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

A high-resolution HST/STIS spectrum (R=30,000) is presented of the threeMgII-selected absorption systems (A, B, and C, clustered within 1500km/s) atz~0.93 toward the quasar PG 1206+459. A WIYN Gunn i-band image of the quasarfield and spectroscopy of two galaxy candidates are also presented. Amulti-phase medium is seen in all three systems, consistent with smaller,denser clouds producing low-ionization transitions (MgII, FeII, and SiII) andlarger, diffuse clouds giving rise to high-ionization transitions (CIV, NV,and/or OVI). (1) System A, a multi-cloud, weak MgII absorber at z=0.9254,requires a super-solar metallicity in both low- and high-ionization phases,unless an alpha-group enhancement is included. With the unusually complexvelocity structure resolved in the NV profiles, this system is unlikely torepresent a traditional galaxy disk/corona. The most likely candidate hostgalaxy is a ~2L^*, apparently warped, spiral at an impact parameter of 43h^-1kpc. (2) System B, at z=0.9276, has the strongest MgII absorption and has anapproximately solar metallicity in the low-ionization phase. The smooth, broadhigh-ionization profiles may indicate a coronal structure similar to that ofthe Milky Way. The redshift of an L^* galaxy (z=0.9289), at an impact parameterof 38h^-1 kpc is consistent with the redshift of this system. (3) System C, atz=0.9342, has a single component in MgII, separated from the other two systemsby ~1000km/s. It lacks the small, low-ionization cloud characteristic of anisolated single-cloud, weak MgII absorber. Its absorption properties aresimilar to the ``satellite clouds'' of classic strong MgII absorbers, so thiscould be a high-velocity cloud in the galaxy group responsible for the systems,possibly related to a 0.2L^* galaxy at an impact parameter of 43h^-1 kpc.Comment: 52 pages, 9 figures; to appear in ApJ, June 20, 200

The Multiphase Absorption Systems toward PG 1206+459