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 Tools annual

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 monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

To provide the census of the sources contributing to the X-ray backgroundpeak above 10 keV, NuSTAR is performing extragalactic surveys using athree-tier "wedding cake" approach. We present the NuSTAR survey of the COSMOSfield, the medium sensitivity and medium area tier, covering 1.7 deg2 andoverlapping with both Chandra and XMM-Newton data. This survey consists of 121observations for a total exposure of ~3 Ms. To fully exploit these data, wedeveloped a new detection strategy, carefully tested through extensivesimulations. The survey sensitivity at 20% completeness is 5.9, 2.9 and 6.4 x10^-14 erg/cm2/s in the 3-24 keV, 3-8 keV and 8-24 keV bands, respectively. Bycombining detections in 3 bands, we have a sample of 91 NuSTAR sources with10^42 -10^45.5 erg/s luminosities and redshift z=0.04-2.5. Thirty two sourcesare detected in the 8-24 keV band with fluxes ~100 times fainter than sourcesdetected by Swift-BAT. Of the 91 detections, all but four are associated with aChandra and/or XMM-Newton point-like counterpart. One source is associated withan extended lower energy X-ray source. We present the X-ray (hardness ratio andluminosity) and optical-to-X-ray properties. The observed fraction of candidateCompton-thick AGN measured from the hardness ratio is between 13-20%. Wediscuss the spectral properties of NuSTAR J100259+0220.6 (ID 330) at z=0.044,with the highest hardness ratio in the entire sample. The measured columndensity exceeds 10^24 /cm2, implying the source is Compton-thick. This sourcewas not previously recognized as such without the >10 keV data.

The NuSTAR Extragalactic Surveys: Overview and Catalog from the COSMOS Field