The universe has been expanding ever since, so astronomers are able to age galaxies by computing how much. the wavelength of their light has stretched―or redshifted―as the expansion takes the galaxies farther from Earth. The redder the light is, the older and more distant the galaxy is. ...
~ 1. The host\ngalaxies span a range of luminosities and morphologies, and appear to be\nbroadly typical for the normal, evolving, actively star-forming galaxy\npopulations at comparable redshifts and magnitudes, but may have somewhat\nelevated SFR per unit luminosity. There are also spectrosco...
We determine the redshift evolution of the RLF under the assumption that its overall shape does not change with redshift. Our results are consistent with a pure luminosity evolution of the RLF in the range 0.1 < z < 0.3 from the optical cluster sample. The X-ray sample extends to higher...
From a survey for redshifted HI 21-cm and OH 18-cm absorption in the hosts of a sample of radio galaxies and quasars, we detect HI in three of the ten and OH in none of the fourteen sources for which useful data were obtained. As expected from our recent result, all of the 21-...
Although starburst galaxies have relatively flat spectral energy distributions, their strong optical emission lines and near-UV continua make it very feasible to estimate their redshifts photometrically. In this work, I describe a photometric technique that simultaneously (1) identifies galaxies by star...
If the TD1 results are correct, the large ultraviolet flux, which is now considerably closer to the U band, suggests the possibility of detecting more distant galaxies with deep ultraviolet plates than the usual deep B, V or R plates, since this region of high flux will be redshifted ...
We study the growth of galaxy masses, via gas accretion and galaxy mergers. We introduce a toy model that describes (in a single equation) how much baryonic mass is accreted and retained into galaxies as a function of halo mass and redshift. In our model
The global star formation rate in high redshift galaxies, based on optical surveys, shows a strong peak at a redshift of z=1.5, which implies that we have already seen most of the formation. High redshift galaxies may, however, emit most of their energy at submillimeter wavelengths if ...
They are on average about 0.6 mag brighter than BL Lac host galaxies at indicative of evolution, whereas their half-light radii are similar. By combining our data with literature data at low-redshift and applyingevolutionary models to them, we show that the properties of the host galaxiesof ...
Although these nebulae glow in the visible band, the light has been greatly redshifted into the infrared by the expansion of the universe to be detectable by Spitzer. It found that the early galaxies produced much more ionizing radiation that do modern galaxies. A detailed analysis of these ...