How many parsecs is it when the redshift z=1

  • Thread starter nenyan
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In summary, converting red shift to parsecs depends on the concept of distance used and can be calculated using the lightcone calculator tool. The attached file provides more information and examples, including a conversion for z=0.4. The top row in the provided table shows the result for converting red shift to parsecs in flat geometry with WMAP parameters.
  • #1
nenyan
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How to convert red shift to parsecs? Is there a simple converting equation?
 
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  • #2
nenyan said:
How to convert red shift to parsecs?

This depends on which concept of distance is used. See the first paragraph of the attached file.

nenyan said:
s there a simple converting equation?

I wrote up an answer for someone else, who specified z = 0.4. I didn't use dimensionless parameters. See the last two graphs in the attached file.
 

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  • #3
very useful. thanks
 
  • #4
George Jones said:
This depends on which concept of distance is used. See the first paragraph of the attached file.



I wrote up an answer for someone else, who specified z = 0.4. I didn't use dimensionless parameters. See the last two graphs in the attached file.

thats one of the better quality articles I've read. Far better than some of my attempts lol. Thank you for showing it.
 
  • #5
My signature first link has a handy tool called the lightcone calculator here I set stretch to 2.0 for S_upper. S=1+z. I set a randon value for lower stretch.
then I selected the columns I wanted and decimal places. Clicked linear steps.
here is the result with WMAP
flat geometry parameters.

[tex]{\small\begin{array}{|c|c|c|c|c|c|}\hline R_{0} (Gly) & R_{\infty} (Gly) & S_{eq} & H_{0} & \Omega_\Lambda & \Omega_m\\ \hline 14.4&17.3&3400&67.9&0.693&0.307\\ \hline \end{array}}[/tex] [tex]{\small\begin{array}{|r|r|r|r|r|r|r|r|r|r|r|r|r|r|r|r|} \hline a=1/S&S&z&T (Gy)&D_{now} (Gly)&D_{then}(Gly) \\ \hline 0.500&2.000&1.000&5.8636&11.046&5.523\\ \hline 1.000&1.000&0.000&13.7872&0.000&0.000\\ \hline 1.668&0.599&-0.401&21.7987&6.249&10.425\\ \hline 2.783&0.359&-0.641&30.4437&10.300&28.660\\ \hline 4.642&0.215&-0.785&39.2497&12.776&59.303\\ \hline 7.743&0.129&-0.871&48.0918&14.267&110.467\\ \hline 12.915&0.077&-0.923&56.9418&15.162&195.824\\ \hline 21.544&0.046&-0.954&65.7934&15.698&338.212\\ \hline 35.938&0.028&-0.972&74.6452&16.020&575.729\\ \hline 59.948&0.017&-0.983&83.4973&16.213&971.932\\ \hline 100.000&0.010&-0.990&92.3494&16.328&1632.838\\ \hline \end{array}}[/tex]

the top row has the result you want you just need to convert to parsecs.
 

1. How is redshift related to distance in parsecs?

Redshift is a measure of the expansion of the universe and is directly related to distance. The higher the redshift value, the farther the object is from us. This means that the distance in parsecs increases as the redshift value increases.

2. What is the formula for converting redshift to distance in parsecs?

The formula for converting redshift to distance in parsecs is: distance (in parsecs) = (speed of light * redshift value) / Hubble constant. The Hubble constant is a value that represents the rate of expansion of the universe.

3. How do we measure the redshift of an object?

The redshift of an object is measured by observing its spectrum. The spectrum of a distant object will have a redshifted pattern, which can be compared to the spectrum of a stationary object to determine the redshift value.

4. What does a redshift of z=1 mean in terms of distance in parsecs?

A redshift value of z=1 means that the object is located at a distance of approximately 3.26 billion parsecs from Earth. This distance is equivalent to 10.6 billion light years.

5. Can redshift values be negative and what does this mean in terms of distance?

Redshift values can be negative if the object is moving towards us, which is known as a blueshift. A negative redshift value indicates that the object is located closer to us than its rest frame. The distance in parsecs for a negative redshift value will be smaller than the distance for a positive redshift value.

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