New observations made with the help of the Hubble Space Telescope have revealed that galactic halos are larger and more complex than it was previously thought, as the spacecraft mapped the galactic halo of the nearby Andromeda galaxy.
The Andromeda galaxy, which is located at a distance of 2.5 million light-years, it is a prime subject for galactic observation due to its convenient position. It is estimated that the galaxy, which has the shape of a spiral, is almost as big as the Milky Way, containing 1 trillion stars.
Measuring the halo
A team of researchers wanted o to learn more about the galactic halo and surveyed more than 40 sightlines to gather information. The sightlines are generated by the supermassive black holes, which are found on opposite sides of the galaxy.
The black holes power quasars, which generate an impressive amount of light, and researchers can observe the way in which the light is absorbed by the gases found in the galactic halo to learn more about it. Some researchers also argue that by studying Andromeda, we could learn more about the Milky Way.
It is essential to learn more about the halos of gas, which can be found around galaxies since they contain the material needed for the formation of new stars, as well as gas released from large-scale events like supernova explosions. There are also potential hints related to the past and current evolution of a galaxy.
The new observations revealed that the halo is much larger than what the researchers thought, as it stretched over a distance of 1.3 million light-years, reaching 2 million light-years in some regions. Due to its sheer size, the halo covers half of the distance between the Milky Way and Andromeda.
More information is available in a paper that was published in a scientific journal.