Fermi's Large Area Telescope has detected gamma-ray pulsations from a radio pulsar with one of the highest magnetic fields known. The object appears to be a missing link between standard pulsars and the more extreme magnetars.
May 5, 2015 | A Gamma-ray Pulsar With a Record-breaking Magnetic Field
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.
Although the Fermi Gamma-ray Space Telescope is primarily a gamma-ray instrument, its most cited paper reports a measurement of the combined electron and positron cosmic-ray spectrum. Now a team, led by KIPAC researchers, has built on this result by using a novel technique to separate the cosmic-ray electrons and positrons and measure the spectrum of each component individually. The result will keep theorists busy thinking about pulsars and dark matter.
Centaurus A (Cen A) is one of the brightest radio sources in the sky: it is a giant elliptical Galaxy about 10 million light years away, making it the closest active galaxy we know. A remarkable feature of the radio image of this galaxy is that the bright central source is accompanied by a pair of giant radio "lobes," thought to be fuelled by relativistic jets generated in the dynamical process of gas accretion around the super-massive black hole residing at the galaxy's center.
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.
Gamma-ray observations of the Universe by the Fermi Gamma-ray Space Telescope have enabled another astrophysical constraint on the properties of particle dark matter.
The Fermi Gamma-ray Space Telescope continues to bridge astronomy and particle physics.
The only way to accurately predict the conditions near black holes is with extensive computer simulations of the complicated physics involved. While black holes are the quintessential manifestation of Einstein's General Relativity, very few precision tests of the theory have been based on actual observations of black holes. New simulation results point to an observable property of such systems that could be used as a precision test of Einstein's theory.
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 | A Flare in the Jet of Pictor A
Long (up to Megaparsec scale), highly collimated jets of magnetized plasma emanating from the active nuclei of galaxies pose many astrophysical puzzles - including the mechanism by which those outflows are accelerated to relativistic velocities, and the structure of the jet magnetic field. Recent high resolution X-ray imaging of the jet in famous radio galaxy Pictor A shows some surprising and unexpected variability.
The extent to which the cool, dense gas at the centers of massive galaxy clusters can be disrupted remains an outstanding question in astrophysics. Although physical processes such as mergers and central galaxy activity have been shown to suppress cooling and therefore star formation in the central gas, the cool core has almost always been observed to remain more or less intact. Recently, however, a team of KIPAC researchers has found the most extreme example yet of these processes disrupting the core.
The Fermi LAT has observed, for the first time, gamma-rays produced in cosmic-ray interactions in several neighboring galaxies - and is even able to spatially resolve one of those galaxies. This has given us a unique global view of cosmic ray acceleration, that previous Milky Way studies could not provide.
Gamma-ray emission from the LMC
May 5, 2015 | Understanding Dark Energy Through CMB Observations
A KIPAC astrophysicist has published some of the first constraints on dark energy and other cosmological parameters using the measured signal from "shadows" of galaxy clusters in the CMB.
The Atacama Cosmology Telescope (ACT), located in the Atacama desert in Chile.