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

Document Type

Article

Publication Date

6-20-2003

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.

Identifier

0041654631 (Scopus)

Publication Title

Astrophysical Journal

External Full Text Location

https://doi.org/10.1086/376749

e-ISSN

15384357

ISSN

0004637X

First Page

L119

Last Page

L122

Issue

2 II

Volume

590

Grant

ATM-0077624

Fund Ref

National Science Foundation

This document is currently not available here.

Share

COinS