Carriers of 4964 and 6196 diffuse interstellar bands and environments dominated by either CH or CH$^{+}$ molecules

TL;DR

This study investigates the relationship between specific diffuse interstellar bands and molecular environments, revealing that certain DIB carriers are spatially associated with either CH or CH$^{+}$ molecules, based on spectral analysis of multiple stars.

Contribution

It provides new evidence linking the carriers of the 4964 and 6196 DIBs to environments dominated by CH and CH$^{+}$, respectively, through analysis of a large stellar sample.

Findings

4964 DIB correlates strongly with CH column density.

6196 DIB shows marginally better correlation with CH$^{+}$ than CH.

Spectral analysis supports spatial association of DIB carriers with specific molecules.

Abstract

The analysis of radial velocities of interstellar spectral features: CH, CH$^{+}$ as well as 4964 and 6196 diffuse interstellar bands, seen in spectra of HD 151932 and 152233, suggests that carrier of the former is spatially correlated with CH while that of the latter -- with CH$^{+}$. A further analysis, done in this paper and based on the sample of 106 reddened OB stars, partly confirms this suggestion, showing that the CH column density correlates indeed much better with the equivalent width of the 4964 DIB than with that of the 6196 DIB. However, the strengths of the 6196 DIB correlate only marginally better with CH$^+$ than with CH.