[bqmjjx0kac]

You nerd sniped me :) In this context, I believe it is a kilo-Jansky, not a kilo-Joule * year.

https://en.wikipedia.org/wiki/Jansky

[dotancohen]

I don't think that replacing two ill fitting but probable units with a single obscure unit is much of an improvement!

[8bitsrule]

It appears to have something to do with CGS units.

1 Jy = 10-23 erg s-1 cm-2 Hz-1 (cgs)

only their figure: L9.9 GHz < 2.1 × 10^25 erg s−1 Hz−1

leaves out the cm-2. (So not a density, like Jy. Perhaps 'L' is luminosity? ... As in: "The solar luminosity unit is a measure of the Sun's radiant energy and is equal to 3.828×10^(26) Watts." -(NRAO)

While groping, I found this helpful page called Brightness in Radio Astronomy: http://physics.wku.edu/~gibson/radio/brightness.html

[guenthert]

I don't think it's obscure in that field or for the target audience. You might want to read the soon to be published distilled and transposed article in popular mechanics ...

[rbanffy]

It’s mentioned in Contact, both movie and book.