elt science case
... decelerated universe to the acceleration took place. First results are expected in a few years. If is ruled out by the current experiments, we have to contend with at least two physical fields, which have changed the expansion history of the universe in dramatic fashions. Given such a situation, i ...
... decelerated universe to the acceleration took place. First results are expected in a few years. If is ruled out by the current experiments, we have to contend with at least two physical fields, which have changed the expansion history of the universe in dramatic fashions. Given such a situation, i ...
Dark Matter
... Which of the following statements is incorrect? a) The mass of a galaxy can be measured from its rotation curve. b) More than 90% of the mass of the universe is dark matter c) When Milky Way & Andromeda Galaxy merge, GMC (Giant Molecular Clouds) will collide & lots of new stars will form d) Gal ...
... Which of the following statements is incorrect? a) The mass of a galaxy can be measured from its rotation curve. b) More than 90% of the mass of the universe is dark matter c) When Milky Way & Andromeda Galaxy merge, GMC (Giant Molecular Clouds) will collide & lots of new stars will form d) Gal ...
Comments
... mutual feedback between star-forming spheroidal galaxies and the active nuclei growing in their cores to overcome, in the framework of the hierarchical clustering scenario for galaxy formation, one of the main challenges facing such scenario, the fact that massive spheroidal galaxies appear to have ...
... mutual feedback between star-forming spheroidal galaxies and the active nuclei growing in their cores to overcome, in the framework of the hierarchical clustering scenario for galaxy formation, one of the main challenges facing such scenario, the fact that massive spheroidal galaxies appear to have ...
Astronomy 401 Lecture 18 Galaxy Interactions Here we briefly
... Astronomy 401 Lecture 18 Galaxy Interactions Here we briefly consider some of the important processes involved in galaxy interactions. ...
... Astronomy 401 Lecture 18 Galaxy Interactions Here we briefly consider some of the important processes involved in galaxy interactions. ...
Deep $ I $-band imaging of $ z=\ mathsf {5.99} $ quasar
... extended X-ray source is statistically significant. It is comprised of 7 counts, which exceeds by far the expected background flux of 0.13 counts. He estimated that the probability of observing 7 photons in a 10 arcsec2 box is 5.8×10−9. What are the chances of observing a galaxy with the given magni ...
... extended X-ray source is statistically significant. It is comprised of 7 counts, which exceeds by far the expected background flux of 0.13 counts. He estimated that the probability of observing 7 photons in a 10 arcsec2 box is 5.8×10−9. What are the chances of observing a galaxy with the given magni ...
Word
... found to be the same by all observers, no matter how they are moving relative to one another. Ultimately this is because the speed of light is the constant conversion factor between measures of space and time, the same for all observers. It is often useful to think of the speed of light as simply un ...
... found to be the same by all observers, no matter how they are moving relative to one another. Ultimately this is because the speed of light is the constant conversion factor between measures of space and time, the same for all observers. It is often useful to think of the speed of light as simply un ...
The Discovery of Quasars - CSIRO Parkes Observatory
... study of the enhanced activity in the nuclei of six galaxies (or as he called them, “extragalactic nebulae”). Seyfert, as well as his predecessors, commented on the similarity with the emission line spectrum of planetary and other gaseous nebulae and that the lines are apparently Doppler broadened. ...
... study of the enhanced activity in the nuclei of six galaxies (or as he called them, “extragalactic nebulae”). Seyfert, as well as his predecessors, commented on the similarity with the emission line spectrum of planetary and other gaseous nebulae and that the lines are apparently Doppler broadened. ...
A limit on the number density of bright z ≈ 7 galaxies
... is sensitive to galaxies at z > 7, at which redshift flux longwards of the Lyman break becomes shifted beyond the optical. Given that the mean transmitted flux fraction through the Lyman α forest at z ≈ 6 is less than 5 per cent (Songaila & Cowie 2002) and may well fall to zero between z ≈ 6.0 and 6 ...
... is sensitive to galaxies at z > 7, at which redshift flux longwards of the Lyman break becomes shifted beyond the optical. Given that the mean transmitted flux fraction through the Lyman α forest at z ≈ 6 is less than 5 per cent (Songaila & Cowie 2002) and may well fall to zero between z ≈ 6.0 and 6 ...
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).