Astrophysics & Particle Physics-APPC 2026

Dark halos are areas of dark, unseen matter enveloping galaxies and stretching far beyond the stars, gas, and dust that can be seen. Halos dictate the gravitational potential of galaxies, affecting rotation curves, stability, and overall structure. Understanding dark halos is key to understanding galaxy formation, cosmic mass distribution, and the nature of dark matter.Dark halos are at the center of models for galaxy formation. Hierarchical formation scenario proposes that galaxies develop within dark matter halos, which coalesce and add smaller halos through time. Dark halos also have substructures—small clumps of dark matter that can potentially host dwarf galaxies or control tidal streams.Overall, dark halos are unseen, massive, dark-matter-filled structures that envelop galaxies. They are central to galaxy evolution, formation, and dynamics, influencing the distribution of luminous and dark matter within the universe. Deciphering the nature of dark halos holds the key to unlocking the secrets of dark matter and the universe's large-scale structure.