Research

Formation of galaxy clusters

Galaxy clusters are the largest gravitationally bound structures in the Universe, serving as powerful laboratories for understanding cosmic evolution. By studying their formation and growth, we gain critical insights into the nature of dark matter, the behavior of baryonic matter under extreme conditions, and the fundamental processes driving structure formation across cosmic time. Observations of merging clusters, in particular, offer a unique opportunity to test alternative models of dark matter and to explore the physics of the intracluster medium. Advancing our knowledge in this field is essential for refining cosmological models and deepening our understanding of the Universe at the largest scales.

Key Scientific Questions:

Do dark matter particles interact through a force beyond gravity? If so, what is the strength of this interaction?
Does the cluster merger kinematics deviate from the cosmological predictions of the ΛCDM model?
How can the age and geometry of cluster mergers be determined with the highest possible precision and accuracy?
What is the fraction of galaxy clusters undergoing major mergers, and how does this compare to predictions based on the ΛCDM model?
How do cluster mergers influence their constituent properties? Specifically, is the star formation rate enhanced, suppressed, or unaffected?

Growth and identification of superclusters of galaxies

Superclusters of galaxies are immense, dynamically evolving structures that provide crucial insights into the large-scale organization of the Universe. Though not yet virialized, their study is essential for understanding the distribution of matter and the underlying forces shaping cosmic evolution. Identifying superclusters involves advanced techniques such as redshift surveys, weak gravitational lensing, and multi-wavelength imaging, allowing us to map their spatial distribution and study their internal dynamics. These techniques help trace the role of dark matter, dark energy, and gravitational interactions in the formation of the cosmic web, providing a critical testing ground for cosmological models like ΛCDM. Through supercluster research, we gain deeper insights into the fundamental processes driving the Universe’s structure and evolution.

Key Scientific Questions:

What is the most accurate physical criterion for defining the boundaries of a supercluster of galaxies?
What are the most significant environmental effects on galaxy members before the collapse of a supercluster?
What is the impact of dark energy on the future evolution of superclusters of galaxies?

Galaxies and their surrounding environments

Studying galaxies and their environments is a fundamental pursuit in astrophysics, offering critical insights into structure formation and large-scale cosmic evolution. Galaxies do not exist in isolation; their properties—such as morphology, star formation rates, and chemical enrichment—are deeply influenced by their surroundings, from dense clusters to low-density voids. Investigating these interactions reveals the roles of tidal forces, ram pressure stripping, and galaxy mergers in shaping their evolution. With advancements in multi-wavelength surveys, hydrodynamic simulations, and next-generation telescopes, this field is at the forefront of uncovering the physical processes governing the universe.

Key Scientific Questions:

Is there a connection between BCG evolution and its host cluster?
Are the kinematic and photometric evolution of BCGs linked?
How is galaxy morphology affected by its environment?
What drives the transition of galaxies from star-forming to quiescent in dense environments?

Weak gravitational lensing

Weak gravitational lensing (WL) is a powerful tool for mapping the distribution of dark matter and studying the large-scale structure of the universe. As light from distant galaxies travels through cosmic web filaments, galaxy clusters, and voids, it is subtly distorted by the gravitational potential of intervening matter. By statistically analyzing these distortions, we can infer the mass distribution of foreground structures—even where no visible matter is present. WL is particularly crucial for constraining cosmological parameters (e.g., σ₈, Ωₘ) and testing theories of gravity. Advances in deep, wide-field surveys (e.g., Euclid, LSST, Roman) are revolutionizing WL measurements, enabling unprecedented precision in studying dark matter halos and galaxy evolution in diverse environments.

Key Scientific Questions:

What advancements in shape measurement techniques are necessary to study weak lensing by low-mass halos at high redshift?
How do baryonic effects in galaxy formation introduce biases in weak lensing-derived halo mass estimates?
What are the best methods for accurately deriving cluster masses during mergers, and how can we address the weak lensing mass bias?
How can weak lensing data be combined with kinematic measurements to resolve degeneracies in halo mass modeling?