Search found 1130 matches
- Wed Oct 23, 2024 9:09 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Dark Matter in a Simulated Universe (2024 Oct 20)
- Replies: 36
- Views: 6366
Re: APOD: Dark Matter in a Simulated Universe (2024 Oct 20)
"Dark charge"? Victor conjectured that dark matter might possess a "dark charge" in his prior post (which for some reason isn't appearing in my reply to your reply that does show it). Yeah, well maybe it possesses dark magnetism or dark unicorns. Making up a word without any und...
- Wed Oct 23, 2024 6:28 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Dark Matter in a Simulated Universe (2024 Oct 20)
- Replies: 36
- Views: 6366
Re: APOD: Dark Matter in a Simulated Universe (2024 Oct 20)
I don't think the concept of a dark matter black hole makes any sense. The nature of the matter is completely lost in a black hole. It's a singularity with mass. Why would one formed from baryonic matter be any different from one formed from dark matter? They say an electric charge is conserved aft...
- Wed Oct 23, 2024 2:59 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Dark Matter in a Simulated Universe (2024 Oct 20)
- Replies: 36
- Views: 6366
Re: APOD: Dark Matter in a Simulated Universe (2024 Oct 20)
Except in actual usage, "temperature" simply isn't used that way. Absent a large enough population of particles for statistics to be meaningful, you would just consider the energy of a particle (which could be all over the place as it absorbs or emits photons and changes its energy state)...
- Mon Oct 21, 2024 3:15 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Dark Matter in a Simulated Universe (2024 Oct 20)
- Replies: 36
- Views: 6366
Re: APOD: Dark Matter in a Simulated Universe (2024 Oct 20)
I wonder if baryon clumps (orange) are dots and dark matter clumps (grey) are filaments. Because we arbitrarily set a threshold level to treat a more dense thing as a clump and the rest as an empty background. We could have used the same density threshold for baryons and the dark matter. But then th...
- Mon Oct 21, 2024 3:03 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Dark Matter in a Simulated Universe (2024 Oct 20)
- Replies: 36
- Views: 6366
Re: APOD: Dark Matter in a Simulated Universe (2024 Oct 20)
So many stupid questions: - Dark matter is affected by gravity and has gravity of its own, so presumably it could create clumps of greater density due to random concentration fluctuations, correct? - Dark matter is unaffected by the electromagnetic field and so doesn't generate any photons. Does th...
- Mon Oct 21, 2024 2:54 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Dark Matter in a Simulated Universe (2024 Oct 20)
- Replies: 36
- Views: 6366
Re: APOD: Dark Matter in a Simulated Universe (2024 Oct 20)
What about black holes in relation to dark matter? Is it fair to presume that they swallow it like everything else? Might the billions of solar masses of the largest ones include copious amounts of dark matter pulled in early on in the history of the universe? Well, for the most part black holes do...
- Thu Oct 10, 2024 6:32 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: M106: A Spiral Galaxy with a Strange... (2024 Oct 09)
- Replies: 37
- Views: 6655
Re: APOD: M106: A Spiral Galaxy with a Strange... (2024 Oct 09)
M106 combo.jpgM106 combo-.jpg https://asterisk.apod.com/download/file.php?id=50401&mode=view to my eye the dust lanes in the optic picture are not in the plane of the disk at all. They form a cylinder wall above the disk to the right of the core, seen clearly, and a wall below the disk, to the ...
- Thu Oct 10, 2024 12:13 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: M106: A Spiral Galaxy with a Strange... (2024 Oct 09)
- Replies: 37
- Views: 6655
Re: APOD: M106: A Spiral Galaxy with a Strange... (2024 Oct 09)
https://cdn.mos.cms.futurecdn.net/hCXYB5YKXzdq2WEHYEe36d-970-80.jpg.webp And what is Andromeda doing here? Ann https://apod.nasa.gov/apod/image/2410/M106_Obaidly_960.jpg my first thought was: a little galaxy beside may somehow have to do with some of the large galaxy's peculiarities Like a blue rin...
