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

We present a generic and fully-automatic method aimed at detecting absorptionlines in the spectra of astronomical objects. The algorithm estimates thesource continuum flux using a dimensionality reduction technique, nonnegativematrix factorization, and then detects and identifies metal absorption lines.We apply it to a sample of ~100,000 quasar spectra from the Sloan Digital SkySurvey and compile a sample of ~40,000 Mg II & Fe II absorber systems, spanningthe redshift range 0.4< z < 2.3. The corresponding catalog is publiclyavailable. We study the statistical properties of these absorber systems andfind that the rest equivalent width distribution of strong Mg II absorbersfollows an exponential distribution at all redshifts, confirming previousstudies. Combining our results with recent near-infrared observations of Mg IIabsorbers we introduce a new parametrization that fully describes the incidencerate of these systems up to z~5. We find the redshift evolution of strong Mg IIabsorbers to be remarkably similar to the cosmic star formation history over0.4<z<5.5 (the entire redshift range covered by observations), suggesting aphysical link between these two quantities.

The JHU-SDSS metal absorption line catalog: redshift evolution and properties of Mg II absorbers