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... • Sub-mm observations, e.g., at CSO or JCMT using SCUBA instrument reveal a population of luminous obscured sources ...
... • Sub-mm observations, e.g., at CSO or JCMT using SCUBA instrument reveal a population of luminous obscured sources ...
Chapter 34: Cosmology FYI 1. Radar Ranging 2. Triangulation idea
... P5:Forces slowing the expansion of the universe are due to ...
... P5:Forces slowing the expansion of the universe are due to ...
Measurements of Dark Energy Lecture 2: Expansion Kinematics
... WMAP5+BAO+SNall samples, compute luminosity distance to redshift z for each one, take standard deviation to get error(z): ...
... WMAP5+BAO+SNall samples, compute luminosity distance to redshift z for each one, take standard deviation to get error(z): ...
MS 1512–CB58 - Columbia University Department of Astronomy
... Thanks to its gravitationally lensed nature, the z = 2.7276 galaxy MS 1512−cB58 (or cB58 for short) provides an unusually clear window on the population of starforming galaxies identified at these redshifts through the Lyman break technique (Steidel et al., 1996). Discovered by Yee et al. (1996), cB ...
... Thanks to its gravitationally lensed nature, the z = 2.7276 galaxy MS 1512−cB58 (or cB58 for short) provides an unusually clear window on the population of starforming galaxies identified at these redshifts through the Lyman break technique (Steidel et al., 1996). Discovered by Yee et al. (1996), cB ...
Hubble - schoolphysics
... This means that: The velocity of recession of a galaxy increases by 70 kms-1 for every 1 Mpc increase in distance. The value of H can be found by measuring the distance of another galaxy using the periodluminosity relationship for a Cepheid variable star. The period of intensity variation is directl ...
... This means that: The velocity of recession of a galaxy increases by 70 kms-1 for every 1 Mpc increase in distance. The value of H can be found by measuring the distance of another galaxy using the periodluminosity relationship for a Cepheid variable star. The period of intensity variation is directl ...
department of physics - Bishopston Comprehensive School Moodle
... Now we’ve just discussed the Doppler effect using sound waves, but the Doppler effect applies to ALL waves not just sound waves. So for example if we looked at stars from a distant galaxy and the light wave received on earth was slightly stretched, then that would mean that the galaxy must be moving ...
... Now we’ve just discussed the Doppler effect using sound waves, but the Doppler effect applies to ALL waves not just sound waves. So for example if we looked at stars from a distant galaxy and the light wave received on earth was slightly stretched, then that would mean that the galaxy must be moving ...
The homogeneous and isotropic universe: Cosmology
... The age of the universe? Hubble’s constant H0 = 100h kms-1Mpc-1 where h =0.72 ± 0.08 The units are a little unusual so on converting kilometres into parsecs and converting seconds to years we find the Hubble time ...
... The age of the universe? Hubble’s constant H0 = 100h kms-1Mpc-1 where h =0.72 ± 0.08 The units are a little unusual so on converting kilometres into parsecs and converting seconds to years we find the Hubble time ...
Chapter 5 Light and Matter: Reading Messages from the Cosmos
... What have we learned? • How does light tell us the speed of a distant object? – The Doppler effect tells us how fast an object is moving toward or away from us. • Blueshift:objects moving toward us • Redshift: objects moving away from us • How does light tell us the rotation rate of an object? – Th ...
... What have we learned? • How does light tell us the speed of a distant object? – The Doppler effect tells us how fast an object is moving toward or away from us. • Blueshift:objects moving toward us • Redshift: objects moving away from us • How does light tell us the rotation rate of an object? – Th ...
Document
... • Frequency is the number of cycles per second • Since speed of light is constant, higher the frequency the shorter the wavelength and viceversa • Wavelengths are measured in Angstroms: ...
... • Frequency is the number of cycles per second • Since speed of light is constant, higher the frequency the shorter the wavelength and viceversa • Wavelengths are measured in Angstroms: ...
Our galaxy is the centre of the universe, `quantized` red shifts show
... Hubble’s law, redshifts are proportional to the distances of the galaxies from us. Then it would be the distances themselves that fall into groups. That would mean the galaxies tend to be grouped into ...
... Hubble’s law, redshifts are proportional to the distances of the galaxies from us. Then it would be the distances themselves that fall into groups. That would mean the galaxies tend to be grouped into ...
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).