
2P33.pdf
... using the formula of Dale et al. (2003) which considers the difference between both sides of the rotation curve but also the dispersion of the velocity points. Lopsidedness in galaxies is very common (50% of the HI profiles are asymmetric; Haynes et al., 1998; warps in U-shape of the disks; asymmetr ...
... using the formula of Dale et al. (2003) which considers the difference between both sides of the rotation curve but also the dispersion of the velocity points. Lopsidedness in galaxies is very common (50% of the HI profiles are asymmetric; Haynes et al., 1998; warps in U-shape of the disks; asymmetr ...
Natasha Wood
... Sy1 galaxies are viewed from above the accretion disk whereas Sy2 are viewed from a more edge-on view with respect to the accretion disk. If this is the case the reflection component (X-ray emission from the hot corona) which is scattered by the accretion disk or the inside walls of the molecular to ...
... Sy1 galaxies are viewed from above the accretion disk whereas Sy2 are viewed from a more edge-on view with respect to the accretion disk. If this is the case the reflection component (X-ray emission from the hot corona) which is scattered by the accretion disk or the inside walls of the molecular to ...
CONSTRAINTS ON THE VERY HIGH ENERGY
... VHE sources in the universe. The limits are tighter than those obtained by considering cascading on the microwave background alone and restrict significantly, for example, the parameter space available for the exotic particle physics scenarios recently proposed to explain the highest energy cosmic-r ...
... VHE sources in the universe. The limits are tighter than those obtained by considering cascading on the microwave background alone and restrict significantly, for example, the parameter space available for the exotic particle physics scenarios recently proposed to explain the highest energy cosmic-r ...
Evidence for 1000 km/s Molecular Outflows in the Local ULIRG
... energy injection rate of ∼ 1.3 × 1044 ergs s−1 . Assuming an energy output per supernova of ∼ 1051 ergs (Veilleux et al. 1995), our estimated dE/dt yields a supernova rate, νSN,yr−1 of 4 yr−1 . Using a Scalo initial mass function (IMF) with a mass range of 5 − 100 M⊙ , the star formation rate inferr ...
... energy injection rate of ∼ 1.3 × 1044 ergs s−1 . Assuming an energy output per supernova of ∼ 1051 ergs (Veilleux et al. 1995), our estimated dE/dt yields a supernova rate, νSN,yr−1 of 4 yr−1 . Using a Scalo initial mass function (IMF) with a mass range of 5 − 100 M⊙ , the star formation rate inferr ...
Chapter 16 Galaxies and Dark Matter
... 16.1 Dark Matter in the Universe Galaxy mass measurements show that galaxies need between 3 and 10 times more mass than can be observed to explain their rotation curves. The discrepancy is even larger in galaxy clusters, which need 10 to 100 times more mass. The total needed is more than the sum of ...
... 16.1 Dark Matter in the Universe Galaxy mass measurements show that galaxies need between 3 and 10 times more mass than can be observed to explain their rotation curves. The discrepancy is even larger in galaxy clusters, which need 10 to 100 times more mass. The total needed is more than the sum of ...
Test#4
... 30. What observation of the Galaxy suggests it is much larger than the halo and contains a large amount of matter not in the form of stars? a) The rotation curve, b) Motions of the globular clusters c) The shape of the spiral arms, d) Infrared observations of the center of the Galaxy 31. Quasars wer ...
... 30. What observation of the Galaxy suggests it is much larger than the halo and contains a large amount of matter not in the form of stars? a) The rotation curve, b) Motions of the globular clusters c) The shape of the spiral arms, d) Infrared observations of the center of the Galaxy 31. Quasars wer ...
II. The Universe Around Us
... violate the Cosmological Principle? • If no acceleration/deceleration, galaxies were together at time: ...
... violate the Cosmological Principle? • If no acceleration/deceleration, galaxies were together at time: ...
