Toward understanding physical origin of 2175Å extinction bump in interstellar medium

Abstract

The 2175 Å ultraviolet (UV) extinction bump in interstellar medium (ISM) of the Milky Way was discovered in 1965. After intensive exploration of more than a half century, however, its exact origin still remains a big conundrum that is being debated. Here we propose a mixture model by which the extinction bump in ISM is argued possibly relevant to the clusters of hydrogenated T-carbon (HTC) molecules (C40H16) that have intrinsically a sharp absorption peak at the wavelength 2175 Å. By linearly combining the calculated absorption spectra of HTC mixtures, graphite, MgSiO3 and Fe2SiO4, we show that the UV extinction curves of optional six stars can be nicely fitted. This present work poses an alternative explanation toward understanding the physical origin of the 2175 Å extinction bump in ISM of the Milky Way.

Monthly Notices of the Royal Astronomical Society accepted

References in corpus (2)

• An Analysis of the Shapes of Interstellar Extinction Curves. V. The IR-Through-UV Curve Morphology
• Observational Evidence Linking Interstellar UV Absorption to PAH Molecules

Cited by in corpus (5)

• The 2175 Angstrom Interstellar Extinction Bump: Is the Wavelength Variable?
• Mapping the aliphatic hydrocarbon content of interstellar dust in the Galactic plane
• What causes the ultraviolet extinction bump at the cosmic dawn?
• GRB 180325A: dust grain-size distribution and interstellar iron nanoparticles contribution
• Constraining the Metallicities of Damped Ly$\alpha$ Systems Using Extinction Curves