Diffuse interstellar bands in the HII region M17: Insights into their relation with the total-to-selective visual extinction $R_V$

M. C. Ramírez-Tannus, N. L. J. Cox, L. Kaper +1

Diffuse interstellar bands (DIBs) are broad absorption features measured in sightlines probing the diffuse interstellar medium. Although large carbon-bearing molecules have been pr…