On the Solar Origin of the Signal at 220.7 μHz: A Possible Component of a g-Mode?

Jiménez, A.; García, R. A.
Bibliographical reference

The Astrophysical Journal Supplement, Volume 184, Issue 2, pp. 288-297 (2009).

Advertised on:
10
2009
Number of authors
2
IAC number of authors
1
Citations
17
Refereed citations
12
Description
Gravity modes in the Sun have been the object of a long and difficult search in recent decades. Thanks to the data accumulated with the last generation of instruments (BiSON, GONG, and three helioseismic instruments aboard the Solar and Heliospheric Observatory (SOHO)), scientists have been able to find signatures of their presence. However, the individual detection of such modes remains evasive. In this article, we study the signal at 220.7 μHz which is a peak that is present in most of the helioseismic data of the last 10 years. This signal has already been identified as being a component of a g-mode candidate detected in the GOLF Doppler velocity signal. The nature of this peak is studied in particular using the VIRGO/SPM instrument aboard SOHO. First we analyze all the available instrumental data of VIRGO and SOHO (housekeeping) to reject any possible instrumental origin. No relation was found, implying that the signal has a solar origin. Using Monte Carlo simulations, we find, with more than 99% confidence level, that the signal found in VIRGO/SPM is very unlikely to be due to pure noise.
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