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

Wanting on the night time sky with the bare eye, we are able to solely see an infinitesimal a part of what the Universe comprises, and the most important half can’t even be “seen”. Radio wavelengths have gifted us a few of the most fascinating astronomical sources: radio-loud energetic galactic nuclei within the facilities of galaxies, which might produce jets that stretch approach farther out from the optical galaxy itself.

Essentially 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 quick commentary, comparable to sizzling, X-ray emitting fuel round our supply.

This supply could be very removed from us and, subsequently, very far up to now. Optical, radio and X-ray observations have been essential to attract the total image of such a strong, and outdated, astronomical supply. Initially of this journey, we wished 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 way of the glow of the recent fuel they include, but in addition 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 giant distances from Earth. However there comes the contradiction: the detection of sizzling fuel with Chandra pointed towards the presence of a galaxy cluster, i.e. we anticipated that a few 100 or extra galaxies needs to be round 3C 297. Optical knowledge revealed, as a substitute, no galaxies.

We subsequently assume that we’ve got 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 lots of as it’s for galaxy clusters), which might be known as “fossil” after we observe solely a single remoted big elliptical galaxy with out companions. The companions have, certainly, merged to kind 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 a beautiful worldwide collaboration, and reveals the worth of perseverance and arduous work. Actually, we had simply accomplished our preparation for optical observations with the Gemini telescope to check whether or not the large elliptical galaxy had companions when the pandemic hit and the telescopes closed. The primary program lapsed with out science knowledge, 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 knowledge! Within the meantime, Chandra observations have been delivered in over two years.