- Wed Oct 09, 2024 9:44 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: M106: A Spiral Galaxy with a Strange... (2024 Oct 09)
- Replies: 37
- Views: 6655
Re: APOD: M106: A Spiral Galaxy with a Strange... (2024 Oct 09)
M106 combo.jpgM106 combo-.jpg https://asterisk.apod.com/download/file.php?id=50401&mode=view ...I'm not sure if the galaxy really has a flat disk... https://live.staticflickr.com/65535/54054583532_dd39f4840c_b.jpg Credit: NASA/ESA X-ray in blue (CHANDRA) IR in red (SST) To me looks like a dense...
- Wed Oct 09, 2024 8:15 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: M106: A Spiral Galaxy with a Strange... (2024 Oct 09)
- Replies: 37
- Views: 6655
- Wed Oct 09, 2024 6:31 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: M106: A Spiral Galaxy with a Strange... (2024 Oct 09)
- Replies: 37
- Views: 6655
Re: APOD: M106: A Spiral Galaxy with a Strange... (2024 Oct 09)
About those 4 "anomalous arms", are they arms of stars and gas like normal galactic arms, or are they just jets of X-ray hot gas emitted either long ago and distorted over time, or still being added to by central BH activity? I suppose there might be the odd star in those arms, but for th...
- Wed Oct 09, 2024 6:15 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: M106: A Spiral Galaxy with a Strange... (2024 Oct 09)
- Replies: 37
- Views: 6655
Re: APOD: M106: A Spiral Galaxy with a Strange... (2024 Oct 09)
Yeah, the closeup Chandra X-ray view of the center of M106 composite hardly looks like the same galaxy! Composite image features X-rays from Chandra (blue), radio waves from the VLA (purple), optical data from Hubble (yellow and blue), and infrared with Spitzer (red). Two anomalous arms, which aren...
- Wed Oct 09, 2024 4:21 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: The Large Magellanic Cloud Galaxy (2024 Oct 02)
- Replies: 21
- Views: 4588
Re: APOD: The Large Magellanic Cloud Galaxy (2024 Oct 02)
I'm not understanding your concern. With galaxies the tidal forces distort structures because the structures are weakly bound and exist in a gradient force field. There is nothing "bilateral" about that. it's a stretching and therefore the core sees the opposite parts pulled off at two op...
- Wed Oct 09, 2024 1:35 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: The Large Magellanic Cloud Galaxy (2024 Oct 02)
- Replies: 21
- Views: 4588
Re: APOD: The Large Magellanic Cloud Galaxy (2024 Oct 02)
Tidal forces are not bilateral! The effect of the Moon's gravity on the Earth is that the force is greater on the side facing the Moon than it is on the opposite side. So the net force across the Earth creates tension, which distorts both the planet and its oceans. That creates a deviation above th...
- Wed Oct 09, 2024 12:44 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: M106: A Spiral Galaxy with a Strange... (2024 Oct 09)
- Replies: 37
- Views: 6655
Re: APOD: M106: A Spiral Galaxy with a Strange... (2024 Oct 09)
This is exactly the kind of APOD that I should comment on, but I have no time this morning! (Yes, it's morning here in Sweden). BBL. But before I go, I'll leave you with two pictures that you might want to ponder in relation to the APOD. https://upload.wikimedia.org/wikipedia/commons/thumb/b/b9/Mes...
- Wed Oct 09, 2024 10:15 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: The Large Magellanic Cloud Galaxy (2024 Oct 02)
- Replies: 21
- Views: 4588
Re: APOD: The Large Magellanic Cloud Galaxy (2024 Oct 02)
I am confused when they picture the one-armed Large Magellanic Cloud Galaxy as a victim of the tidal forces from the Milky Way Galaxy or the Small Magellanic Cloud Galaxy. Because you see the tidal forces are bilateral. For example our Earth has one high tide under the moon and another high tide 12...
