A Data on galaxy rotation curves vs visible matter

AI Thread Summary
The discussion focuses on the need for raw data comparing visible mass versus total mass in galaxies to test dark matter theories. A user seeks a table format of this data, including error percentages, and mentions difficulty in interpreting existing data. Recommendations include exploring Stacy McGaugh's "SPARC" database, which contains extensive research on dark matter fitting. Additional resources such as McGaugh's blog and specific academic papers on the Radial Acceleration Relation are suggested for further understanding. Engaging with the community on McGaugh's blog may provide additional insights and answers.
bakerjay
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TL;DR Summary
I'm after some raw data (visible mass vs total mass within different radii) for testing theories of dark matter in galaxies.
I'm after some raw data for testing theories of dark matter in galaxies.

Basically what I want is table showing visible mass vs total mass within different radii (or, observed rotational velocity vs expected rotational velocity without dark matter). Plus error percentages. And ideally, for multiple different galaxies.

I've been able to find lots of low-res graphs such as this, which show the sort of data I'm after, but can't seem to find it in table form...

ation_curve_of_spiral_galaxy_Messier_33_Triangulum.png
 
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bakerjay said:
TL;DR Summary: I'm after some raw data (visible mass vs total mass within different radii) for testing theories of dark matter in galaxies.
I guess you have not yet found Stacy McGaugh's website and the extensive, high quality "SPARC" database, together with his data pages?

Prof McGaugh and colleagues have already done vast amounts of that kind of attempted DM fitting, eventually leading himself into deep disappointment about DM. If you can adopt a truly unbiased scientific approach, you would profit by familiarizing yourself with their work over the past 20+ yrs.
 
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strangerep said:
I guess you have not yet found Stacy McGaugh's website and the extensive, high quality "SPARC" database, together with his data pages?

Prof McGaugh and colleagues have already done vast amounts of that kind of attempted DM fitting, eventually leading himself into deep disappointment about DM. If you can adopt a truly unbiased scientific approach, you would profit by familiarizing yourself with their work over the past 20+ yrs.
Oh great, thanks! That looks like the kind of thing I'm after.

I'm having a bit of trouble interpreting some of that - for instance, in the 'Newtonian Mass Models' data, there is observed velocity, and then velocity contributions from gas, and from disk. I would have anticipated that {observed - gas - disk} would give you the velocity contribution from dark matter, but often the gas+disk contributions are actually greater than the observed velocity. What am I missing here?
 
Alas, I'm not an expert, and you didn't quote the data examples that you're puzzled about.

So I'll just note that, at low accelerations, one finds that ##\,g_{obs} \propto \sqrt{g_{bar}}## .

For more detail, try these papers:

One Law to Rule them All: the Radial Acceleration Relation of Galaxies

The Radial Acceleration Relation in Rotationally Supported Galaxies

You might also benefit by following McGaugh's blog Triton Station, and also reading some of his older blog posts therein.

If you reply quickly to any of his (new) blog posts, and ask questions, sometimes he (or another poster) will answer helpfully, even if your question is not quite on the topic of his post.
 
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The formal paper is here. The Rutgers University news has published a story about an image being closely examined at their New Brunswick campus. Here is an excerpt: Computer modeling of the gravitational lens by Keeton and Eid showed that the four visible foreground galaxies causing the gravitational bending couldn’t explain the details of the five-image pattern. Only with the addition of a large, invisible mass, in this case, a dark matter halo, could the model match the observations...
Hi, I’m pretty new to cosmology and I’m trying to get my head around the Big Bang and the potential infinite extent of the universe as a whole. There’s lots of misleading info out there but this forum and a few others have helped me and I just wanted to check I have the right idea. The Big Bang was the creation of space and time. At this instant t=0 space was infinite in size but the scale factor was zero. I’m picturing it (hopefully correctly) like an excel spreadsheet with infinite...
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