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| Paper IPM / Astronomy / 18378 |
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NGC 6822 is a dwarf irregular galaxy in the local group at a distance of ~ 490 kpc. Several studies show that NGC 6822 began forming stars around 12-13 billion years ago, harboring a significant population of evolved stars. When stars with low to intermediate mass (approximately between 0.5 and 8 solar mass) reach the final stages of their evolution, they evolve into asymptotic giant branch (AGB) stars. Pulsating AGB stars, known as long-period variables (LPV), and red super-giants (RSG) enrich the interstellar medium (ISM) and are significant sources of dust production in galaxies. To study the dust production in NGC 6822, the mass-loss rates of LPV and RSG stars are measured. The utilized sample consists of the photometric data in 12 photometric bands spanning the near- to mid-infrared, collected from several published surveys. The mass-loss of the stars is estimated through spectral energy distribution (SED) modeling, adopting an age-metallicity relation (AMR) to account for the variation of metallicity by time. It is estimated that the overall mass-loss rate in NGC 6822 is approximately ~ 0.00080 solar mass per year. RSGs contribute ~ %15 to this value with an overall mass-loss of ~ 0.00012 solar mass per year. The estimated overall mass-loss from the AGB stars is not sufficient to account for the current star formation rate (SFR) of ~ 0.007. This suggests that the mass must have been provided through other feedback factors or the surrounding environment.
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