Questions regarding the inner portion of a galaxy; in the Milky Way, this is the area around Sagittarius A*.

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11
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1answer
519 views

Explaining Dark Matter and Dark Energy to layman

With my little knowledge, I know this: Dark Matter The center of a galaxy controls/attracts its objects (stars, planets, comets etc.) towards itself because of gravity. But the mass of the center of ...
7
votes
2answers
3k views

Why don't we see the galaxy center?

When we look at the sky, and see the Milky Way, we mainly see a band, with no real center. On a more accurate picture we can guess the center of the galaxy (see this picture), but we still don't see ...
7
votes
1answer
130 views

Supermassive black holes at the center of galaxies

The fact is, many, if not most large galaxies have a supermassive black hole at their center. My question is why? Is it because when these galaxies were first formed supermassive black holes were ...
6
votes
1answer
97 views

What is in the brightest area of the night sky?

When I look up in the night sky, I assume the brightest area, commonly known as "The Milky Way", is the Galactic Center of our home galaxy. But then I stumbled upon this illustration, which seems ...
6
votes
1answer
109 views

Best approximation for Sun's trajectory around galactic center?

What is the current best approximation for the path the Sun takes around the center of the Milky Way? I have found some information on the approximate position of the Milky Way's center, the speed of ...
4
votes
2answers
88 views

Why are stars more metallic closer as you move closer to the galactic bulge?

As I see it, most of the stars in the galactic bulge are Population I stars. However, as one moves farther from the galactic bulge, star metallicity decreases. In fact, halo stars are almost entirely ...
3
votes
1answer
61 views

Is metallicity low at the central region or nucleus of the Milky Way?

Is metallicity low at the central region or nucleus of the Milky Way? Does metallicity decrease or increase as we move from the center out to the edges of our galaxy?
3
votes
2answers
277 views

Orbiting supermassive black hole or galactic center of mass?

One of the ways they measure the (supposed?) supermassive black hole at the galactic center of the milky way is to measure those tens of stars right at the galactic center that are orbiting what ...
2
votes
5answers
297 views

Could light be dark matter?

Is it possible that light itself is dark matter? I am speaking of photons (e.g. visible light, infrared, ultraviolet, etc...). I realize light is understood to be massless, but it is obvious it at ...
2
votes
1answer
246 views

How many light years away is Earth from the closest outer edge of the black hole at the center of the Milky Way?

How many light years is Earth away from the closest outer edge of the supermassive black hole in Sagittarius A* at the center of the Milky Way? I don't mean the distance to the center of the galaxy, ...
2
votes
2answers
103 views

Metal rich or metal poor?

What does the image in the link mean? Are the stars in the halo high in metallicity or low? How about at the bottom by the disk? ...
2
votes
1answer
77 views

How can we infer the mass of SMBH in galaxies that are not active anymore?

I know it is possible to infer the mass of a supermassive black hole (SMBH) by many methods, i.e., stellar orbits for out Galaxy, Iron line profile from the accretion disk, and probably other methods ...
2
votes
0answers
39 views

Torus of the AGN

How much do we know about the structure of the torus surrounding the galactic nuclei? Is the shape defined or still under speculations? And are there different structures for this torus possible i.e., ...