Redshift Along Galactic Plane: Study & Research

In summary, the redshift changes along the galactic plane or ortoganal to the galactic plane due to the rotation of the galaxy and the distribution of dust. There is no redshift from the expansion of the universe as that doesn't have an effect within our galaxy.
  • #1
Ennio
26
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How do the redshift change along the galactic plane or ortoganal to the galactic plane? If we measure a redshift of a star on the backgorund of other side of our galactic plane (where most stars are concentrated) are the redshifts avaraged higher? Is there a study or research discussing this topic? Thank you
 
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  • #2
Within our galaxy red- and blueshift just comes from the overall rotation of the galaxy plus a bit of random motion. What exactly you measure depends on where you look plus a bit of random chance. There is no redshift from the expansion of the universe as that doesn't have an effect within our galaxy.
Ennio said:
of other side of our galactic plane (where most stars are concentrated)
Huh?
 
  • #3
mfb said:
Within our galaxy red- and blueshift just comes from the overall rotation of the galaxy plus a bit of random motion. What exactly you measure depends on where you look plus a bit of random chance. There is no redshift from the expansion of the universe as that doesn't have an effect within our galaxy.Huh?

"There is no redshift from the expansion of the universe as that doesn't have an effect within our Galaxy"
But we measure the cosmological redshift from Earth and the light, coming from the Background stars, goes through the milky way.. Do we measure higher redshifts along the galactic plane or not? You mean the distribution of the redshifts is the the same all over the sky..
 
  • #4
Ennio said:
But we measure the cosmological redshift from Earth and the light, coming from the Background stars, goes through the milky way.. Do we measure higher redshifts along the galactic plane or not? You mean the distribution of the redshifts is the the same all over the sky..

again HUH!

what background stars. We can only see around 1/3 to 1/2 of the stars in our galaxy (the Milky Way) ... the rest are hidden from us behind the core and other arms.

what background stars ??

There won't be any cosmological red shift seen from stars within our galaxy because they are all gravitationally bound
 
  • #5
Ennio said:
"There is no redshift from the expansion of the universe as that doesn't have an effect within our Galaxy"
But we measure the cosmological redshift from Earth and the light, coming from the Background stars, goes through the milky way.. Do we measure higher redshifts along the galactic plane or not? You mean the distribution of the redshifts is the the same all over the sky..
Are you asking about the integrated Sachs-Wolfe effect? Our galaxy contributes a bit to it, but the contribution is tiny.
 
  • #6
Dust causes a reddening effect called extinction. That is not the same as a red shift.

Suppose you build a few huge stoplights out in space. Dust in Milky Way will make the green light dimmer when compared to the red light. That is the same as the Sunset/Sunrise. The Sun's light has not changed but you see more of a part of that light.

If you launch the stoplight away at relativistic speeds the stop light will have a yellow-orange-infrared cycle instead of green-yellow-red. If you approach a stoplight at relativistic speeds you would see a blue-green-orange cycle. The shifts do not effect the intensity of the lights.

The Milky Way has a lot of dust and does cause extinction. Part of the disk is rotating away from us and the other part is rotating toward us. That causes a slight Doppler red-shift. The stars on the opposite side of the galaxy are not visible because they are completely blocked by dust. If they were visible there would be on average no measurable red-shift because they are not moving toward or away from us. The far side has perpendicular motion. Individual stars could be coming or going same as nearby stars.
 
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1. What is redshift along the galactic plane?

Redshift along the galactic plane refers to the phenomenon where light from distant objects, such as galaxies or stars, appears to have a longer wavelength (shifted towards the red end of the spectrum) due to the expansion of the universe.

2. Why is studying redshift along the galactic plane important?

Studying redshift along the galactic plane allows scientists to better understand the structure, evolution, and dynamics of the universe. It can also provide insights into the distribution and movement of matter in the universe.

3. How do scientists measure redshift along the galactic plane?

Scientists measure redshift along the galactic plane by analyzing the spectrum of light emitted from distant objects. This involves measuring the shift in wavelengths of specific spectral lines, such as the hydrogen alpha line, to determine the amount of redshift.

4. What are some potential challenges when researching redshift along the galactic plane?

Some potential challenges when researching redshift along the galactic plane include the need for advanced and expensive equipment, the difficulty in obtaining clear and accurate data due to interference from Earth's atmosphere, and the complex nature of the subject matter.

5. What are some potential implications of redshift along the galactic plane for our understanding of the universe?

The study of redshift along the galactic plane has significant implications for our understanding of the universe, as it can provide insights into the expansion rate of the universe, the distribution of dark matter and dark energy, and the potential fate of the universe. It can also help scientists refine and test theories such as the Big Bang theory and the theory of general relativity.

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