Dark Matter Puzzle of Galaxy NGC 1052-DF2: IIA Study
Why in the news
Scientists at the Indian Institute of Astrophysics (IIA) proposed why the distant galaxy NGC 1052-DF2 contains so little dark matter, an anomaly for standard cosmology.
Key facts
- NGC 1052-DF2 is a distant ultra-diffuse galaxy (UDG) that seems to lack dark matter.
- Earlier estimates: total dynamical mass below 340 million solar masses, of which stars alone give around 200 million, so dark matter plays a minor role.
- Lead researcher: Dr. K. Aditya.
- Method: stellar density models tested with and without dark matter; cuspy halo models (denser centres) were statistically similar to no-dark-matter models.
- Published in the peer-reviewed journal Astronomy & Astrophysics.
Background
- Dark matter is thought essential to galaxy formation and structure.
- Most galaxies, including the Milky Way, have a vast dark matter halo outweighing visible matter.
Significance
- Challenges the hierarchical formation view, which needs a dark matter scaffold.
- Raises questions on how galaxies with minimal dark matter form and on the nature and behaviour of dark matter.
Exam angle
- Institute: Indian Institute of Astrophysics.
- Galaxy type: ultra-diffuse galaxy.
- Journal: Astronomy & Astrophysics.