English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

A large number of interstellar absorption features at ~ 4000\AA\ -- 1.8{\mu}m, known as the "diffuse interstellar bands" (DIBs), remains unidentified.Most recent works relate them to large polycyclic aromatic hydrocarbon (PAH)molecules or ultrasmall carbonaceous grains which are also thought to beresponsible for the 2175 \AA\ extinction bump and/or the far ultraviolet (UV)extinction rise at $\lambda^{-1} > 5.9\ {\mu}m^{-1}$. Therefore, one mightexpect some relation between the UV extinction and DIBs. Such a relationship,if established, could put important constraints on the carrier of DIBs. Overthe past four decades, whether DIBs are related to the shape of the UVextinction curves has been extensively investigated. However, the results areoften inconsistent, partly due to the inconsistencies in characterizing the UVextinction. Here we re-examine the connection between the UV extinction curveand DIBs. We compile the extinction curves and the equivalent widths of 40 DIBsalong 97 slightlines. We decompose the extinction curve into three Drude-likefunctions composed of the visible/near-infrared component, the 2175 \AA\ bump,and the far-UV extinction at $\lambda^{-1} > 5.9\ {\mu}m^{-1}$. We argue thatthe wavelength-integrated far-UV extinction derived from this decompositiontechnique best measures the strength of the far-UV extinction. No correlationis found between the far-UV extinction and most (~90\%) of the DIBs. We havealso shown that the color excess E(1300-1700), the extinction difference at1300 \AA\ and 1700 \AA\ often used to measure the strength of the far-UVextinction, does not correlate with DIBs. Finally, we confirm the earlierfindings of no correlation between the 2175 \AA\ bump and DIBs or between the2175 \AA\ bump and the far-UV extinction.

Diffuse Interstellar Bands and the Ultraviolet Extinction Curves: The Missing Link Revisited