For the first time, thanks to the Fermi Space Telescope, high energy gamma rays gave been detected coming from another spiral galaxy much like our own Milky Way. It is now evident that the differences in gamma-ray luminosity among galaxies show that the density of cosmic rays varies and is correlated with the formation of new stars.
May 5, 2015 | Fermi Space Telescope Sees the Andromeda Galaxy
May 5, 2015 | A Cosmic Bullet Shoots Extra X-rays
Galaxy clusters are a well known source of X-rays. KIPAC researchers have shown that at least one cluster, the famous 'Bullet' Cluster, has an extra component of X-ray emission detectable beyond the dominant one seen ubiquitously elsewhere.
May 5, 2015 | Cosmic Archaeology With the Leader of a Group
A team of astronomers, including two from KIPAC, have created a map of X-ray emission from around the central galaxy of a galaxy group. Along with data from other wavelengths, it dramatically shows the effects of outbursts from the central active galactic nucleus that occurred millions of years ago.
Among the successes of the Fermi Gamma-ray Space Telescope is its discovery of the gamma-ray emission from many pulsars, the fascinating beacons in space. Additionally, KIPAC scientists have also used what Fermi has not seen from some pulsars to learn more about them.
May 5, 2015 | Telltale Modulation In Gamma Rays Implies Orbit
Data from the Fermi Gamma-ray Space Telescope has revealed a new gamma-ray binary, a rare class of object in which a gamma ray source is in orbit around a star.
Artist's conception of an X-ray binary in which a star and a black hole are in orbit around each other. The black hole pulls mass off the star, which interacts in the extreme conditions surrounding the black hole.
May 5, 2015 | Life In the Dark Matter Fast Lane
A new prediction of the density and velocity distribution of dark matter particles at our position in the Galaxy has provided a revised estimate of the likely detection rates for dark matter in particle physics experiments.
Typical conception of the halo of dark matter surrounding the Galaxy.
May 5, 2015 | Let the Sun Shine (In Gamma Rays) II
Unifying the astronomically near and far, the Fermi Gamma-ray Space Telescope has seen its first signature of cosmic rays interacting with the light from our Sun.
The left panel shows the LAT gamma rays per pixel from near the Sun and the right panel shows the same for another patch of sky. There is a clear large flux from the solar disk and a less dense but extended flux surrounding it.
Photometric redshift determination is crucial to the success of dark energy missions such as LSST and DES. A KIPAC postdoc has developed an important tool for photometric redshift estimation and applied it to 60 million galaxies from the Sloan Digital Sky Survey.
Six randomly chosen galaxies' photometric redshift probability distributions from Cunha and colleagues' SDSS galaxy sample.
May 5, 2015 | Learning About Dark Matter From Invisible Satellites
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.
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.