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August 1, 2014

Search: Cosmology

Number of results: 33

the third dimension
During what time frame did the notion that more than 3-Dimensions may exist become accepted? At this site there is a history of dimensionality. http://scholar.uwinnipeg.ca/courses/38/4500.6-001/Cosmology/dimensionality.htm
July 28, 2007 by Debra

Cosmology
In the Tully-Fisher relation, the scatter is minimized at which wavelength? * Red * Blue * Infrared * UV
January 16, 2013 by qwerty

Cosmology
The majority of galaxies (by number) are: lenticulars barred spirals dwarfs giant ellipticals
March 1, 2013 by C

Cosmology
In an Einstein-de Sitter (matter-dominated) universe, the scale factor is proportional to time to the power of: * 3/2 * 2/3 * 1/2 * -1/3
January 16, 2013 by qwerty

Cosmology
The scale factor, R, describes how universal expansion changes with: - time - curvature - location - all of the above
January 8, 2013 by qwerty

Cosmology
Cosmological redshift is defined as R(t0)/R(te) = - 1+z - 1 / 1−z - 1−z - 1 / 1+z
January 8, 2013 by qwerty

Cosmology
The Hubble sequence is useful for distinguishing galaxies on the basis of many properties. Which of these does not correlate well with Hubble type? stellar age dust content luminosity color
March 1, 2013 by C

Cosmology
A curvature constant of k=0, as used in the Friedmann equation, means: * The universe is open * The universe is matter-dominated * There is no dark energy * The universe is flat
January 16, 2013 by qwerty

Cosmology
Most of the energy in the Universe today is... - contained in the motion of galaxies. - released through supernova explosions. - in the form of dark energy. - the energy of the CMB photons.
January 8, 2013 by qwerty

Cosmology
Which type of emission closely traces the star-forming regions of a galaxy? none of these coronal X-ray emission 21 cm emission molecular CO emission
March 1, 2013 by C

cosmology
We observe a galaxy at z = 1, and a quasar at z = 2. What is the redshift of the quasar as observed from that galaxy? Enter a numeric answer.
January 19, 2014 by simar

Cosmology
The solution of Olbers' Paradox is: - The universe is opaque at large scales - The universe expands - There is simply not enough starlight in the universe - Matter is clustered in such a way that the integral brightness converges
January 8, 2013 by qwerty

Cosmology
The equation describing the geometry and mass-energy distribution of a homogeneous and isotropic universe is known as: - The Einstein Equation - The Friedmann Equation - The Robertson-Walker Equation - The Hubble Equation
January 8, 2013 by qwerty

Cosmology
Which of the following phenomena is NOT a consequence of Special Relativity? - Mass-energy curves space-time - Length contraction - Time dilation - Mass can not travel faster than the speed of light
January 8, 2013 by qwerty

Cosmology
How do we explore the large-scale structure of the Universe in the modern day? - Using large spectroscopic redshift surveys. - By accurately measuring positions of nearby galaxies. - By observing galaxies in the Local Supercluster. - By studying clusters of stars in the Milky Way
January 8, 2013 by qwerty

Cosmology
Which of these is NOT a good estimate of the age of the universe? * Decay times of 238U and 232Th in metal-poor stars. * Isochrone fits for globular clusters. * Ages of the faintest white dwarfs. * Ages of the hottest main-sequence stars in distant galaxies.
January 16, 2013 by qwerty

Cosmology
Which of the following statements is not true of spiral arms: they tend to trail the rotation of the galaxy they are sites of star formation they are amplified by resonances between the epicyclic frequencies of stars and the angular frequency of the spiral pattern they arise ...
March 1, 2013 by C

Cosmology
A Megaparsec is: - The distance to the Andromeda galaxy - The distance from which 1 AU subtends an angle of 1 microarcsecond - The distance from which 1 AU subtends an angle of 1 arcsecond - The size of the observable universe
January 8, 2013 by qwerty

