A victim exposed to thalaron radiation
Thalaron radiation is a type of electromagnetic radiation in the tertiary EM band, once considered merely theoretical by Federation scientists. Research on thalaron was banned by the Federation sometime prior to 2379 due to its biogenic properties.
Thalaron radiation consumes organic material at the subatomic level. Whereas gamma radiation merely causes the mutation of an organism's genome, thalaron radiation causes instant and complete necrosis in every cell it irradiates. Following exposure, the organism degenerates into an ash-like material, completely devoid of life.
Even a minuscule amount of thalaron radiation could kill every living being aboard a starship in a matter of seconds. Due to its massive destructive potential, thalaron radiation is considered to be a biogenic weapon.
A small cascading biogenic pulse
Thalaron is generated and emitted through a cascading biogenic pulse.
For the purposes of his plot to overthrow the Romulan Senate and install himself as praetor, Shinzon and his Reman allies developed a small cascading biogenic pulse, which Shinzon's accomplice, Senator Tal'aura, utilized to simultaneously assassinate the entire Senate during one of its sessions. In addition to this smaller implementation, a much larger thalaron generator was installed in the Reman warbird Scimitar. This weapon was theoretically capable of creating a thalaron radiation field large enough to encompass an entire M-class planet. Shinzon planned to use the device on Earth to test this point.
Shinzon's thalaron generator was destroyed along with the Scimitar itself when Lieutenant Commander Data fired a phaser into the generator as it was charging in preparation for a strike on the USS Enterprise-E. The explosion in the radiation generator caused a monstrous chain reaction which culminated in the destruction of the warbird. (Star Trek Nemesis)