相关论文: Lyalpha heating and its impact on early structure …
X-ray emission from hot (T = 10^7 K) interstellar gas in massive elliptical galaxies indicates that 10^{10} M_sun has cooled over a Hubble time, but optical and radio evidence for this cold gas is lacking. We provide detailed theoretical…
Statistical sampling from the stellar initial mass function (IMF) for all star-forming regions in the Galaxy would lead to the prediction of ~1000 Msun stars unless there is a rapid turn-down in the IMF beyond several hundred solar masses.…
The first phase of stellar evolution in the history of the universe may be Dark Stars, powered by dark matter heating rather than by fusion. Weakly interacting massive particles, which are their own antiparticles, can annihilate and provide…
We determine the thermal evolution of the intergalactic medium (IGM) over $3\, \mathrm{Gyr}$ of cosmic time $1.8<z<5.4$ by comparing measurements of the Ly{\alpha} forest power spectrum to a suite of $\sim70$ hydrodynamical simulations. We…
It is well established that the [alpha/Fe] ratios in elliptical galaxies increase with galaxy mass. This relation holds also for early-type dwarf galaxies, although it seems to steepen at low masses. The [alpha/Fe] vs. mass relation can be…
Chemical and photometric models of elliptical galaxies with infall of primordial gas, and subsequent ejection of processed material via galactic winds, are described. Ensuring that these models are consistent with the present-day…
In this paper, we present a new derivation of the shape and evolution of the integrated galaxy-wide initial mass function (IGIMF), incorporating explicitly the effects of cosmic rays (CRs) as regulators of the chemical and thermal state of…
Observations of the Lyman-alpha forest and of high-redshift galaxies at z~5-10 imply that there were just enough photons to maintain the universe in an ionized state at z~5-6, indicating a "photon-starved" end to reionization. The ionizing…
The tentative detection by the EDGES experiment of a global 21-cm absorption trough centered at redshift 17 opens up the opportunity to study the birth of the first luminous sources, the intensity of radiation backgrounds at cosmic dawn,…
We use detailed Lyalpha radiative transfer calculations to further test the claim of Rauch et al. (2008) that they have detected spatially extended faint Lyalpha emission from the elusive host population of Damped Lyalpha Absorption systems…
This work presents and releases a catalog of new photometrically-derived physical properties for the $\sim 10^5$ most well-measured galaxies in the COSMOS field on the sky. Using a recently developed technique, spectral energy distributions…
The recent measurement by WMAP of a large electron scattering optical depth tau_e = 0.17 +- 0.04 is consistent with a simple model of reionization in which the intergalactic medium (IGM) is ionized at redshift z ~ 15, and remains highly…
Observational studies are showing that the galaxy-wide stellar initial mass function are top-heavy in galaxies with high star-formation rates (SFRs). Calculating the integrated galactic stellar initial mass function (IGIMF) as a function of…
We determine an absolute calibration of the initial mass function (IMF) of early-type galaxies, by studying a sample of 56 gravitational lenses identified by the SLACS Survey. Under the assumption of standard Navarro, Frenk & White dark…
There is mounting evidence that the stellar initial mass function (IMF) could extend much beyond the canonical Mi ~100, Msun limit, but the impact of such hypothesis on the chemical enrichment of galaxies still remains to be clarified. We…
Primordial magnetic fields (PMF) damp at scales smaller than the photon diffusion and free-streaming scale. This leads to heating of ordinary matter (electrons and baryons), which affects both the thermal and ionization history of our…
The formation of the first galaxies is accompanied by large accretion flows and virialization shocks, during which the gas is shock-heated to temperatures of $\sim10^4$ K, leading to potentially strong fluxes in the Lyman alpha line.…
A method is presented here for investigating variations in the upper end of the stellar Initial Mass Function (IMF) by probing the production rate of ionizing photons in unresolved, compact star clusters with ages<10 Myr and covering a…
Cosmological simulations show that, at the present time, a substantial fraction of the gas in the intergalactic medium (IGM) has been shock-heated to T>10^5 K. Here we develop an analytic model to describe the fraction of shocked,…
We have assembled a sample of high spatial resolution far-UV (Hubble Space Telescope Advanced Camera for Surveys Solar Blind Channel) and Halpha (Maryland-Magellan Tunable Filter) imaging for 15 cool core galaxy clusters. These data provide…