分类： 天文学 >> 天文学 提交时间： 2023-02-19
Christina C. Williams
Sandro Tacchella
Michael V. Maseda
Brant E. Robertson
Benjamin D. Johnson
Chris J. Willott
Daniel J. Eisenstein
Christopher N. A. Willmer
Zhiyuan Ji
Kevin N. Hainline
Jakob M. Helton
Stacey Alberts
Stefi Baum
Rachana Bhatawdekar
Kristan Boyett
Andrew J. Bunker
Stefano Carniani
Stephane Charlot
Jacopo Chevallard
Emma Curtis-Lake
摘要： We present JEMS (JWST Extragalactic Medium-band Survey), the first public
medium-band imaging survey carried out using JWST/NIRCam and NIRISS. These
observations use $\sim2\mu$m and $\sim4\mu$m medium-band filters (NIRCam F182M,
F210M, F430M, F460M, F480M; and NIRISS F430M & F480M in parallel) over 15.6
square arcminutes in the Hubble Ultra Deep Field (UDF), thereby building on the
deepest multi-wavelength public datasets available anywhere on the sky. We
describe our science goals, survey design, NIRCam and NIRISS image reduction
methods, and describe our first data release of the science-ready mosaics. Our
chosen filters create a JWST imaging survey in the UDF that enables novel
analysis of a range of spectral features potentially across the redshift range
of $0.31$ magnitude)
across redshifts $1.5
分类： 天文学 >> 天文学 提交时间： 2023-02-19
Jakob M. Helton
Fengwu Sun
Charity Woodrum
Kevin N. Hainline
Christopher N. A. Willmer
George H. Rieke
Marcia J. Rieke
Sandro Tacchella
Brant Robertson
Benjamin D. Johnson
Stacey Alberts
Daniel J. Eisenstein
Ryan Hausen
Nina R. Bonaventura
Andrew Bunker
Stephane Charlot
Mirko Curti
Emma Curtis-Lake
Tobias J. Looser
Roberto Maiolino
摘要： We report the discovery of an extreme galaxy overdensity at $z = 5.4$ 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 $\lambda = 0.4-5.0\ \mu\mathrm{m}$. These data provide accurate and well-constrained photometric redshifts down to $m \approx 29-30\,\mathrm{mag}$. We subsequently confirmed $N = 96$ potential members of the overdensity using JWST slitless spectroscopy over $\lambda = 3.9-5.0\ \mu\mathrm{m}$ through a targeted line search for $\mathrm{H} \alpha$ around the best-fit photometric redshift. We verified that $N = 53$ galaxies reside in the field at $z = 5.2-5.5$ while $N = 43$ galaxies reside in an overdensity at $z = 5.4$ around $\sim 10-12$ 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 $13.0 \lesssim \mathrm{log}_{10} \left( M_{\mathrm{halo}}/M_{\odot} \right) \lesssim 13.5$ using an empirical stellar mass to halo mass relation, although this 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.
点击量
待评议
点击量
下载量
评论
