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CosmicRami

The smoking gun signature of detection is this violin plot, known as the Hellings & Downs correlation. It tells us that all the pulsars across the sky are showing a correlated signal that is expected to be produced by the gravitational wave background of supermassive black hole binaries.

We're seeing the Universe shake, rattle and rolling!

Interestingly, data from our PPTA paper - the amplitude signal strength is time-dependent, which is not expected if gravitational wave signals are equally isotropic.

Could be a processing issue, or the pulsars (weirdos) OR potentially GWs stronger in one part of the sky! 🤯

This is wild to me!

#Astrodon #Astrophysics #RadioAstronomy #GravitationalWaves #Science #Pulsars

📸Reardon et al. 2023

a plot that shows eight violin plots that are green and inflated towards their centres. They follow a curved line from left to right. In the background are several grey histogram boxes.
Two plots side by side. Both have an x-axis that runs from 2004 to 2022. The y-axis indicates the amplitude of the gravitational wave signal. In the left graph there are violin plots in orange and purple. The orange violins sink a little before the purple start and commence rising. On the right graph, the orange violins are already lower than the purple, and so everything is rising towards the right.
29 Jun 2023 at 4:13 | Open on aus.social
8 comments
Kote Isaev

@CosmicRami Either Universe has some "geometric entry point" where the root singularity or other source of big bang was, or may be Universe have another web-like structure, but "dots" in that "gravitational web" are points of events having strongest impact on large-scale space-time, or both.

29 Jun 2023 at 4:22 | Open on mastodon.online
WallOffTrump
Chris Walter
DELETED

@CosmicRami congrats on your findings!

Can I ask like how we know it's not just earth shaking locally? Do the ripples happen all at once or does the ripple propagate at the speed of light for example?

29 Jun 2023 at 5:24 | Open on mindly.social
CosmicRami

@silo_bear oh this wasn't just me, it was our team but also an army of global pulsar astronomers. Thank you though!

Yep, GWs propagate at speed of light, and we know it is not a localised effect because different observatories are seeing the signal independently.

29 Jun 2023 at 6:49 | Open on aus.social
Dr David Mills

@CosmicRami could a pair of SMBHs in say M31 swamp the data and skew it in one direction? Or would that be too obvious, so it must be further away?

29 Jun 2023 at 6:46 | Open on mastodon.social
CosmicRami

@Dtl yeah, we can't resolve individual sources as yet, but 'loud' binaries are likely to be resolved once several more years of data is collected. I'm not sure M31 has more than 1 SMBH though? An example of one I am keeping my eye out for is OJ287 - eccentric orbit, short period, radiating GWs and we have an EM counterpart signal we can try to fit with it as well!

29 Jun 2023 at 6:48 | Open on aus.social
Dr David Mills

@CosmicRami I just picked M31 as a big nearby chunk of stuff. Interesting, I didn't know about OJ287. Will do some reading, thank you.

29 Jun 2023 at 6:55 | Open on mastodon.social
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