Related papers: The X-ray Evolution of Merging Galaxies
This white paper is motivated by open questions in star formation, which can be uniquely addressed by high resolution X-ray imaging and require an X-ray observatory with large collecting area along good spectral resolution. A complete…
We investigate the magnetic field evolution in a series of galaxy minor mergers using the N-body/smoothed particle hydrodynamics (SPH) code \textsc{Gadget}. The simulations include the effects of radiative cooling, star formation and…
Today's sensitive, high-resolution X-ray observations allow the study of populations of X-ray sources, in the luminosity range of Galactic X-ray binaries, in galaxies as distant as 20-30 Mpc. The traditional astronomical tools of…
High redshift galaxies permit the study of the formation and evolution of X-ray binary populations on cosmological timescales, probing a wide range of metallicities and star-formation rates. In this paper, we present results from a large…
The galaxy evolution is believed to be conditioned by the environment. Isolated galaxies or galaxies in poor groups are an excellent laboratory to study evolutionary mechanisms where effects of the environment are minimal. We present new…
Cosmological simulations predict that early-type galaxies (ETGs) are the results of extended mass accretion histories. The latter are characterized by different numbers of mergers, mergers mass ratios and gas fractions, and timing.…
Available data on the magnesium - velocity dispersion (Mg-sigma) relation for \~2000 early-type galaxies is collected and compared. As noted previously, the Mg residuals from a fitted line are roughly Gaussian near the mean but have an…
Observations indicate that much of the interstellar gas in merging galaxies may settle into extended gaseous disks. Here, I present simulations of disk formation in mergers of gas-rich galaxies. Up to half of the total gas settles into…
We simulate mergers between galaxies containing collisionally-relaxed nuclei around massive black holes (MBHs). Our galaxies contain four mass groups, representative of old stellar populations; a primary goal is to understand the…
I review the major surveys of high redshift galaxies observed using integral field spectroscopy techniques in the visible and in the infrared. The comparison of various samples has to be done with care since they have different properties…
We discuss how the conditions at high redshift differ from those at low redshift, and what the impact is on the galaxy population. We focus in particular on the role of gaseous dissipation and its impact on sustaining high star formation…
Can the present dynamics of spiral galaxies tell us something about the merging history, the formation and evolution of disks? Galaxy interactions thicken or destroy disks; the simultaneous presence of thick and thin disks is a tracer of…
A search was conducted for a hot intragroup medium in 109 low-redshift galaxy groups observed with the ROSAT PSPC. Evidence for diffuse, extended X-ray emission is found in at least 61 groups. Approximately one-third of these detections…
Comparison of the high resolution X-ray ROSAT HRI image of A2218 with the optical HST image shows several interesting correlations. The X-ray emission within a 1' radius core is resolved into several components; the central dominant galaxy…
Galaxy clusters are hotter and more X-ray luminous than in quiescence while they undergo major mergers, which also transiently increase their strong-lensing efficiency. We use semi-analytic models for both effects to study how cluster…
We have undertaken a large set of simulations of galaxy interactions and mergers (GalMer Project) in order to study the physical processes related to galaxy encounters. All morphological types along the Hubble sequence are considered in the…
Massive quiescent galaxies at high redshift are significantly more compact than their present-day counterparts. We investigate the roles, in determining this evolution, of major and minor mergers, and of the accretion of diffuse envelopes…
We study galaxy mergers with various mass ratios using N-body simulations, with an emphasis on the unequal-mass mergers in the relatively unexplored range of mass-ratios 4:1-10:1. Our recent work (Bournaud et al. 2004) shows that the above…
Elliptical galaxies formed in a major merger tend to become more nearly spherical with time, thanks to the gravitational effect of their central black hole (or black holes). Observational results indicate that elliptical galaxies with older…
Clusters of galaxies generally form by the gravitational merger of smaller clusters and groups. Major cluster mergers are the most energetic events in the Universe since the Big Bang. The basic properties of cluster mergers and their…