![(a) Evolution of the Hα luminosity and five emission-line ratios for Z= 0.0001 (SAL2). The ratios are [O iii]λλ5007,4959/Hβ, [O ii]λ3727/Hβ, [O ii]/[O iii], [O i]λ6300/Hα and [N ii]λ6584/Hα. The more appropriate hydrogen recombination line has been chosen for normalization in order to minimize reddening effects. Solid lines correspond to models with nH= 10 cm−3 while dotted lines correspond to models with nH= 100 cm−3. Black, red, green, blue, yellow, brown and grey lines correspond to different cluster masses: 0.12, 0.20, 0.40, 0.60, 1.00, 1.50 and 2.00 ×105 M⊙, respectively. (b) Evolution of emission lines for Z= 0.0004 (SAL2). (c) Evolution of emission lines for Z= 0.004 (SAL2). (d) Evolution of emission lines for Z= 0.008 (SAL2). (e) Evolution of emission lines for Z= 0.02 (SAL2). Different colours and line code have the same meaning as in Fig. 2(a) for all of them.](https://oup.silverchair-cdn.com/oup/backfile/Content_public/Journal/mnras/403/4/10.1111_j.1365-2966.2009.16239.x/3/mnras0403-2012-f2a.gif?Expires=1750535895&Signature=vXaftCkz8PmVV08azh-LHdQOh2dkHDl7wpJyN2dFu1YUAn4SzqEk0kJ3H8HNfcWNdmTgLjLK1LIuu9MiMnyh2N9HAva9XrnteJ6EO7-lbtrrjrVhMPfnpqAlLV8svr55Kwny0simOBMeRSoYSZ~QRO0Z3oQPUUHZ37jBBxrilcvEO3LHeaSwvqc5iPynF-qhvSRNXkFVLz7RW0q6e06EpBwLbk5KDgwtdCOmTyrKlgEVKMrdeVmElDg9mXSysG97~OaeKIQBCcoiDOAKccHpl8xv5-WdAjmARq-kHakx23rBBN~wenKRq9BJY5D7ZiuFWJc9c0vSLSTWis0k0ib3Cw__&Key-Pair-Id=APKAIE5G5CRDK6RD3PGA)
(a) Evolution of the Hα luminosity and five emission-line ratios for Z= 0.0001 (SAL2). The ratios are [O iii]λλ5007,4959/Hβ, [O ii]λ3727/Hβ, [O ii]/[O iii], [O i]λ6300/Hα and [N ii]λ6584/Hα. The more appropriate hydrogen recombination line has been chosen for normalization in order to minimize reddening effects. Solid lines correspond to models with nH= 10 cm−3 while dotted lines correspond to models with nH= 100 cm−3. Black, red, green, blue, yellow, brown and grey lines correspond to different cluster masses: 0.12, 0.20, 0.40, 0.60, 1.00, 1.50 and 2.00 ×105 M⊙, respectively. (b) Evolution of emission lines for Z= 0.0004 (SAL2). (c) Evolution of emission lines for Z= 0.004 (SAL2). (d) Evolution of emission lines for Z= 0.008 (SAL2). (e) Evolution of emission lines for Z= 0.02 (SAL2). Different colours and line code have the same meaning as in Fig. 2(a) for all of them.
