Amateur (Job Geheniau) shows Dark Matter

[Macavity]

Amateur (Job Geheniau) shows Dark Matter! Came across his link in a Youtube Video:
https://www.rtl-sdr.com/wp-content/uploads/2020/10/Rotation-Curve-with-JRT_English.pdf
Apologies, Job, if you/he... is/are an SGL member - Just thought it exciting stuff? 😎
(He has other websites / stuff, if you do a name search...)

[saac]

Now that is interesting, I think I may be able to make use of that in school - thanks for sharing it Chris. I like the wiki animations, very clear and easy to understand. 

Jim  

[Victor Boesen]

That's excellent. Job has done a large variety of interesting things in the amateur radio astronomy community! I did something similar myself a couple years ago, albeit with some more modest equipment due to my current life situation

My setup consisted of a simple wifi grid antenna I bought on ebay, together with a dedicated LNA and an RTL-SDR.

Here are the observations I used to determine the rotational velocity from, showing the change in dopplershift across the galactic plane.

And finally, my achieved results below.

The blue dots represent the initial results, whereas the red results were corrected to the barycenter, ie. with the orbital velocity of the Earth taken into account.

It's always fascinating to see what Job achieves with his amateur equipment, and it's very fun to push the limits - just like in astrophotography!

Victor

[SteveBz]

On 07/08/2023 at 20:26, Victor Boesen said:

That's excellent. Job has done a large variety of interesting things in the amateur radio astronomy community! I did something similar myself a couple years ago, albeit with some more modest equipment due to my current life situation

My setup consisted of a simple wifi grid antenna I bought on ebay, together with a dedicated LNA and an RTL-SDR.

Here are the observations I used to determine the rotational velocity from, showing the change in dopplershift across the galactic plane.

And finally, my achieved results below.

The blue dots represent the initial results, whereas the red results were corrected to the barycenter, ie. with the orbital velocity of the Earth taken into account.

It's always fascinating to see what Job achieves with his amateur equipment, and it's very fun to push the limits - just like in astrophotography!

Victor

Nice Victor. I didn't know you had gone on to do this. Good job.

[athornett]

I am hoping to also produce rotation curve like that in next month or two

Andy

[athornett]

Success! Now also got rotation curve and demonstrated dark matter see www.astronomy.me.uk

Helped greatly by using Ted Cline's ezRA suite of software

[SteveBz]

On 27/12/2023 at 12:37, athornett said:

got rotation curve and demonstrated dark matter

Flat rotation curve and dark matter aren't really the same thing.  You got a flat rotation curve - amazing, but there are other explanations to the flat rotation curve such as MOND (Modified Newtonian Gravity/ Milgromian Gravity) or Quantised Inertia.  Honestly none of these theories are really very intuitive.  For instance, it seems very counter-intuitive to me at least, that the amount of dark matter that you need is an exact straight line from an apparantly random point midway out from the centre of the galaxy.