The period-age relation of long-period variables

Abstract

Pieces of empirical evidence suggest the existence of a period-age relation for long-period variables (LPVs). Yet, this property has hardly been studied on theoretical grounds thus far. We aim to examine the period-age relation using the results from recent nonlinear pulsation calculations. We combined isochrone models with theoretical periods to simulate the distribution of fundamental mode LPV pulsators, which include Miras, in the period-age plane, and we compared it with observations of LPVs in Galactic and Magellanic Clouds' clusters. In agreement with observations, models predict that the fundamental mode period decreases with increasing age because of the dominant role of mass in shaping stellar structure and evolution. At a given age, the period distribution shows a non-negligible width and is skewed toward short periods, except for young C-rich stars. As a result, the period-age relations of O-rich and C-rich models are predicted to have different slopes. We derived best-fit relations describing age and initial mass as a function of the fundamental mode period for both O- and C-rich models. The study confirms the power of the period-age relations to study populations of LPVs of specific types, either O-rich or C-rich, on statistical grounds. In doing so, it is recommended not to limit a study to Miras, which would make it prone to selection biases, but rather to include semi-regular variables that pulsate predominantly in the fundamental mode. The use of the relations to study individual LPVs, on the other hand, requires more care given the scatter in the period distribution predicted at any given age.

Accepted for publication in A&A Letters; Main text: 5 pages, 6 figures, 2 tables. Three appendices. Replaced with language-revised version

References in corpus (17)

• Array Programming with NumPy
• Constraining the thermally-pulsing asymptotic giant branch phase with resolved stellar populations in the Small Magellanic Cloud
• A double main sequence turn-off in the rich star cluster NGC 1846 in the Large Magellanic Cloud
• Constraining the thermally pulsing asymptotic giant branch phase with resolved stellar populations in the Large Magellanic Cloud
• Extended Main Sequence Turnoffs in Intermediate-Age Star Clusters: A Correlation Between Turnoff Width and Early Escape Velocity
• The metallicity spread and the age-metallicity relation of Omega Centauri
• AGB Stars in the Fornax Dwarf Spheroidal Galaxy
• A new interpretation of the period-luminosity sequences of long-period variables
• Age Demographics of the Milky Way Disk and Bulge
• Carbon-Rich Mira Variables: Kinematics and Absolute Magnitudes
• Binarity as the Origin of Long Secondary Periods in Red Giant Stars
• Asymptotic Giant Branch Stars in the Phoenix Dwarf Galaxy
• Modelling Long-Period Variables -- II. Fundamental mode pulsation in the nonlinear regime
• Toward an internally consistent astronomical distance scale
• The AGB stars of the intermediate-age LMC cluster NGC 1846 Variability and age determination
• Star Clusters in the Magellanic Clouds-1: Parameterisation and Classification of 1072 Clusters in the LMC
• Updated theoretical Period-Age and Period-Age-Color relations for Galactic Classical Cepheids: an application to the Gaia DR2 sample

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