Context: Indian astronomers from the Indian Institute of Astrophysics (IIA) have found the reason behind the strange lack of dark matter in the galaxy NGC 1052-DF2.
Relevance : GS 3(Science and Technology)
Background:
- Dark Matter’s Role: Dark matter is believed to be a key component in galaxy formation.
- Galaxy’s Unusual Nature: NGC 1052-DF2 is an Ultra-diffuse galaxy (UDG), which has been found to be deficient in dark matter, contradicting standard galaxy formation models.
Previous Studies:
- Earlier models suggested that the dynamical mass of the galaxy is around 340 million solar masses, while the stars alone account for about 200 million solar masses.
- This indicates that the galaxy has a significant lack of dark matter compared to spiral galaxies like the Milky Way.
Surprising Findings:
- The mass within the galaxy’s observed extent is primarily composed of stars, with dark matter being less than expected.
- This finding challenges the established understanding of dark matter’s role in forming hierarchical structures in the universe.
New Learnings:
- Galaxy Formation: The study raises questions about how galaxies can form with minimal dark matter and what astrophysical processes regulate this.
- Nature of Dark Matter: The findings may offer clues about the true nature of dark matter itself.
Model Construction:
- K. Aditya, the lead astronomer, constructed new models to address the discrepancies in mass estimations of NGC 1052-DF2.
- The models examined different types of dark matter halos, particularly focusing on “cuspy” halos (which have higher densities in the central regions).
- The results showed that models with no dark matter closely resemble models with a “cuspy” dark matter halo, further questioning the traditional view of dark matter’s role.
Implications:
- This study challenges our current understanding of galaxy formation and dark matter, offering new perspectives on both.
- The results could reshape future research on dark matter and its relationship with galaxy evolution.
