Letters of Intent received in 2013

LoI 2015-222
Focus Meeting: The Impact of Massive Binaries throughout the Universe

Topics

(i) Origin of the high multiplicity of massive stars
- Constraints on the primordial binary properties
- Advances in the theory of massive star formation

(ii) Physics of binary interaction
- Advances and challenges for computational models
- Direct and indirect observational constraints

(iii) Post-interaction and final stages
- Modeling the late stages of evolution
- Constraints from transient surveys

(iv) The cosmological implications.
- Stellar population synthesis applied to the low-to-high redshift universe
- Feedback from massive (X-ray) binaries throughout cosmic times

Rationale

Massive stars have a dual role in the Universe and in astrophysics: as cosmic engines (IAUS250) and as cosmological probes (IAUS 279). A wide variety of astrophysical problems thus rely on the input of models of massive stars. Most of these models treat single stars, but the overwhelming majority of massive stars are now observed to be in higher multiplicity systems.

The last years have further seen growing evidence that the idealized picture of a single massive star living its life in isolation is oversimplified: a very significant – possibly dominant – fraction of all massive stars will experience interaction with a binary companion before its final explosion as a supernova or gamma-ray burst. It is evident that such interaction has drastic consequences for further evolution and final fate of both components. However, the exploration of these effects on entire stellar populations, – nearby and at high redshift – is still in its infancy.

A key objective of this focus meeting is to bridge the gap between the massive stars and extragalactic communities, to explore how binarity affects the role of massive stars as Cosmic Engines (through radiative, mechanical and chemical feedback) and as Cosmic Probes (in star forming galaxies, through their bright explosions and to probe the extreme physics of compact objects).

This focus meeting will exploit the new statistical constraints that are currently coming available from large spectroscopic surveys and automated transient surveys and confront them with recent computational advances (in depth multidimensional modeling of binary interaction, large-scale simulations of stellar populations). During this meeting, envisioned to last for three days, we intent to share expertise beyond the borders of the traditional communities and address the following topics:

(i) Origin of the high multiplicity of massive stars
- Constraints on the primordial binary properties
- Advances in the theory of massive star formation
(ii) Physics of binary interaction
- Advances and challenges for computational models
- Direct and indirect observational constraints
(iii) Post-interaction and final stages
- Modeling the late stages of evolution
- Constraints from transient surveys
(iv) The cosmological implications.
- Stellar population synthesis (with binaries) applied to the low-to-high redshift universe
- Feedback from massive (X-ray) binaries throughout cosmic times

The proposed Focus Meeting is of interest across commissions C26 Double and multiple stars, C27 Variable stars, C29 Stellar Spectra, C35 Stellar constitution, C36 Theory of stellar atmosphere, C37 Star Clusters & Associations, C42 Close binary star, C44 Space and high-energy astrophysics, C47 Cosmology and C54 Optical and IR interferometry. This letter of intent is cosigned by active scientists from these different fields and has the official support of IAU Division G Stars, and Stellar physics, and of the Massive Star working group. The full scientific program along with the details of the proposal will be provided by December 15.