|20th of September 2017|
|Boom times for radio continuum surveys|
|(by Ray Norris)|
The plot above shows the number of radio sources detected by the largest
extragalactic radio surveys, from the birth of radio astronomy to the
next-generation surveys. Radio continuum surveys grew in size from
the start of radioastronomy until the 1990’s. Then came a surge as the
technology enabled large-area surveys like NVSS, FIRST, WENSS, and
SUMSS, which increased the number of known radio sources by about an
order of magnitude. Then came a 20-year lull in which no radio
telescope could improve significantly on the size of those
surveys. Now, a new generation of technology is driving another surge
of large-area surveys, driven by telescopes such as ASKAP, LOFAR,
JVLA, uGMRT, MWA, and MeerKAT, increasing the number of known radio
sources by well over an order of magnitude.
We are now at a watershed. Behind us are the first tentative steps of discovery, then the gradual realization of the vast diversity of radio sources. Ahead of us is the data-driven era in which we apply ingenuity to devising the key questions with which to mine our samples of tens of millions of objects. Radio astronomy is about to take its place in the toolbox of every astronomer, opening a new window of radio photometry on many objects studied at other wavelengths. Above all, we are opening up new tracts of unexplored parameter space, in which history tells us we are likely to make completely unexpected discoveries, provided we have the tools and the insight to do so.
From "Extragalactic radio continuum surveys and the transformation of radio astronomy", published in Nature Astronomy this week.