Astronomers observe a strong shock front in galaxy cluster SPT-CLJ 2031-4037

Utilizing NASA’s Chandra X-ray spacecraft, astronomers from the College of Alabama in Huntsville have noticed a merging galaxy cluster often known as SPT-CLJ 2031-4037. They detected a hardly ever seen sturdy shock entrance on this galaxy cluster. The discovering was reported in a analysis paper published June 27 on the pre-print server arXiv.

Galaxy clusters are shaped by way of hierarchical mergers of smaller subclusters and comprise as much as 1000’s of galaxies sure collectively by gravity. They’re the most important identified gravitationally sure constructions within the universe, and will function glorious laboratories for learning galaxy evolution and cosmology.

Mergers of galaxy clusters are essentially the most energetic occasions within the universe after the Massive Bang. A fraction of the kinetic power launched throughout these mergers is dissipated into the intracluster medium by way of shocks and turbulence. The so-called shock fronts, seen as sharp discontinuities in X-ray brightness and temperature, give astronomers a uncommon alternative to watch and examine such merger programs and their geometry.

SPT-CLJ 2031-4037 (or SPT J2031 for brief) is a merging galaxy cluster at a redshift of 0.34. It’s a huge system with an estimated mass of about 800 trillion solar masses and X-ray luminosity at a degree of 1.04 quattuordecillion erg/s.

A workforce of astronomers led by College of Alabama’s Purva Diwanji has carried out a seek for shock fronts in SPT J2031 with the assistance of the Chandra X-ray observatory.

“SPT J2031 was noticed by the Chandra Superior CCD Imaging Spectrometer (ACIS) detector within the Very Faint (VFAINT) mode for a total of 256 ks unfold over 10 observations,” the researchers wrote within the paper.

The statement allowed the workforce to detect two shock fronts in SPT J2031—the stronger one to the northwest and the weaker one to the southeast (the southeastern edge). The stronger shock entrance has a density leap of three.16 throughout the sharp floor brightness edge and a Mach variety of 3.36, whereas the weaker one has a density leap of 1.53 and a Mach variety of 1.36.

The authors of the paper underline that the discovering makes SPT J2031 one of many uncommon merging programs with a Mach variety of over 2.0. They be aware that solely a handful of merger shock fronts with such a excessive Mach quantity have been found by Chandra.

The examine additionally discovered that SPT J2031 displays merger geometry and that the post-shock electron temperature of the stronger shock entrance is decrease than the temperature predicted for the immediate shock heating mannequin and favors the collisional equilibration mannequin. These findings are in line with outcomes offered by earlier research.

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