DUST PRODUCTION BY EVOLVED STARS IN THE MAGELLANIC CLOUDS

AbstractThe sensitivity of the Infrared Spectrograph on the Spitzer Space Telescope has enabled detailed surveys of mass-losing stars in the Large and Small Magellanic Clouds. Comparisons of samples from these galaxies and the Milky Way reveal how the dust produced by evolved stars depends on the metallicity of the host environment. Oxygen-rich stars show several trends with metallicity. In more metal-poor environments, fewer of them show dust excesses, the circumstellar SiO absorption grows weaker, the quantity of silicate dust decreases, and alumina dust grows rare. As carbon stars grow more metal-poor, the amount of circumstellar acetylene gas increases, while the amount of trace dust elements like SiC and MgS decreases. However, there is little dependence on metallicity in the amount of amorphous carbon dust produced by carbon stars, because they produce the carbon needed to make dust themselves. As galaxies grow more metal-poor, the composition of the dust they produce should grow more carbon rich.

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Chemical Peculiarities, Mass Loss, and Final Evolution of AGB Stars in the Magellanic Clouds

International Astronomical Union Colloquium ◽

10.1017/s0252921100093362 ◽

1988 ◽

Vol 108 ◽

pp. 31-37

Author(s):

P.R. Wood

Keyword(s):

Mass Loss ◽

Great Majority ◽

Magellanic Clouds ◽

Asymptotic Giant Branch ◽

Agb Stars ◽

Long Period ◽

Evolved Stars ◽

The Galaxy ◽

Shed Light ◽

Final Evolution

The Magellanic Clouds are sufficiently close that evolved stars which exhibit chemical peculiarities and the effects of mass loss can be readily observed. Such objects include carbon stars, S stars, long-period variables, OH/IR stars and planetary nebulae. Because of the relatively well-known distances of the Magellanic Clouds, the intrinsic luminosities of these objects can be accurately determined, in contrast to the situation in the Galaxy where the great majority of asymptotic giant branch (AGB) stars occur in the field population. In this review, observations of AGB stars in the Magellanic Clouds will be discussed with particular reference to those features which can shed light on mass loss and chemical peculiarities resulting from stellar evolution.

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Detection and Photometry of Red Giants in the Magellanic Clouds

Symposium - International Astronomical Union ◽

10.1017/s007418090004016x ◽

1984 ◽

Vol 108 ◽

pp. 183-194

Author(s):

Marc Aaronson

Keyword(s):

Stellar Population ◽

Near Infrared ◽

Formation Rate ◽

Magellanic Clouds ◽

Red Giants ◽

Chemical Enrichment ◽

Evolved Stars ◽

Photometric Observations ◽

Infrared Measurements ◽

History Of

This review will focus on photometric observations of evolved stars in the Magellanic Clouds. Emphasis is placed on red and near-infrared measurements, as these allow reasonable estimates to be made of bolometric magnitude and temperature for reliable placement in the physical HR diagram. The review is divided into three parts: field stars, cluster stars, and red variables; a summary of the surveys for objects in each of these areas is also given. Particular attention is drawn to the intermediate-age stellar population, as this component appears to be the primary tracer of the star formation rate and chemical enrichment history of the Clouds.

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Global Dust Budgets of the Magellanic Clouds

Proceedings of the International Astronomical Union ◽

10.1017/s1743921313001336 ◽

2012 ◽

Vol 8 (S292) ◽

pp. 267-270 ◽

Cited By ~ 1

Author(s):

Mikako Matsuura

Keyword(s):

Life Cycle ◽

Large Magellanic Cloud ◽

Magellanic Cloud ◽

Magellanic Clouds ◽

Agb Stars ◽

Dust Production ◽

Space Observatory ◽

Great Opportunity ◽

Dust Sources ◽

Nearby Galaxies

AbstractWithin galaxies, gas and dust are constantly exchanged between stars and the interstellar medium (ISM). The life-cycle of gas and dust is the key to the evolution of galaxies. Despite its importance, it is has been very difficult to trace the life-cycle of gas and dust via observations. The Spitzer Space Telescope and Herschel Space Observatory have provided a great opportunity to study the life-cycle of the gas and dust in very nearby galaxies, the Magellanic Clouds. AGB stars are more important contributors to the dust budget in the Large Magellanic Cloud (LMC), while in the Small Magellanic Cloud (SMC), SNe are dominant. However, it seems that the current estimates of the total dust production from AGB stars is insufficient to account for dust present in the ISM. Other dust sources are needed, and supernovae are promising sources. Alternatively the time scale of dust lifetime itself needs some revisions, potentially because they could be unevenly distributed in the ISM or clumps.

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OH/IR stars in the Large Magellanic Cloud: the observations

Symposium - International Astronomical Union ◽

10.1017/s007418090020096x ◽

1991 ◽

Vol 148 ◽

pp. 386-387

Author(s):

P. R. Wood ◽

M. S. Bessell ◽

S.M.G. Hughes ◽

A. R. Hyland ◽

J. B. Whiteoak ◽

...

