29 research outputs found

    High-redshift Galaxy Candidates at z = 9-10 as Revealed by JWST Observations of WHL0137-08

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    We report the discovery of four galaxy candidates observed 450–600 Myr after the Big Bang with photometric redshifts between z ∌ 8.3 and 10.2 measured using James Webb Space Telescope (JWST) NIRCam imaging of the galaxy cluster WHL0137−08 observed in eight filters spanning 0.8–5.0 ÎŒm, plus nine Hubble Space Telescope filters spanning 0.4–1.7 ÎŒm. One candidate is gravitationally lensed with a magnification of ÎŒ ∌ 8, while the other three are located in a nearby NIRCam module with expected magnifications of ÎŒ 1.1. Using SED fitting, we estimate the stellar masses of these galaxies are typically in the range log M M = 8.3–8.7. All appear young, with mass-weighted ages < 0.15 mag, and specific star formation rates sSFR ∌0.25–10 Gyr−1 for most. One z ∌ 9 candidate is consistent with an ageBased on observations with the NASA/ESA/CSA James Webb Space Telescope obtained from the Mikulski Archive for Space Telescopes (MAST) at the Space Telescope Science Institute (STScI), which is operated by the Association of Universities for Research in Astronomy (AURA), Incorpo rated, under NASA contract NAS5-03127. Support for Program number JWST-GO-02282 was provided through a grant from the STScI under NASA contract NAS5-03127. The data described here may be obtained from the MAST archive at doi:10.17909/cqfq-5n80. Also based on observations made with the NASA/ESA Hubble Space Telescope, obtained at STScI, which is operated by AURA under NASA contract NAS5-26555. The HST observations are associated with programs HST-GO-14096, HST-GO-15842, and HST-GO 16668. Cloud-based data processing and file storage for this work is provided by the AWS Cloud Credits for Research program. The Cosmic Dawn Center is funded by the Danish National Research Foundation (DNRF) under grant #140. A.Z. and L.F. acknowledge support by grant No. 2020750 from the United States–Israel Binational Science Foundation (BSF) and grant No. 2109066 from the United States National Science Foundation (NSF), and by the Ministry of Science & Technology, Israel

    High-Redshift Galaxy Candidates at z=9−13z = 9-13 as Revealed by JWST Observations of WHL0137-08

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    JWST was designed to peer into the distant universe and study galaxies nearer the beginning of time than previously. Here we report the discovery of 12 galaxy candidates observed 300-600 Myr after the Big Bang with photometric redshifts between z ~ 8.5-13 measured using JWST NIRCam imaging of the galaxy cluster WHL0137 observed in 8 filters spanning 0.8-5.0 ÎŒ\mum, plus 9 HST filters spanning 0.4-1.7 ÎŒ\mum. Three of these candidates are gravitationally lensed by the foreground galaxy cluster and have magnifications of Ό∌3−8\mu \sim 3 - 8. The remaining nine candidates are located in a second JWST NIRCam module, centered ~29' from the cluster center, with expected magnifications of ÎŒ\mu <~ 1.1. Our sample of high-redshift candidates have observed F200W AB magnitudes between 25.9 and 28.1 mag and intrinsic F200W AB magnitudes between 26.4 and 29.7 mag (MUVM_{UV} = -22.5 to -17). We find the stellar masses of these galaxies are in the range log⁥M∗/M⊙\log M_{*}/M_{\odot} = 8 - 9, and down to 7.5 for the lensed galaxies. All are young with mass-weighted ages < 100 Myr, low dust content AVA_V < 0.15 mag, and high specific star formation rates sSFR ~10-50 Gyr−1^{-1} for most. One z ~ 9 candidate is consistent with an age < 5 Myr and a sSFR ~250 Gyr−1^{-1}, as inferred from a strong F444W excess, implying [OIII]+H-beta rest-frame equivalent width ~2000 Angstrom, although an older and redder z~ 10 object is also allowed. Another z~9 candidate ID9356 is lensed into an arc 2.6" long by the effects of strong gravitational lensing (ÎŒ\mu~8), and has at least two bright knots of unevenly distributed star formation. This arc is the most spatially-resolved galaxy at z~9 known to date, revealing structures ~30 pc across. Follow-up spectroscopy of WHL0137 with JWST/NIRSpec is planned for later this year, which will validate some of these candidates and study their physical properties in more detail.Comment: submitted to Ap

