Cosmic Ecosystems

How do the stars and galaxies form, from the very first stars formed after the Big Bang to the complex array of galaxies we see today? What makes up the stuff between the stars, the Interstellar Medium, or ISM for short, and how does all that gas and dust behave? How do galaxies interact with their neighbors to form clusters?  How are these clusters distributed throughout the universe and how do they evolve over time? And what can all of this tell us about the nature of the universe, dark energy, and dark matter?

Researchers at KIPAC study these cosmic ecosystems - from the gas, dust, and stars that make up individual galaxies to galaxies and their satellites to the largest galaxy clusters - hoping to understand more about how our universe works. By studying these questions across a range of time and length scales, KIPAC scientists hope to better understand the nature of dark matter, dark energy, the creation of elements, the influence of unseen magnetic fields, and so much more.

Galaxy Formation

Research at KIPAC is revealing the lifecycle of galaxies: how galaxies were born in the darkness of the early Universe, how their different components interact as they live and grow, and how they die. KIPAC scientists are studying early galaxies with computer simulations to understand the formation of the first stars and galaxies, and use a combination of observations and theoretical models to figure out how the supermassive black hole in the center of each galaxy controls the galaxy’s growth. KIPAC researchers are at the forefront of modeling the connection between galaxies and the halos of dark matter surrounding them and of using galaxies as laboratories to test the nature of dark matter and other cosmological theories.

Astrophysical Magnetism and the Interstellar Medium

The interstellar medium (ISM) is the stuff between the stars in our Galaxy. The matter in the ISM spans an enormous range of physical conditions, from hot, tenuous plasma to the cold, dense molecular clouds that are the birthplaces of stars. KIPAC scientists study a diverse range of interstellar phenomena, with an emphasis on understanding the magnetic fields that pervade the ISM. The ISM and Cosmic Magnetism Group at Stanford is tackling open questions like the structure of the Milky Way’s magnetic field, the nature of interstellar turbulence, and the role of magnetism in star formation.

Galaxy Clusters

Clusters, containing thousands of galaxies, held together by the force of gravity, are the largest bound objects in the Universe. At KIPAC, astrophysicists are studying galaxy clusters to better understand how the largest structures in the Universe are assembled, the interplay of the galaxies, the hot intracluster medium that surrounds them and dark matter, and the roles the supermassive black holes in the central galaxies play in the growth of the cluster and the galaxies.

Gravitational Lensing

As light travels across the Universe from distant galaxies, its path is bent around massive objects, leading to gravitational lensing. At KIPAC, cosmologists are able to measure how gravitational lensing distorts the shapes of galaxies to create maps locating all of the matter in the Universe. This technique is a particularly powerful tool to reveal the distribution of the dark matter that dominates the Universe’s mass, and to trace the Universe’s expansion and growth of structure over time.