Please refer to the link below from a phys.org article.. https://www.google.co.in/amp/s/phys.org/news/2014-11-astronomers-puzzle-bizarre-center-galaxy.amp 1. Can anyone explain, how the pointed region correspond to centre of our Galaxy? Simple geometrical explanation. 2. Is there any evidence of same or almost similar amount of x ray originating from other regions of our milky way? 3. Do we have any recorded observation of massive BHs (comparable to Sgr A) in other regions of our Milky Way? It's like have we ruled out that there is no other region as x-ray active as that?
Calculate the rotation of the galaxy find the center of rotation. No. No. It is not that they are ruled out, there are just none detected.
1. Are you able to figure out from the pic, that the pointed region is the centre? And if so, can you elaborate.
The center of the galaxy is in the visible Milky way, which represents the plane of the galaxy. Other observations lead us to the conclusion that the center the galaxy is in the direction of a certain point of the Milky way. The image shows the lines converging on that part of the Milky way. What other "elaboration" do you need? Are you asking as to whether or not this particular image is accurate in where it indicates the center? If this is the case, then you would have to compare it to one where the center of the Galaxy is. From a quick comparison on my part, it looks like they got it correct.
This appears to be the true image, not some artistic impression. Even if I consider milky way as spiral as per text, I am not able to place the directed region as centre and hence the question #1.
No, I am not disputing the shape or mainstream text on milky way. I am just trying to understand, how the centre is offside in the pic. Should it not be somewhere at the middle of the huge arc in the pic.
Oh I see. The issue I believe is that you are assuming that the arc is centerned in the picture so the center should be directly on the verticle. Since the earth rotates the center of the galaxy can be at any angle from the horizon depending on the time the picture was taken. The amount of ambient light will also tend to washout the parts of the galaxy near the horizon. Here is a picture of the milkyway with the center of the galaxy in the center of the picture. Notice the dust lanes are identical for both pictures indicating that they both are showing the same center - just different views. Please Register or Log in to view the hidden image!
Where the center of the galaxy, or any other object, is in the sky relative to any ground observation point depends on the time of day and year. It can even be below the horizon. That arc in the picture is just that part of the Milky way visible in the sky at the time the picture was taken. The whole Milky way is a band that wraps around the Earth, as it is the disk of the galaxy as seen from within the disk, and only a fraction of it is visible in the sky at any given moment. The fact that the center of the Galaxy is not at the "top" of the arc is just because the photographer, due to his sense of esthetics, wanted a certain type of lighting in his photo.
The center can be ascertained by observing the orbits of the internal stellar objects (& of G2) & computing the barycenter of all the orbits. The arrow is 'off-center' [in my opinion] because it is not trying to indicate the location of the central BH [Sgr A] but of the binary pair, G2. Ghez (initial locator of CBH?, who directs the UCLA Galactic Center Group) has been mapping the inner core for years.
