Study of the satellite bands of RbCs molecule in the near UV

•Comparison of high-resolution absorption spectra of Rb, Cs and RbCs vapor mixture.•Satellite bands of RbCs molecule at 362.2 nm, 372.5 nm and 390.7 nm.•Avoided crossings of potential curves at long-range inter-atomic region.•The observed satellite bands may be observed in the mixed Rb-Cs MOT.•The satellite bands can be used for comparison with ab initio RbCs calculations.

By comparing high-resolution absorption spectra of Rb and Cs vapor with Rb-Cs vapor mixture spectrum we were able to identify several satellite bands of RbCs molecule at 362.2 nm, 372.5 nm and 390.7 nm. These bands represent lower Rydberg states of the RbCs molecule which may be further studied at ultracold conditions.