This giant spiral disk of stars, dust and gas is 170,000 light-years across, or nearly twice the diameter of our Milky Way galaxy. (Credit for Hubble Image: NASA, ESA, K. Kuntz (JHU), F. Bresolin (University of Hawaii), J. Trauger (Jet Propulsion Lab), J. Mould (NOAO), Y.-H. Chu (University of Illinois, Urbana), and STScI)

Galaxies are gravitationally bound collections of stars, planets, gas, dust, dark matter and other objects, including black holes. They represent the standard "building blocks" of large-scale structure in the universe. Galaxies group hierarchically into clusters of galaxies and superclusters. These groupings in turn comprise larger structures of long, luminous filaments and sheets of galaxies, separated by gaping voids containing few galaxies. In general, galaxies come in three broad shapes and sizes: giant ellipticals, spirals, and small dwarfs. Astrophysicists study phenomena such as the mergers of galaxies, star formation rates and the influences from supernovae and black holes to understand the development of these and other galactic types over cosmic history. Cosmologists, meanwhile, use the evolution of the large-scale structures composed of galaxies to probe how the universe has changed since the Big Bang 13.8 billion years ago. A topic of major interest is the distribution of dark matter, which corresponds to the location of superclusters and filaments. Another is the effect of dark energy, which is accelerating the universe's expansion as evidenced by the speed of distant galaxies receding from our own galaxy, the Milky Way.

Shining a Light on Dark Galaxies

The sky around the quasar HE0109-3518
Oct 05, 2012

Dark galaxies – galaxies with few if any stars and made predominately of dense gas – have been impossible to detect directly until now. Members of an international team of astronomers discuss their discovery and the place these galaxies hold in the universe.

Spotlight Live: Hubble's eXtreme View

Sep 26, 2012

Pascal Oesch, a Hubble Fellow at the University of California at Santa Cruz, and Michele Trenti of the Kavli Institute of Cosmology, University of Cambridge, discuss the Hubble telescope deepest ever image of the universe.

Phoenix Rising: A Galaxy Cluster That's Breaking Cosmic Records

Pheonix cluster
Aug 13, 2012

On the eve of their NASA press conference, Michael McDonald, Kavli Institute for Astrophysics and Space Research at MIT, and Bradford Benson, Kavli Institute for Cosmological Physics, University of Chicago, discuss the discovery of the Phoenix Cluster -- a galaxy cluster for the record books.

"Dark Matters" - Incredible Simulations of an Invisible Universe

Jul 06, 2012

At the Kavli Institute for Particle Astrophysics and Cosmology, scientists are using massive computer simulations to create 3-D movies that reveal the mysteries of the universe in ways that almost let you reach out and grasp entire galaxies... and from any angle.

Now, Brought to the Big Screen by Astrophysicists at KIPAC: the Universe

Apr 20, 2012

Dramatic 3-D videos, created from actual data, bring to life the origins of the universe... And are now playing on screens at KIPAC, as well as museums in San Francisco and New York.

Searching For The First Stars

Feb 16, 2012

As astronomers detect ever more distant galaxies, they are homing in on some of the first sources of light in the universe. Researchers hope new instruments and observational techniques will reveal how the first stars and galaxies brought the young universe out of its dark ages and into the light.

Kavli Institute for the Physics and Mathematics of the Universe, University of Tokyo

Feb 06, 2012

On February 8th in Japan, the University of Tokyo (Todai) announced that The Kavli Foundation had established an endowment for the university’s Institute for the Physics and Mathematics of the Universe (IPMU). With the endowment, the Institute also became the 16th Kavli institute worldwide – the sixth in astrophysics, third in theoretical physics, and the first to be established in Japan.

Risa Wechsler: Shedding Light on the Dark Side

Ruth Weschler
Apr 09, 2010

Risa Wechsler, a member of the Kavli Institute for Particle Physics and Cosmology (KIPAC) at Stanford University, has a career path that has led to three Kavli institutes and one program, giving her particularly extensive roots in the Kavli community.


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