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Large redshifts move the positions of spectral lines to longer wavelengths and change what can be observed from the ground. For example, suppose a quasar has a redshift of
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- Assuming stars to behave as black bodies stefan-boltzmann law to show that the luminosity of a star is related to its surface temperature and size in the following way: L = 4(3.14)R^2oT^4 where o= 5.67 ×10^-8 Wm^-2 K-4 is the stefan- boltzmann constant. Then use this expression together with the knowledge that the sun has a surface temperature of 5700k and radius 695 500km to calculate the luminosity of the Sun in units of Wattsarrow_forwardIn the Check Your Learning section of Example 27.1, you were told that several lines of hydrogen absorption in the visible spectrum have rest wavelengths of 410 nm, 434 nm, 486 nm, and 656 nm. In a spectrum of a distant galaxy, these same lines are observed to have wavelengths of 492 nm, 521 nm, 583 nm, and 787 nm, respectively. The example demonstrated that z=0.20 for the 410 nm line. Show that you will obtain the same redshift regardless of which absorption line you measure.arrow_forwardA gamma ray burst delivers approximately 1.0 X10-6 joules/m2 to a detector on an orbiting space telescope. Assuming that the red shift indicates that the source is 5 X109 light years away (1 yr =3.16X107 seconds) and that the energy at the detector has been corrected for the redshift, what is the energy output of the source and how does it compare to the rest energy of the Sun. The speed of light is 3.0 X 108 m/sec. A year is 3.16 X 107 sec. The mass of the Sun is 2 X 1030 kg. Rest mass energy is E=mc2. The surface area of a sphere is 4πr2. Answer choices: 1.2 X1045joules and 0.7 % 8 X 1047 joules and 100% 5 X 1046 joules and 8% 2.8 X 1046 joules and 16%arrow_forward
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- A gamma ray burst delivers approximately 5.0 X10-6 joules/m2 to a detector on an orbiting space telescope. Assuming that the red shift indicates that the source is 5 X109 light years away (1 yr =3.16X107 seconds) and that the energy at the detector has been corrected for the redshift, what is the energy output of the source in units of 1047 joules and how does it compare to the rest energy of the Sun. The speed of light is 3.0 X 108 m/sec. A year is 3.16 X 107 sec. The mass of the Sun is 2 X 1030 kg. Rest mass energy is E=mc2. The surface area of a sphere is 4ππr2. Group of answer choices 1.9 and 8% 1.41 and 78% 80 and 100% 0.12 and 0.7%arrow_forwardWhat is the wavelength in micrometers of peak emission for a black body at 33.5°C? (c = 3.0 × 108 m/s, Wien displacement law constant is 2.9 × 10-3 m ∙ K, σ = 5.67 × 10-8 W/m2 ∙ K4). Please give your answer with one decimal place.arrow_forwardP2 X The image to the left is a Feynman diagram with time increasing upward. P1 (a) If p1 is an electron and X is a W+ what must p2 be? Why? (b) If p1 is a μ+ and p2 is a different flavor of lepton, what must p2 be? Why? (c) In the last question, what must X be? Why? (d) If p1 and p2 are both electron neutrinos, what must X be? Why? (e) If p1 and p2 are both the same flavor of charged lepton, what might X be? (There are two possibilities.) Why?arrow_forward
- Consider a spherical blackbody of constant temperature and mass M whose surface lies at radial coordinater = R. An observer located at the surface of the sphere and a distant observer both measure the blackbody radiation given off by the sphere. If the observer at the surface of the sphere measures the luminosity of the blackbody to be L, use the gravitational time dilation formula, to show that the observer at infinity measures. 2GM L̟ = L] 1- Rc?arrow_forwardThe peak intensity of the CMBR occurs at a wavelength of 1.1 mm. (a) What is the energy in eV of a 1.1-mm photon? (b) There are approximately 109 photons for each massive particle in deep space. Calculate the energy of 109 such photons. (c) If the average massive particle in space has a mass half that of a proton, what energy would be created byconverting its mass to energy? (d) Does this imply that space is “matter dominated”? Explain briefly.arrow_forwardAt rest, hydrogen has a spectral line at 124 nm. If this line is observed at 133 nm for the star Sirius, how fast is Sirius moving in km/s?arrow_forward
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