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

In area and depth, the Pan-STARRS1 (PS1) 3$\pi$ survey is unique amongmany-epoch, multi-band surveys and has enormous potential for all-skyidentification of variable sources. PS1 has observed the sky typically seventimes in each of its five bands ($grizy$) over 3.5 years, but unlike SDSS notsimultaneously across the bands. Here we develop a new approach for quantifyingstatistical properties of non-simultaneous, sparse, multi-color lightcurvesthrough light-curve structure functions, effectively turning PS1 into a $\sim35$-epoch survey. We use this approach to estimate variability amplitudes andtimescales $(\omega_r, \tau)$ for all point-sources brighter than$r_{\mathrm{P1}}=21.5$ mag in the survey. With PS1 data on SDSS Stripe 82 as``ground truth", we use a Random Forest Classifier to identify QSOs and RRLyrae based on their variability and their mean PS1 and WISE colors. We findthat, aside from the Galactic plane, QSO and RR Lyrae samples of purity$\sim$75\% and completeness $\sim$92\% can be selected. On this basis we haveidentified a sample of $\sim 1,000,000$ QSO candidates, as well as anunprecedentedly large and deep sample of $\sim$150,000 RR Lyrae candidates withdistances from $\sim$10 kpc to $\sim$120 kpc. Within the Draco dwarfspheroidal, we demonstrate a distance precision of 6\% for RR Lyrae candidates.We provide a catalog of all likely variable point sources and likely QSOs inPS1, a total of $25.8\times 10^6$ sources.

Finding, characterizing and classifying variable sources in multi-epoch sky surveys: QSOs and RR Lyrae in PS1 3$\pi$ data