When it comes to telescopes, size really does matter. And to look farther away, at higher resolution, we need to build larger and larger instruments. Building large telescopes is expensive and complex, but for radio telescopes the laws of physics help you out: the resolution depends only on how far apart you place your antennae.
Thanks to this trick, astronomers combined the data from a space radio telescope and telescopes on Earth to create a 101,000-kilometer-wide (63,000 miles) radio telescope and snapped the highest resolution astronomical image ever take. The picture is of a supermassive black hole 900 million light-years away in the BL Lacertae galaxy.
The radio image might not be awe-inspiring at first but it’s an incredible feat. The resolution of the combined radio telescope’s resolution is equivalent to seeing a 50-cent coin on the surface of the Moon. The incredible resolution has allowed researchers for the first time to understand the finer details of this fascinating galaxy. The region that has been observed would fit within our own Solar System.
The bright part is the closest point to the supermassive black hole. Gomez, et al., Bill Saxton, NRAO/AUI/NSF
BL Lacertae is in a special class of active galaxies, characterized by rapid and significant changes in their light emission. The emission comes from the powerful supermassive black holes at their centers. The black holes are surrounded by large accretion disks of material which heat up as they rotate and generate intense magnetic fields. The magnetic fields are responsible for accelerated charged particles, which in turn generate powerful relativistic jets.
The radio telescope was able to look at the region where the jets came from, and discovered that the stream of particles is not constant but the region is subjected to intense flares, producing the observed gaps.
The project is called RadioAstron and used radio telescopes in Europe, antennae from the National Science Foundation's Very Long Baseline Array (VLBA), and the Russian radio space telescope Spektr-R.
“RadioAstron polarimetric space VLBI observations provide a unique tool to study the innermost regions of AGN jets and their magnetic fields with unprecedented high angular resolutions,” the researchers wrote in the paper, which is published in the latest issue of the Astrophysical Journal.