Analysis of Time-Distance Helioseismology for Detection of Emerging Active Regions

Document Type

Article

Publication Date

6-1-2021

Abstract

A time-distance helioseismic technique, similar to the one used by Ilonidis et al., is applied to two independent numerical models of subsurface sound-speed perturbations to determine the spatial resolution and accuracy of phase travel time shift measurements. The technique is also used to examine pre-emergence signatures of several active regions observed by the Michelson Doppler Imager and the Helioseismic Magnetic Imager. In the context of similar measurements of quiet-Sun regions, three of the five studied active regions show strong phase travel time shifts several hours prior to emergence. These results form the basis of a discussion of noise in the derived phase travel time maps and possible criteria to distinguish between true and false-positive detection of emerging flux.

Identifier

85107679990 (Scopus)

Publication Title

Astrophysical Journal

External Full Text Location

https://doi.org/10.3847/1538-4357/abf2bf

e-ISSN

15384357

ISSN

0004637X

Issue

2

Volume

913

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