Quadruply imaged quasars

39:44those are actually the ones we like. That's why there's four. >> Very interesting. Okay. >> Let's look at Let's look at one. So number seven. >> Yes. >> Uh so this is a quadruply imaged quasar. >> Wow. >> So nature provides point-like background sources in the form of uh quasars. So a quasar is a black hole that is uh eating matter. Uh and so all of the matter around it gets really, really hot and it shines extremely brightly. And they are extremely compact, so they're essentially like like point sources. >> Mhm. >> And in this case, you have this yellow blob in the middle. >> Yes. >> So, that's a regular galaxy. >> Yes.

40:24>> Uh and that regular galaxy is situated directly in front of another galaxy that has a quasar in it. >> Mhm. >> And so, in addition to this ring, which is uh lensed light from the background galaxy coming around, and so we see it, you know, around the the deflector in front, we actually see four images of the central quasar. Uh so >> one of the coolest things. >> So, those are four duplicate images of the bright point-like center of that background galaxy. >> This is unbelievable. And so, you And we're saying one of them is kind of that uh solitary one slightly to the right of the center like galaxy cluster, and then we sort of have three on the edge of

41:07what this like outer ring of the lens looks like. Um and so, I just want to make sure and clarify that I'm understanding these correctly. There's two things happening here. It is both the lens of the background galaxy itself, which is kind of the orange ring, and then in addition to that, because the quasar inside that background galaxy, based on the way you describe it, is such a high It has a um It's such a key source of light because it's eating so much and creating a lot of heat, and subsequently giving off a ton of light in and of itself as an individual That's

41:47the purple that we're seeing in addition to the lens of the whole galaxy that the quasar's inside itself. >> Yeah, so if if you saw an image of that background source, which here it's being lensed, so it looks really weird, right? But if you saw an image of that galaxy without lensing happening, it would probably be a spiral galaxy with a really bright spot right in the middle. >> Right. Right. >> Now, if you put a giant galaxy in front of it, instead of seeing a spiral galaxy with a bright spot right in the middle, we're seeing four images of that bright spot, and then the galaxy around that bright spot being lens around into this really really cool looking thing.

42:27>> so fascinating. My goodness. Oh my god, that's so interesting. >> Yeah, so these things are I mean, it's one of the most in your face examples of Einstein's general relativity, right? I mean, you point a really good telescope into space and you find these things. >> This is the whole the space-time curvature piece, like like the that it that um greatly like gravity creates these wells that light travels around and is so concentrated gravity and all like it's such a it's so not intuitive to me, like just it like it makes sense. Everything you're saying makes sense. But thinking about it makes my brain hurt a little bit.

43:10Because it's like, well, why does it do that? But like I know there's a reason why it does that, but it still is not naturally intuitive for me. >> Yeah, I mean, it's it takes a while to wrap your head around. >> But that's fascinating. And and so now I think it makes a lot of sense why with that explanation of strong lensing, strong gravitational lensing, and an understanding of dark matter and the base research question around wanting to find and be able to measure these small clumps of dark matter, I I I can sort of now get why these concentrated point light back source background galaxies

43:51that create like the tight ring that then have these multiple images, because what I would sort of guess from the way we set this up is that each of those you now have four in that case four images of the same thing that you can then analyze in a variety of different ways as opposed to just having one image of the same thing with a well-characterized understanding of the gravitational impacts and things like that. >> Yeah, so it's actually it's really important to have and this is why strong lensing is so important. It's important to have the multiple images because if you just have one image, it's not possible to disentangle what the source actually intrinsically looks

44:32like and what kind of, you know, lensing deformation might be happening in between you and the source, right? >> Right. Right. >> But if you have multiple images of the same source, it's much easier to disentangle what the source actually looks like from what kind of distortions might be there. >> What's so funny is I mean, if you if as many know, I'm the resident UAP guy on the podcast unidentified anomalous phenomenon and one of the challenges with um detection characterization and evaluation is you need a multi-sensor systems because if you just have one source, an infrared detector, or a you know, electro-optical or you know, full motion video, it's it's hard to understand

45:13distance and speed and and all these things with only one reference point. So, a similar like it tracks conceptually that you want to be able to have multiple points to be able to triangulate to disentangle in the way that you described. Does it also help with disentangling the impacts of the regular gravity versus the gravity driven by dark matter? >> Uh yeah, so that's a it's a good