The associated absorption features in quasar spectra of the Sload Digital Sky survey .I. \MgII\ absorption doublets.
Using the SDSS spectra of quasars included in the DR7Q or DR12Q catalogs, we search for Mg II narrow absorption doublets in the spectra data around Mg II emission lines. We obtain 17,316 Mg II doublets, within the redshift range of 0.3299<= z_abs <= 2.5663. We find that a velocity offset of v_r < 6000 km/s is a safe boundary to constrain the vast majority of associated Mg II systems, although we find some doublets at v_r > 6000 km/s. If associated Mg II absorbers are defined by v_r < 6000 km/s, ~33.3% of the absorbers supposed to be contaminants of intervening systems. Removing the 33.3% contaminants, ~4.5% of the quasars present at least one associated Mg II system with W_r\lambda2796>=0.2 \AA. The fraction of associated Mg II systems with high velocity outflows correlates with the average luminosities of their central quasars, indicating a relationship between outflows and the quasar feedback power. The v_r distribution of the outflow Mg II absorbers is peaked at 1023 km/s, which is smaller than the corresponding value of the outflow C IV absorbers. The redshift number density evolution of absorbers (dn/dz) limited by v_r > -3000 km/s differs from that of absorbers constrained by v_r > 2000 km/s. While, absorbers limited by v_r > 2000 km/s and higher values exhibit similar profile of dn/dz. In addition, the dn/dz is smaller when absorbers are constrained with larger v_r. The distributions of equivalent widths, and the ratio of W_r\lambda2796/W_r\lambda2803 is the same for associated and intervening systems, and independent on quasar luminosity.
Publisher URL: http://arxiv.org/abs/1801.07998
Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.
Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.