Synthetic photometry for carbon-rich giants. III. Tracing the sequence of mass-losing galactic C-type Miras

Abstract

With the help of model calculations we aim at reproducing the observational photometric findings for a large sample of well-characterised galactic C-type Mira variables losing mass at different rates. We used dynamic model atmospheres, describing the outer layers of C-rich Miras, which are severly affected by dynamic effects. Based on the resulting structures and under the assumptions of chemical equilibrium as well as LTE, we computed synthetic spectra and synthetic broad-band photometry (Johnson-Cousins-Glass). A set of five representative models with different stellar parameters describes a sequence from less to more evolved objects with steadily increasing mass-loss rates. This allowed us to study the significant influence of circumstellar dust on the spectral energy distributions and the (amplitudes of) lightcurves in different filters. We tested the photometric properties (mean NIR magnitudes, colours, and amplitudes) and other characteristics of the models (mass-loss rates, periods, and bolometric corrections) by comparing these with the corresponding observational data adopted from the literature. Using different kinds of diagrams we illustrate where the models are located in a supposed evolutionary sequence defined by observed C-type Mira samples. Based on comparisons of galactic targets with empirical relations derived for C stars in the Large Magellanic Cloud we discuss the relevance of metallicity and excess carbon (C--O) for the development of dust-driven winds. Having investigated the dynamic model atmospheres from different (mainly photometric) perspectives, we conclude that our modelling approach (meaning the combination of numerical method and a suitable choice of model parameters) is able to describe C-rich long-period variables over a wide range of mass-loss rates, i.e., from moderately pulsating objects without any dusty wind to highly dust-enshrouded Carbon Miras.

Accepted for publication in A&A

References in corpus (55)

• Final Results from the Hubble Space Telescope Key Project to Measure the Hubble Constant
• Evolution of asymptotic giant branch stars II. Optical to far-infrared isochrones with improved TP-AGB models
• Color Transformations for the 2MASS Second Incremental Data Release
• Age and Metallicity Distribution of the Galactic Bulge from Extensive Optical and Near-IR Stellar Photometry
• Self-similarity and scaling behavior of IR emission from radiatively heated dust: I. Theory
• AGB Variables and the Mira Period-Luminosity Relation
• Stellar Populations in the Large Magellanic Cloud from 2MASS
• Models of circumstellar molecular radio line emission: Mass loss rates for a sample of bright carbon stars
• Red Giant Branch stars: the theoretical framework
• Spitzer SAGE survey of the Large Magellanic Cloud II: Evolved Stars and Infrared Color Magnitude Diagrams
• Near-Infrared Photometry of Carbon Stars
• Luminosities and mass-loss rates of SMC and LMC AGB stars and Red Supergiants
• Synthetic photometry for carbon rich giants, I. Hydrostatic dust-free models
• Surveying the Agents of Galaxy Evolution in the Tidally-Stripped, Low Metallicity Small Magellanic Cloud (SAGE-SMC) II. Cool Evolved Stars
• Low-extinction windows in the inner Galactic Bulge
• Variable Stars in the Magellanic Clouds: Results from OGLE and SIRIUS
• The mid- and far-infrared colours of AGB and post-AGB stars
• Stellar populations in the Galactic bulge
• AGB stars in the Magellanic Clouds. II. The rate of star formation across the LMC
• The Mass-Loss Return From Evolved Stars to The Large Magellanic Cloud VI: Luminosities and Mass-Loss Rates on Population Scales
• A Review of the Distance and Structure of the Large Magellanic Cloud
• The AGB superwind speed at low metallicity
• A Spitzer mid-infrared spectral survey of mass-losing carbon stars in the Large Magellanic Cloud
• Extinction Map of the Galactic center: OGLE-II Galactic bulge fields
• Towards the absolute planes: a new calibration of the Bolometric Corrections and Temperature scales for Population II Giants
• AGB stars in the Magellanic Clouds. I. The C/M ratio
• Dust driven mass loss from carbon stars as a function of stellar parameters - I. A grid of Solar-metallicity wind models
• Line formation in AGB atmospheres including velocity effects. Molecular line profile variations of long period variables
• Synthetic Spectra and Color-Temperature Relations of M Giants
• The Mass-Loss Return From Evolved Stars to the LMC: Empirical Relations for Excess Emission at 8 and 24 μm
• The Red Giant Branch in Near-Infrared Colour-Magnitude Diagrams. II: The luminosity of the Bump and the Tip
• A new LMC K-band distance from precision measurements of nearby red clump stars
• The mass-loss return from evolved stars to the Large Magellanic Cloud V. The GRAMS carbon-star model grid
• The red tail of carbon stars in the LMC: Models meet 2MASS and DENIS observations
• 2-Dust : a Dust Radiative Transfer Code for an Axisymmetric System
• Mira Variables in the OGLE Bulge fields
• Spitzer spectroscopy of carbon stars in the Small Magellanic Cloud
• Long period variables in 47 Tuc: direct evidence for lost mass
• The Mass-Loss Return from Evolved Stars to the Large Magellanic Cloud IV: Construction and Validation of a Grid of Models for Oxygen-Rich AGB Stars, Red Supergiants, and Extreme AGB Stars
• Long Period Variables in the Magellanic Clouds: OGLE + 2MASS + DENIS
• An Upper Limit to the Age of the Galactic Bar
• Intense Mass Loss from C-rich AGB Stars at low Metallicity?
• Period-Magnitude relation of Mira-like variables in the Large Magellanic Cloud as a tool to understand circumstellar extinction
• Variable Evolved Stars and YSOs Discovered in the Large Magellanic Cloud using the SAGE Survey
• Atmospheric dynamics in carbon-rich Miras. I. Model atmospheres and synthetic line profiles
• Synthetic photometry for carbon-rich giants II. The effects of pulsation and circumstellar dust
• The VMC survey III. Mass-loss rates and luminosities of LMC AGB stars
• Atmospheric dynamics in carbon-rich Miras. II. Models meet observations
• Mira variables in the Galactic bulge with OGLE-II data
• A study of bright Southern Long Period Variables
• Evidence of a link between the evolution of clusters and their AGN fraction
• Long-period variables in NGC147 and NGC185
• Interferometric properties of pulsating C-rich AGB stars I. Intensity profiles and uniform disc diameters of dynamic model atmospheres
• Australia Telescope Compact Array imaging of circumstellar HCN line emission from R Scl
• Uncertainties and systematics in stellar evolution models of Red Giant Stars

