What does km/s Mpc mean?

What does km/s Mpc mean?

The common unit of velocity used to measure the speed of a galaxy is km/sec, while the most common unit of for measuring the distance to nearby galaxies is called the Megaparsec (Mpc) which is equal to 3.26 million light years or 30,800,000,000,000,000,000 km! Thus the units of the Hubble constant are (km/sec)/Mpc.

What is the age of the Universe if the constant rate of expansion is 71 km/s Mpc?

According to their estimates the universe is 13.7 billion years old with an uncertainty of 200 million years. The WMAP value of Ho is 71 ± 4 km/s/Mpc which is in agreement with the HST key project.

When the Hubble’s constant is chosen to be 75 km SEC MPC the age of the Universe can be calculated as?

The age of the Universe is known as about 14 billion years old based on WMAP observation.

What is stopping a galaxy from collapsing?

The rotation of stars around the center of the Milky Way prevents the galaxy from collapsing on itself.

What describes an elliptical galaxy?

An elliptical galaxy is a type of galaxy with an approximately ellipsoidal shape and a smooth, nearly featureless image. They are preferentially found close to the centers of galaxy clusters. Elliptical galaxies range in size from tens of millions to over one hundred trillion stars.

How do they know the universe is 13.7 billion years old?

We do not know the exact age of the universe, but we believe that it is around 13 billion years – give or take a few billion. Astronomers estimate the age of the universe in two ways: (a) by looking for the oldest stars; and (b) by measuring the rate of expansion of the universe and extrapolating back to the Big Bang.

What did the COBE observations tell cosmologists about the early universe?

What did the COBE observations tell cosmologists about the early universe? Recent observations indicate that the universe is expanding faster today than it was a few billion years ago (that, in other words, the expansion of the universe is accelerating).

How does Hubble’s Law determine the age of the universe?

So, the time it has taken for the galaxies to reach their current separations is t=D/v . But, from Hubble’s Law, we know that v=H0D . So, t=D/v=D/(H0×D)=1/H0 . So, you can take 1/H0 as an estimate for the age of the Universe.

How Hubble discovered that the universe is expanding?

Hubble’s brilliant observation was that the red shift of galaxies was directly proportional to the distance of the galaxy from earth. That meant that things farther away from Earth were moving away faster. In other words, the universe must be expanding. He announced his finding in 1929.

What is the Hubble distance?

This is the distance of an object based on the Hubble flow. It is the speed of light, c times the Hubble time, tH (or equivalently c divided by the Hubble constant H0) and is called the Hubble distance DH.