a comparison of the initial mass functions and is presented here, based on deep HST... (More)
- The stellar initial mass function at high redshift is an important defining property of the first stellar systems to form and may also play a role in various dark matter problems. We here determine the faint stellar luminosity function in an apparently dark-matter-dominated external galaxy in which the stars formed at high redshift. The Ursa Minor dwarf spheroidal galaxy is a system with a particularly simple stellar population-all of the stars being old and metal-poor-similar to that of a classical halo globular cluster. A direct comparison of the faint luminosity functions of the UMi dSph and of similar metallicity, old globular clusters is equivalent to a comparison of the initial mass functions and is presented here, based on deep HST WFPC2 and STIS imaging data. We find that these luminosity functions are indistinguishable, down to a luminosity corresponding to similar to0.3 M-.. Our results show that the low-mass stellar IMF for stars that formed at very high redshift is apparently invariant across environments as diverse as those of an extremely low-surface-brightness, dark-matter-dominated dwarf galaxy and a dark-matter-free, high-density globular cluster within the Milky Way. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/325968
- author
- Wyse, RFG
; Gilmore, G
; Houdashelt, ML
; Feltzing, Sofia
LU
; Hebb, L
; Gallagher, JS
and Smecker-Hane, TA
- organization
- publishing date
- 2002
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- individual : Ursa Minor, mass function, stars : luminosity function, dark matter, galaxies : stellar content, kinematics and dynamics, galaxies :
- in
- New Astronomy
- volume
- 7
- issue
- 7
- pages
- 395 - 433
- publisher
- Elsevier
- external identifiers
-
- wos:000178496100003
- scopus:31244436674
- ISSN
- 1384-1092
- DOI
- 10.1016/S1384-1076(02)00156-2
- language
- English
- LU publication?
- yes
- id
- 08c7f35d-b070-4e9e-9b0b-a81c237c42a2 (old id 325968)
- alternative location
- http://arxiv.org/abs/astro-ph/0206144
- date added to LUP
- 2016-04-01 11:52:41
- date last changed
- 2024-01-07 23:55:26
@article{08c7f35d-b070-4e9e-9b0b-a81c237c42a2,
abstract = {{The stellar initial mass function at high redshift is an important defining property of the first stellar systems to form and may also play a role in various dark matter problems. We here determine the faint stellar luminosity function in an apparently dark-matter-dominated external galaxy in which the stars formed at high redshift. The Ursa Minor dwarf spheroidal galaxy is a system with a particularly simple stellar population-all of the stars being old and metal-poor-similar to that of a classical halo globular cluster. A direct comparison of the faint luminosity functions of the UMi dSph and of similar metallicity, old globular clusters is equivalent to a comparison of the initial mass functions and is presented here, based on deep HST WFPC2 and STIS imaging data. We find that these luminosity functions are indistinguishable, down to a luminosity corresponding to similar to0.3 M-.. Our results show that the low-mass stellar IMF for stars that formed at very high redshift is apparently invariant across environments as diverse as those of an extremely low-surface-brightness, dark-matter-dominated dwarf galaxy and a dark-matter-free, high-density globular cluster within the Milky Way.}},
author = {{Wyse, RFG and Gilmore, G and Houdashelt, ML and Feltzing, Sofia and Hebb, L and Gallagher, JS and Smecker-Hane, TA}},
issn = {{1384-1092}},
keywords = {{individual : Ursa Minor; mass function; stars : luminosity function; dark matter; galaxies : stellar content; kinematics and dynamics; galaxies :}},
language = {{eng}},
number = {{7}},
pages = {{395--433}},
publisher = {{Elsevier}},
series = {{New Astronomy}},
title = {{Faint stars in the Ursa Minor dwarf spheroidal galaxy: implications for the low-mass stellar initial mass function at high redshift}},
url = {{http://dx.doi.org/10.1016/S1384-1076(02)00156-2}},
doi = {{10.1016/S1384-1076(02)00156-2}},
volume = {{7}},
year = {{2002}},
}