    Entrepreneurs’ achieved success: developing a multi-faceted measure

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    Firm performance is typically measured via objective financial indicators. However, researchers increasingly acknowledge that entrepreneurs do not measure their success solely in financial terms but that a range of often subjective indicators matter to them. This article contributes to the debate on entrepreneurial performance by studying how entrepreneurs assess their achieved success. ‘Entrepreneurs’ achieved success’ was conceptualized as a multi-faceted construct that includes entrepreneurs’ self-reported achievement of firm performance, workplace relationships, personal fulfilment, community impact, and personal financial rewards. It was measured via the Subjective Entrepreneurial Success–Achievement Scale (SES-AS). Over the course of three studies (N = 390) the factorial structure of ‘entrepreneurs’ achieved success’ was established and largely replicated in two cultures. Based on a nomological network, we documented relationships among ‘entrepreneurs’ achieved success’, quasi-objective indicators of firm performance, and entrepreneurs’ financial satisfaction, creativity, and health. Based on our research, we propose a new conceptual framework to study performance in the context of entrepreneurship. This framework acknowledges both the success criteria that entrepreneurs wish to achieve and those that they actually achieve, and extends our understanding of firm performance

    JWST reveals a possible z∌11z \sim 11 galaxy merger in triply-lensed MACS0647−-JD

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    MACS0647−-JD is a triply-lensed z∌11z\sim11 galaxy originally discovered with the Hubble Space Telescope. Here we report new JWST imaging, which clearly resolves MACS0647−-JD as having two components that are either merging galaxies or stellar complexes within a single galaxy. Both are very small, with stellar masses ∌108 M⊙\sim10^8\,M_\odot and radii r<100 pcr<100\,\rm pc. The brighter larger component "A" is intrinsically very blue (ÎČ∌−2.6\beta\sim-2.6), likely due to very recent star formation and no dust, and is spatially extended with an effective radius ∌70 pc\sim70\,\rm pc. The smaller component "B" appears redder (ÎČ∌−2\beta\sim-2), likely because it is older (100−200 Myr100-200\,\rm Myr) with mild dust extinction (AV∌0.1 magA_V\sim0.1\,\rm mag), and a smaller radius ∌20 pc\sim20\,\rm pc. We identify galaxies with similar colors in a high-redshift simulation, finding their star formation histories to be out of phase. With an estimated stellar mass ratio of roughly 2:1 and physical projected separation ∌400 pc\sim400\,\rm pc, we may be witnessing a galaxy merger 400 million years after the Big Bang. We also identify a candidate companion galaxy C ∌3 kpc\sim3\,{\rm kpc} away, likely destined to merge with galaxies A and B. The combined light from galaxies A+B is magnified by factors of ∌\sim8, 5, and 2 in three lensed images JD1, 2, and 3 with F356W fluxes ∌322\sim322, 203203, 86 nJy86\,\rm nJy (AB mag 25.1, 25.6, 26.6). MACS0647−-JD is significantly brighter than other galaxies recently discovered at similar redshifts with JWST. Without magnification, it would have AB mag 27.3 (MUV=−20.4M_{UV}=-20.4). With a high confidence level, we obtain a photometric redshift of z=10.6±0.3z=10.6\pm0.3 based on photometry measured in 6 NIRCam filters spanning 1−5ÎŒm1-5\rm\mu m, out to 4300 A˚4300\,\r{A} rest-frame. JWST NIRSpec observations planned for January 2023 will deliver a spectroscopic redshift and a more detailed study of the physical properties of MACS0647−-JD.Comment: 27 pages, 14 figures, submitted to Natur

    Prosociality in business: a human empowerment framework

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    This study introduces a human empowerment framework to better understand why some businesses are more socially oriented than others in their policies and activities. Building on Welzel’s theory of emancipation, we argue that human empowerment—comprised of four components: action resources, emancipative values, social movement activity, and civic entitlements—enables, motivates, and entitles individuals to pursue social goals for their businesses. Using a sample of over 15,000 entrepreneurs from 43 countries, we report strong empirical evidence for two ecological effects of the framework components on prosociality. We find that human empowerment (1) lifts entrepreneurs’ willingness to choose a social orientation for their business, and (2) reinforces the gender effect on prosociality in business activity. We discuss the human empowerment framework’s added value in understanding how modernization processes fully leverage the potential of social business activities for societies
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