Interesting Astronomy & Astrophysics news from the week of 2/21/2021

Next Week’s Night Sky:

With the full moon nearly completely gone from Friday’s night sky, this is a great time to get some stargazing in! Bring your favorite pair of binoculars, and feast you eyes on the many beautiful objects in the night sky.

My Own Research

I found eight blue E+A galaxies in a galactic filament in the Coma cluster of galaxies. An E+A galaxy is a galaxy that has just transformed from its “young” stage to its “old stage.” A galactic filament is simply a large collection of galaxies that looks like a spiderweb. By further studying these galaxies, we can continue to learn about the evolution of galaxies. To learn more, go here: Eight Blue E+A Galaxy Candidates Located inside a Large-scale Filament in the Coma Cluster.

Heart of the Crab Nebula

The Crab Nebula (M1) is one of the most famous objects in our sky. This cloud of dust and gas marks the gravesite of a massive star that went supernova some 5,300 years ago.

Although it appears as a smudgy, fuzzy patch of light through smaller scopes, larger instruments reveal a complicated, twisting structure. And a stunning new 3D reconstruction of the remnant’s central regions is now taking our view of this millennia-old object to the next level.

Researchers generated the new view using the Spectromètre Imageur à Transformée de Fourier pour l’Etude en Long et en Large de raies d’Emission (SITELLE) instrument on the 3.6-meter Canada France Hawaii Telescope (CFHT) on Mauna Kea. Their reconstruction shows the Crab in exquisite detail from every angle, allowing viewers to zoom in and around the structure. The most striking feature is the remnant’s delicate lattice of gas filaments, which crisscross each other like a honeycomb.

Supermassive Black Holes from Dark Matter

A new theoretical study has proposed a novel mechanism for the creation of supermassive black holes from dark matter. 

Exactly how supermassive black holes initially formed is one of the biggest problems in the study of galaxy evolution today. Supermassive black holes have been observed as early as 800 million years after the Big Bang, and how they could grow so quickly remains unexplained.

Standard formation models involve normal baryonic matter—the atoms and elements that that make up stars, planets, and all visible objects—collapsing under gravity to form black holes, which then grow over time. However the new work investigates the potential existence of stable galactic cores made of dark matter, and surrounded by a diluted dark matter halo, finding that the centers of these structures could become so concentrated that they could also collapse into supermassive black holes once a critical threshold is reached.

According to the model this could have happened much more quickly than other proposed formation mechanisms, and would have allowed supermassive black holes in the early Universe to form before the galaxies they inhabit, contrary to current understanding.

This new formation scenario may offer a natural explanation for how supermassive black holes formed in the early Universe, without requiring prior star formation or needing to invoke seed black holes with unrealistic accretion rates.

Another intriguing consequence of the new model is that the critical mass for collapse into a black hole might not be reached for smaller dark matter halos, for example those surrounding some dwarf galaxies. The authors suggest that this then might leave smaller dwarf galaxies with a central dark matter nucleus rather than the expected black hole. Such a dark matter core could still mimic the gravitational signatures of a conventional central black hole, whilst the dark matter outer halo could also explain the observed galaxy rotation curves.

Further studies with this model in mind should shed more light on supermassive black hole formation in the very earliest days of our Universe. To learn more, go here: https://academic.oup.com/mnras/article/502/3/4227/6056505. 

Do you have any cool astronomy research news from this week? Share it in the comments below!