vubion.blogg.se - Redshift equation hubble

Typically for galaxies we tend to use km/s, so the speed of light in this case would be 3.0 x 10 5 km/sġ. The units you use for velocity and for "c" are sort of arbitrary. If it is positive, the motion is away from you, if it is negative the motion is towards you. It should be noted that is the difference or change in the value of the spectral feature from its normal wavelength ( ), and the change could be positive or negative.

= the wavelength the feature should have, often measured in Ångstroms.

= Shift in the wavelength of a feature in the spectra, often measured in Ångstroms, just so the units are the same as used for.

c = speed of light, either 3.0 x 10 8 m/s or 3.0 x 10 5 km/s.

v = velocity of the object, in m/s or km/s - same units used by "c".

Basically it shows how much light is effected by velocity and allows us (astronomers) to determine velocities based upon the measurable effects. If the Hubble Constant is 68 km/s/Mpc, how fast should NGC 4442 be moving due to the expansion of the Universe?ĭoppler Shift - This formula was originally introduced when light was discussed, but now we're looking at it again. Solution: You can again just pop them into the formulaģ. What is the value of the Hubble constant based upon these values? Galaxy NGC 2342 has a velocity of 5,690 km/s and is at a distance of 74 Mpc away. Solution: Pop the values into the formulaĢ.

How far away is the galaxy according to Hubble's Law?

Galaxy NGC 123 has a velocity away from us of 1,320 km/s and the Hubble Constant's value is 70 km/s/Mpc. Technically, this is a very simplified version of the what the Universe is doing, but it is a good first approximation for what we see in the sky.ġ. d = distance of a galaxy, in Mpc (mega-parsecs)Ī rather simple formula for a very important thing, the Universe.H o = Hubble Constant, measured in km/s/Mpc.It shows the expansion of the Universe by showing how distant galaxies are moving away from us. Hubble's Law - One of the most important formulas of the 20th century.