Figure 17
![The emissivities of several of the prominent optical atomic and low-ionization lines seen in the filaments are shown. The lines include [O i]λ6300, [O ii]λ3727, [N i]λ5199 and [N ii]λ6584. The shaded rectangle indicates thermally unstable regions.](https://oup.silverchair-cdn.com/oup/backfile/Content_public/Journal/mnras/392/4/10.1111/j.1365-2966.2008.14153.x/2/mnras0392-1475-f17.jpeg?Expires=1750584119&Signature=vo~s~Spz9Xeob8kXOjAxd2kgxEmPwYeHnp8bSbAyPM8PD9BMIhLAKpZ~LRbXpfSwGc--Q7RhaV7FiZ0S-p3WUm2b5MB6s3fgg6vrlyRUQI4IV2d0lC0EUcCngL0soLTeLtrR3zp2dPS~aiWuPwUX2E9NxKyFN8cVVQEi2PPSdeb4FERiwe3nzjJ1xQ2x-SteCcDR~GviK05WjunerUWNZRXxqgKomjOyJeX6TgK9V0xUYV0MQMGd5ofJCvlxOkh1hRbFO1w6ler9Wbz0tJBjjxvknBMMsu0UyJEt1gc~cQ-AQHALpW4r9LYMP5kTm1Js2J7AqkbOQYf2y9EdDAzNbw__&Key-Pair-Id=APKAIE5G5CRDK6RD3PGA)
The emissivities of several of the prominent optical atomic and low-ionization lines seen in the filaments are shown. The lines include [O i]λ6300, [O ii]λ3727, [N i]λ5199 and [N ii]λ6584. The shaded rectangle indicates thermally unstable regions.
