The Future Landscape of High-Redshift Galaxy Cluster Science

Large scale structure and cosmolog

Galaxy populations in the most distant SPT-SZ clusters: I. Environmental quenching in massive clusters at 1.4 ≲ z ≲ 1.7

© 2019 ESO. We present the first results from a galaxy population study in the highest redshift galaxy clusters identified in the 2500 deg 2 South Pole Telescope Sunyaev Zel'dovich effect (SPT-SZ) survey, which is sensitive to M 500 ≳ 3 × 10 14 M · clusters from z ∼ 0.2 out to the highest redshifts where such massive structures exist. The cluster selection is to first order independent of galaxy properties, making the SPT-SZ sample particularly well suited for cluster galaxy population studies. We carried out a four-band imaging campaign with the Hubble and Spitzer Space Telescopes of the five z≳ 1.4, S/N SZE > 5 clusters, that are among the rarest most massive clusters known at this redshift. All five clusters show clear overdensities of red galaxies whose colors agree with the initial cluster redshift estimates, although one (SPT-CLJ0607-4448) shows a galaxy concentration much less prominent than the others. The highest redshift cluster in this sample, SPT-CLJ0459-4947 at z ∼ 1.72, is the most distant M 500 > 10 14 M · cluster discovered thus far through its intracluster medium, and is one of only three known clusters in this mass range at z≳ 1.7, regardless of selection. Based on UVJ-like photometric classification of quiescent and star-forming galaxies, we find that the quiescent fraction in the cluster central regions (r/r 500 10.85. We have explored the impact of emission from star formation on the selection of this sample, concluding that all five clusters studied here would still have been detected with S/N SZE > 5, even if they had the same quiescent fraction as measured in the field. Our results thus point towards an efficient suppression of star formation in the central regions of the most massive clusters, occurring already earlier than z ∼ 1.5

The Future Landscape of High-Redshift Galaxy Cluster Science

The Decadal Survey on Astronomy and Astrophysics (Astro2020) of the US National Academies of ScienceWe describe the opportunities for galaxy cluster science in the high- redshift regime where massive, virialized halos first formed and where star formation and AGN activity peaked. New observing facilities from radio to X-ray wavelengths, combining high spatial/spectral resolution with large collecting areas, are poised to uncover this population

The Future Landscape of High-Redshift Galaxy Cluster Science

We describe the opportunities for galaxy cluster science in the high- redshift regime where massive, virialized halos first formed and where star formation and AGN activity peaked. New observing facilities from radio to X-ray wavelengths, combining high spatial/spectral resolution with large collecting areas, are poised to uncover this population

The Future Landscape of High-Redshift Galaxy Cluster Science

The Decadal Survey on Astronomy and Astrophysics (Astro2020) of the US National Academies of ScienceWe describe the opportunities for galaxy cluster science in the high- redshift regime where massive, virialized halos first formed and where star formation and AGN activity peaked. New observing facilities from radio to X-ray wavelengths, combining high spatial/spectral resolution with large collecting areas, are poised to uncover this population

Teknologinen kehitys ajaa ikääntyneitä varhaiseläkkeelle

Tässä artikkelissa tarkastelemme teknologisen muutoksen ja varhaiseläkereittien vaikutuksia ikääntyneiden työllisyyteen. Aiempi tutkimus on osoittanut, että anteliailla varhaiseläkereiteillä, kuten eläkepäivillä ja työkyvyttömyysetuuksilla, voi olla merkittävä työuria lyhentävä vaikutus. Teknologinen kehitys saattaa voimistaa näiden institutionaalisten tekijöiden työllisyysvaikutuksia. Eläkeputki lisää etenkin teknologian muutokselle alttiissa ammateissa työskentelevien ikääntyneiden ennenaikaista poistumista työelämästä. Sen sijaan eläkeputken merkitys on huomattavasti pienempi ammattiryhmissä, joiden työtehtäviä on vaikeampi korvata roboteilla tai tietokoneilla.nonPeerReviewe