The impact of binary stars on the colors of high-redshift galaxies

Abstract

Evolutionary population synthesis (EPS) models play an important role in many studies on the formation and evolution of galaxies. Most EPS models are still poorly calibrated for certain stellar evolution stages, especially for the treatment of binary stars, which are very different from single stars. We aim to present color-magnitude (C-M) and color-color (C-C) relations for passive model galaxies in the redshift z$\sim 0.0-3.0$ and to study the effect of binary interactions on these relations for high-redshift passive galaxies. Assuming exponentially declining star formation rate, we used a set of theoretical galaxy templates obtained from Yunnan EPS models (with and without binary interactions) to present the C-M and C-C relations for passive galaxies via Monte Carlo simulation. In Yunnan EPS models with binary interactions, various processes are included, such as mass transfer, mass accretion, common-envelope evolution, collisions, supernova kicks, tidal evolution, and all angular momentum loss mechanisms. In these models, approximately 50 per cent of the stellar systems are binary systems with orbital periods less than 100\,yr. This fraction is a typical value for the Milky Way. We find that the inclusion of binary interactions in the model galaxies' spectra can dramatically alter the predicted C-M and C-C relations and their evolution with redshift. For $z\sim 0.0$ and $1.0$, the binary interactions have a minor effect on the C-M and C-C relations, but at $z\sim 2.0$ and $3.0$ the binary interactions have a major effect on the C-M and C-C relations. Especially for the redshift $z\sim 2.0$, the $g-$band magnitude becomes smaller by $1.5$\,mag, the $g-r$ color becomes bluer by $1.0$\,mag, and the $u-g$ color becomes redder by $1.0$\,mag when binary interactions are included.

References in corpus (16)

• The propagation of uncertainties in stellar population synthesis modeling I: The relevance of uncertain aspects of stellar evolution and the IMF to the derived physical properties of galaxies
• An ultra-deep near-infrared spectrum of a compact quiescent galaxy at z=2.2
• Evolution of asymptotic giant branch stars I. Updated synthetic TP-AGB models and their basic calibration
• A binary model for the UV-upturn of elliptical galaxies (MNRAS version)
• The fraction of binary systems in the core of thirteen low-density Galactic globular clusters
• The role of minor mergers in the recent star formation history of early-type galaxies
• The Detection of a Red Sequence of Massive Field Galaxies at z~2.3 and its Evolution to z~0
• Biases and Uncertainties in Physical Parameter Estimates of Lyman Break Galaxies from Broad-band Photometry
• Dynamical population synthesis: Constructing the stellar single and binary contents of galactic field populations
• Inclusion of Binaries in Evolutionary Population Synthesis
• Color Distributions, Number and Mass Densities of Massive Galaxies at 1.5 < z < 3: Comparing Observations with Merger Simulations
• The initial period function of late-type binary stars and its variation
• Passive and star-forming galaxies at $1.4\le z\le 2.5$ in the Aegis field
• Integrated Spectral Energy Distributions and Absorption Feature Indices of Single Stellar Populations
• Testing three derivative methods of stellar population synthesis models
• A Library of Lick/IDS Indices for Binary Stellar Populations

Cited by in corpus (3)

• Stellar Population Effects on the Inferred Photon Density at Reionization
• Efficient early stellar feedback can suppress galactic outflows by reducing supernova clustering
• The effects of binary interactions on parameter determinations for early-type galaxies