kal, gar, kacal, tâs
Having little or no hair on the scalp. → bald patch.
Bald from M.E. ball(e)d; Celtic bal "white patch, blaze;" Gk. phalios "having a white spot;" L. fulica "coot;" → patch.
Kal "bald," Mid.Pers. gar "bald;"
Av. kaurva- "bald;" cf. Skt. kulva- "bald, thin-haired;"
L. calvus "naked, bald."
pac-e tâs, tekke-ye ~
Fr.: zone chauve
Fr.: diagram de Baldwin-Phillips-Terlevich
A set of nebular → emission line diagrams used to distinguish the ionization mechanism of → nebular gas. The most famous version consists of [N II]λ6584/Hα versus [OIII] λ5007/Hβ. The next two more commonly used BPT diagnostics are [S II] λλ6717,6731/Hα versus [O III] λ5007/Hβ and [O I] λ6300/Hα versus [O III]λ5007/Hβ. These diagrams use strong, optical lines of close proximity in the ratios to limit → reddening and → spectrophotometric effects. They are able to clearly distinguish different classes of → ionization, for example → LINERs from normal → H II regions and → active galactic nuclei.
Baldwin, J. A., Phillips, M. M., Terlevich, R., 1981 PASP 93, 5; → diagram.