Rate coefficients for inelastic processes in low-energy Co + H, 
 
 
 
 
 
 Co
 
 +
 
 +
 
 
 H
 
 −
 
 
 
 
 , 
 
 
 
 
 
 Co
 
 +
 
 +
 H
 
 
 
 , and 
 
 
 
 
 
 Co
 
 
 2
 +
 
 
 +
 
 
 H
 
 −
 
 
 
 
 collisions are estimated using the quantum simplified model. Considerations include 44 triplet and 55 quintet molecular states of CoH, as well as 91 molecular states of CoH
 
 
 
 
 +
 
 
 
 . The estimations provide the rate coefficients for the 4862 partial processes (mutual neutralization, ion-pair formation, excitation, and de-excitation) in the neutral CoH system, and for the 
 
 
 
 8190
 
 
 
 partial processes in the ionized CoH
 
 
 
 
 +
 
 
 
 system, 
 
 
 
 13
 ,
 052
 
 
 
 processes in total. At 
 
 
 
 T
 =
 6000
 
 
 
 K, the rate coefficients with the largest values around 
 
 
 
 6
 ×
 
 10
 
 −
 8
 
 
 
 
 
 cm
 
 3
 
 
 
 s
 
 
 −
 1
 
 
 
 
 
 correspond to the mutual neutralization processes into the 
 
 
 
 Co
 (
 
 e
 2
 
 F
 )
 +
 H
 
 
 
 and 
 
 
 
 
 Co
 +
 
 
 (
 
 g
 5
 
 F
 )
 
 +
 H
 
 
 
 final channels in the neutral and ionized systems, respectively. Among the excitation and de-excitation processes in Co + H and in Co
 
 
 
 
 +
 
 
 
 + H collisions, at 
 
 
 
 T
 =
 6000
 
 
 
 K, the largest rate coefficients have values around 
 
 
 
 7
 ×
 
 10
 
 −
 9
 
 
 
 
 
 cm
 
 3
 
 
 
 s
 
 
 −
 1
 
 
 
 
 
 and correspond to the processes 
 
 
 
 
 Co
 (
 
 y
 2
 
 
 S
 ∘
 
 )
 +
 H
 
 →
 
 Co
 (
 
 e
 2
 
 F
 ;
 
 
 v
 4
 
 
 D
 ∘
 
 )
 +
 H
 
 
 
 
 and 
 
 
 
 
 
 Co
 +
 
 
 (
 
 h
 3
 
 P
 )
 
 +
 H
 
 →
 
 
 Co
 +
 
 
 (
 
 g
 3
 
 P
 ;
 
 
 g
 5
 
 P
 ;
 
 
 g
 5
 
 F
 )
 
 +
 H
 
 
 
 
 , respectively. The calculations single out inelastic processes important for non-local thermodynamic equilibrium (NLTE) modelling of Co I and Co II spectra in stellar atmospheres. The test NLTE calculations are carried out, and it is found that the new collision rates have a strong effect on the line formation and NLTE abundance corrections.
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