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

We present new far-ultraviolet spectra from the Cosmic Origins Spectrograph(HST/COS) of the BL Lac object 1ES1553+113 covering the wavelength range1135-1795 A. The data show a smooth continuum with a wealth of narrowabsorption features arising in the ISM and IGM. These features include 41 Lyaabsorbers at 0<z<0.43, fourteen of which are detected in multiple Lyman linesand six in one or more metal lines. We analyze a metal-rich triplet of Lyaabsorbers at z=0.188 in which OVI, NV, and CIII absorption is detected. Siliconions (SiIII/IV) are not detected to fairly strong upper limits, and we use themeasured SiIII/CIII upper limit to derive an abundance limit [C/Si]>0.6 for thestrongest component of the absorber complex. Galaxy redshift surveys show anumber of massive galaxies at approximately the same redshift as thisabsorption complex, suggesting that it arises in a large-scale galaxy filament.As one of the brightest extragalactic X-ray and gamma-ray sources, 1ES1553+113is of great interest to the high-energy astrophysics community. With nointrinsic emission or absorption features, 1ES1553+113 has no direct redshiftdetermination. We use intervening Lya absorbers to place a direct limit on theredshift: z_em>0.395 based on a confirmed Lya+OVI absorber and z_em>0.433 basedon a single-line detection of Lya. COS/FUV data are only sensitive to Lyaabsorbers at z<0.47, but we present statistical arguments that z_em<0.58 basedon the non-detection of any Lyb absorbers at z>0.4.

HST/COS Observations of the Ly alpha Forest toward the BL Lac Object 1ES1553+113