Related papers: The Intergalactic Medium
During the last decade, numerous and varied observations, along with increasingly sophisticated numerical simulations, have awakened astronomers to the central role the circumgalactic medium (CGM) plays in regulating galaxy evolution. It…
We present an argument for a {\it lower limit} to the Compton-$y$ parameter describing spectral distortions of the cosmic microwave background (CMB). The absence of a detectable Gunn-Peterson signal in the spectra of high redshift quasars…
The modeling of galaxy formation and reionization, two central issues of modern cosmology, relies on the accurate follow-up of the intergalactic medium (IGM). Unfortunately, owing to the complex nature of this medium, the differential…
I present a review by epoch of baryons in the intergalactic medium (IGM), from the first star until today. Recent observations indicate a protracted period of reionization, suggesting multiple populations of reionizers; detection of these…
The warm-hot intergalactic medium (warm-hot IGM, or WHIM) pervades the filaments of the Cosmic Web and harbours half of the Universe's baryons. The WHIM's thermodynamic properties are notoriously hard to measure. Here we estimate a galaxy…
The angular power spectrum and polarization of the cosmic microwave background radiation (CMB), the relative abundances of primordial hydrogen, deuterium and helium isotopes, and the large-scale structure of the universe all indicate that…
In this white paper, we summarize current observations of the baryon census at low redshift (Shull, Smith, & Danforth 2012). Measurements of Lya, O-VI, and broad Lya absorbers, together with more careful corrections for metallicity and…
The circumgalactic medium (CGM) plays a crucial role in galaxy evolution as it fuels star formation, retains metals ejected from the galaxies, and hosts gas flows in and out of galaxies. For Milky Way-type and more massive galaxies, the…
In this paper we review the current predictions of numerical simulations for the origin and observability of the warm hot intergalactic medium (WHIM), the diffuse gas that contains up to 50 per cent of the baryons at z~0. During structure…
Observations of interstellar gas and dust towards nearby stars and within the solar system show that the Sun is embedded in a warm diffuse partially-ionized cloud. This cloud is the leading edge of a flow of interstellar matter (ISM)…
We use a particle tracking analysis to study the origins of the circumgalactic medium (CGM), separating it into (1) accretion from the intergalactic medium (IGM), (2) wind from the central galaxy, and (3) gas ejected from other galaxies.…
The distribution of diffuse gas in the intergalactic medium (IGM) imprints a series of hydrogen absorption lines on the spectra of distant background quasars known as the Lyman-$\alpha$ forest. Cosmological hydrodynamical simulations…
Standard big bang nucleosynthesis predicts the average baryon density of the Universe to be a few percent of the critical density. Only about one tenth of the predicted baryons have been seen. A plausible respository for the missing baryons…
Recent years have seen major advances in understanding the state of the intergalactic medium (IGM) at high redshift. Some aspects of this understanding are reviewed here. In particular, we discuss: (1) Different probes of IGM like…
The development of our understanding of the gaseous component of the interstellar medium is reviewed. During the 20th century our picture of diffuse material in space has grown from a simple model of isolated clouds in thermal equilibrium…
A major goal of observational and theoretical cosmology is to observe the largely unexplored time period in the history of our universe when the first galaxies form, and to interpret these measurements. Early galaxies dramatically impacted…
The thermal evolution of the intergalactic medium (IGM) can serve as a sensitive probe of cosmological heat sources and sinks. We employ it to limit interactions between dark matter and baryons. After reionization the IGM temperature is set…
The majority of baryons reside beyond the optical extent of a galaxy in the circumgalactic and intergalactic media (CGM/IGM). Gaseous halos are inextricably linked to the appearance of their host galaxies through a complex story of…
Ionization balance in the intergalactic medium (IGM) is central to the interpretation of quasar absorption spectra, linking observed ionic columns to the underlying gas density, temperature, metallicity, and ionizing radiation field.…
The enrichment of the intergalactic medium with heavy elements is a process that lies at the nexus of poorly-understood aspects of physical cosmology. We review current understanding of the processes that may remove metals from galaxies,…