Powerful yet lonely: The distant quasar left alone in its group

Trying on the evening sky with the bare eye, we will solely see an infinitesimal a part of what the Universe comprises, and the biggest half can not even be “seen”. Radio wavelengths have gifted us a few of the most fascinating astronomical sources: radio-loud lively galactic nuclei within the facilities of galaxies, which may produce jets that reach means farther out from the optical galaxy itself.

Probably the most {powerful} radio sources within the northern hemisphere are listed in a well- studied catalog, the Third Cambridge Catalog (3C), which comprises the supply we investigated with multiwavelength observations: 3C 297. This supply appeared very intriguing in observations carried out with Chandra in 2016. Due to this fact, we requested extra time to higher examine options that we uncovered because of this primary brief commentary, comparable to scorching, X-ray emitting gasoline round our supply.

This supply may be very removed from us and, due to this fact, very far previously. Optical, radio and X-ray observations had been essential to attract the total image of such a strong, and outdated, astronomical supply. At first of this journey, we needed to analyze if this supply was hosted in a galaxy cluster, that’s, the ensemble of 100 galaxies or extra. At the moment within the universe’s evolution, galaxy clusters are nonetheless forming and X-ray observations can be utilized not solely to determine a galaxy cluster by the glow of the new gasoline they include, but additionally to confirm if mergers with different clusters are occurring or not.

Furthermore, {powerful} radio sources inform us the place to search for galaxy clusters at massive distances from Earth. However there comes the contradiction: the detection of scorching gasoline with Chandra pointed towards the presence of a galaxy cluster, i.e. we anticipated that a few 100 or extra galaxies must be round 3C 297. Optical information revealed, as a substitute, no galaxies.

We due to this fact assume that we now have noticed a so-called “fossil group”, that’s, a system with an quantity of X-rays that’s typical for a galaxy group. Galaxy teams are ensembles of tens of galaxies (not a whole lot as it’s for galaxy clusters), which can be referred to as “fossil” after we observe solely a single remoted big elliptical galaxy with out companions. The companions have, certainly, merged to type one entity within the early universe. That is the primary time a fossil group has been noticed at such a excessive distance from us.

Other than all of the thrilling science we carried out, this work can be an exquisite worldwide collaboration, and exhibits the worth of perseverance and arduous work. The truth is, we had simply accomplished our preparation for optical observations with the Gemini telescope to check whether or not the enormous elliptical galaxy had companions when the pandemic hit and the telescopes closed. The primary program lapsed with out science information, and the second proposal submission was unsuccessful. We then utilized (a 3rd time) to the quick turnaround program at Gemini North and eventually obtained science information! Within the meantime, Chandra observations had been delivered in over two years.