Modelling gas and dust around carbon stars in the Large Magellanic Cloud

2018 ◽  
Vol 14 (S343) ◽  
pp. 504-505
Author(s):  
Sundar Srinivasan ◽  
I.-K. Chen ◽  
P. Scicluna ◽  
J. Cami ◽  
F. Kemper
Keyword(s):  
Production Rate ◽  
Strong Correlation ◽  
Column Density ◽  
Preliminary Investigation ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Carbon Stars ◽  
Molecular Absorption ◽  
Dust Production ◽  
Absorption Features

AbstractIn order to investigate the effect of dust production on the molecular absorption, we model the dust continuum and the 7.5 and 13.7 μm acetylene absorption features in the Spitzer IRS spectra of 148 carbon stars in the Large Magellanic Cloud (LMC). Our preliminary investigation does not find a strong correlation between the dust-production rate and the column density of acetylene for the LMC sample. However, we will construct more models at high optical depths and probe a larger range of dust properties for more robust results.

scholarly journals Estimating the dust production rate of carbon stars in the Small Magellanic Cloud

2017 ◽  
Vol 473 (4) ◽  
pp. 5492-5513 ◽  
Author(s):  
Ambra Nanni ◽  
Paola Marigo ◽  
Léo Girardi ◽  
Stefano Rubele ◽  
Alessandro Bressan ◽  
...  
Keyword(s):  
Production Rate ◽  
Magellanic Cloud ◽  
Small Magellanic Cloud ◽  
Carbon Stars ◽  
Dust Production

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

2019 ◽  
Vol 487 (1) ◽  
pp. 502-521 ◽  
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

scholarly journals Detection of a repeated transit signature in the light curve of the enigma star KIC 8462852: A possible 928-day period

2017 ◽  
Vol 608 ◽  
pp. A132 ◽  
Author(s):  
F. Kiefer ◽  
A. Lecavelier des Étangs ◽  
A. Vidal-Madjar ◽  
G. Hébrard ◽  
V. Bourrier ◽  
...  
Keyword(s):  
Light Curve ◽  
Production Rate ◽  
A Priori ◽  
Ring System ◽  
Striking Similarity ◽  
Dust Production ◽  
High Quality ◽  
Bad Weather ◽  
Absorption Features

As revealed by its peculiar Kepler light curve, the enigmatic star KIC 8462852 undergoes short and deep flux dimmings at a priori unrelated epochs. This star presents nonetheless all other characteristics of a quiet 1 Gyr old F3V star. These dimmings resemble the absorption features expected for the transit of dust cometary tails. The exocomet scenario is therefore most commonly advocated. We reanalysed the Kepler data and extracted a new high-quality light curve to allow for the search of shallow signatures of single or a few exocomets. We discovered that among the 22 flux dimming events that we identified, two events present a striking similarity. These events occurred 928.25 days apart and lasted for 4.4 days with a drop in the star brightness by 1000 ppm. We show that the light curve of these events is well explained by the occultation of the star by a giant ring system or by the transit of a string of half a dozen exocomets with a typical dust production rate of 105–106 kg s-1. Assuming that these two similar events are related to the transit of the same object, we derive a period of 928.25 days. The following transit was expected in March 2017 but bad weather prohibited us from detecting it from ground-based spectroscopy. We predict that the next event will occur between 3−8 October 2019.

Three luminous carbon stars in the Large Magellanic Cloud

1978 ◽  
Vol 219 ◽  
pp. 452 ◽  
Author(s):  
H. B. Richer ◽  
B. E. Westerlund ◽  
N. Olander
Keyword(s):  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Carbon Stars

scholarly journals Molecular gas in the Small Magellanic Cloud

1991 ◽  
Vol 148 ◽  
pp. 429-430
Author(s):  
Monica Rubio
Keyword(s):  
Molecular Hydrogen ◽  
Molecular Clouds ◽  
Column Density ◽  
Angular Resolution ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Molecular Gas ◽  
Small Magellanic Cloud ◽  
Hydrogen Column Density ◽  
Co Emission

We summarize the results of observations of molecular gas from the Small Magellanic Cloud (SMC) made with low angular resolution (8'.8). These observations show that the CO emission is weak (TA˜ 0.04K) and that the CO luminosities of the Clouds are low compared to those of Galactic molecular clouds. The factor to convert the CO luminosity to molecular hydrogen column density for the SMC is ˜20 and three times larger than those derived for clouds in our Galaxy and in the Large Magellanic Cloud (LMC) respectively. In addition, we present preliminary results of high resolution (40″) observations of SMC molecular clouds made with the SEST telescope.

Merrill-Sanford bands in Large Magellanic Cloud carbon stars

2004 ◽  
Vol 355 (4) ◽  
pp. 1196-1206 ◽  
Author(s):  
D. H. Morgan ◽  
D. Hatzidimitriou ◽  
R. D. Cannon
Keyword(s):  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Carbon Stars

scholarly journals Lithium in Large Magellanic Cloud carbon stars

2003 ◽  
Vol 341 (4) ◽  
pp. 1290-1298 ◽  
Author(s):  
D. Hatzidimitriou ◽  
D. H. Morgan ◽  
R. D. Cannon ◽  
B. F. W. Croke
Keyword(s):  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Carbon Stars

scholarly journals Understanding the evolution and dust formation of carbon stars in the Large Magellanic Cloud via the JWST

2021 ◽  
Author(s):  
E. Marini ◽  
F. Dell'Agli ◽  
M. A. T. Groenewegen ◽  
D. A. García-Hernández ◽  
L. Mattsson ◽  
...  
Keyword(s):  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Dust Formation ◽  
Carbon Stars
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