Cosmic rays hit the Earth and produce showers of particles that can be detected on the ground. Understanding where these cosmic rays come from can help scientists pin down their sources and construct models for the magnetic field in our neighborhood.
Gas in clusters is predicted to cool quickly, but observations suggest otherwise. What prevents the gas from cooling? The authors explore the incidence and impact of heating by active galactic nuclei.
How small and faint can galaxies get? The authors of this paper report on the discovery of a dwarf galaxy in the Sculptor group.
Gravitational waves passing through our solar system make the Sun ring like a bell. Can their effect be measured to learn about the violent phenomena that caused them?
Can we find galaxies using the light emitted by their star forming regions? The authors of this paper explore a technique that would allow us to reach relatively unexplored epochs of the Universe.
Much like the Cosmic Microwave Background, the Cosmic Neutrino Background permeates our Universe and it could take us back to 1 second after the Big Bang. Today, we discuss the effect of the Sun on modulating the expected signal from the neutrino background.
For a few years now, excess emission of gamma-rays in the direction of the Galactic Center has puzzled scientists. In the paper we discuss today, the authors re-analyze data from the Fermi telescope to get new insights into the origin of this excess emission. They make the case for the signal being described by dark matter particles annihilating in the center of our Galaxy.
What do the sizes of galaxies have to tell us about cosmology? Today, we discuss how the velocity of a galaxy can change its observed size and tell us about the properties of the Universe.
There might be more information in the Hubble diagram of supernovae than we first thought. Far away supernovae are subject to gravitational lensing and in the upcoming decades, they could be used to determine how much matter there is in the Universe and how it clusters.
Gravitational lensing is the deflection of the trajectory of a photon by gravity, and it is a natural consequence of the theory of General Relativity. Lensing distorts the shapes and orientations of galaxies and in today’s post, we discuss a new method to reconstruct dark matter maps of our Universe using the position angles of galaxies.