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Table 3

Mean optical colours and hardness ratios with their corresponding standard deviations (in brackets) for the different spectroscopic types of sources.

Class B–R R–I ⟨HR⟩

BLAGN 0.67 (0.53) 0.48 (0.44) –0.47 (0.26)
NELG 1.17 (0.54) 0.68 (0.28) –0.23 (0.47)
ALG 1.46 (0.38) 0.80 (0.18) –0.62 (0.41)

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