How to convert between different mass measurements for CDM H

In summary, you need to convert the mass of a cluster to a velocity dispersion in terms of M_500c instead of M_200c to find an equivalent dispersion.
  • #1
floyd0117
6
0
If I have a cluster with a mass measured in M_500c, then how do I go about converting that mass to M_200c given some concentration and an NFW profile?
 
Space news on Phys.org
  • #2
What do you mean converting the mass? What are you converting? Why?
 
  • #3
Chalnoth said:
What do you mean converting the mass? What are you converting? Why?

I have a dataset of cluster masses, expressed in units of M_500c, which I need to relate to a velocity dispersion. But the relation between cluster mass and velocity dispersion is in terms of M_200c, so I need to convert the masses in the dataset before I can find the equivalent dispersions.
 
  • #4
floyd0117 said:
I have a dataset of cluster masses, expressed in units of M_500c, which I need to relate to a velocity dispersion. But the relation between cluster mass and velocity dispersion is in terms of M_200c, so I need to convert the masses in the dataset before I can find the equivalent dispersions.
Ahh, okay. I'm honestly not sure. I did find this resource, which describes these measures a bit:
https://www.princeton.edu/astro/undergraduate/astro-jps-senior-theses-a/bilhudathesis-2.pdf [Broken]

It looks like [itex]M_{500}[/itex] is the mass within [itex]R_{500}[/itex], while [itex]M_{200}[/itex] is the mass within [itex]R_{200}[/itex], where [itex]R_{500} \approx 0.7 R_{200}[/itex]. If you've got a good understanding of the NFW profile, you might be able to use that to do the conversion.

That said, my guess is it'd be even better to convert the relation between mass and dispersion to be in terms of [itex]M_{500}[/itex] instead of [itex]M_{200}[/itex], as that's most likely a far simpler operation.
 
Last edited by a moderator:
  • #5
Chalnoth said:
Ahh, okay. I'm honestly not sure. I did find this resource, which describes these measures a bit:
https://www.princeton.edu/astro/undergraduate/astro-jps-senior-theses-a/bilhudathesis-2.pdf [Broken]

It looks like [itex]M_{500}[/itex] is the mass within [itex]R_{500}[/itex], while [itex]M_{200}[/itex] is the mass within [itex]R_{200}[/itex], where [itex]R_{500} \approx 0.7 R_{200}[/itex]. If you've got a good understanding of the NFW profile, you might be able to use that to do the conversion.

That said, my guess is it'd be even better to convert the relation between mass and dispersion to be in terms of [itex]M_{500}[/itex] instead of [itex]M_{200}[/itex], as that's most likely a far simpler operation.

Perhaps, but I'm trying to follow the methodology presented in a specific paper and replicate their results. Thanks anyway
 
Last edited by a moderator:
  • #6
floyd0117 said:
Perhaps, but I'm trying to follow the methodology presented in a specific paper and replicate their results. Thanks anyway
Makes sense. Sorry I can't be of more help.
 

1. How do I convert between grams (g) and kilograms (kg) for CDM H?

To convert from grams to kilograms, divide the number of grams by 1000. To convert from kilograms to grams, multiply the number of kilograms by 1000.

2. What is the conversion factor for converting between milligrams (mg) and grams (g) for CDM H?

The conversion factor for milligrams to grams is 0.001. To convert from milligrams to grams, divide the number of milligrams by 1000. To convert from grams to milligrams, multiply the number of grams by 1000.

3. How can I convert between ounces (oz) and pounds (lb) for CDM H?

To convert from ounces to pounds, divide the number of ounces by 16. To convert from pounds to ounces, multiply the number of pounds by 16.

4. What is the formula for converting between metric tons (t) and kilograms (kg) for CDM H?

The formula for converting metric tons to kilograms is 1 t = 1000 kg. To convert from metric tons to kilograms, multiply the number of metric tons by 1000. To convert from kilograms to metric tons, divide the number of kilograms by 1000.

5. How do I convert between different units of volume, such as liters (L) and milliliters (mL) for CDM H?

To convert from liters to milliliters, multiply the number of liters by 1000. To convert from milliliters to liters, divide the number of milliliters by 1000.

Similar threads

Replies
2
Views
1K
  • High Energy, Nuclear, Particle Physics
Replies
13
Views
2K
  • Astronomy and Astrophysics
Replies
8
Views
360
  • Introductory Physics Homework Help
Replies
3
Views
115
Replies
1
Views
785
  • Other Physics Topics
Replies
27
Views
1K
  • High Energy, Nuclear, Particle Physics
Replies
4
Views
1K
  • Special and General Relativity
Replies
5
Views
865
  • Introductory Physics Homework Help
Replies
4
Views
399
Replies
5
Views
1K
Back
Top