Spitzer spectra of evolved stars in ω Centauri and their low-metallicity dust production

@article{McDonald2011SpitzerSO,
  title={Spitzer spectra of evolved stars in $\omega$ Centauri and their low-metallicity dust production},
  author={Iain McDonald and Jacco Th. van Loon and G. C. Sloan and Andrea K. Dupree and Albert A. Zijlstra and Martha L. Boyer and Robert D. Gehrz and Aneurin Evans and Charles E. Woodward and Christian I. Johnson},
  journal={Monthly Notices of the Royal Astronomical Society},
  year={2011},
  volume={417},
  pages={20-31}
}
Dust production is explored around 14 metal-poor ([Fe/H] =− 1.91 to −0.98) giant stars in the Galactic globular cluster ω Centauri using new Spitzer Infrared Spectrograph spectra. This sample includes the cluster’s post-asymptotic giant branch (AGB) and carbon stars and is thus the first representative spectral study of dust production in a metal-poor ([Fe/H] < −1) population. Only the more metal-rich stars V6 and V17 ([Fe/H] =− 1.08, −1.06) exhibit silicate emission, while the five other stars… Expand
THE DUST BUDGET OF THE SMALL MAGELLANIC CLOUD: ARE ASYMPTOTIC GIANT BRANCH STARS THE PRIMARY DUST SOURCE AT LOW METALLICITY?
We estimate the total dust input from the cool evolved stars in the Small Magellanic Cloud, using the 8 μm excess emission as a proxy for the dust-production rate (DPR). We find that asymptotic giantExpand
Asymptotic Giant Branch Stars in the Nearby Dwarf Galaxy Leo P
We have conducted a highly sensitive census of the evolved-star population in the metal-poor dwarf galaxy Leo P and detected four asymptotic giant branch (AGB) star candidates. Leo P is one of theExpand
A Luminous Yellow Post-AGB Star in the Galactic Globular Cluster M79
We report discovery of a luminous F-type post-asymptotic-giant-branch (PAGB) star in the Galactic globular cluster (GC) M79 (NGC 1904). At visual apparent and absolute magnitudes of V=12.20 andExpand
An Infrared Census of Dust in nearby Galaxies with Spitzer (DUSTiNGS). I. Overview
Nearby resolved dwarf galaxies provide excellent opportunities for studying the dust-producing late stages of stellar evolution over a wide range of metallicity (–2.7 ≲ [Fe/H] ≲ –1.0). Here, weExpand
On the metallicity dependence of crystalline silicates in oxygen-rich asymptotic giant branch stars and red supergiants
We investigate the occurrence of crystalline silicates in oxygen-rich evolved stars across a range of metallicities and mass-loss rates. It has been suggested that the crystalline silicate featureExpand
An Infrared Census of DUST in Nearby Galaxies with Spitzer (DUSTiNGS). II. Discovery of Metal-poor Dusty AGB Stars
The DUSTiNGS survey (DUST in Nearby Galaxies with Spitzer) is a 3.6 and 4.5 ?m imaging survey of 50 nearby dwarf galaxies designed to identify dust-producing asymptotic giant branch (AGB) stars andExpand
Discovery of Stars Surrounded by Iron Dust in the Large Magellanic Cloud
We consider a small sample of oxygen-rich, asymptotic giant branch stars in the Large Magellanic Cloud, observed by the Spitzer Space Telescope, exhibiting a peculiar spectral energy distribution,Expand
Circumstellar CO J = 3→2 detected around the evolving metal-poor ([Fe/H] ≈ −1.15 dex) AGB star RU Vulpeculae
We report the first detection of CO J = 3→2 around a truly metal-poor evolved star. RU Vulpeculae is modelled to have Teff ≈ 3620 K, L ≈ 3128 ± 516 L⊙, log(g) = 0.0 ± 0.2 dex and [Fe/H] = −1.3 toExpand
Circumstellar CO in metal-poor stellar winds: the highly irradiated globular cluster star 47 Tucanae V3
We report the first detection of circumstellar CO in a globular cluster. Observations with ALMA have detected the CO J=3-2 and SiO v=1 J=8-7 transitions at 345 and 344 GHz, respectively, around V3 inExpand
Fundamental parameters and infrared excesses of Tycho–Gaia stars
Effective temperatures and luminosities are calculated for 1,475,921 Tycho-2 and 107,145 Hipparcos stars, based on distances from Gaia Data Release 1. Parameters are derived by comparingExpand
...
1
2
3
...

References

SHOWING 1-10 OF 76 REFERENCES
Giants in the globular cluster ω Centauri: dust production, mass-loss and distance
We present spectral energy distribution modelling of 6875 stars in ω Centauri, obtaining stellar luminosities and temperatures by fitting literature photometry to state-of-the-art MARCS stellarExpand
CHEMICAL ABUNDANCES FOR 855 GIANTS IN THE GLOBULAR CLUSTER OMEGA CENTAURI (NGC 5139)
We present elemental abundances for 855 red giant branch (RGB) stars in the globular cluster Omega Centauri (ω Cen) from spectra obtained with the Blanco 4 m telescope and Hydra multifiberExpand
SPITZER SPECTROSCOPY OF MASS LOSS AND DUST PRODUCTION BY EVOLVED STARS IN GLOBULAR CLUSTERS
We have observed a sample of 35 long-period variables (LPVs) and four Cepheid variables in the vicinity of 23 Galactic globular clusters using the Infrared Spectrograph on the Spitzer SpaceExpand
Metallicities, Relative Ages, and Kinematics of Stellar Populations in ω Centauri*
We present results of an extensive spectroscopic survey of subgiant stars in the stellar system ω Cen. Using infrared Ca II triplet lines, we derived metallicities and radial velocities for more thanExpand
The Magellanic zoo: mid‐infrared Spitzer spectroscopy of evolved stars and circumstellar dust in the Magellanic Clouds
We observed a sample of evolved stars in the Large and Small Magellanic Clouds (LMC and SMC) with the Infrared Spectrograph on the Spitzer Space Telescope. Comparing samples from the SMC, LMC, andExpand
FAST WINDS AND MASS LOSS FROM METAL-POOR FIELD GIANTS*
Echelle spectra of the infrared He I λ10830 line were obtained with NIRSPEC on the Keck 2 telescope for 41 metal-deficient field giant stars including those on the red giant branch (RGB), asymptoticExpand
Dust, pulsation, chromospheres and their rôle in driving mass loss from red giants in Galactic globular clusters
Context. Mass loss from red giants in old globular clusters affects the horizontal branch (HB) morphology and post-HB stellar evolution including the production of ultraviolet-bright stars, dredge upExpand
Tracing the development of dust around evolved stars: The case of 47 Tuc
We observed mid-infrared (7.5-22 μm) spectra of asymptotic giant branch (AGB) stars in the globular cluster 47 Tuc with the Spitzer Space Telescope, and we find significant dust features of variousExpand
Dust Production and Mass Loss in the Galactic Globular Cluster 47 Tucanae
Dust production among post-main-sequence stars is investigated in the Galactic globular cluster 47 Tucanae (NGC 104) based on infrared photometry and spectroscopy. We identify metallic iron grains asExpand
A Spitzer Space Telescope atlas of ω Centauri: The stellar population, mass loss, and the intracluster medium
We present a Spitzer Space Telescope imaging survey of the most massive Galactic globular cluster, ω Centauri, and investigate stellar mass loss at low metallicity and the intracluster medium (ICM).Expand
...
1
2
3
4
5
...