The sub-mm variability of IRC+10216 and o Ceti
| Autor: | J. G. A. Wouterloot, Jonathan P. Marshall, Thavisha E. Dharmawardena, Peter Scicluna, Sofia Wallström, Francisca Kemper |
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| Rok vydání: | 2019 |
| Předmět: |
individual: o Ceti [stars]
Phase (waves) FOS: Physical sciences Astrophysics Astronomy & Astrophysics 01 natural sciences 0103 physical sciences Calibration Radiative transfer SCUBA-2 010303 astronomy & astrophysics Solar and Stellar Astrophysics (astro-ph.SR) James Clerk Maxwell Telescope Physics Science & Technology 010308 nuclear & particles physics Order (ring theory) Astronomy and Astrophysics Light curve AGB and post-AGB [stars] Wavelength Stars Astrophysics - Solar and Stellar Astrophysics variables: general [stars] Space and Planetary Science Physical Sciences individual: IRC+10216 [stars] EMISSION |
| Zdroj: | Monthly Notices of the Royal Astronomical Society. 489:3492-3505 |
| ISSN: | 1365-2966 0035-8711 |
| DOI: | 10.1093/mnras/stz2263 |
| Popis: | We present the sub-mm variability of two of the most well studied AGB stars, IRC+10216 and $o$ Ceti. The data are obtained at $450~\micron$ and $850~\micron$ as part of pointing calibration observations for the James Clerk Maxwell Telescope's SCUBA-2 instrument over a span of 7 years. The periods are derived using non-parametric methods, \texttt{Gatspy Supersmoother} and \texttt{P4J} in order not to assume an underlying shape to the periodicity. These were compared to two Lomb-Scargle parametric methods. We find that for both sources and wavelengths the periods derived from all methods are consistent within $1\sigma$. The $850~\micron$ phase folded light curves of IRC+10216 show a time lag of $\sim 540$ days compared to its optical counterpart. We explore the origins of the sub-mm variability and the phase lag using radiative transfer models. Combining the modelling with findings in the literature, we find that the sub-mm emission and phase lag can be partially attributed to the dust formation/destruction cycle. A second, unknown mechanism must be invoked; we defer an investigation of the origin and nature of this mechanism to a future work. Comment: Accepted for publication in MNRAS |
| Databáze: | OpenAIRE |
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