The stellar mass assembly of galaxies in the Illustris simulation: growth by mergers and the spatial distribution of accreted stars. Spitzer observations of massive, red galaxies at high redshift. The sizes of massive quiescent and star-forming galaxies at z ∼ 4 with ZFOURGE and CANDELS. A substantial population of massive quiescent galaxies at z ∼ 4 from ZFOURGE. SPT0346–52: negligible AGN activity in a compact, hyper-starburst galaxy at z = 5.7. A dust-obscured massive maximum-starburst galaxy at a redshift of 6.34. A massive proto-cluster of galaxies at a redshift of z ∼ 5.3. Luminosity function of emission-line galaxies in the MassiveBlack-II simulation. MUFASA: galaxy formation simulations with meshless hydrodynamics. (submitted) preprint at (2016)ĭavé, R., Thompson, R. The most massive galaxies and black holes allowed by ΛCDM. The formation of massive, compact galaxies at z = 2 in the Illustris simulation. Stellar populations from spectroscopy of a large sample of quiescent galaxies at Z > 1: measuring the contribution of progenitor bias to early size growth. The early early type: discovery of a passive galaxy at zspec ∼ 3. Superdense passive galaxies: how did they form and evolve? Astron. GMASS ultradeep spectroscopy of galaxies at z ∼ 2. Evolved galaxies at z > 1.5 from the Gemini Deep Deep Survey: the formation epoch of massive stellar systems. The early formation of such massive systems implies that our picture of early galaxy assembly requires substantial revision.ĭunlop, J. This ancestral starburst appears similar to those being found by submillimetre-wavelength surveys 11, 12, 13, 14. These observations demonstrate that the galaxy must have formed the majority of its stars quickly, within the first billion years of cosmic history in a short, extreme starburst. We derive its age to be nearly half the age of the Universe at this redshift and the absorption line spectrum shows no current star formation. Here we report the spectroscopic confirmation of one such galaxy at redshift z = 3.717, with a stellar mass of 1.7 × 10 11 solar masses. However, these early, massive, quiescent galaxies are not predicted by the latest generation of theoretical models 7, 8, 9, 10. Deeper surveys have reported evidence for populations of massive, quiescent galaxies at even higher redshifts and earlier times, using coarsely sampled photometry. Their age and formation processes have now been explained by an improved generation of galaxy-formation models 7, 8, 9, in which they form rapidly at z ≈ 3–4, consistent with the typical masses and ages derived from their observations. These surveys have revealed the presence of massive, quiescent early-type galaxies 1, 2, 3, 4, 5, 6 appearing as early as redshift z ≈ 2, an epoch three billion years after the Big Bang. (Their width indicates that they do not have the same speed).Finding massive galaxies that stopped forming stars in the early Universe presents an observational challenge because their rest-frame ultraviolet emission is negligible and they can only be reliably identified by extremely deep near-infrared surveys. Narrows lines all forbidden such as the lines, and which are present in the galaxy but not in the accretion disk.Measuring the FWHM of these lines (see calculation above) makes it possible to calculate the rotational velocity of this disc, more wider is the line, greater is the rotational velocity. Wide hydrogen lines of the Balmer series (Hα, Hβ, Hγ and Hδ) which correspond to the matter of the accretion disk in rapid rotation around the black hole, a dense region where only permited lines can exist.On the spectrum, there are 2 types of emission lines : To calculate the redshift of the galaxy, we will measure the shift of each line identified in wavelength (λ1) and will be compared with the respective value of each line “at rest” (λ0) With c, the speed of light in km/s, Δλ the width of the line in Ångström and λ the nominal wavelength of the line (for example Hα = 6562,82 Å).
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