Hi there,
I am wondering about the definition of ckpc/h. I am aware that h is a constant, is ckpc speed of light times kpc?

Dylan Nelson

21 Jun '19

Hi David,

The "c" means "comoving", as opposed to physical. To convert a length from ckpc/h to "physical kpc" you should divide by h and multiply by a (the scalefactor, = 1.0 at z=0).

David Wang

21 Jun '19

Thank you!

Chengkai Yu

12 Jul '22

Hi,

I wonder that if I use TNG50-4, are the values of little h different for different redshifts?

Or I should use the little h value (0.6774) given at the top of the web page for all redshifts?

Hi there,

I am wondering about the definition of ckpc/h. I am aware that h is a constant, is ckpc

speed of lighttimes kpc?Hi David,

The "c" means "comoving", as opposed to physical. To convert a length from

`ckpc/h`

to "physical kpc" you should divide by`h`

and multiply by`a`

(the scalefactor, = 1.0 at z=0).Thank you!

Hi,

I wonder that if I use TNG50-4, are the values of little h different for different redshifts?

Or I should use the little h value (0.6774) given at the top of the web page for all redshifts?

The value of

`h`

is independent of redshift.Thanks!

Thanks!