Related papers: Massive Stars: Key to Solving the Cosmic Puzzle
Massive stars are at the core of our observations of the Universe up to the reionization epoch, both through their intense ionizing fluxes and through the energetic end products that release fresh elements into the interstellar medium. Our…
This article presents recent work to constrain the physical and chemical properties in high-mass star formation based largely on interferometric high-spatial-resolution continuum and spectral line studies at (sub)mm wavelengths. After…
Large telescopes have allowed astronomers to observe galaxies that formed as early as 850 million years after the Big Bang. We predict when the first star that astronomers can observe formed in the universe, accounting for the first time…
Cloud environment is thought to play a critical role in determining the mechanism of formation of massive stars. In this contribution we review the physical characteristics of the environment around recently formed massive stars. Particular…
Massive stars have a profound influence on the Universe, but their formation remains poorly understood. We review the current status of observational and theoretical research in this field, describing the various stages of an evolutionary…
Star formation occurs on physical scales corresponding to individual star forming regions, typically of order ~100 parsecs in size, but current observational facilities cannot resolve these scales within field galaxies beyond the local…
The formation of the first stars and the subsequent population of X-ray binaries represents a fundamental transition in the state of the Universe as it evolves from near homogeneity to being abundant in collapsed structures such as…
All measurements of cosmic star formation must assume an initial distribution of stellar masses -- the stellar initial mass function -- in order to extrapolate from the star-formation rate measured for typically rare, massive stars (> 8…
The first stars are believed to have formed a few hundred million years after the big bang in so-called dark matter minihalos with masses ~10^6 M_sun. Their radiation lit up the Universe for the first time, and the supernova explosions that…
Despite their paucity, massive hot stars are real cosmic engines of fundamental importance in shaping our Universe, from its very early stages up to its current appearance. Understanding the physics of massive stars is then a key issue for…
Star formation is a multi-scale, multi-physics problem ranging from the size scale of molecular clouds ($\sim$10s pc) down to the size scales of dense prestellar cores ($\sim$0.1 pc) that are the birth sites of stars. Several physical…
The observable characteristics and subsequent evolution of young stellar populations is dominated by their massive stars. As our understanding of those massive stars and the factors affecting their evolution improves, so our interpretation…
The formation environment of stars in massive stellar clusters is similar to the environment of stars forming in galaxies at a redshift of 1 - 3, at the peak star formation rate density of the Universe. As massive clusters are still forming…
We summarize some of the compelling new scientific opportunities for understanding stars and stellar systems that can be enabled by sub-milliarcsec (sub-mas) angular resolution, UV-Optical spectral imaging observations, which can reveal the…
Stars and planets are the fundamental objects of the Universe. Their formation processes, though related, may differ in important ways. Stars almost certainly form from gravitational collapse and probably have formed this way since the…
Observations of star-forming galaxies in the distant Universe (z > 2) are starting to confirm the importance of massive stars in shaping galaxy emission and evolution. Inevitably, these distant stellar populations are unresolved, and the…
We consider some aspects of the evolution of massive stars which can only be elucidated by means of "indirect" observations, i.e. measurements of the effects of massive stars on their environments. We discuss in detail the early evolution…
Background: low-mass stars are the dominant product of the star formation process, and they trace star formation over the full range of environments, from isolated globules to clusters in the central molecular zone. In the past two decades,…
The determination of chemical abundances in star-forming galaxies and the study of their evolution on cosmological timescales are powerful tools for understanding galaxy formation and evolution. This contribution presents the latest results…
Massive galaxies, such as nearby ellipticals, have relatively low number densities, yet they host the majority of the stellar mass in the universe. Understanding their origin is a central problem of galaxy formation. Age dating of stellar…