Practical cosmology with the Local Volume galaxies
... While having accurate velocities and distances for ~250 LV galaxies, one can study distribution of peculiar velocities within the Volume. A peculiar velocity map for the LV galaxies in the LG reference frame shows the local Hubble flow to be generally calm with peculiar velocity variations within ± ...
... While having accurate velocities and distances for ~250 LV galaxies, one can study distribution of peculiar velocities within the Volume. A peculiar velocity map for the LV galaxies in the LG reference frame shows the local Hubble flow to be generally calm with peculiar velocity variations within ± ...
A UV study of nearby luminous infrared galaxies: star formation
... blue peaks may change depending on the magnitude cut employed, the colour at which the population divides remains stable (see e.g. Figure 2 in Strateva et al. 2001). We find that, in the (u − r) colour, the LIRG population peaks around the colour bimodality point (u − r ∼ 2.2) with a large fraction ...
... blue peaks may change depending on the magnitude cut employed, the colour at which the population divides remains stable (see e.g. Figure 2 in Strateva et al. 2001). We find that, in the (u − r) colour, the LIRG population peaks around the colour bimodality point (u − r ∼ 2.2) with a large fraction ...
zone inverse Doppler effect
... sionson inverseDopplereffectin freespace[Engheta When an observerin free spaceis in motion rela- et al., 1980;Engheta,1990],whichanalyzethe elective to a monochromaticsource,the frequencymea- tromagneticfield of an oscillatingthree-dimensional of a moving sured by him/her will be higher than the sou ...
... sionson inverseDopplereffectin freespace[Engheta When an observerin free spaceis in motion rela- et al., 1980;Engheta,1990],whichanalyzethe elective to a monochromaticsource,the frequencymea- tromagneticfield of an oscillatingthree-dimensional of a moving sured by him/her will be higher than the sou ...
sections 23-25 powerpoint
... Elliptical galaxy (E). A spheroidal galaxy containing millions to billions of old low-mass stars and no gas or dust. Spiral Galaxy (S). A galaxy with a spheroidal bulge of several million old low-mass stars and a flattened pancake-like disk of billions of old low-mass and young high-mass stars, alon ...
... Elliptical galaxy (E). A spheroidal galaxy containing millions to billions of old low-mass stars and no gas or dust. Spiral Galaxy (S). A galaxy with a spheroidal bulge of several million old low-mass stars and a flattened pancake-like disk of billions of old low-mass and young high-mass stars, alon ...
A Project Underway to Build an Inexpensive 8-Meter Telescope
... The primary challenge is likely to be control of systematic errors. One method of dealing with this might be to split the sample of 100,000 well-sampled light curves into redshift bins (~0.1) small enough that residual error in cosmological parameters are insignificant (see next slide), then perform ...
... The primary challenge is likely to be control of systematic errors. One method of dealing with this might be to split the sample of 100,000 well-sampled light curves into redshift bins (~0.1) small enough that residual error in cosmological parameters are insignificant (see next slide), then perform ...
Nuclear Activity in UZC Compact Groups of Galaxies M.A. Martinez
... The classification of the nuclear activity has been made mainly using three diagnostic diagrams: 1) log([OIII]5007Å/Hβ ) versus log([NII]6584Å/ Hα ) or [NII]-Diagram, 2) log([OIII]5007Å)/Hβ ) versus log([SII]6717Å+6731Å/Hα) or [SII]-Diagram and 3) log([OIII]5007Å/Hβ ) vs log([OI]6300Å/Hα) als ...
... The classification of the nuclear activity has been made mainly using three diagnostic diagrams: 1) log([OIII]5007Å/Hβ ) versus log([NII]6584Å/ Hα ) or [NII]-Diagram, 2) log([OIII]5007Å)/Hβ ) versus log([SII]6717Å+6731Å/Hα) or [SII]-Diagram and 3) log([OIII]5007Å/Hβ ) vs log([OI]6300Å/Hα) als ...
instructor notes: weeks 9/10
... early universe. At early times the universe is assumed to have been very hot, but a few hundred thousand years after the Big Bang the fireball had cooled considerably, although still at high temperatures. When the fireball had cooled to T ≈ 3000 K it became transparent to energy. The thermal energy ...
... early universe. At early times the universe is assumed to have been very hot, but a few hundred thousand years after the Big Bang the fireball had cooled considerably, although still at high temperatures. When the fireball had cooled to T ≈ 3000 K it became transparent to energy. The thermal energy ...
Lecture 2
... The greater the redshift, the further back in time – redshift of 0.1 is 1.4 billion ly which means we are looking 1.4 billion years into the past. All galaxies are moving away from each other à in the past all galaxies were closer to each other. All the way back in time, it would mean that everythi ...
... The greater the redshift, the further back in time – redshift of 0.1 is 1.4 billion ly which means we are looking 1.4 billion years into the past. All galaxies are moving away from each other à in the past all galaxies were closer to each other. All the way back in time, it would mean that everythi ...
Chapter 2 Observing the Electromagnetic Spectrum
... the entire electromagnetic region, they too are sources of increasing ’pollution’ for ground-based observations, when recorded as streaks of light across long exposure wide-field images near to, or through (Figure 2.3) objects of interest. Of July, 2009 there were ∼900 operational satellites, with ∼ ...
... the entire electromagnetic region, they too are sources of increasing ’pollution’ for ground-based observations, when recorded as streaks of light across long exposure wide-field images near to, or through (Figure 2.3) objects of interest. Of July, 2009 there were ∼900 operational satellites, with ∼ ...
![arXiv:0705.3323v2 [astro-ph] 12 Oct 2007](http://s1.studyres.com/store/data/014343898_1-81883919b9b58f47cea02891b863ef0c-300x300.png)
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).