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.
Observing dark worlds is a public competition for improving algorithms to find dark matter halos in weak gravitational lensing maps. Today, we discuss citizen science projects and describe the results of the challenge.
We are used to thinking about planet transits in visible wavelengths. What can we learn from planet transits in the radio band? Today, we discuss what these transits might tell us about the magnetic activity and the atmosphere of a star.
Gravitational lensing causes distortions in the polarization of the Cosmic Microwave Background. In this astrobite, we discuss recent results from the South Pole Telescope collaboration measuring patterns caused by lensing in the CMB polarization. What do these patterns tell us about the Universe?
Short gamma-ray bursts, extremely energetic explosions in the Universe, might be caused by the merger of two compact objects. In the two papers we discuss today, the authors test this scenario by looking for light emitted still a few days after the explosion.
In today’s astrobite, we discuss the opacity of the Universe to high energy photons. The cosmic gamma-ray horizon, constrained by the authors of this paper, is a measure of this opacity, a cosmological probe and means of estimating blazar redshifts.
In today’s astrobite, we discuss the puzzling results from the AMS-02 experiment, which has detected an excess of positrons in cosmic rays with respect to what we expect from known physical sources. Where are those positrons coming from?
The quest for identifying the dark matter particle is well underway. Today, we discuss the work of the ANTARES collaboration, which is using a neutrino telescope to search for signals of dark matter annihilation in the Sun.
Dust is really ubiquitous in the Universe: it is everywhere from our Solar System to stars and the interstellar medium. However, the observations of dust in galaxies fall short of the prediction of how much dust there is in the Universe. In this work, the authors try to alleviate this problem by estimating the amount of dust present in clouds of gas that inhabit galaxy halos while they look for clues regarding the origin of these clouds.