Cited by in corpus (21)

• Luminosities and mass-loss rates of Local Group AGB stars and Red Supergiants
• Synthetic photometry for carbon-rich giants. IV. An extensive grid of dynamic atmosphere and wind models
• The UK Infrared Telescope M33 monitoring project. III. Feedback from dusty stellar winds in the central square kiloparsec
• Symbiotic stars and other Halpha emission line stars towards the Galactic Bulge
• Is there a metallicity ceiling to form carbon stars? - A novel technique reveals a scarcity of C stars in the inner M31 disk
• The mass-loss, expansion velocities and dust production rates of carbon stars in the Magellanic Clouds
• Exploring the origin of clumpy dust clouds around cool giants. A global 3D RHD model of a dust-forming M-type AGB star
• Carbon stars in the X-shooter Spectral Library
• Dust-driven winds of AGB stars: The critical interplay of atmospheric shocks and luminosity variations
• Abundance analysis for long-period variables II. RGB and AGB stars in the globular cluster 47\,Tuc
• Carbon stars with increased oxygen and nitrogen abundances: hydrostatic dust-free model atmospheres
• Carbon Stars in the Satellites and Halo of M31
• The adventure of carbon stars - Observations and modelling of a set of C-rich AGB stars
• The curious case of II Lup: a complex morphology revealed with SAM/NACO and ALMA
• LX Cygni: A carbon star is born
• Constraining stellar parameters and atmospheric dynamics of the carbon AGB star V Oph
• Synthetic photometry for carbon-rich giants. V. Effects of grain-size-dependent dust opacities
• Effects of Metallicity on Graphite, TiC, and SiC Condensation in Carbon Stars
• Dynamical Mass Loss at the End of TP-AGB stars
• 3D models of the circumstellar environments of evolved stars: Formation of multiple spiral structures
• Carbon stars in the X-Shooter Spectral Library: II. Comparison with models