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 Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Studies of the correlation between different diffuse interstellar bands(DIBs) are important for exploring their origins. However, the Gaia-RVSspectral window between 846 and 870 nm contains few DIBs, the strong DIB at 862nm being the only convincingly confirmed one. Here we attempt to confirm theexistence of a broad DIB around 864.8 nm and estimate its characteristics usingthe stacked Gaia-RVS spectra of a large number of stars. We study thecorrelations between the two DIBs at 862 nm and 864.8 nm, as well as theinterstellar extinction. We obtained spectra of the interstellar mediumabsorption by subtracting the stellar components using templates constructedfrom real spectra at high Galactic latitudes with low extinctions. We thenstacked the ISM spectra in Galactic coordinates, pixelized by the HEALPixscheme, to measure the DIBs. The stacked spectrum is modeled by the profiles ofthe two DIBs, Gaussian for $\lambda$862 and Lorentzian for $\lambda$864.8, anda linear continuum. We obtain 8458 stacked spectra in total, of which 1103(13%) have reliable fitting results after applying numerous conservativefilters. This work is the first of its kind to fit and measure $\lambda$862 and$\lambda$864.8 simultaneously in cool-star spectra. We find that the EWs andCDs of the two DIBs are well correlated with each other. The full width at halfmaximum (FWHM) of $\lambda$864.8 is estimated as $1.62 \pm 0.33$ nm whichcompares to $0.55 \pm 0.06$ nm for $\lambda$862. We also measure the vacuumrest-frame wavelength of $\lambda$864.8 to be $\lambda_0 = 864.53 \pm 0.14$ nm,smaller than previous estimates. We find a solid confirmation of the existenceof the DIB around 864.8 nm based on an exploration of its correlation with$\lambda$862 and estimation of its FWHM. $\lambda$862 correlates better withE(BP-RP) than $\lambda$864.8.

Solid confirmation of the broad DIB around 864.8 nm using stacked Gaia-RVS spectra