Smalley, B and Antoci, V and Holdsworth, DL and Kurtz, DW and Murphy, SJ and De Cat, P and Anderson, DR and Catanzaro, G and Collier Cameron, A and Hellier, C and Maxted, PFL and Norton, AJ and Pollacco, D and Ripepi, V and West, RG and Wheatley, PJ (2016) Pulsation versus metallicism in Am stars as revealed by LAMOST and WASP. Monthly Notices of the Royal Astronomical Society. ISSN 1365-2966

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Abstract

We present the results of a study of a large sample of A and Am stars with spectral types from LAMOST and light curves from WASP. We find that, unlike normal A stars, δ Sct pulsations in Am stars are mostly confined to the effective temperature range 6900<Teff<76006900<Teff<7600 K. We find evidence that the incidence of pulsations in Am stars decreases with increasing metallicism (degree of chemical peculiarity). The maximum amplitude of the pulsations in Am stars does not appear to vary significantly with metallicism. The amplitude distributions of the principal pulsation frequencies for both A and Am stars appear very similar and agree with results obtained from Kepler photometry. We present evidence that suggests turbulent pressure is the main driving mechanism in pulsating Am stars, rather than the κ-mechanism, which is expected to be suppressed by gravitational settling in these stars.

Item Type: Article
Additional Information: This is the published version of an article accepted for publication in Monthly Notices of the Royal Astronomical Society. The version of record Smalley, B. et al., 2016. Pulsation versus metallicism in Am stars as revealed by LAMOST and WASP. Monthly Notices of the Royal Astronomical Society, p.stw2903 is available online at: http://dx.doi.org/10.1093/mnras/stw2903
Uncontrolled Keywords: asteroseismology, stars, chemically peculiar stars, oscillations, variables, delta scuti techniques, photometric, astrophysics
Subjects: Q Science > QB Astronomy
Q Science > QC Physics
Divisions: Faculty of Natural Sciences > School of Physical and Geographical Sciences
Depositing User: Symplectic
Date Deposited: 15 Nov 2016 15:55
Last Modified: 20 Oct 2017 13:07
URI: http://eprints.keele.ac.uk/id/eprint/2478

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