Related papers: Galaxies appear simpler than expected
The empirical laws of star formation suggest that galactic-scale gravity is involved, but they do not identify the actual triggering mechanisms for clusters in the final stages. Many other triggering processes satisfy the empirical laws…
Each galaxy is observed only once along its life, making galaxy evolution fundamentally an inverse statistical problem: time-dependent physics must be inferred from ensembles of single-epoch snapshots. To move beyond descriptive scaling…
The present-day globular cluster populations of galaxies reflect the cumulative effects of billions of years of galaxy evolution via such processes as mergers, tidal stripping, accretion, and in some cases the partial or even complete…
Properties of galaxies like their absolute magnitude and their stellar mass content are correlated. These correlations are tighter for close pairs of galaxies, which is called galactic conformity. In hierarchical structure formation…
It is widely believed that structure in the Universe evolves hierarchically, as primordial density fluctuations, amplified by gravity, collapse and merge to form progressively larger systems. The structure and evolution of X-ray clusters,…
The theory of structure formation predicts that galaxies form within extended massive dark matter halos built from smaller pieces that collided and merged, resulting in the hierarchy of galaxies, groups, and clusters observed today. Here we…
Galaxies are not uniformly distributed in space. On large scales the Universe displays coherent structure, with galaxies residing in groups and clusters on scales of ~1-3 Mpc/h, which lie at the intersections of long filaments of galaxies…
Galaxies can be characterized by many internal properties such as stellar mass, gas metallicity, and star-formation rate. We quantify the amount of cosmological and astrophysical information that the internal properties of individual…
Today we have numerous evidences that spirals evolve dynamically through various secular or episodic processes, such as bar formation and destruction, bulge growth and mergers, sometimes over much shorter periods than the standard galaxy…
The concept that stars form in the modern era began some 60 years ago with the key observation of expanding OB associations. Now we see that these associations are an intermediate scale in a cascade of hierarchical structures that begins on…
We present a simple heuristic model to demonstrate how feedback related to the galaxy formation process can result in a scale-dependent bias of mass versus light, even on very large scales. The model invokes the idea that galaxies form…
Globular clusters are compact, gravitationally bound systems of up to a million stars. The GCs in the Milky Way contain some of the oldest stars known, and provide important clues to the early formation and continuing evolution of our…
Astrocladistics, a methodology borrowed from biology, is an objective way of understanding galaxy diversity through evolutionary relationships. It is based on the evolution of all the available parameters describing galaxies and thus…
The formation of galaxies by gradual hierarchical co-assembly of baryons and cold dark matter halos is a fundamental paradigm underpinning modern astrophysics and predicts a strong decline in the number of massive galaxies at early cosmic…
The central problem of galaxy formation is understanding the cooling and condensation of gas in dark matter halos. It is now clear that to match observations this requires further physics than the simple assumptions of single phase gas…
When and how did galaxies form and their metals accumulate? Over the last decade, this has moved from an archeological question to a live investigation: there is now a broad picture of the evolution of galaxies in dark matter halos: their…
Star formation history shows a gradual decline since the last 8-9 Gyr (z=1). The bulk of present-day stellar mass and metal content was formed at redshifts lower than 2-3, which is consistent with a hierarchical scenario of galaxy…
According to the current understanding of cosmic structure formation, the precursors of the most massive structures in the Universe began to form shortly after the Big Bang, in regions corresponding to the largest fluctuations in the cosmic…
We use FIRE-2 cosmological zoom-in hydrodynamic simulations to investigate the co-evolution between Milky Way-size galaxies and their host dark matter halos. We find that the formation of these galaxies follows a two-phase pattern, with an…
In the current most plausible Cold Dark Matter (CDM) cosmology, larger clumps increase their mass by the progressive merger of smaller clumps. During the evolution, a several merger events, e.g., many minor and a few major merger events,…