Lecture 29: Ellipticals and Irregulars
... Methods of learning about what’s in galaxies: Images: use blue and red filters to measure colors and make H-R diagram from individual stars Integrated light/spectra Emission lines, particularly from neutral hydrogen and molecular gas. ...
... Methods of learning about what’s in galaxies: Images: use blue and red filters to measure colors and make H-R diagram from individual stars Integrated light/spectra Emission lines, particularly from neutral hydrogen and molecular gas. ...
EBL - UCSC Physics - University of California, Santa Cruz
... Figure 4. The predicted z = 0 EBL spectrum from our fiducial WMAP5 model (solid black) and WMAP5+fixed (dash–dotted violet) dust parameters, and C!CDM (dotted black) models, compared with experimental constraints at a number of wavelengths. D11 is shown for comparison in dashed–dotted red with the s ...
... Figure 4. The predicted z = 0 EBL spectrum from our fiducial WMAP5 model (solid black) and WMAP5+fixed (dash–dotted violet) dust parameters, and C!CDM (dotted black) models, compared with experimental constraints at a number of wavelengths. D11 is shown for comparison in dashed–dotted red with the s ...
DTU 8e Chap 17 Quasars and Other Active Galaxies
... An active galaxy is an extremely luminous galaxy that has one or more unusual features: an unusually bright, starlike nucleus; strong emission lines in its spectrum; rapid variations in luminosity; and jets or beams of radiation that emanate from its core. Active galaxies include quasars, Seyfert ga ...
... An active galaxy is an extremely luminous galaxy that has one or more unusual features: an unusually bright, starlike nucleus; strong emission lines in its spectrum; rapid variations in luminosity; and jets or beams of radiation that emanate from its core. Active galaxies include quasars, Seyfert ga ...
A NEW METHOD FOR MEASURING EXTRAGALACTIC DISTANCES
... curves of radio-quiet AGNs (Gaskell et al. 2004). In order to obtain ΔtAGN in the rest frame of the AGN, two cosmological effects must be considered. The observed Δt must be corrected for time dilation, a factor of (1 + z)−1 , where z is the redshift. We also consider an effect that arises from the ...
... curves of radio-quiet AGNs (Gaskell et al. 2004). In order to obtain ΔtAGN in the rest frame of the AGN, two cosmological effects must be considered. The observed Δt must be corrected for time dilation, a factor of (1 + z)−1 , where z is the redshift. We also consider an effect that arises from the ...
Galaxies Slide Show and Videos
... Galaxies Black holes are thought to be at the center of galaxies. These are extremely dense quantities of matter in space. They have such strong gravitational pulls that nothing – not even light – is fast enough to escape. 10 Mind-Bending Facts About Black Holes ...
... Galaxies Black holes are thought to be at the center of galaxies. These are extremely dense quantities of matter in space. They have such strong gravitational pulls that nothing – not even light – is fast enough to escape. 10 Mind-Bending Facts About Black Holes ...
ppt
... kinematics Measurements of - or upper limits on - the stellar continuum constrains the IMF Sources expected to cover a range of metallicity from Z ~ 0 to 10-3 ...
... kinematics Measurements of - or upper limits on - the stellar continuum constrains the IMF Sources expected to cover a range of metallicity from Z ~ 0 to 10-3 ...
Astronomy 100—Exam 3
... 11. An astronomer now living in another galaxy far away from ours would see A. some of the most distant galaxies coming toward her and some going away from her. B. our Galaxy moving away from her. C. more-or-less the same relation between velocity and distance that we see. D. A and B. E. B and C. 12 ...
... 11. An astronomer now living in another galaxy far away from ours would see A. some of the most distant galaxies coming toward her and some going away from her. B. our Galaxy moving away from her. C. more-or-less the same relation between velocity and distance that we see. D. A and B. E. B and C. 12 ...
Review for final
... 7. Explain azimuth and altitude as parts of a celestial coordinate system. Include when are they useful 8. Find objects in the sky by computing altitude and azimuth using your hand o If your fist fits 9 times between the horizon and the zenith, it covers 10o. Explain why o find how many degrees a ha ...
... 7. Explain azimuth and altitude as parts of a celestial coordinate system. Include when are they useful 8. Find objects in the sky by computing altitude and azimuth using your hand o If your fist fits 9 times between the horizon and the zenith, it covers 10o. Explain why o find how many degrees a ha ...
Revealing Galactic Scale Bars with the help of Galaxy Zoo
... We use visual classifications of the brightest 250,000 galaxies in the Sloan Digital Sky Survey Main Galaxy Sample provided by citizen scientists via the Galaxy Zoo project (www.galaxyzoo.org, Lintott et al. 2008) to identify a sample of local disc galaxies with reliable bar identifications. These d ...
... We use visual classifications of the brightest 250,000 galaxies in the Sloan Digital Sky Survey Main Galaxy Sample provided by citizen scientists via the Galaxy Zoo project (www.galaxyzoo.org, Lintott et al. 2008) to identify a sample of local disc galaxies with reliable bar identifications. These d ...
Media Alert A new spin on star-forming galaxies
... He said the majority of stars in the sky today, including our five billion-year-old Sun, were probably born inside these clumpy formations. “The clumpy galaxies produce stars at phenomenal rates,” Dr Obreschkow said. “A new star pops up about once a week, whereas spiral galaxies like our Milky Way o ...
... He said the majority of stars in the sky today, including our five billion-year-old Sun, were probably born inside these clumpy formations. “The clumpy galaxies produce stars at phenomenal rates,” Dr Obreschkow said. “A new star pops up about once a week, whereas spiral galaxies like our Milky Way o ...
Q1. Describe, in as much detail as you can: • the evidence that the
... To gain full marks for this question you should write your ideas in good English. Put them into a sensible order and use the correct scientific words. Explain how red shift provides evidence for the big bang theory. ...
... To gain full marks for this question you should write your ideas in good English. Put them into a sensible order and use the correct scientific words. Explain how red shift provides evidence for the big bang theory. ...
Gravitationally Lensed Galaxy
... One of the most striking examples of a gravitational lens is the nearly 90-degree arc of light in the galaxy cluster RCS2 032727-132623, located in the constellation Eridanus. Magnified and distorted light from a distant galaxy creates this arc. It is the brightest gravitationally lensed object yet ...
... One of the most striking examples of a gravitational lens is the nearly 90-degree arc of light in the galaxy cluster RCS2 032727-132623, located in the constellation Eridanus. Magnified and distorted light from a distant galaxy creates this arc. It is the brightest gravitationally lensed object yet ...
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).