How does the Tully-Fisher relationship work?

What is our galaxy called?

The Milky Way is a huge collection of stars, dust and gas. It’s called a spiral galaxy because if you could view it from the top or bottom, it would look like a spinning pinwheel. The Sun is located on one of the spiral arms, about 25,000 light-years away from the center of the galaxy.

Is the Tully-Fisher relation a standard candle?

is relatively easy to determine from spectra, and so we have found a good way of measuring distances to distant galaxies! . And so from the apparent size of the galaxy, we can estimate its distance.

What are the two most powerful standard candles?

The most commonly used standard candles in astronomy are Cepheid Variable stars and RR Lyrae stars. In both cases, the absolute magnitude of the star can be determined from its variability period.

What standard candle did Hubble use?

Cepheids are what Edwin Hubble used to determine the distances of “nebulae” (ie. galaxies) and derive the Hubble law. There are several types of ‘standard candle’ objects for which we can predict the luminosity from some other measurement. Two of the most important are Cepheid variable stars and type 1A supernovae.

What makes a good standard candle?

(2) Cepheid variable stars and Type Ia supernovae are the most useful standard candles. Cepheid variable stars are good standard candles. First, their luminosity is quite high (the most luminous Cepheids are 40,000 times more luminous than the Sun), so they can be seen to large distances.

Which two primary factors are correlated by the Tully-Fisher relation that will lead to determining the luminosity of a galaxy and thus its distance?

A more massive galaxy also contains a larger number of stars and is therefore more luminous. The result is a correlation between the luminosity and the rotational speed for spiral galaxies, the Tully–Fisher relation. There are a few complications to this simple explanation.

What is the Tully-Fisher Relationship How can we use this to measure distance over what distances can it be used?

The Tully-Fisher relation is a relation between the luminosity of a galaxy and the velocity at which it rotates, which can be used to measure distances to galaxies.

How does the Tully-Fisher relation allow astronomers to measure the distances to galaxies?

How is the Tully-Fisher relation used to measure distances to galaxies? By measuring the amount of broadening in emission lines, we can determine a galaxy’s rotation. Once we know the rotation, we can determine luminosity. Comparing a galaxy’s luminosity with its apparent brightness gives us its distance.

What is the most accurate method to calculate the distance to the stars?

Astronomers use an effect called parallax to measure distances to nearby stars. Parallax is the apparent displacement of an object because of a change in the observer’s point of view.

What technique was used to find the distance to the galaxies?

Astronomers can use what are called surface brightness fluctuations (SBF, for short), along with the color of a galaxy, to calculate how far away it is from earth. Most galaxies measured in this way are millions of light years away.

What technique is used to determine the distances to the furthest galaxies?

For more-distant galaxies, astronomers rely on the exploding stars known as supernovae. Like Cepheids, the rate at which a certain class of supernovae brighten and fade reveals their true brightness, which then can be used to calculate their distance.

How we know that we live in an expanding universe?

It was during the 1920’s that Edwin Hubble provided the first evidence that we live in an expanding Universe. Hubble discovered that there is a simple relationship between the distance to a remote galaxy and the redshift in the spectral lines from that galaxy. This redshift is know as the cosmological redshift.

What are 5 methods that astronomers use to measure cosmic distances?