2023

The Cassiopeia A supernova remnant as seen by the James Webb Space Telescope

0

An image of the supernova remnant cataloged as Cassiopeia A (NASA, ESA, CSA, D. Milisavljevic (Purdue University), T. Temim (Princeton University), I. De Looze (UGent), J. DePasquale (STScI)), or simply Cas A, captured by the James Webb Space Telescope shows never-before-seen details of the structures present within the materials surrounding what remains of the progenitor star. These are useful details for astronomers to reconstruct the processes that take place in the last stages of the life of a massive star and the consequences of a supernova. Elements generated by the star are scattered into space, including cosmic dust in quantities that could explain the abundance discovered in early galaxies.

The two quasars of SDSS J0749+2255 as seen by Hubble (Image NASA, ESA, Yu-Ching Chen (UIUC), Hsiang-Chih Hwang (IAS), Nadia Zakamska (JHU), Yue Shen (UIUC))

0

An article published in the journal “Nature” reports the discovery of a pair of merging galaxies cataloged as SDSS J0749+2255 which has the peculiarity of hosting a double quasar. A team of researchers led by the University of Illinois at Urbana-Champaign used various ground-based and space telescopes to study SDSS J0749+2255 to obtain observations detailed enough to resolve the two quasars, both of which are extremely bright. The difficulty in these observations is also given by the fact that this pair is very distant and we see it as it was when the universe was about three billion years old and the distance between the two supermassive black holes that power their respective quasars is only about ten thousand light-years.

Galaxy Z 229-15 (Image ESA/Hubble & NASA, A. Barth, R. Mushotzky)

0

An image captured by the Hubble Space Telescope shows galaxy Z 229-15. A combination of the Advanced Camera for Surveys (ACS) and Wide Field Camera 3 (WFC3) instruments with three different filters was used to obtain observations including ultraviolet, optical, and near-infrared emissions. Z 229-15 is a galaxy that defies simple classification criteria because it has a set of features not normally found together. The result is that it fits different definitions showing how sometimes classes and subclasses of galaxies don’t have precise boundaries but can overlap making different classifications valid.

The concentric rings generated by the GRB221009A gamma-ray burst as seen by the XMM-Newton space telescope (Image ESA/XMM-Newton/M. Rigoselli (INAF))

0

A special issue of “The Astrophysical Journal Letters” is focused on the gamma-ray burst cataloged as GRB221009A, indicated since the first estimates of its characteristics as the gamma-ray burst of the century. Various teams of researchers conducted various types of analyzes of the data collected by many instruments that detected the emissions from GRB221009A and the so-called afterglow, meaning from the residues of its emissions, in several electromagnetic bands. The wealth of data indicates that this is the most powerful gamma-ray burst ever observed and offers new insights into these extremely energetic phenomena. In this case, it was a long gamma-ray burst, probably generated by the collapse of the core of a massive star and the subsequent birth of a black hole.

The galaxy protocluster around the Spiderweb Galaxy with gas from the intracluster medium in blue (Image ESO/Di Mascolo et al.; HST: H. Ford)

0

An article published in the journal “Nature” reports the results of a study on the formation of a primordial galaxy cluster, observed in its early stages. A team of researchers led by Luca Di Mascolo of the University of Trieste, Italy, used the ALMA radio telescope to study the intracluster medium, the gas that permeates the protocluster around the galaxy MRC 1138-262, known as the Spiderweb Galaxy, and has an overall mass greater than the mass of the galaxies that form it. Observations of the intracluster medium in forming clusters are scarce, making those observations precious to understand the formation processes of galaxy clusters.