Keyword(s):

Large Magellanic Cloud ◽

Magellanic Clouds ◽

Evolved Stars ◽

Dual Channel ◽

Integration Period ◽

Ir Stars ◽

System Temperature ◽

Circumstellar Shells ◽

Digital Correlator ◽

Highly Evolved

In 1985 we began a search for OH/IR objects in the Magellanic Clouds. The first detection was reported by Wood, Bessell & Whiteoak (1986). Subsequent searches have yielded several of these objects and other highly-evolved stars obscured by thick circumstellar shells.The 1612-MHz OH observations were made using the Parkes 64-m radio telescope. Most of the observations utilized a dual-channel cryogenic receiver providing a system temperature of around 38 K on cold sky. The OH spectra were obtained with the Parkes digital correlator split into 512-channel segments. Bandwidths of 2 MHz provided a resolution of 7.8 kHz (equivalent to 1.5 km s−1 in radial velocity) after Hanning smoothing. The mode of observation has been described by Whiteoak and Gardner (1976). Typically, an integration period of 60 minutes was used; this yielded a detection limit (3a) of around 50 mJy for an OH feature. Detected emission was reobserved with a 1-MHz bandwidth. A search was also made for 1665-MHz OH emission.

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The mass-loss, expansion velocities, and dust production rates of carbon stars in the Magellanic Clouds

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stz1255 ◽

2019 ◽

Vol 487 (1) ◽

pp. 502-521 ◽

Cited By ~ 10

Author(s):

Ambra Nanni ◽

Martin A T Groenewegen ◽

Bernhard Aringer ◽

Stefano Rubele ◽

Alessandro Bressan ◽

...

Keyword(s):

Mass Loss ◽

Mass Loss Rate ◽

Large Magellanic Cloud ◽

Magellanic Cloud ◽

Magellanic Clouds ◽

Spectral Energy ◽

Carbon Stars ◽

Dust Production ◽

Production Rates ◽

Total Dust

ABSTRACT The properties of carbon stars in the Magellanic Clouds (MCs) and their total dust production rates are predicted by fitting their spectral energy distributions (SED) over pre-computed grids of spectra reprocessed by dust. The grids are calculated as a function of the stellar parameters by consistently following the growth for several dust species in their circumstellar envelopes, coupled with a stationary wind. Dust radiative transfer is computed taking as input the results of the dust growth calculations. The optical constants for amorphous carbon are selected in order to reproduce different observations in the infrared and optical bands of Gaia Data Release 2. We find a tail of extreme mass-losing carbon stars in the Large Magellanic Cloud (LMC) with low gas-to-dust ratios that is not present in the Small Magellanic Cloud (SMC). Typical gas-to-dust ratios are around 700 for the extreme stars, but they can be down to ∼160–200 and ∼100 for a few sources in the SMC and in the LMC, respectively. The total dust production rate for the carbon star population is ∼1.77 ± 0.45 × 10−5 M⊙ yr−1, for the LMC, and ∼2.52 ± 0.96 × 10−6 M⊙ yr−1, for the SMC. The extreme carbon stars observed with the Atacama Large Millimeter Array and their wind speed are studied in detail. For the most dust-obscured star in this sample the estimated mass-loss rate is ∼6.3 × 10−5 M⊙ yr−1. The grids of spectra are available at:1 and included in the SED-fitting python package for fitting evolved stars.2

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The evolution of dust in the local and high-redshift universe

Proceedings of the International Astronomical Union ◽

10.1017/s1743921316004804 ◽

2015 ◽

Vol 11 (A29B) ◽

pp. 182-183

Author(s):

Eli Dwek ◽

Richard G. Arendt ◽

Johannes Staguhn ◽

Tea Temim

Keyword(s):

Shock Waves ◽

Interstellar Medium ◽

Size Distribution ◽

High Redshift ◽

Magellanic Clouds ◽

Core Collapse ◽

Agb Stars ◽

Dust Production ◽

Great Debate ◽

High Redshift Universe

AbstractDust is a ubiquities component of the interstellar medium (ISM) of galaxies, and manifests itself in many different ways. Yet, its origin, composition, and size distribution are still a matter of great debate. Most of the thermally condensed dust is produced in the explosively expelled ejecta of core collapse supernovae (CCSNe) and in the quiescent winds of AGB stars. Following its injection into the ISM it is destroyed by supernova (SN) shock waves. Knowing the relative rates of these processes is crucial for understanding the nature and evolution of dust in galaxies. In the following we will review three aspects of the evolution of dust in galaxies: the evolution of dust in the ejecta of SN1987A; the rates of dust production and destruction rates in the Magellanic Clouds (MCs), and the evolution of dust in CLASH 2882, a gravitationally-lensed galaxy at z=1.

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The Complex Upper HR Diagram

Galaxies ◽

10.3390/galaxies7030075 ◽

2019 ◽

Vol 7 (3) ◽

pp. 75

Author(s):

Roberta M. Humphreys

Keyword(s):

Mass Loss ◽

Massive Stars ◽

Magellanic Clouds ◽

Historical Overview ◽

Ob Stars ◽

Luminous Blue Variables ◽

Evolved Stars ◽

Nearby Galaxies ◽

Introductory Review ◽

Hr Diagram

Several decades of observations of the most massive and most luminous stars have revealed a complex upper HR Diagram, shaped by mass loss, and inhabited by a variety of evolved stars exhibiting the consequences of their mass loss histories. This introductory review presents a brief historical overview of the HR Diagram for massive stars, highlighting some of the primary discoveries and results from their observation in nearby galaxies. The sections in this volume include reviews of our current understanding of different groups of evolved massive stars, all losing mass and in different stages of their evolution: the Luminous Blue Variables (LBVs), B[e] supergiants, the warm hypergiants, Wolf–Rayet stars, and the population of OB stars and supergiants in the Magellanic Clouds.

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