46 research outputs found
The JWST Advanced Deep Extragalactic Survey: Discovery of an Extreme Galaxy Overdensity at with JWST/NIRCam in GOODS-S
We report the discovery of an extreme galaxy overdensity at in the
GOODS-S field using JWST/NIRCam imaging from JADES and JEMS alongside
JWST/NIRCam wide field slitless spectroscopy from FRESCO. We identified
potential members of the overdensity using HST+JWST photometry spanning
. These data provide accurate and
well-constrained photometric redshifts down to .
We subsequently confirmed galaxies at using JWST
slitless spectroscopy over through a
targeted line search for around the best-fit photometric
redshift. We verified that of these galaxies reside in the field while
galaxies reside in a density around times that of a random
volume. Stellar populations for these galaxies were inferred from the
photometry and used to construct the star-forming main sequence, where
protocluster members appeared more massive and exhibited earlier star formation
(and thus older stellar populations) when compared to their field galaxy
counterparts. We estimate the total halo mass of this large-scale structure to
be using an empirical stellar mass to halo mass relation, which is
likely an underestimate as a result of incompleteness. Our discovery
demonstrates the power of JWST at constraining dark matter halo assembly and
galaxy formation at very early cosmic times.Comment: Resubmitted to ApJ based on reviewer report; main text has 15 pages,
6 figures and 1 table; appendix has 1 page, 2 figure sets, and 2 table
The JWST Advanced Deep Extragalactic Survey: Discovery of an Extreme Galaxy Overdensity at z = 5.4 with JWST/NIRCam in GOODS-S
© 2024 The Author(s). Published by the American Astronomical Society. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY), https://creativecommons.org/licenses/by/4.0/We report the discovery of an extreme galaxy overdensity at in the GOODS-S field using JWST/NIRCam imaging from JADES and JEMS alongside JWST/NIRCam wide field slitless spectroscopy from FRESCO. We identified potential members of the overdensity using HST+JWST photometry spanning . These data provide accurate and well-constrained photometric redshifts down to . We subsequently confirmed galaxies at using JWST slitless spectroscopy over through a targeted line search for around the best-fit photometric redshift. We verified that of these galaxies reside in the field while galaxies reside in a density around times that of a random volume. Stellar populations for these galaxies were inferred from the photometry and used to construct the star-forming main sequence, where protocluster members appeared more massive and exhibited earlier star formation (and thus older stellar populations) when compared to their field galaxy counterparts. We estimate the total halo mass of this large-scale structure to be using an empirical stellar mass to halo mass relation, which is likely an underestimate as a result of incompleteness. Our discovery demonstrates the power of JWST at constraining dark matter halo assembly and galaxy formation at very early cosmic times.Peer reviewe
The Survey of H5N1 Flu Virus in Wild Birds in 14 Provinces of China from 2004 to 2007
The highly pathogenic H5N1 avian influenza emerged in the year 1996 in Asia, and has spread to Europe and Africa recently. At present, effective monitoring and data analysis of H5N1 are not sufficient in Chinese mainland.)) were obviously higher than those in other 13 provinces. The results of sequence analysis indicated that the 17 strains isolated from wild birds were distributed in five clades (2.3.1, 2.2, 2.5, 6, and 7), which suggested that genetic diversity existed among H5N1 viruses isolated from wild birds. The five isolates from Qinghai came from one clade (2.2) and had a short evolutionary distance with the isolates obtained from Qinghai in the year 2005.We have measured the prevalence of H5N1 virus in 56 species of wild birds in 14 provinces of China. Continuous monitoring in the field should be carried out to know whether H5N1 virus can be maintained by wild birds