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

The combination of optical and mid-infrared (MIR) photometry has beenextensively used to select red active galactic nuclei (AGNs). Our aim is toexplore the obscuration properties of these red AGNs with both X-rayspectroscopy and spectral energy distributions (SEDs). In this study, were-visit the relation between optical/MIR extinction and X-ray absorption. Weuse IR selection criteria, specifically the $W1$ and $W2$ WISE bands, toidentify 4798 AGNs in the $\it{XMM-XXL}$ area ($\sim 25$deg$^2$). Applicationof optical/MIR colours ($r- W2 > 6$) reveals 561 red AGNs (14$\%$). Of these,47 have available X-ray spectra with at least 50 net (background-subtracted)counts per detector. For these sources, we construct SEDs from the optical tothe MIR using the CIGALE code. The SED fitting shows that 44 of these latter 47sources present clear signs of obscuration based on the AGN emission and theestimated inclination angle. Fitting the SED also reveals ten systems($\sim20\%$) which are dominated by the galaxy. In these cases, the red coloursare attributed to the host galaxy rather than AGN absorption. Excluding theseten systems from our sample and applying X-ray spectral fitting analysis showsthat up to $76\%$ (28/37) of the IR red AGNs present signs of X-ray absorption.Thus, there are nine sources ($\sim20\%$ of the sample) that although opticallyred, are not substantially X-ray absorbed. Approximately $50\%$ of thesesources present broad emission lines in their optical spectra. We suggest thatthe reason for this apparent discrepancy is that the r-W2 criterion issensitive to smaller amounts of obscuration relative to the X-ray spectroscopy.In conclusion, it appears that the majority of red AGNs present considerableobscuration levels as shown by their SEDs. Their X-ray absorption is moderatewith a mean of $\rm N_H \sim 10^{22}\, \rm{cm^{-2}}$.

The $\it{XXL}$ survey: XL. Obscuration properties of red AGN in $\it{XXL-N}$