29 research outputs found
High-redshift Galaxy Candidates at z = 9-10 as Revealed by JWST Observations of WHL0137-08
We report the discovery of four galaxy candidates observed 450â600 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 WHL0137â08 observed in eight filters spanning 0.8â5.0 ÎŒm, plus nine Hubble Space Telescope filters spanning 0.4â1.7 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 = 8.3â8.7. All appear young, with mass-weighted ages < 0.15 mag, and specific star formation rates sSFR âŒ0.25â10 Gyrâ1 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 StatesâIsrael 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 as Revealed by JWST Observations of WHL0137-08
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 m, plus 9 HST
filters spanning 0.4-1.7 m. Three of these candidates are gravitationally
lensed by the foreground galaxy cluster and have magnifications of . The remaining nine candidates are located in a second JWST NIRCam module,
centered ~29' from the cluster center, with expected magnifications of <~
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 ( = -22.5 to -17). We find the stellar masses of these
galaxies are in the range = 8 - 9, and down to 7.5 for
the lensed galaxies. All are young with mass-weighted ages < 100 Myr, low dust
content < 0.15 mag, and high specific star formation rates sSFR ~10-50
Gyr for most. One z ~ 9 candidate is consistent with an age < 5 Myr and
a sSFR ~250 Gyr, 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 (~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
Entrepreneursâ achieved success: developing a multi-faceted measure
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. âEntrepreneursâ achieved successâ was conceptualized as a multi-faceted construct that includes entrepreneursâ self-reported achievement of firm performance, workplace relationships, personal fulfilment, community impact, and personal financial rewards. It was measured via the Subjective Entrepreneurial SuccessâAchievement Scale (SES-AS). Over the course of three studies (Nâ=â390) the factorial structure of âentrepreneursâ achieved successâ was established and largely replicated in two cultures. Based on a nomological network, we documented relationships among âentrepreneursâ achieved successâ, quasi-objective indicators of firm performance, and entrepreneursâ 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 galaxy merger in triply-lensed MACS0647JD
MACS0647JD is a triply-lensed galaxy originally discovered with
the Hubble Space Telescope. Here we report new JWST imaging, which clearly
resolves MACS0647JD as having two components that are either merging
galaxies or stellar complexes within a single galaxy. Both are very small, with
stellar masses and radii . The brighter
larger component "A" is intrinsically very blue (), likely due
to very recent star formation and no dust, and is spatially extended with an
effective radius . The smaller component "B" appears redder
(), likely because it is older () with mild dust
extinction (), and a smaller radius . 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 ,
we may be witnessing a galaxy merger 400 million years after the Big Bang. We
also identify a candidate companion galaxy C away, likely
destined to merge with galaxies A and B. The combined light from galaxies A+B
is magnified by factors of 8, 5, and 2 in three lensed images JD1, 2, and
3 with F356W fluxes , , (AB mag 25.1, 25.6, 26.6).
MACS0647JD is significantly brighter than other galaxies recently discovered
at similar redshifts with JWST. Without magnification, it would have AB mag
27.3 (). With a high confidence level, we obtain a photometric
redshift of based on photometry measured in 6 NIRCam filters
spanning , out to rest-frame. JWST NIRSpec
observations planned for January 2023 will deliver a spectroscopic redshift and
a more detailed study of the physical properties of MACS0647JD.Comment: 27 pages, 14 figures, submitted to Natur
Prosociality in business: a human empowerment framework
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 Welzelâs theory of emancipation, we argue that human empowermentâcomprised of four components: action resources, emancipative values, social movement activity, and civic entitlementsâenables, 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 entrepreneursâ 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 frameworkâs added value in understanding how modernization processes fully leverage the potential of social business activities for societies