- Fri Oct 04, 2024 10:05 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: The Large Magellanic Cloud Galaxy (2024 Oct 02)
- Replies: 21
- Views: 4588
Re: APOD: The Large Magellanic Cloud Galaxy (2024 Oct 02)
I am confused when they picture the one-armed Large Magellanic Cloud Galaxy as a victim of the tidal forces from the Milky Way Galaxy or the Small Magellanic Cloud Galaxy. Because you see the tidal forces are bilateral. For example our Earth has one high tide under the moon and another high tide 12 ...
- Fri Oct 04, 2024 4:08 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: The Large Magellanic Cloud Galaxy (2024 Oct 02)
- Replies: 21
- Views: 4588
Re: APOD: The Large Magellanic Cloud Galaxy (2024 Oct 02)
Well, I also like the comparison with NGC 4449, where you can clearly see that the center of the LMC is drifting out of the middle. I would assume that it is being "sucked out" by the Milky Way :wink: https://live.staticflickr.com/65535/54039426489_a7da7648ae_b.jpg https://live.staticflic...
- Wed Oct 02, 2024 9:19 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: The Large Magellanic Cloud Galaxy (2024 Oct 02)
- Replies: 21
- Views: 4588
Re: APOD: The Large Magellanic Cloud Galaxy (2024 Oct 02)
I wonder if Tarantula Nebula is what's left of the LMC's lost armChristian G. wrote: ↑Wed Oct 02, 2024 12:14 pm if the LMC has a central bar but only one arm coming out of it, what happens at the other end of the bar? Do Magellanians believe this is where the world ends?
- Mon Sep 23, 2024 10:05 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Aurora Australis and the ISS (2024 Sep 13)
- Replies: 2
- Views: 1365
Re: APOD: Aurora Australis and the ISS (2024 Sep 13)
The auroral glow is caused by emission from excited oxygen atoms in the extremely rarefied upper atmosphere still present at the level of the orbiting outpost. So, the ISS is actually embedded within the aurora I suppose, in addition to being able to see it while looking through a long enough colum...
- Mon Sep 23, 2024 5:16 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: The Mermaid Nebula Supernova Remnant (2024 Sep 18)
- Replies: 9
- Views: 2064
- Mon Sep 23, 2024 12:36 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Sunrise Shadows in the Sky (2024 Sep 21)
- Replies: 7
- Views: 1459
- Mon Sep 23, 2024 12:35 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Sunrise Shadows in the Sky (2024 Sep 21)
- Replies: 7
- Views: 1459
Re: APOD: Sunrise Shadows in the Sky (2024 Sep 21)
another attempt to make the low sun redder
New Red = Old Red + Old Green - Old Blue
New Green = -0.3 Old Red + Old Green + 0.3 Old Blue
New Red = Old Red + Old Green - Old Blue
New Green = -0.3 Old Red + Old Green + 0.3 Old Blue
- Mon Sep 23, 2024 10:09 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: The Mermaid Nebula Supernova Remnant (2024 Sep 18)
- Replies: 9
- Views: 2064
Re: APOD: The Mermaid Nebula Supernova Remnant (2024 Sep 18)
the link won't open
- Sun Sep 22, 2024 9:32 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: The Mermaid Nebula Supernova Remnant (2024 Sep 18)
- Replies: 9
- Views: 2064
Re: APOD: The Mermaid Nebula Supernova Remnant (2024 Sep 18)
The supernova remnant G295.5+09.7 is estimated to be between 7,000 and 10,000 years old. The distance of this remnant is somewhere between 4,000 and 13,000 light years from Earth. It contains the pulsar PSR J1210-5226 (yellow circle). https://live.staticflickr.com/65535/54003923134_eaa8397349_b.jpg...