- #71
Buzz Bloom
Gold Member
- 2,519
- 467
Hi @JMz:
I have looked over my spreadsheet and my source articles, and I have decided I need to make some revisions, primarily because some of the more recently found references seem to be more reliable. When I complete this, I will report the means and standard deviations as well as quartile numbers with standard deviations from multiple Monte Carlo runs.
I have listed below the various variable values I will use in the next version, and the sources for the data, as well as a few comments.
https://www.sciencenews.org/article/we-share-milky-way-100-million-black-holes
It is difficult to judge from this abstract any range and confidence limits.
However, I guess that it is plausible to assume that the 1 sigma base 10 logarithmic stdev is 0.5
The total mass of all the stars in the Milky Way is estimated to be between
4.6×1010 M☉ and 6.43×1010 M☉.
Average: 5.515 1010 M☉.
Stdev = 1.3 1010 M☉.
Geometric average: 5.44 1010 M☉.
Average mass of a MW star is 0.54 M☉.
Estimated number of stars: 10 +/- 2.4 x 1010 M☉ or 1011 +/- log10(2.4)
It is not clear whether I should consider this to be a Gaussian distribution, or the logarithm to be a Gaussian distribution.
Estimated number of stars per BH = 1000 - Stdev to be calculated.
33 stars within 12.5 ly (bigger than brown dwarfs)
1000 stars at this density would require a sphere of radius (1000/33)^(1/3) * 12.5 = 39 ly.
Average distance from center for a random point is 39 * 3/4 ~= 29 ly.
Regards,
Buzz
I have looked over my spreadsheet and my source articles, and I have decided I need to make some revisions, primarily because some of the more recently found references seem to be more reliable. When I complete this, I will report the means and standard deviations as well as quartile numbers with standard deviations from multiple Monte Carlo runs.
I have listed below the various variable values I will use in the next version, and the sources for the data, as well as a few comments.
https://www.sciencenews.org/article/we-share-milky-way-100-million-black-holes
It is difficult to judge from this abstract any range and confidence limits.
However, I guess that it is plausible to assume that the 1 sigma base 10 logarithmic stdev is 0.5
The total mass of all the stars in the Milky Way is estimated to be between
4.6×1010 M☉ and 6.43×1010 M☉.
Average: 5.515 1010 M☉.
Stdev = 1.3 1010 M☉.
Geometric average: 5.44 1010 M☉.
Average mass of a MW star is 0.54 M☉.
Estimated number of stars: 10 +/- 2.4 x 1010 M☉ or 1011 +/- log10(2.4)
It is not clear whether I should consider this to be a Gaussian distribution, or the logarithm to be a Gaussian distribution.
Estimated number of stars per BH = 1000 - Stdev to be calculated.
33 stars within 12.5 ly (bigger than brown dwarfs)
1000 stars at this density would require a sphere of radius (1000/33)^(1/3) * 12.5 = 39 ly.
Average distance from center for a random point is 39 * 3/4 ~= 29 ly.
Regards,
Buzz
Last edited: