Survey of Li-rich giants among Kepler and LAMOST fields: Determination of Li-rich giants Evolutionary Phase
Autor: | Yerra Bharat Kumar, Bacham E. Reddy, H. M. Antia, Raghubar Singh |
---|---|
Jazyk: | angličtina |
Rok vydání: | 2019 |
Předmět: |
Physics
010504 meteorology & atmospheric sciences Phase (waves) FOS: Physical sciences Astronomy and Astrophysics Astrophysics 01 natural sciences Kepler LAMOST Large sample Astrophysics - Solar and Stellar Astrophysics Space and Planetary Science 0103 physical sciences Astrophysics::Solar and Stellar Astrophysics Astrophysics::Earth and Planetary Astrophysics 010303 astronomy & astrophysics Red clump Solar and Stellar Astrophysics (astro-ph.SR) Astrophysics::Galaxy Astrophysics 0105 earth and related environmental sciences Systematic search |
Popis: | In this letter, we report the discovery of 24 new super Li-rich (A(Li) $\ge$ 3.2) giants of He-core burning phase at red clump region. Results are based on systematic search of a large sample of about 12,500 giants common to the LAMOST spectroscopic and Kepler time resolved photometric surveys. The two key parameters derived from Kepler data; average period spacing ($\Delta p$) between $l=1$ mixed gravity dominated g-modes and average large frequency separation ($\Delta \nu$) $l=0$ acoustic p-modes, suggest all the Li-rich giants are in He-core burning phase. This is the first unbiased survey subjected to a robust technique of asteroseismic analysis to unambiguously determine evolutionary phase of Li-rich giants. The results provide a strong evidence that Li enhancement phenomenon is associated with giants of He-core burning phase, post He-flash, rather than any other phase on RGB with inert He-core surrounded by H-burning shell. Comment: 8 pages, 4 figures, Accepted in ApJL |
Databáze: | OpenAIRE |
Externí odkaz: |