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 report spectroscopic results from our 40-orbit $Hubble~Space~Telescope$slitless grism spectroscopy program observing the 20 densest CARLA candidategalaxy clusters at $1.4 < z < 2.8$. These candidate rich structures, among therichest and most distant known, were identified on the basis of $[3.6]-[4.5]$color from a $408~$hr multi-cycle $Spitzer$ program targeting $420$ distantradio-loud AGN. We report the spectroscopic confirmation of $16$ distantstructures at $1.4 < z < 2.8$ associated with the targeted powerfulhigh-redshift radio-loud AGN. We also report the serendipitous discovery andspectroscopic confirmation of seven additional structures at $0.87 < z < 2.12$not associated with the targeted radio-loud AGN. We find that $10^{10} -10^{11}\,M_{\odot}$ member galaxies of our confirmed CARLA structures formsignificantly fewer stars than their field counterparts at all redshifts within$1.4\leq z\leq 2$. We also observe higher star-forming activity in thestructure cores up to $z = 2$, finding similar trends as cluster surveys atslightly lower redshifts ($1.0 < z < 1.5$). By design, our efficient strategyof obtaining just two grism orbits per field only obtains spectroscopicconfirmation of emission-line galaxies. Deeper spectroscopy will be required tostudy the population of evolved, massive galaxies in these (forming) clusters.Lacking multi-band coverage of the fields, we adopt a very conservativeapproach of calling all confirmations "structures", although we note that anumber of features are consistent with some of them being bona fide galaxyclusters. Together, this survey represents a unique and large homogenous sampleof spectroscopically confirmed structures at high redshifts, potentially morethan doubling the census of confirmed, massive clusters at $z > 1.4$.

$HST$ Grism Confirmation of $16$ Structures at $1.4 < z < 2.8$ from the Clusters Around Radio-Loud AGN (CARLA) Survey