Discovery of an Extended Dust Emission around IRAS 18576+0341 (AFGL 2298) at 10.3 and 18.0 Microns: A New Luminous Blue Variable Candidate?
| Autor: | Giovanni G. Fazio, Lynne K. Deutsch, Toshiya Ueta, William F. Hoffmann, Aditya Dayal, Joseph L. Hora, Margaret Meixner |
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| Rok vydání: | 2001 |
| Předmět: |
010504 meteorology & atmospheric sciences
Astrophysics::High Energy Astrophysical Phenomena Star (game theory) Young stellar object Shell (structure) FOS: Physical sciences Astrophysics::Cosmology and Extragalactic Astrophysics Astrophysics 01 natural sciences Atmospheric radiative transfer codes 0103 physical sciences Astrophysics::Solar and Stellar Astrophysics 010303 astronomy & astrophysics Astrophysics::Galaxy Astrophysics 0105 earth and related environmental sciences Physics Nebula Astrophysics (astro-ph) Astronomy and Astrophysics Luminous blue variable 13. Climate action Space and Planetary Science Circumstellar dust Astrophysics::Earth and Planetary Astrophysics Dust emission |
| Zdroj: | The Astrophysical Journal. 548:1020-1028 |
| ISSN: | 1538-4357 0004-637X |
| Popis: | We report detection of an extended mid-infrared emission from \iras 18576+0341 (AFGL 2298). The object shows a dusty circumstellar shell that has diameter of $\age 7\arcsec$ at 10.3 and 18.0 $\um$. The dust nebula shows two emission peaks concentrically elongated and symmetrically oriented on the opposite sides of the third, central peak, which appears to be the central star of the system. The observed mid-infrared morphology indicates that the circumstellar dust shell has an equatorially-enhanced material distribution, which is a common signature of stellar objects that have experienced mass loss. Radiative transfer model calculations suggest that the central star is an extremely bright ($\lstar = 10^{6.4} \lsun$) star at a distance of about 10 kpc: this object is best described as a new luminous blue variable candidate. The circumstellar dust shell seems to have been generated by an equatorially-enhanced mass loss process with ${\dot M} \ge 6.8 \times 10^{-6} \msun$ yr$^{-1}$ and ${\dot M}_{\rm pole}/{\dot M}_{\rm eq} \sim 0.5$. 21 pages, 4 figures, to appear in ApJ |
| Databáze: | OpenAIRE |
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