Related papers: Fuel for Galaxy Disks
The Local Group member M33 is a pure disk galaxy bearing no prominent bulge or stellar halo. It constitutes a challenge for any hierarchical galaxy formation theory and an ideal laboratory for studying quiescent star formation. Using…
We discuss the main ingredients necessary to build models of chemical evolution of spiral galaxies and in particular the Milky Way galaxy. These ingredients include: the star formation rate, the initial mass function, the stellar yields and…
Our Galaxy is thought to have undergone an active evolutionary history dominated by star formation, the accretion of cold gas, and, in particular, mergers up to 10 gigayear ago. The stellar halo reveals rich fossil evidence of these…
Spiral galaxies appear to be dynamical systems whose disks are still forming at the current epoch and which continue to accrete mass. The presence of extraplanar gas in spirals indicates that galactic halos can contain at least part of the…
The circumgalactic medium (CGM) is fed by galaxy outflows and accretion of intergalactic gas, but its mass, heavy element enrichment, and relation to galaxy properties are poorly constrained by observations. In a survey of the outskirts of…
We present a dynamical model for the formation and evolution of a massive disk galaxy, within a growing dark halo whose mass evolves according to cosmological simulations of structure formation. The galactic evolution is simulated with a…
We use a series of high-resolution N-body simulations of a `Milky-Way' halo, coupled to semi-analytic techniques, to study the formation of our own Galaxy and of its stellar halo. Our model Milky Way galaxy is a relatively young system…
Potential condensed clouds of gas in the Galactic halo are examined in the context of the recent models of cooling, fragmenting clouds building up the baryonic mass of the Galaxy. 582 high-velocity clouds (HVCs) are defined as the potential…
The Galactic halo has a complex assembly history, which can be seen in its wealth of kinematic and chemical substructure. Globular clusters lose stars through tidal interactions with the Galaxy and cluster evaporation processes, meaning…
While studies of galaxy evolution generally focus on extensive HI surveys at large redshifts, we argue in this paper that the understanding of detailed physical processes that drive HI evolution in galaxies is equally important.…
New information on the relations between the Galactic disks, the halo, and satellite galaxies is being obtained from elemental abundances of stars having metallicities in the range -1.5 < [Fe/H] < -0.5. The first results for a sample of 26…
We study stellar-halo formation using six Milky Way-mass galaxies in FIRE-2 cosmological zoom simulations. We find that $5-40\%$ of the outer ($50-300$ kpc) stellar halo in each system consists of $\textit{in-situ}$ stars that were born in…
I review some of the evidences for dust in the Local Bubble and in galactic halos and show that a general mechanism based on radiation pressure is capable of evacuating dust grains from regions dominated by massive star energy input and…
Small values of lithium observed in a small, primitive, Galaxy-Halo star SDSS J102915 + 172927 cannot be explained using the standard cold dark matter CDM theory of star formation, but are easily understood using the Gibson/Schild 1996…
Gas that escapes from the Galactic disk, rises into the halo, cools and falls back, constitutes a "Galactic Fountain". Three-Dimensional simulations show that such a fountain model reproduces many of the features that have been observed in…
The stellar halos of large galaxies represent a vital probe of the processes of galaxy evolution. They are the remnants of the initial bouts of star formation during the collapse of the proto-galactic cloud, coupled with imprint of ancient…
A new idea is proposed for the origin of bulges in spiral galaxies. Numerical simulations for the protogalactic collapse suggest strongly that galactic bulges have been assembled from massive clumps formed in the galactic disks in their…
Formation process(es) of galactic bulges are not yet clarified although several mechanisms have been proposed. In a previous study, we suggested one possibility that galactic bulges have been formed from the cold gas inflowing through…
Galaxies can form in a sufficiently deep gravitational potential so that efficient gas cooling occurs. We estimate that such potential is provided by a halo of mass $M \gtsim M_{c} \approx 7.0 \times 10^{12} ~ (\Delta_{c}(z)…
The largest galaxies in the Universe reside in galaxy clusters. Using sensitive observations of carbon-monoxide, we show that the Spiderweb Galaxy -a massive galaxy in a distant protocluster- is forming from a large reservoir of molecular…