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 give an overview and describe the rationale, methods, and testing of theHubble Space Telescope (HST) Archival Legacy project "SKYSURF." SKYSURF usesHST's unique capability as an absolute photometer to measure the ~0.2-1.7$\mu$m sky surface brightness (SB) from 249,861 WFPC2, ACS, and WFC3 exposuresin ~1400 independent HST fields. SKYSURF's panchromatic dataset is designed toconstrain the discrete and diffuse UV to near-IR sky components: Zodiacal Light(ZL; inner Solar System), Kuiper Belt Objects (KBOs; outer Solar System),Diffuse Galactic Light (DGL), and the discrete plus diffuse ExtragalacticBackground Light (EBL). We outline SKYSURF's methods to: (1) measure sky-SBlevels between its detected objects; (2) measure the integrated discrete EBL,most of which comes from AB$\simeq$17-22 mag galaxies; and (3) estimate howmuch diffuse light may exist in addition to the extrapolated discrete galaxycounts. Simulations of HST WFC3/IR images with known sky-values and gradients,realistic cosmic ray (CR) distributions, and star plus galaxy counts wereprocessed with nine different algorithms to measure the "Lowest EstimatedSky-SB" (LES) in each image between the discrete objects. The best algorithmsrecover the inserted LES values within 0.2% when there are no image gradients,and within 0.2-0.4% when there are 5-10% gradients. SKYSURF requiresnon-standard re-processing of these HST images that includes restoring thelowest sky-level from each visit into each drizzled image. We provide a proofof concept of our methods from the WFC3/IR F125W images, where any residualdiffuse light that HST sees in excess of the Kelsall et al. (1998) Zodiacalmodel prediction does not depend on the total object flux that each imagecontains. This enables us to present our first SKYSURF results on diffuse lightin Carleton et al. (2022).

the astronomical journal

SKYSURF: Constraints on Zodiacal Light and Extragalactic Background  Light through Panchromatic HST All-Sky Surface-Brightness Measurements: I.  Survey Overview and Methods