2022ApJ...940L..25M -
Astrophys. J., 940, L25 (2022/November-3)
A Segmented Period-Luminosity Relation for Nearby Extragalactic Delta Scuti Stars.
MARTINEZ-VAZQUEZ C.E., SALINAS R., VIVAS A.K. and CATELAN M.
Abstract (from CDS):
The period-luminosity relations (PLRs) of Milky Way δ Scuti (δ Sct) stars have been described to the present day by a linear relation. However, when studying extragalactic systems such as the Magellanic Clouds and several dwarf galaxies, we notice for the first time a nonlinear behavior in the PLR of δ Sct stars. Using the largest sample of ∼3700 extragalactic δ Sct stars from data available in the literature-mainly based on the Optical Gravitational Lensing Experiment and the Super MAssive Compact Halo Object project in the Large Magellanic Cloud (LMC)-we obtain that the best fit to the period-luminosity (MV) plane is given by the following piecewise linear relation with a break at logP = -1.03 ± 0.01 (or 0.093 ± 0.002 days) for shorter periods (sp) and longer periods (lp) than the break-point: \begin{eqnarray*}{M}_{V}^{\mathrm{sp}}=-7.08(\pm 0.25)\mathrm{log}P-5.74(\pm 0.29);\quad \mathrm{log}P\lt -1.03\end{eqnarray*} \begin{eqnarray*}{M}_{V}^{\mathrm{lp}}={M}_{V}^{\mathrm{sp}}+4.38(\pm 0.32)\cdot (\mathrm{log}P+1.03(\pm 0.01));\quad \mathrm{log}P\geqslant -1.03.\end{eqnarray*} Geometric or depth effects in the LMC, metallicity dependence, or different pulsation modes are discarded as possible causes of this segmented PLR seen in extragalactic δ Sct stars. The origin of the segmented relation at ∼0.09 days remains unexplained based on the current data.
Abstract Copyright:
© 2022. The Author(s). Published by the American Astronomical Society.
Journal keyword(s):
Delta Scuti variable stars - SX Phoenicis variable stars - Variable stars - Dwarf galaxies - Globular star clusters
Simbad objects:
15
Full paper
View the references in ADS
To bookmark this query, right click on this link: simbad:2022ApJ...940L..25M and select 'bookmark this link' or equivalent in the popup menu