Simulations suggest that our Milky Way galaxy has many dark-matter-dominated satellites swarming around it, but without large numbers of stars they are too dim to be seen as satellite galaxies. However, KIPAC astrophysicists using data from the Fermi Gamma-ray Space Telescope can learn about dark matter by fishing for these dark satellites with gamma rays.
May 5, 2015 | Learning About Dark Matter From Invisible Satellites
Simulations of accretion flows around black holes, involving General Relativity and relativistic plasma physics, have led to a new model of how extreme particle acceleration is achieved in the hearts of galaxies, gamma-ray bursts, and elsewhere.
May 5, 2015 | Nomadic Planets May Swarm the Galaxy
Much public attention has focused on the recent discoveries of many hundreds of planets around other stars. A group of KIPAC scientists has now estimated that there may be up to ten thousand times as many planet-sized objects flying freely through our Galaxy as there are planets orbiting stars. They explore the implications for future sky surveys such as LSST, as well as our view of planet formation and even the origin of life.
May 5, 2015 | Crab Flares Return For Even More Dramatic Encore
The discovery of gamma-ray flares in the Crab Nebula was rated by Astronomy Magazine as the number two space story of 2011. Now KIPAC scientists report on another, larger, flaring episode, and are beginning to crack the mystery of why this source can be so variable.
Gamma-ray flux from the Crab Nebula as measured by the Fermi-LAT for 14 days in April, 2011.
May 5, 2015 | Fermi Shines (High Energy) Light On Supersymmetry
Scientists from KIPAC and the SLAC theory department have demonstrated that astrophysical observations from the Fermi Gamma-ray space telescope can probe the validity of a class of famous particle physics theories known as supersymmetry.
May 5, 2015 | Scientists TCB With Simulated GRBs
By realistically simulating a population of gamma-ray bursts, KIPAC scientists have demonstrated the extent to which these explosions can be mischaracterized when they are far away.
The observed duration of a GRB pulse as a function of distance (redshift) for both an ideal (Without Noise) and a realistic (With Noise) observing instrument. The actual observed duration deviates from the expected duration.
May 5, 2015 | Mystery Object Revealed to be "Black Widow" Pulsar
A KIPAC professor and graduate student have used savvy astronomical detective work to piece together the identity of a previously enigmatic gamma-ray source. The object is a black widow pulsar which is destroying its companion star.
Optical brightness (top 2 panels) and inferred velocity (bottom panel) for the stellar companion to the black widow pulsar. The light blue data points are from the Stanford student telescope.
May 5, 2015 | The Crab Nebula Is Not So Steady
The Crab Nebula is a system with a pulsar and a surrounding ball of material that emits light all across the electromagnetic spectrum. For many years it was thought to be a constant steady source and was used as a calibration reference for telescopes. Now, KIPAC scientists using the Fermi Space telescope have shown that the emission from the Crab in gamma rays varies with time.
May 5, 2015 | Fermi Sees Giant Gamma-Ray 'Bubbles' in the Milky Way
The Fermi Gamma-Ray Space Telescope has seen giant unexpected gamma-ray structures in the center of our Milky Way galaxy. The structures, which protrude above and below the Galactic plane in the center of the Galaxy like two opposing bubbles being blown up, are approximately 50,000 light-years tall.
An all-sky map of gamma-ray emission as seen by the Fermi LAT, showing the Galactic diffuse component and the bubbles.
May 5, 2015 | The Milky Way's Unusual Companions
By most accounts, the Milky Way is a fairly unexceptional galaxy in the Universe at large. However, a team of KIPAC scientists has shown that it has one very unusual feature: its two lesser companions, the Magellanic Clouds.
Images of systems from the SDSS spectroscopic catalog where Milky Way-like hosts have two Magellenic Cloud-like companions
May 5, 2015 | Probing Dark Energy Using Clusters of Galaxies
Of the four established ways to study dark matter astronomically, looking at the evolving properties of galaxy clusters is the most reliant on non-optical observations of our Universe. A KIPAC faculty member has proposed satellite observations for a new era of cluster constraints on dark energy.
May 5, 2015 | Hard X-rays Reveal Powerful Objects Near and Far
Creating the first ever catalog of the entire Galactic plane in hard x-rays, a KIPAC scientist has paved the way for a deeper understanding of the most luminous compact objects in our Galaxy, and of the x-ray emission from other galaxies.
Map of catalogued hard x-ray emitters in the Galactic center region with their significance in signal to noise