The lightcurve of a Type la supernova explosion is observed to peak at an apparent magnitude of m= 16.4 mag. a) Estimate the distance to the galaxy where this explosion occurred in. (Recall that Type la supernovae have a characteristic light curve and associated maximal luminosity. See slides from Lecture 16!) b) Assuming a Hubble constant of 72.9 km/s/M pc, calculate the recession velocity of the supernova (and its host galaxy). c) A characteristic feature observed in the spectra of Type la supernovae is the silicon absorption feature with a rest-frame wavelength of = 635.5 nm. At what wavelength is this feature expected to be observed for the Type la SN considered, given the recession velocity calculated in part (b)?

The lightcurve of a Type la supernova explosion is observed to peak at an apparent magnitude of m= 16.4 mag. a) Estimate the distance to the galaxy where this explosion occurred in. (Recall that Type la supernovae have a characteristic light curve and associated maximal luminosity. See slides from Lecture 16!) b) Assuming a Hubble constant of 72.9 km/s/M pc, calculate the recession velocity of the supernova (and its host galaxy). c) A characteristic feature observed in the spectra of Type la supernovae is the silicon absorption feature with a rest-frame wavelength of = 635.5 nm. At what wavelength is this feature expected to be observed for the Type la SN considered, given the recession velocity calculated in part (b)?

Astronomy

1st Edition

ISBN:9781938168284

Author:Andrew Fraknoi; David Morrison; Sidney C. Wolff

Publisher:Andrew Fraknoi; David Morrison; Sidney C. Wolff

Chapter25: The Milky Way Galaxy

Section: Chapter Questions

Problem 18E: Assume that the Sun orbits the center of the Galaxy at a speed of 220 km/s and a distance of 26,000...

See similar textbooks

Similar questions

Can an elliptical galaxy evolve into a spiral? Explain your answer. Can a spiral turn into an elliptical? How?
The Kormendy relation for ellipticals can be written as He = 20.2+ 3.0 log R. where R. is the half-light radius (in kpc) and 4e is the surface brightness (in magnitudes per square arc second) at R.. An elliptical galaxy obeying this relation will have a total luminosity Lo R for some index 7. What is the correct value of n? O a. n=-6/5 O b. n= 4/5 T23D Oc n= 16/5 O d. n cannot be determined with the information we have.
An observational survey of distant galaxies is undertaken that involves measuring their distances using cepheid variables and red-shifts using spectroscopy. Explain how cepheid variables can be used to measure the distances to galaxies. A spectral line is observed whose wavelength in the laboratory is de length of this spectral line observed in each galaxy, Xo, is listed in the table, along with the distance, d, to the galaxy. Determine the red-shift and the recession velocity of each galaxy and tabulate your results by making a copy of the table and filling in the blank spaces. Sketch a Hubble diagram using your results and determine the value of the Hubble constant Ho in units of km s-1 Mpc. 650 nm. The wave- Galaxy 1 652.69 Galaxy 2 Galaxy 3 Galaxy 4 Galaxy 5 653.01 do (nm) d (Mpc) 658.54 662.18 681.63 17 19 54 77 200 v (km s-1)
Recall that Hubbleʹs law is written v = H0d, where v is the recession velocity of a galaxy located a distance d away from us, and H0 is Hubbleʹs constant. Suppose H0 = 80 km/s/Mpc. How fast would a galaxy located 800 megaparsecs distant be receding from us? A. 64 Mpc/s B. 64,000 km/s C. 0.1 times the speed of light D. 10 km/s E. 64 km/s
What are the characteristics of an E7 Galaxy? What about E0 galaxy? Explain.
Indicate whether the following statements are true or false. (Select T-True, F-False. If the first is T and the rest F, enterTFFFFF). A) The three main classifications of galaxies are elliptical, spiral and prime.B) The mass of a spiral galaxy can be found from its rotational velocity. The greater the rotation, the greater the mass.C) Galaxies sometimes collide with each other.D) It wasn't until the 1920s that we knew the Milky Way was only one of many galaxies.E) Most galaxies are elliptical.F) The shorter the pulsation period of a Cepheid variable star, the more luminous it is.
How astronomers determine the distance of a galaxy? Explain.
A Type la supernova explodes in a galaxy at a distance of 6.10×107 light-years from Earth. If astronomers detect the light from the supernova today, how many years T have passed since the supernova exploded? T= 2.07 x10 -5 years Given a Hubble constant of 74.3 km/s/Mpc, at what speed v is this galaxy moving away from Earth? v= km/s What is this galaxy's redshift? redshift:
What are the angular diameters of the following, as seen from Earth? a. The Sun, with radius R = Rsun = 7x10^5 km. b. Betelgeuse, with MV = -5.5 mag, mv = 0.8 mag, and R = 650Rsun. c. The galaxy M31, with R = 30 kpc at a distance D = 0.7Mpc. d. The Coma cluster of galaxies, with R = 3 Mpc at a distance D = 100 Mpc.
) what are some fundamental properties of late type galaxies that our theories of galaxy formation must reproduce? 2.) what are some fundamental properties of early type galaxies that our theories of galaxy formation must reproduce?
Suppose that a galaxy has 109 M⊙ of neutral HI gas with a temperature of about 10 K. Estimate the luminosity of the 21 cm wavelength radiation that is expected from the galaxy. Answer in watts.
Each point on the above diagram shows the line-of-sight recession velocity versus distance for a number of distant galaxies. Describe how the recession velocities of galaxies are measured by astronomers. Explain the different techniques used by astronomers to measure the distances to galaxies, and describe how these methods are used to construct the distance ladder.