- #1
Radiohannah
- 49
- 0
Hey
I'm getting very muddled with my units, and would really appreciate some clarity :-)
I have angular distances between galaxies at some redshift, in arcseconds
I want to calculate the distance in parsecs, taking into account the luminosity distance.
In the equation;
[tex]r = \frac{D_{L}}{(1+z)^{2}} \theta[/tex]
I'm assuming that "r" in this will be my distance in parsecs.
"[tex]D_{L}[/tex]" will be the luminosity distance.
and...[tex] \theta[/tex] will be the angular distance (in arcseconds..?) between the galaxies.
What units would my luminosity distance have to be in, in order to calculate my "r" in parsecs?
I know that the equation for the luminosity distance is
[tex] D_{L} =(1+z)\frac{2c}{H_{0} } \frac{\Omega_{z + (\Omega - 2)[\sqrt{1+\Omega_{z}}-1]}}{\Omega^{2}(1+z)}[/tex]
Does this give the correct units for "r" to be in parsecs? I am getting so confused!
Thank you
I'm getting very muddled with my units, and would really appreciate some clarity :-)
I have angular distances between galaxies at some redshift, in arcseconds
I want to calculate the distance in parsecs, taking into account the luminosity distance.
In the equation;
[tex]r = \frac{D_{L}}{(1+z)^{2}} \theta[/tex]
I'm assuming that "r" in this will be my distance in parsecs.
"[tex]D_{L}[/tex]" will be the luminosity distance.
and...[tex] \theta[/tex] will be the angular distance (in arcseconds..?) between the galaxies.
What units would my luminosity distance have to be in, in order to calculate my "r" in parsecs?
I know that the equation for the luminosity distance is
[tex] D_{L} =(1+z)\frac{2c}{H_{0} } \frac{\Omega_{z + (\Omega - 2)[\sqrt{1+\Omega_{z}}-1]}}{\Omega^{2}(1+z)}[/tex]
Does this give the correct units for "r" to be in parsecs? I am getting so confused!
Thank you