The NANOGrav project searches for ultra-low frequency gravitational waves, a constant murmur from the cosmos. To do this, it uses pulsars as precision clocks and combines their data with observations of quasars and active galactic nuclei. This approach allows directing the search toward sky regions where it is more likely to find supermassive binary black holes in slow merger.
From Background Statistics to Individual Source Identification 📡
Detection is based on measuring tiny perturbations in pulse arrival times. By correlating these signals among multiple pulsars, the common background is extracted. The next step is to isolate individual contributions. For this, promising candidates have been selected, nicknamed Gondor and Rohan, which serve as testbeds to refine analysis algorithms and protocols in search of a continuous and persistent signal.
When Middle-earth Becomes an Astronomical Catalog 🧙♂️
It seems that astrophysicists also have a weakness for Tolkien's work. While looking for names for their stellar candidates, they opted for Gondor and Rohan instead of technical codes. It remains to be seen if the next discovery will be Mordor, although a black hole with that name would command quite a bit of respect. At least, this nomenclature makes following a scientific paper more entertaining.