International School of Advanced Studies, Italy (SISSA) | 2019 Dec 18
A study by SISSA provides important information on its composition and on its interaction with luminous matter
They are called low-surface-brightness galaxies and it is thanks to them that important confirmations and new information have been obtained on one of the largest mysteries of the cosmos: dark matter. “We have found that disc galaxies can be represented by a universal relationship. In particular, in this study we analysed the so-called Low-Surface-Brightness (LSB) galaxies, a particular type of galaxy with a rotating disc called this way because they have a low-density brightness “says Chiara di Paolo ...
The researchers analysed the speed at which the stars and gases that compose the galaxies subject matter of the study rotate, noting that the LSBs also have a very homogenous behaviour. This result consolidates several clues on the presence and behaviour of dark matter, opening up new scenarios on its interactions with bright matter.
It is there but you cannot see it. Dark matter appears to account for approximately 90% of the mass of the Universe; it has effects that can be detected on the other objects present in the cosmos, and yet it cannot be observed directly because it does not emit light (at least for the way in which it has been searched for to date). One of the methods for studying it is that of rotation curves of the galaxies, systems that describe the trend of the speed of stars based on their distance from the centre of the galaxy. The variations observed are connected to the gravitational interactions due to the presence of stars and to the dark component of matter. Consequently, the rotation curves are a good way to have information on the dark matter based on its effects on what it is possible to observe. In particular, the analysis of the rotation curves can be conducted individually or on groups of galaxies that share similar characteristics according to the universal rotation curve (URC) method. ...
The Universal Rotation Curve of Low Surface Brightness Galaxies
IV: The Interrelation Between Dark and Luminous Matter ~ Chiara Di Paolo, Paolo Salucci, Adnan Erkurt
- Monthly Notices of the RAS 490(4):5451 (Dec 2019) DOI: 10.1093/mnras/stz2700
- arXiv.org > astro-ph > arXiv:1805.07165 > 18 May 2018 (v1), 20 Sep 2019 (v2)