The space telescope has just handed over a new unique image of an object well known to astronomers: the Messier 74 galaxy, sometimes called the Ghost Galaxy, an impressive spiral galaxy. The new image provides an unprecedented detail of the internal structure of the galaxy, which has been observed for more than two centuries.
The Messier 74 galaxy is characterized by a large number of young or emerging stars in spiral sleeves; it is estimated to contain about 100 billion stars; because of its low luminous intensity, it is particularly difficult to observe by amateur astronomers.
The galaxy has already been captured several times by the Hubble telescope, mostly in visible light, showing billions of yellow, red, and blue stars in a giant spiral. James Webb's telescope has also not made it difficult to capture all the details. Since it operates in a wide range of infrared radiation, it can observe through gas and dust, directly revealing the structure of an object: the galaxy appears to us to be a giant vortex with holes that seem to have no matter.
Unprocessed data were recorded by the PHANGS team, which monitors all nearby high-resolution galaxies using several ground and space telescopes, and the aim is to create a data set that will shed light on the links between young stars and the cold dense gas clouds in which they are formed in a variety of galaxy environments.
Astronomer Gabriel Brammer of the Niels Bor Institute at Copenhagen University recomplicated , which, when combined, is purple.
Judy Schmidt, an expert in the processing of space images, also published an equally impressive image of M74. Various filters used clearly show the color skeleton of the galaxy with the mysterious light center in its center.
The quality of these images is not only due to the performance of the James Webb telescope, as Brammer explained: "", he notes.
A galaxy centre that raises questions
The experts have not yet had time to study and interpret the data collected, but some scientists have noticed that the empty galaxy center is very different from the visible images provided by Hubbles, which can reveal previously unknown physics about galaxy nuclei. New data can also help us understand how dust in spiral galaxies like ours is formed and then redistributed.
Note that Judy Schmidt shared another picture, another spiral galaxy targeted by James Webb. This is the NGC 7496 galaxy, which is over 24 million light-years away in the constellation Juraval. This was the first spiral galaxy that Webb had targeted at at the beginning of his scientific mission. Compared to the image that Hubbles had previously received, this image also shows remarkable structural details showing different dust strips and star clusters of this spiral galaxy with a lock-in.
According to Michael Merrifild, a professor of astronomy at Nottingham University, data collected by James Webb are almost "too precise" and images are too detailed to draw general conclusions about the formation and evolution of galaxies, but the spacecraft has only just begun its observation campaign and, fortunately, much more interesting ahead.