It has long been suspected that the processes at the center of active galaxies prevent the gas from forming stars. Now, for the first time, a KIPAC team has seen that happening before our eyes.
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 | Blazars Blare Bright But Below Background
The origin of the extragalactic gamma-ray background remains a cosmic and high energy physics enigma as KIPAC scientists have estimated the contribution to it from blazars in two different ways.
Estimate of the total cumulative flux from blazars above a given flux value. The level of the gamma-ray background is shown by the dashed line.
Active galactic nuclei reveal the presence of enormous amounts of matter interacting with a supermassive black hole at the center of a galaxy. Because galaxies merge over the history of the Universe, we should see the signatures of supermassive black holes merging in some places. An analysis of X-ray observations may have shown just that.
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.
In recent years a dozen small 'dwarf' galaxies that surround our Milky Way have been discovered. A KIPAC team shows how these tiny galaxies are great places to look for the signatures of dark matter and determine its properties.
Core-collapse supernovae are some of the biggest explosions in the universe - but exactly how the immense amount of energy released is converted into a form we can observe has puzzled astrophysicists for many decades. The Computational Astrophysics Consortium, which includes KIPAC, studies these systems via state-of-the-art hydrodynamic (HD) and magneto-hydrodynamic (MHD) simulations, and met in May to discuss their recent results.
By turning their gaze to small satellite galaxies where the total mass is most dominated by dark matter, astrophysicists using data from the Fermi Gamma-ray Space Telescope have achieved the tightest constraints on the properties of dark matter particles to date.
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.
Among the many opportunities in the LSST project, it necessitates a new understanding of our own atmosphere. LSST science depends on photometric redshift determination, which in turn depends on accurate measurements of the flux from celestial objects. At wavelengths where our atmosphere glows, this presents a novel challenge.
The LSST filter bands, showing total system throughput
May 5, 2015 | Knowing The Telescope Before It Is Built
By the end of the decade, the Large Synoptic Survey Telescope (LSST) will begin gazing at the sky and revolutionizing the study of dark energy and astronomy. Today, however, scientists are already hard at work learning how to analyze LSST's unprecedented amount and complexity of data with the Image Simulator.
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.