Cosmology
In a universe where the scale factor is proportional to t^α, where t is time and α is a constant less than one, the universe has: * the sign of the acceleration is undetermined * negative acceleration * positive acceleration * zero acceleration
January 16, 2013 by qwerty

Cosmology
What can we say about the future evolution of irregular clusters? They will become less centrally concentrated and assume a roughly uniform spatial density. They are not yet in a dynamical equilibrium, but will likely reach it eventually. They will keep contracting until they ...
March 1, 2013 by C

Cosmology
Which of the following is evidence that the evolution of disk galaxies can be greatly affected by their large scale environment? Comparison of emissions from elliptical galaxies in x-ray and optical bands Hydrogen gas deficiency in spiral galaxies near cluster cores The ...
March 1, 2013 by C

Cosmology
What explains the observation that galaxy clustering is stronger at higher redshifts, which is an apparent reversal of the trend out to about z ~ 1? It is difficult to measure peculiar velocities Rich clusters have more galaxies than poor clusters Density contrast seems to ...
March 1, 2013 by C

Cosmology
magine you look through a really strong telescope and see a rich cluster. Your telescope is so good that you can see a single galaxy at the center of the cluster. What can you say about that galaxy and be pretty confident that you are correct? It has mass smaller than that of ...
March 1, 2013 by C

Cosmology
What observations were used by Edwin Hubble to show that the universe is expanding? - The distance to a galaxy is proportional to its luminosity. - The distance to a galaxy is inversely proportional to its apparent size. - The distance to a galaxy is proportional to its ...
January 8, 2013 by qwerty

Cosmology
The universe is homogeneous and isotropic on: - large scales (more than 100 Mpc) - neither small nor large scales - small scales (less than 100 Mpc) - both small and large scales
January 8, 2013 by qwerty

Cosmology
As compared to Cepheids, RR Lyrae stars are... * fainter and slower pulsating. * brighter and faster pulsating. * fainter and faster pulsating. * brighter and slower pulsating.
January 16, 2013 by qwerty

Cosmology
In order from earlier to later times, the dominant components of our universe have been: * dark energy, matter, then radiation * dark energy, radiation, then matter * matter, radiation, then dark energy * radiation, matter, then dark energy
January 16, 2013 by qwerty

Cosmology
The single largest uncertainty in the measurement of the Hubble constant using gravitational lenses comes from uncertainty of... * the distance to the lensing cluster or galaxy. * the mass distribution of the lensed quasar. * the distance to the lensed quasar. * the mass ...
January 16, 2013 by qwerty

cosmology
A galaxy with an apparent magnitude in the V band (λc ~ 5550 angstroms, width δλ ~ 800 angstroms) of mV = 22.5 mag is observed with the Palomar 200-inch telescope. How many photons per second are collected from this galaxy over the 200-inch (~ 500 cm) diameter ...
January 19, 2014 by simar

Cosmology
The most cosmological measurements show that the universe is extremely flat (Ωk≈0) and that the surface brightness of objects scales with the fourth power of redshift (SB∝z^−4). If the universe was still expanding, but had strong negative curvature (&#...
January 16, 2013 by qwerty

Cosmology
Lookback time for a given redshift, tL(z), is... * time between the given redshift and the beginning of the Universe. * time between the infinite and the given redshift. * equal to the age of the Universe at the given redshift. * time between now and the given redshift.
January 16, 2013 by qwerty

astronomy
Imagine that you live in a distant galaxy far far away. This galaxy is in a different universe, and so may have different cosmology. It seems that in this distant universe, all galaxies have the same luminosity, which you have worked out is 7.0*10^30 W. You are studying a ...
April 11, 2014 by keitanako

unsolved mysteries astrophysics
Q3.2 COLLAPSE TIMESCALE (5 points possible) Imagine that you live in a distant galaxy far far away. This galaxy is in a different universe, and so may have different cosmology. It seems that in this distant universe, all galaxies have the same luminosity, which you have worked...
April 15, 2014 by JuanPro

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