Millimeter-wave spectropolarimetry of evolved stars: Evidence for polarized molecular line emission

Jason Glenn, Christopher K Walker, John H Bieging, P. R. Jewell

Research output: Contribution to journalArticle

12 Citations (Scopus)

Abstract

We present spectropolarimetry of CSJ = 2-1 emission from the evolved stars IRC +10216 and CRL 2688 and spectropolarimetry of the HCN J = 1-0 transition from CRL 2688. We detected a line-averaged linear polarization of ∼1% toward IRC +10216 on three separate occasions. We found no evidence for velocity dependence of the polarization within the emission line. A deviation from spherical symmetry in the radiative transfer of the envelope is implied because polarization was detected toward the central star. The polarization position angle of about -70° is orthogonal to the envelope elongation apparent in previous observations. Polarizations of 5.1% ± 1.5% (1 σ) and less than 0.9% (3 σ), respectively, were derived for CS and HCN from CRL 2688.

Original languageEnglish (US)
JournalAstrophysical Journal
Volume487
Issue number1 PART II
StatePublished - 1997

Fingerprint

millimeter waves
polarization
stars
envelopes
linear polarization
radiative transfer
elongation
symmetry
deviation

Keywords

  • Circumstellar matter
  • Polarization
  • Stars: AGB and post-AGB

ASJC Scopus subject areas

  • Space and Planetary Science

Cite this

Millimeter-wave spectropolarimetry of evolved stars : Evidence for polarized molecular line emission. / Glenn, Jason; Walker, Christopher K; Bieging, John H; Jewell, P. R.

In: Astrophysical Journal, Vol. 487, No. 1 PART II, 1997.

Research output: Contribution to journalArticle

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abstract = "We present spectropolarimetry of CSJ = 2-1 emission from the evolved stars IRC +10216 and CRL 2688 and spectropolarimetry of the HCN J = 1-0 transition from CRL 2688. We detected a line-averaged linear polarization of ∼1{\%} toward IRC +10216 on three separate occasions. We found no evidence for velocity dependence of the polarization within the emission line. A deviation from spherical symmetry in the radiative transfer of the envelope is implied because polarization was detected toward the central star. The polarization position angle of about -70° is orthogonal to the envelope elongation apparent in previous observations. Polarizations of 5.1{\%} ± 1.5{\%} (1 σ) and less than 0.9{\%} (3 σ), respectively, were derived for CS and HCN from CRL 2688.",
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T2 - Evidence for polarized molecular line emission

AU - Glenn, Jason

AU - Walker, Christopher K

AU - Bieging, John H

AU - Jewell, P. R.

PY - 1997

Y1 - 1997

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AB - We present spectropolarimetry of CSJ = 2-1 emission from the evolved stars IRC +10216 and CRL 2688 and spectropolarimetry of the HCN J = 1-0 transition from CRL 2688. We detected a line-averaged linear polarization of ∼1% toward IRC +10216 on three separate occasions. We found no evidence for velocity dependence of the polarization within the emission line. A deviation from spherical symmetry in the radiative transfer of the envelope is implied because polarization was detected toward the central star. The polarization position angle of about -70° is orthogonal to the envelope elongation apparent in previous observations. Polarizations of 5.1% ± 1.5% (1 σ) and less than 0.9% (3 σ), respectively, were derived for CS and HCN from CRL 2688.

KW - Circumstellar matter

KW - Polarization

KW - Stars: AGB and post-AGB

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