The Migdal effect inside detectors provides a new possibility of probing the sub-GeV dark matter (DM) particles. While there has been well-established methods treating the Migdal effect in isolated atoms, a coherent and complete description of the valence electrons in a semiconductor is still absent. The bremstrahlunglike approach is a promising attempt, but it turns invalid for DM masses below a few tens of MeV. In this paper, we lay out a framework where phonon is chosen as an effective degree of freedom to describe the Migdal effect in semiconductors. In this picture, a valence electron is excited to the conduction state via exchange of a virtual phonon, accompanied by a multiphonon process triggered by an incident DM particle. Under the incoherent approximation, it turns out that this approach can effectively push the sensitivities of the semiconductor targets further down to the MeV DM mass region.

Having a virtual telescope the size of Earth continues to pay off.

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The Event Horizon Telescope (EHT) has released new observations that are once again at the cutting edge of science. The team that gave us the first image of our very own supermassive black hole has now revealed the most detailed radio image of a blazer, J1924-2914.

A blazar, not to be confused with a bright dinner jacket, is an active supermassive black hole whose jet is being shot towards us. The EHT has delivered observations with unprecedented angular resolution: it can resolve structures within 3 light-years of the black hole. Not bad given the host galaxy is located over 4 billion light-years from us.

Published in The Astrophysical Journal, the achievement is based on data conducted during the original observation campaign in April 2017 that gave us the first-ever image of a black hole. The team studied structures just a few light-years in size to hundreds of light-years wide thanks to the combination of multiple observatories around the world acting as one Earth-sized telescope.

From the smallest bacterium to the greatest galaxy, death looms on the horizon; even if, in cosmic terms, the time scales are too large for us to truly comprehend. Eventually, even the Universe itself should come to an end – when the last light winks out, and the cold, dense lumps of dead stars are all that remain.

That is, at least, how it is under current cosmological models. What if our Universe doesn’t die a cold death, but collapses, reinflates, and collapses again, over and over, like a giant cosmic lung?

It’s not exactly a widely accepted theory, but for some cosmologists, our Universe could be just one in a long series of births, deaths and rebirths that is without beginning or end – not a Big Bang, but a Big Bounce.

Webb was expected to merely confirm the Standard Model of the universe but its images are “surprisingly smooth, surprisingly small and surprisingly old.”

Using a magnetically stirred liquid metal, researchers have reproduced a key feature of astrophysical accretion disks: a turbulence-based transfer of angular momentum.

Astrophysical disks are ubiquitous objects in the cosmic landscape: we observe them around matter-gobbling black holes and planet-forming stellar systems. The gas and dust in these disks slowly drift inward and eventually reach the central star or black hole. The energy released in this accretion process makes some of these disks very luminous. However, the physical mechanism responsible for this accretion remains elusive despite 40 years of active research. Now Marlone Vernet from Sorbonne University in France and his colleagues model astrophysical disks with an experimental system based on a rotating disk of liquid metal [1]. The novelty in this experiment is that the disk is set into rotation thanks to electrical currents and magnetic fields in a way that mimics gravity. The experiment provides strong evidence of angular momentum transport, which is thought to be a key feature in astrophysical accretion.