Two For One

Quasars are the hearts of lively galaxies. They’re powered by supermassive black holes, however are so distant they seem virtually point-like much like stars, therefore the time period quasi-stellar objects. We now know that probably the most distant quasars, these with the best redshift, are among the many earliest galaxies, so finding out these quasars can inform us an excellent deal about how galaxies fashioned and advanced.

In 2019, observations from the Atacama Massive Millimeter/submillimeter Array (ALMA) discovered {that a} high-redshift quasar named J1253+1046 appeared not as one supply, however as two. Anaïs Martin, an undergraduate pupil on the College of Washington needed to search out out why.

Her first aim was to find out whether or not the 2 sources have been from the identical area of house. This was completed by their redshifts. If J1253+1046 is 2 quasars that simply occur to line up when seen from Earth, then their redshifts can be totally different as a result of one can be extra distant than the opposite. Anaïs discovered their redshifts agreed, which implies both J1253+1046 is a binary quasar of merging galaxies, or it’s a single quasar that has been gravitationally lensed to seem as two.

Right here the information turns into inconclusive. A few third of quasars have a companion, however within the case of J1253+1046, the 2 sources are extremely shut to one another. So shut that they might be an interacting binary seen within the means of merging, which might be a uncommon sight certainly. However, the spectra of the 2 sources are remarkably comparable, which suggests they’re the identical quasar. One which has been gravitationally lensed by a better galaxy to seem as two sources. Nonetheless, one supply is distinctly dimmer than the opposite, which isn’t what we might anticipate to see in a lensed quasar.

The answer, after all, is to collect extra information, which Anaïs hopes to do sooner or later. Excessive-resolution pictures from ALMA and different observatories might reveal mud within the area, which might present flows between the sources if they’re merging, or might clarify why one supply of the lensed quasar is dimmer than the opposite.

The publish Two For One appeared first on Nationwide Radio Astronomy Observatory.

Source link