Starship Asterisk*

APOD Robot wrote:

Featured here, HAWC+ observations of the M82, the Cigar galaxy, show that the central magnetic field is perpendicular to the disk and parallel to the strong supergalactic wind. This observation bolsters the hypothesis that M82's central magnetic field helps its wind transport the mass of millions of stars out from the central star-burst region.

Ars Technica wrote:

At the centers of some massive galaxies, supermassive black holes power incredibly bright objects called quasars. Black holes gobble up matter so quickly that the infalling matter heats up from friction and emits light. While this disk of accreting matter is incredibly bright on its own, the black hole has another source of light: jets erupt from the poles of the black hole, shooting particles at speeds approaching that of light. These jets are incredibly bright—possibly brighter than the accretion disk.

It’s not known for sure what causes the jets. It’s thought that the black hole’s spin and mass interact with the magnetic field near the black hole to accelerate the particles. While some evidence supports this model, it's been difficult to test, mainly because scientists lacked a full knowledge of how bright the accretion disks is. But a new study of a sample of blazars (quasars with jets that point toward Earth) shows a clear correlation between the jets' power and the accretion disk’s brightness. This suggests that the magnetic field is a factor in producing the jets.

orin stepanek wrote: ↑Mon Mar 11, 2019 12:24 pm I wonder if man may someday ride these magnetic currents for space travel? :rocketship:

Cousin Ricky wrote: ↑Mon Mar 11, 2019 3:06 pm Why is there a square around the Milky Way star to the lower right of the galaxy?

JohnD wrote: ↑Mon Mar 11, 2019 6:30 pm By a "square" do you mean the "diffraction spikes".
They are commonly seen in astronomcal photographs, and the brighter the star, the more prominent, and that's the brightest in the pic.
There's an excellent example, top right, on the Wiki page: https://en.wikipedia.org/wiki/Diffraction_spike
The spikes are an artefact, but not significant of a need for special processing are they, Chris?

SOFIA observatory has been successful in detailing distant magnetic fields by observing infrared light polarized by reflection from dust grains.

Odysseus wrote: ↑Mon Mar 11, 2019 8:20 pm

SOFIA observatory has been successful in detailing distant magnetic fields by observing infrared light polarized by reflection from dust grains.

Why is it that magnetic fields need illumination to be detectable? How are light and dust grains affected by these magnetic fields.

• Magnetic fields align small dust grains with other small dust grains over large scales.
  
  Those small dust grains produce polarized light (either by radiation or absorption).
  
  We can observe & measure such light polarized over large scales from far away.

Odysseus wrote: ↑Mon Mar 11, 2019 8:20 pm

SOFIA observatory has been successful in detailing distant magnetic fields by observing infrared light polarized by reflection from dust grains.

Why is it that magnetic fields need illumination to be detectable? How are light and dust grains affected by these magnetic fields.

Guest wrote: ↑Tue Mar 12, 2019 2:57 am Just wondering. If a black hole has infinite mass, and therefore cannot exist in our 'interpretation' of reality, then how can it have 'spin' as we understand it? Kind of the same question as 'was there time before the big bang' type of argument. Without a frame of reference, given infinite density of a super massive black hole, it kind of makes me wonder about our real understanding of physics/space/time/energy & matter, But still a great image.

JohnD wrote: ↑Tue Mar 12, 2019 9:32 am Thanks, Chris! Can't see it, but I'll take your word for it!
John

Guest wrote: ↑Tue Mar 12, 2019 2:57 am Just wondering. If a black hole has infinite mass, and therefore cannot exist in our 'interpretation' of reality, then how can it have 'spin' as we understand it? Kind of the same question as 'was there time before the big bang' type of argument. Without a frame of reference, given infinite density of a super massive black hole, it kind of makes me wonder about our real understanding of physics/space/time/energy & matter, But still a great image.