5 ms·
FTR, if you wondered what they meant by "annihilation signals from the dark matter microhalo", apparently one of the theories for what makes up dark matter is W
by est31 5y ago
FTR, if you wondered what they meant by "annihilation signals from the dark matter microhalo", apparently one of the theories for what makes up dark matter is WIMPs which are special particles that interact weakly with normal particles but can interact with each other and result in creation of other, better observable particles.
The theory is that in the early universe, WIMPs were created spontaneously due to massive temperatures of the primordial plasma, but later as the universe expanded and cooled, this creation didn't work. However, the WIMPs would still be able to react with each other, reducing their numbers, until they'd be so rare that annihilations are such a rare event that they don't significantly reduce their numbers any more. Then space expanded even further.
https://arxiv.org/pdf/1403.4495.pdf https://arxiv.org/pdf/1403.4495.pdf
Apparently due to the strong perturbances of the dark matter that this black hole creates, it creates potentially detectable annihilations, and they discuss which scenarios can be excluded or detected with data generated by the FERMI-LAT gamma ray telescope.
Not a physicist though, so please correct me if I'm wrong.
- da_chicken 5y agoNote for the curious: WIMP simply means "weakly interactive massive particle". And "massive" here means "has mass," not that they're gigantic. Although they're theorized to have a mass closer to the Higgs boson than a proton, which is a lot of mass as far as subatomic particles go.
- Sharlin 5y agoAs opposed to MACHOs ("massive compact halo object") where the "massive" actually does mean "planetary to stellar mass".
- gmadsen 5y agois that synonymous with dark matter as described in galaxy structure models?
- binarybanana 5y agoIANAP, but they're (among others, like MACHOs, primordial BHs, etc.) potential candidates for dark matter, yes.
- AtlasBarfed 5y agoHuh, so the detection of a MACHO candidate would be a WIMP? That is some delicious astrophysics smorgasborg
- deleted 5y ago[deleted]
- rich_sasha 5y agoI think MACHO and WIMP are alternative theories. MACHO came first IIRC
- dnautics 5y agoGP was not well-phrased. I think they meant "the first detection of a MACHO candidates could be via a WIMP detection" (a black hole planet 9 would likely be in the last uneliminated sliver of MACHO candidate space and we'd see it via WIMP annihilation)
- binarybanana 5y agoIIRC, the other way around. The editor who greenlighted the WIMP paper for print (and only because it was already an established name) regretted this decision once he saw the MACHO paper. Apparently he doesn't like cute names.
- Simplicitas 5y ago"annihilation signals" sounds very troubling
- tejtm 5y agomatter / antimatter annihilation is the perfectly normal state of affairs, we only exist as a fluke because it did not happen perfectly.