The Electric Universe by Wallace Thornhill and David Talbott
... Raised in Portland, Oregon, David Talbott has remained in the area all his life. A graduate of Portland State University, where he majored in education and political science, he returned briefly for graduate work in urban studies. His college observations on the failure of modern education led him t ...
... Raised in Portland, Oregon, David Talbott has remained in the area all his life. A graduate of Portland State University, where he majored in education and political science, he returned briefly for graduate work in urban studies. His college observations on the failure of modern education led him t ...
low surface brightness galaxies
... • Compared to ellipticals, the spirals cover a distinctly smaller range in absolute magnitude (and mass). They are limited to −16 > MB > −23 and 109M < סּM < 1012Mסּ • Looking at the sequence of early-type spirals (i.e., Sa’s or SBa’s) to late-type spirals, we find a number of differences that can ...
... • Compared to ellipticals, the spirals cover a distinctly smaller range in absolute magnitude (and mass). They are limited to −16 > MB > −23 and 109M < סּM < 1012Mסּ • Looking at the sequence of early-type spirals (i.e., Sa’s or SBa’s) to late-type spirals, we find a number of differences that can ...
The Milky Way - National Tsing Hua University
... need before you try to understand the birth and evolution of the entire universe and the galaxies that fill it. You will start that journey in the next chapter. ...
... need before you try to understand the birth and evolution of the entire universe and the galaxies that fill it. You will start that journey in the next chapter. ...
Determining Distances to Other Galaxies
... The range and frequency of different morphological types is sensitive to the sample of galaxies studied. Some key results: •The Local Group is the only sample that includes a significant number of very faint galaxies. Of the ~35 galaxies in the Local Group, only the 3 brightest (M31, MW and M33) are ...
... The range and frequency of different morphological types is sensitive to the sample of galaxies studied. Some key results: •The Local Group is the only sample that includes a significant number of very faint galaxies. Of the ~35 galaxies in the Local Group, only the 3 brightest (M31, MW and M33) are ...
Powerpoint Presentation (large file)
... distance ladder uses observations of molecular clouds called masers • “Maser” is an acronym for “microwave amplification by stimulated emission of radiation” ...
... distance ladder uses observations of molecular clouds called masers • “Maser” is an acronym for “microwave amplification by stimulated emission of radiation” ...
Physics 41N Lecture 6: Laser Cooling of Atoms
... ∆ν = ν − νo = νo . c In this equation, νo is the frequency observed when the source is at rest relative to the observer, and ν is the frequency observed when the source is moving towards the observer with velocity v. If the source is moving away from the observer, replace v by −v. The Doppler shift ...
... ∆ν = ν − νo = νo . c In this equation, νo is the frequency observed when the source is at rest relative to the observer, and ν is the frequency observed when the source is moving towards the observer with velocity v. If the source is moving away from the observer, replace v by −v. The Doppler shift ...
Galaxy Evolution
... galaxies have a higher fraction of spirals than nearby clusters • Distant clusters contain more galaxies within a given volume • Distant galaxies show more signs of disturbance by neighboring galaxies (odd shapes, bent arms, twisted disks) ...
... galaxies have a higher fraction of spirals than nearby clusters • Distant clusters contain more galaxies within a given volume • Distant galaxies show more signs of disturbance by neighboring galaxies (odd shapes, bent arms, twisted disks) ...
Lecture 21 (pdf from the powerpoint)
... Distances to other galaxies • We can use Cepheid variable stars to measure the distance to other galaxies • A Cepheid’s luminosity is proportional to its period, so if we know how rapidly it brightens and dims, we know much energy it emits • If we see a Cepheid in another galaxy, we measure its per ...
... Distances to other galaxies • We can use Cepheid variable stars to measure the distance to other galaxies • A Cepheid’s luminosity is proportional to its period, so if we know how rapidly it brightens and dims, we know much energy it emits • If we see a Cepheid in another galaxy, we measure its per ...
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).