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Simultaneously Capturing Real-time Images in Two Emission Channels Using a Dual Camera Emission Splitting System: Applications to Cell Adhesion
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Time-dependent molecular emission in IRC+10216.

J R Pardo1, J Cernicharo1, L Velilla Prieto1

  • 1Consejo Superior de Investigaciones Científicas, Instituto de Física Fundamental, Serrano 123, 28006 Madrid, Spain.

Astronomy and Astrophysics
|September 7, 2018
PubMed
Summary
This summary is machine-generated.

Variability in the molecular envelope of the asymptotic giant branch star CW Leo (IRC+10216) was studied using radio telescope observations. Periods of molecular line variations match infrared variability, suggesting radiative transfer effects drive these changes.

Keywords:
radio lines: starsstars: AGB and post-AGBstars: carbonstars: individual (IRC+10216)stars: variables: general

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Area of Science:

  • Astronomy and Astrophysics
  • Stellar Evolution
  • Astrochemistry

Background:

  • The variability of IRC+10216, the envelope of the asymptotic giant branch (AGB) star CW Leo, is a subject of recent scientific interest.
  • Understanding this variability in molecular emissions necessitates a systematic observational approach.

Purpose of the Study:

  • To identify and characterize the periodic variability in rotational lines of various molecules and radicals within IRC+10216.
  • To compare these molecular variations with previously documented infrared (IR) variability.

Main Methods:

  • Conducted systematic monitoring of IRC+10216 using the IRAM 30m telescope.
  • Observed the frequency range of approximately 80 to 116 GHz.

Main Results:

  • Reported periodic variability in rotational lines of HC3N, HC5N, CCH, C4H, C5H, and CN in IRC+10216.
  • Determined periods for these molecular lines that align with prior IR variability findings.
  • Observed phase lags suggesting radiative transfer and pumping mechanisms, rather than chemical changes, are responsible.

Conclusions:

  • Simultaneous or phase-matched observations of different molecular lines are crucial to prevent data misinterpretation.
  • Combining data from different epochs, such as with ALMA, requires careful consideration of variability.
  • Radiative transfer codes must account for population variability in the rotational levels of CW Leo.