Discovery of an Unusual Optical Transient with the Hubble Space
... slight evidence for emission at 6563 Å in the Keck spectrum, this is not seen in the VLT or Subaru spectra.) The absorption feature at 5890 Å is consistent with Na i λλ5890, 5896. Although the combination of Hγ, Hβ, and Na i consistently fits three of the observed features, the strong feature at 5 ...
... slight evidence for emission at 6563 Å in the Keck spectrum, this is not seen in the VLT or Subaru spectra.) The absorption feature at 5890 Å is consistent with Na i λλ5890, 5896. Although the combination of Hγ, Hβ, and Na i consistently fits three of the observed features, the strong feature at 5 ...
Cosmological dynamics with non-minimally coupled scalar field and
... R in the Einstein-Hilbert action is replaced by some function of R. Such modification has a theoretical motivation for example from the quantum field theory in curved spacetime. f ( R) theories are also widely used as an alternative explanation of the dark energy phenomena which places them amongst ...
... R in the Einstein-Hilbert action is replaced by some function of R. Such modification has a theoretical motivation for example from the quantum field theory in curved spacetime. f ( R) theories are also widely used as an alternative explanation of the dark energy phenomena which places them amongst ...
Galaxy formation in the Planck cosmology - II. Star
... may result in a cascade of mergers at successively higher levels (in the figure, these mergers are represented by red columns joined by braces to the merger product). In this way, the number of bins at ...
... may result in a cascade of mergers at successively higher levels (in the figure, these mergers are represented by red columns joined by braces to the merger product). In this way, the number of bins at ...
The optical afterglow and z = 0.92 early
... We initiated R-band observations of GRB 100117A with the Inamori Magellan Areal Camera and Spectrograph (IMACS) on the Magellan/Baade 6.5-m telescope on 2010 January 18.04 UT (3.9 hr after the burst) and detected the four sources noted by Cenko et al. (2010) within the initial XRT error circle. We s ...
... We initiated R-band observations of GRB 100117A with the Inamori Magellan Areal Camera and Spectrograph (IMACS) on the Magellan/Baade 6.5-m telescope on 2010 January 18.04 UT (3.9 hr after the burst) and detected the four sources noted by Cenko et al. (2010) within the initial XRT error circle. We s ...
The VLT LEGA-C Spectroscopic Survey: The Physics of Galaxies at
... derstand the star formation history, and stellar velocity dispersions are a crucial element in quantifying the dynamical scaling relations such the Faber & Jackson (1976) relation, the Tully & Fisher (1977), and the fundamental plane (Djorgovski & Davis 1987; Dressler et al. 1987), the evolution of ...
... derstand the star formation history, and stellar velocity dispersions are a crucial element in quantifying the dynamical scaling relations such the Faber & Jackson (1976) relation, the Tully & Fisher (1977), and the fundamental plane (Djorgovski & Davis 1987; Dressler et al. 1987), the evolution of ...
The age of elliptical galaxies and bulges in a merger model The age
... outer parts of elliptical galaxies are both older and more metal-poor than the nuclei, consistent with the merger/starburst picture (Faber et al. 1995). The fact remains, however, that the stellar populations of present-day elliptical galaxies appear to be rather homogeneous. The colours, mass-to-li ...
... outer parts of elliptical galaxies are both older and more metal-poor than the nuclei, consistent with the merger/starburst picture (Faber et al. 1995). The fact remains, however, that the stellar populations of present-day elliptical galaxies appear to be rather homogeneous. The colours, mass-to-li ...
PPT - ALFALFA survey
... Schneider (2000). It was a drift-scan survey taken in a series of declination strips with the Arecibo 305-m telescope. The velocity limit of the ADBS is 8000 km/s (it is volume limited!). The full ADBS sample includes 265 galaxies over ~420 sq. deg. • Since it is a “blind” HI survey, it does not suf ...
... Schneider (2000). It was a drift-scan survey taken in a series of declination strips with the Arecibo 305-m telescope. The velocity limit of the ADBS is 8000 km/s (it is volume limited!). The full ADBS sample includes 265 galaxies over ~420 sq. deg. • Since it is a “blind” HI survey, it does not suf ...
Super-solar Metal Abundances in Two Galaxies at ζ ∼ 3.57
... gamma-ray burst GRB 090323. The two systems, at redshift z = 3.5673 and z = 3.5774 (separation ∆v ≈ 660 km s−1 ), are dominated by the neutral gas in the interstellar medium of the parent galaxies. From the singly ionized zinc and sulfur, we estimate oversolar metallicities of [Zn/H] = +0.29 ± 0.10 ...
... gamma-ray burst GRB 090323. The two systems, at redshift z = 3.5673 and z = 3.5774 (separation ∆v ≈ 660 km s−1 ), are dominated by the neutral gas in the interstellar medium of the parent galaxies. From the singly ionized zinc and sulfur, we estimate oversolar metallicities of [Zn/H] = +0.29 ± 0.10 ...
Redshift
In physics, redshift happens when light or other electromagnetic radiation from an object is increased in wavelength, or shifted to the red end of the spectrum. In general, whether or not the radiation is within the visible spectrum, ""redder"" means an increase in wavelength – equivalent to a lower frequency and a lower photon energy, in accordance with, respectively, the wave and quantum theories of light.Some redshifts are an example of the Doppler effect, familiar in the change of apparent pitches of sirens and frequency of the sound waves emitted by speeding vehicles. A redshift occurs whenever a light source moves away from an observer. Another kind of redshift is cosmological redshift, which is due to the expansion of the universe, and sufficiently distant light sources (generally more than a few million light years away) show redshift corresponding to the rate of increase in their distance from Earth. Finally, gravitational redshift is a relativistic effect observed in electromagnetic radiation moving out of gravitational fields. Conversely, a decrease in wavelength is called blueshift and is generally seen when a light-emitting object moves toward an observer or when electromagnetic radiation moves into a gravitational field. However, redshift is a more common term and sometimes blueshift is referred to as negative redshift.Knowledge of redshifts and blueshifts has been applied to develop several terrestrial technologies such as Doppler radar and radar guns. Redshifts are also seen in the spectroscopic observations of astronomical objects. Its value is represented by the letter z.A special relativistic redshift formula (and its classical approximation) can be used to calculate the redshift of a nearby object when spacetime is flat. However, in many contexts, such as black holes and Big Bang cosmology, redshifts must be calculated using general relativity. Special relativistic, gravitational, and cosmological redshifts can be understood under the umbrella of frame transformation laws. There exist other physical processes that can lead to a shift in the frequency of electromagnetic radiation, including scattering and optical effects; however, the resulting changes are distinguishable from true redshift and are not generally referred to as such (see section on physical optics and radiative transfer).