Nature has provided us with spectacular particle accelerators called active galactic nuclei, or AGN. These are galaxies that host tremendously large black holes at their centers, some of which are known to be a million times heavier than our sun.
The Cosmic Microwave Background, or CMB, is a faint glow in microwave radiation that is almost perfectly uniform across the sky. This thermal radiation was emitted about 380,000 years after the Big Bang, as the universe became transparent for the first time.
To better understand our universe, it is often necessary to estimate the mass of an astrophysical object. Those objects span a vast range of sizes, from the Sun, to the solar system, to the Milky Way, and even up to the entire universe.
A leading hypothesis on the nature of Dark Matter is that it is comprised of Weakly Interacting Massive Particles, or WIMPs, that were produced moments after the Big Bang. If WIMPs are the dark matter, then their presence in our galaxy may be detectable via scattering from atomic nuclei in detectors as shown in these cartoons (not to scale):
The first objects to form in the Universe were stars. Some 200 million years after the big bang, the diffuse gas permeating the early Universe is able to contract under its own gravity setting the collapse to the first stars in motion. Once this collapse reaches a critical density, thermonuclear reactions will start and the star will light up as the first luminous object in the Universe.
Galaxy clusters are the largest objects in the universe, spanning distances up to ten million light years, and containing the equivalent mass of a million, billion suns.
Galaxies are collections of stars, gas and dark matter that play host to some of the most extreme processes in nature. Galaxies are also the signposts of the universe, beacons of light scattered throughout a mostly dark universe.
Gamma-ray bursts (GRBs) are short flashes of photons thought to originate from collapsing stars. These strong pulses have energies in the X-ray to gamma-ray ranges and time scales ranging from a few milliseconds to around 100 seconds. The separation between "short" and "long" bursts is around two seconds.
We cannot see one of the universe’s primary constituents: dark matter. The reason is simple: it's dark. However, we can infer where it is located from observations of distant galaxies because of a key property of light, namely that it does not always travel in straight lines.
Astronomers are popularly supposed to observe the cosmos using visible light. However, today they use the whole 70 octave electromagnetic spectrum from the longest wavelength - 20 meter - radio waves to the highest energy - 100 TeV - gamma rays. The gamma rays in particular are thought of as particles, called photons, because that is the way they are detected.
In the traditional model of astronomical observation, individual or small teams of astronomers will study a select class of objects in a small region of sky.
The universe began in a hot big bang 13.7 billion years ago. It is remarkably homogeneous on the large scale and at the time we observe the cosmic microwave background parts that are out of contact with each other are similar at the level of about ten parts per million. How did this remarkable synchronization come about?
Roughly 400,000 years after the Big Bang, the universe – bathing in the afterglow of radiation that we see today as the cosmic microwave background – began to enter the cosmic “dark ages,” so named because the luminous stars and galaxies we see today had yet to form.
As part of the Computational Physics Department, KIPAC's visualization and data analysis facilities provide hardware and software solutions that help users at KIPAC and SLAC to analyze their large-scale scientific data sets.
Observational and theoretical research on the physics of the sun is carried out at Stanford University in several research groups.