7 ms·
Not sure if I missed it, but can we tell which way the accretion disk is from our view of it?
by Pigo 8y ago
Not sure if I missed it, but can we tell which way the accretion disk is from our view of it?
- trickstra 8y agoperpendicular - we see it almost exactly from the top. Mentioned during the Q&A (41:33 to be exact)
- muterad_murilax 8y agoIf we see it almost exactly from the top, then why is one half of the ring so much brighter than the other?
- zenzen 8y agoRelativistic beaming! https://youtu.be/zUyH3XhpLTo?t=490 https://youtu.be/zUyH3XhpLTo?t=490
- hypothete 8y agoSo that would mean that the right side is tipped slightly away from us, right? Because the matter in the accretion disk starts approaching us at about halfway down the ring on the right side?
- thro_away_n 8y agoYes, from paper 1: "Third, adopting an inclination of 17° between the approaching jet and the line of sight (Walker et al. 2018), the west orientation of the jet, and a corotating disk model, matter in the bottom part of the image is moving toward the observer (clockwise rotation as seen from Earth). "
- muterad_murilax 8y agoAlready watched the video, thanks. However in his example the disk is not perpendicular to the viewer so the beaming makes more sense there I think. On the other hand, "almost exactly from the top" is not the same as "exactly from the top".
- pjungwir 8y agoThe video JumpCrisscross shared above says this is the black hole at the center of our galaxy, so why isn't its accretion disk oriented the same as the rest of the galaxy? Isn't that weird?
- alpaca128 8y agoIt's actually in a galaxy called Messier 87 which is 55 million lightyears away.
- pjungwir 8y agoOh, interesting! Wouldn't it be easier to photograph our own? :-)
- losteric 8y agoNope, for the same reason we had photos of the Moon before we had photos of Earth.
- nazgul17 8y agoCan you expand on this?
- CydeWeys 8y agoWhat they're saying is that we had to send a camera away from the Earth (in a rocket) in order to photograph it properly, and similarly you'd need to send a camera away from our galaxy (in a biiiig rocket) in order to be able to photograph it properly.
- deleted 8y ago[deleted]
- jug 8y agoDuring the press conference, they said photographing the M87 black hole was like shooting a hibernating bear, and photographing the Sag A* black hole of our galaxy like photographing a quickly moving toddler. Something about the speed making it much harder. It is also much smaller, but that's less of a problem because it's much closer. All in all apparently making it about the same angular size. But it sounds like they'll get to it, it's just harder.
- return0 8y agoapparently from the top. i hope we get to find another one sideways because they look cool ;)