Weak infrared molecular lines reveal rapid outflow in cool magnetic sunspot penumbral fibrils

M. J. Penn; Wenda Cao; S. R. Walton; G. A. Chapman; W. Livingston

doi:10.1086/376749

Weak infrared molecular lines reveal rapid outflow in cool magnetic sunspot penumbral fibrils

M. J. Penn
, Wenda Cao
, S. R. Walton
, G. A. Chapman
, W. Livingston

Center For Solar Terrestrial Research - Big Bear Solar Observatory

Research output: Contribution to journal › Article › peer-review

9 Scopus citations

Abstract

New imaging spectropolarimetric observations of the Evershed flow in sunspot penumbrae using weak infrared molecular absorption lines are presented. A plane-polar coordinate system in the sunspot frame is defined, allowing averaging of many raw spectra. Molecular lines show Doppler shifts implying typical horizontal outflow speeds of 6 and up to 9 km s^-1. The Ti I polarimetric spectra show the same rapid outflow and suggest an average penumbral magnetic field strength of 1400 G. While these observations show Doppler shifts of the entire line profile, the velocities are in better agreement with previous measurements from spectral line asymmetries.

Original language	English (US)
Pages (from-to)	L119-L122
Journal	Astrophysical Journal
Volume	590
Issue number	2 II
DOIs	https://doi.org/10.1086/376749
State	Published - Jun 20 2003

All Science Journal Classification (ASJC) codes

Astronomy and Astrophysics
Space and Planetary Science

Keywords

Sun: atmospheric motions
Sun: infrared
Sunspots
Techniques: spectroscopic

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10.1086/376749

Cite this

@article{0b24fdc612864503853c2dca3c24dd53,

title = "Weak infrared molecular lines reveal rapid outflow in cool magnetic sunspot penumbral fibrils",

abstract = "New imaging spectropolarimetric observations of the Evershed flow in sunspot penumbrae using weak infrared molecular absorption lines are presented. A plane-polar coordinate system in the sunspot frame is defined, allowing averaging of many raw spectra. Molecular lines show Doppler shifts implying typical horizontal outflow speeds of 6 and up to 9 km s-1. The Ti I polarimetric spectra show the same rapid outflow and suggest an average penumbral magnetic field strength of 1400 G. While these observations show Doppler shifts of the entire line profile, the velocities are in better agreement with previous measurements from spectral line asymmetries.",

keywords = "Sun: atmospheric motions, Sun: infrared, Sunspots, Techniques: spectroscopic",

author = "Penn, \{M. J.\} and Wenda Cao and Walton, \{S. R.\} and Chapman, \{G. A.\} and W. Livingston",

note = "Funding Information: The high-order adaptive optics system used at the NSO Dunn Solar Telescope to produce the image in Figure 1 was made possible through NSF award AST 00-79482. M. J. P. acknowledges support from the Air Force Office of Scientific Research through award F49620-00-1-0355 and support from NSF through ATM-0077624 and thanks T. Rimmele for a thorough review and helpful discussions. W. D. C. gratefully acknowledges the support of the K. C. Wong Education Foundation, Hong Kong, and the National Natural Science Foundation of China through award 10103004 and NSF of Yunnan through 2001A0027Q during his visit to the NSO in Tucson. The NSO/ Kitt Peak data used here are produced cooperatively by NSF/ NOAO, NASA/GSFC, and NOAA/SEL. Funding Information: 1National Solar Observatory (operated by the Association of Universities for Research in Astronomy, Inc., under cooperative agreement with the National Science Foundation), 950 North Cherry Avenue, Tucson, AZ 85719; [email protected].",

year = "2003",

month = jun,

day = "20",

doi = "10.1086/376749",

language = "English (US)",

volume = "590",

pages = "L119--L122",

journal = "Astrophysical Journal",

issn = "0004-637X",

publisher = "American Astronomical Society",

number = "2 II",

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TY - JOUR

T1 - Weak infrared molecular lines reveal rapid outflow in cool magnetic sunspot penumbral fibrils

AU - Penn, M. J.

AU - Cao, Wenda

AU - Walton, S. R.

AU - Chapman, G. A.

AU - Livingston, W.

N1 - Funding Information: The high-order adaptive optics system used at the NSO Dunn Solar Telescope to produce the image in Figure 1 was made possible through NSF award AST 00-79482. M. J. P. acknowledges support from the Air Force Office of Scientific Research through award F49620-00-1-0355 and support from NSF through ATM-0077624 and thanks T. Rimmele for a thorough review and helpful discussions. W. D. C. gratefully acknowledges the support of the K. C. Wong Education Foundation, Hong Kong, and the National Natural Science Foundation of China through award 10103004 and NSF of Yunnan through 2001A0027Q during his visit to the NSO in Tucson. The NSO/ Kitt Peak data used here are produced cooperatively by NSF/ NOAO, NASA/GSFC, and NOAA/SEL. Funding Information: 1National Solar Observatory (operated by the Association of Universities for Research in Astronomy, Inc., under cooperative agreement with the National Science Foundation), 950 North Cherry Avenue, Tucson, AZ 85719; [email protected].

PY - 2003/6/20

Y1 - 2003/6/20

N2 - New imaging spectropolarimetric observations of the Evershed flow in sunspot penumbrae using weak infrared molecular absorption lines are presented. A plane-polar coordinate system in the sunspot frame is defined, allowing averaging of many raw spectra. Molecular lines show Doppler shifts implying typical horizontal outflow speeds of 6 and up to 9 km s-1. The Ti I polarimetric spectra show the same rapid outflow and suggest an average penumbral magnetic field strength of 1400 G. While these observations show Doppler shifts of the entire line profile, the velocities are in better agreement with previous measurements from spectral line asymmetries.

AB - New imaging spectropolarimetric observations of the Evershed flow in sunspot penumbrae using weak infrared molecular absorption lines are presented. A plane-polar coordinate system in the sunspot frame is defined, allowing averaging of many raw spectra. Molecular lines show Doppler shifts implying typical horizontal outflow speeds of 6 and up to 9 km s-1. The Ti I polarimetric spectra show the same rapid outflow and suggest an average penumbral magnetic field strength of 1400 G. While these observations show Doppler shifts of the entire line profile, the velocities are in better agreement with previous measurements from spectral line asymmetries.

KW - Sun: atmospheric motions

KW - Sun: infrared

KW - Sunspots

KW - Techniques: spectroscopic

UR - https://www.scopus.com/pages/publications/0041654631

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DO - 10.1086/376749

M3 - Article

AN - SCOPUS:0041654631

SN - 0004-637X

VL - 590

SP - L119-L122

JO - Astrophysical Journal

JF - Astrophysical Journal

IS - 2 II

ER -

Weak infrared molecular lines reveal rapid outflow in cool magnetic sunspot penumbral fibrils

Abstract

All Science Journal Classification (ASJC) codes

Keywords

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