This galaxy, IC 342, is difficult to observe because it lies behind a thick section of the Milky Way from our angle of view. The WISE space telescope photographed it in infrared
A wondrous cosmic creature has been discovered through the infrared eyes of NASA's Wide Field Sky Scanner, WISE. The spiral beauty known as the IC 342 galaxy, and sometimes also the "hidden galaxy", is hiding behind our own galaxy, the Milky Way.
It is very difficult for astronomers to see the galaxy through the bright stars, dust and gas of the Milky Way. WISE's infrared vision is able to overcome the obstacle and give us a glimpse.
In a spiral galaxy like IC 342, dust and gas are concentrated in the arms. The denser regions of gas contribute to the formation of new stars. These are the areas painted in green and yellow. Even in the core, which is painted red, young stars are constantly being formed, which heat the dust. In the picture the blue stars are those that lie within the Milky Way, between us and the hidden galaxy.
The galaxy is a source of interest to many astronomers, because it is relatively close to us. Despite this, determining its distance from the Milky Way is very difficult because of all the range factors present in the Milky Way. The famous astronomer Edwin Hubble initially thought it was a galaxy belonging to the local group of galaxies, but recent estimates place it in a more distant region, between about 6.6 and 11 million light years.
The image was made using observations by the WISE detector. The blue light exhibits wavelengths between 3.4 and 4.6 microns, which is mostly starlight. The green color represents radiation with a wavelength of between 12 and 22 microns, emitted mainly from hot dust.
15 תגובות
ghosts,
I asked exactly what I meant.
You probably still don't understand the difference between science and practical stories, and your answer only reinforced this assessment.
Noam
My opinion relies mainly on my logic.
Now that I've answered you, maybe tell me how it helped you?
I guess what you wanted to ask is something completely different, you just didn't know how to present your question correctly.
I wrote in the second line in response 11 - that I don't know how to assess at the moment the reason why I think what I think about the shifts to red/blue.
When I know, I'll be happy to elaborate if you'd like to hear.
Regarding the colors in the picture - these are not the result of a physical or chemical effect of any kind.
This is simply a result of the coloring used by humans - whether during the production of the telescope or during another process.
This is clear because the photograph itself is in infrared light which we do not see at all.
ghosts,
You bet that the galaxies are neither moving apart nor moving closer,
In your opinion, the redshift is not due to movement,
Maybe one time you will explain to us what your opinion is based on? After all, science is not a casino, and opinions only have meaning if they are reasoned.
what are you saying?
I would bet that the galaxies are neither moving apart nor moving closer. Instead, I would say that the phenomenon that is occurring is different (which I do not know how to assess at the moment). As a result, the universe is neither expanding nor contracting nor static, but the entity called 'universe' behaves differently.
I would say that the shifts to red/blue are - according to human perception and including the mathematical laws - 'moving in time', but in 'reality' the shifts can be the product of a different phenomenon than 'movement'.
And as a result, the human interpretation of the galaxy as 'moving' (with the help of the red/blue shift) is wrong in my opinion.
(R*H R*Faim)
Friends, in the NASA image above the colors are not due to the Doppler effect. The color of a galaxy can hint at its chemical composition and the temperature differences in its various regions. And if you really want to be petty then we might see some of the galaxy's arms shift a little to the blue and some a little to the red (according to the way they move), but this is negligible. And it is possible that the entire galaxy is shifted a little to the red, but that is not the reason for its colors in the image.
Regarding Gili's question - we see a galaxy redshifted or blueshifted according to its speed and distance from us. Overall, we see all the galaxies in the universe redshifted, meaning they are moving away from us, thus by the way they came to the big bang theory and the expansion of the universe.
There are a number of deviations that result from several things: there is the scaling parameter of the universe that describes the expansion of the universe, there is the cosmological constant (not Einstein's, but the one that describes the acceleration of the universe), and there are normal Doppler shifts that describe the movement of galaxies.
It should be noted that the redshifts throughout the universe do not necessarily result from the actual movement of the galaxies, but rather from the fact that the base of the universe itself is expanding.
Gili
The shift to a certain color (red or blue) is caused by an effect called the Doppler effect (it's not just a band). If you are kind, I will try to explain:
Let's say you are standing in the center of a path where people are walking and you are facing north. If the number of people walking on the path to the south is the same as the number of people walking on it to the north, the same number of people pass you in front and behind.
Now suppose you start walking north - you will now see more people walking south than people walking north and this effect will increase as your walking speed increases. The phenomenon will reach its peak if you walk north exactly at the pace of the other people, in this situation no person walking north will pass you, while the pace of the people walking south will be double the pace you saw while you were resting.
In physical language, it can be said that the frequency of the suit past people depended on the speed of your movement, when you moved with the direction of the people's movement the frequency decreased and when you moved in the opposite direction to their movement the frequency increased.
A very similar effect also happens with light - when you move against the direction of the rays (ie you move towards the light source) - its observed frequency increases and visible light will appear bluer. Conversely, when you move away from the source, the observed frequency will decrease and visible light will appear redder.
I will point out very briefly that the picture is more complex if your movement in relation to a light source is done at speeds close to the speed of light - but in the case of the described galaxy the explanation given is completely sufficient.
If so, what affects the effect is, as Ronen pointed out, only the relative speed of the galaxy in relation to us - if it approaches, the light will shift to blue, and if it moves away, it will shift to red. What is not true is that it has nothing to do with the distance of the galaxy from us.
In general, the farther a galaxy is from us, the faster it moves away from us (in relatively close regions of the universe the relationship is linear - that is, a galaxy that is twice as far away from us will move away from us at twice the speed) - therefore, the degree of redshift is a good indication of their distance of distant galaxies and when talking about very large distances in the universe, it is customary to talk in terms of red shift (ie how much smaller the frequency is) to describe distance.
This distance is related to the basic structure of the universe and its constant expansion since the big bang. If so, at small distances (on a cosmological scale) local disturbances may be more significant than the general expansion trend of the universe and thus for example the closest galaxy to us, Andromeda, is getting closer to us (ie there is a blue shift).
hall. If the distance does not play any role in the deviation to a certain color, but the vector itself, what does this mean for the current measurements? \
Gili
Ronan, is it even possible to reach conclusions and difficulties from pictures and articles from the famous on the net. I am a layman who bases himself on what is written on the internet (including Wikipedia) and on
My inner logic. I can only wish for more words and transparency in "Amor".
Gili
exciting!
Gilly, the red you see in this picture is not the "red shift" that is used to determine the speed of objects moving away. The colors in the picture are not "real" colors.
Any receding galaxy will be redshifted, any approaching galaxy will be blueshifted. regardless of their distance from us.
It's nice that the barely seen galaxy is called IC. Sounds like I SEE
Gilly, that would be a diversion for Blue.
Yael, I have a question about the red diversion.
If a galaxy is close to us, moving at high speed away from us, the redshift is small
A remnant from a distant galaxy moving fast in our direction?
Max Power,
happily
Mrs. Peter, thank you for the article