7 research outputs found
Spectroscopy of four metal-poor galaxies beyond redshift ten
Finding and characterising the first galaxies that illuminated the early
Universe at cosmic dawn is pivotal to understand the physical conditions and
the processes that led to the formation of the first stars. In the first few
months of operations, imaging from the James Webb Space Telescope (JWST) have
been used to identify tens of candidates of galaxies at redshift (z) greater
than 10, less than 450 million years after the Big Bang. However, none of these
candidates has yet been confirmed spectroscopically, leaving open the
possibility that they are actually low-redshift interlopers. Here we present
spectroscopic confirmation and analysis of four galaxies unambiguously detected
at redshift 10.3<z<13.2, previously selected from NIRCam imaging. The spectra
reveal that these primeval galaxies are extremely metal poor, have masses
between 10^7 and a few times 10^8 solar masses, and young ages. The damping
wings that shape the continuum close to the Lyman edge are consistent with a
fully neutral intergalactic medium at this epoch. These findings demonstrate
the rapid emergence of the first generations of galaxies at cosmic dawn.Comment: 32 pages, 9 figures, Submitte
JADES NIRSpec Spectroscopy of GN-z11: Lyman- emission and possible enhanced nitrogen abundance in a luminous galaxy
We present JADES JWST/NIRSpec spectroscopy of GN-z11, the most luminous
candidate Lyman break galaxy in the GOODS-North field with
. We derive a redshift of (lower than previous
determinations) based on multiple emission lines in our low and medium
resolution spectra over m. We significantly detect the continuum
and measure a blue rest-UV spectral slope of . Remarkably, we see
spatially-extended Lyman- in emission (despite the highly-neutral IGM
expected at this early epoch), offset 555 km/s redward of the systemic
redshift. From our measurements of collisionally-excited lines of both low- and
high-ionization (including [O II] , [Ne III] and C
III] ) we infer a high ionization parameter (). We
detect the rarely-seen N IV] and N III] lines in
both our low and medium resolution spectra, with other high ionization lines
seen in low resolution spectrum such as He II (blended with O III]) and C IV
(with a possible P-Cygni profile). Based on the observed rest-UV line ratios,
we cannot conclusively rule out photoionization from AGN. The high C III]/He II
ratios, however, suggest a likely star-formation explanation. If the observed
emission lines are powered by star formation, then the strong N III]
observed may imply an unusually high abundance. Balmer
emission lines (H, H) are also detected, and if powered by star
formation rather than an AGN we infer a star formation rate of (depending on the IMF) and low dust attenuation. Our
NIRSpec spectroscopy confirms that GN-z11 is a remarkable galaxy with extreme
properties seen 430 Myr after the Big Bang.Comment: Submitted to Astronomy & Astrophysics, 14 pages, 9 figure
JADES Initial Data Release for the Hubble Ultra Deep Field: Revealing the Faint Infrared Sky with Deep JWST NIRCam Imaging
© 2023. 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/JWST has revolutionized the field of extragalactic astronomy with its sensitive and high-resolution infrared view of the distant Universe. Adding to the new legacy of JWST observations, we present the first NIRCam imaging data release from the JWST Advanced Deep Extragalactic Survey (JADES), providing nine filters of infrared imaging of âŒ25 arcmin2 covering the Hubble Ultra Deep Field and portions of Great Observatories Origins Deep Survey South. Utilizing 87 on-sky dual-filter hours of exposure time, these images reveal the deepest ever near-infrared view of this iconic field. We supply carefully constructed nine-band mosaics of the JADES bands, as well as matching reductions of five additional bands from the JWST Extragalactic Medium-band Survey. Combining with existing Hubble Space Telescope imaging, we provide 23-band space-based photometric catalogs and photometric redshifts for â47,500 sources. To promote broad engagement with JADES, we have created an interactive FitsMap website to provide an interface for professional researchers and the public to experience these JWST data sets. Combined with the first JADES NIRSpec data release, these public JADES imaging and spectroscopic data sets provide a new foundation for discoveries of the infrared Universe by the worldwide scientific community.Peer reviewe
JADES Initial Data Release for the Hubble Ultra Deep Field: Revealing the Faint Infrared Sky with Deep JWST NIRCam Imaging
JWST has revolutionized the field of extragalactic astronomy with its
sensitive and high-resolution infrared view of the distant universe. Adding to
the new legacy of JWST observations, we present the first NIRCam imaging data
release from the JWST Advanced Deep Extragalactic Survey (JADES) providing 9
filters of infrared imaging of 25 arcmin covering the Hubble Ultra
Deep Field and portions of Great Observatories Origins Deep Survey (GOODS)
South. Utilizing 87 on-sky dual-filter hours of exposure time, these images
reveal the deepest ever near-infrared view of this iconic field. We supply
carefully constructed 9-band mosaics of the JADES bands, as well as matching
reductions of 5 additional bands from the JWST Extragalactic Medium-band Survey
(JEMS). Combining with existing HST imaging, we provide 23-band space-based
photometric catalogs and photometric redshifts for sources. To
promote broad engagement with the JADES survey, we have created an interactive
{\tt FitsMap} website to provide an interface for professional researchers and
the public to experience these JWST datasets. Combined with the first JADES
NIRSpec data release, these public JADES imaging and spectroscopic datasets
provide a new foundation for discoveries of the infrared universe by the
worldwide scientific community.Comment: Several figures were modified to use better line styles. A brief
comparison to IRAC Channel 1 photometry was added along with a few other
clarifications. Paper has been accepted for publication in ApJ
Spectroscopic confirmation of four metal-poor galaxies at z=10.3-13.2
© 2023 Springer Nature Limited. This is the accepted manuscript version of an article which has been published in final form at https://doi.org/10.1038/s41550-023-01918-wFinding and characterising the first galaxies that illuminated the early Universe at cosmic dawn is pivotal to understand the physical conditions and the processes that led to the formation of the first stars. In the first few months of operations, imaging from the James Webb Space Telescope (JWST) have been used to identify tens of candidates of galaxies at redshift (z) greater than 10, less than 450 million years after the Big Bang. However, none of these candidates has yet been confirmed spectroscopically, leaving open the possibility that they are actually low-redshift interlopers. Here we present spectroscopic confirmation and analysis of four galaxies unambiguously detected at redshift 10.3Peer reviewe
JADES Initial Data Release for the Hubble Ultra Deep Field: Revealing the Faint Infrared Sky with Deep JWST NIRCam Imaging
International audienceAbstract JWST has revolutionized the field of extragalactic astronomy with its sensitive and high-resolution infrared view of the distant Universe. Adding to the new legacy of JWST observations, we present the first NIRCam imaging data release from the JWST Advanced Deep Extragalactic Survey (JADES), providing nine filters of infrared imaging of âŒ25 arcmin 2 covering the Hubble Ultra Deep Field and portions of Great Observatories Origins Deep Survey South. Utilizing 87 on-sky dual-filter hours of exposure time, these images reveal the deepest ever near-infrared view of this iconic field. We supply carefully constructed nine-band mosaics of the JADES bands, as well as matching reductions of five additional bands from the JWST Extragalactic Medium-band Survey. Combining with existing Hubble Space Telescope imaging, we provide 23-band space-based photometric catalogs and photometric redshifts for â47,500 sources. To promote broad engagement with JADES, we have created an interactive FitsMap website to provide an interface for professional researchers and the public to experience these JWST data sets. Combined with the first JADES NIRSpec data release, these public JADES imaging and spectroscopic data sets provide a new foundation for discoveries of the infrared Universe by the worldwide scientific community
JADES NIRSpec Spectroscopy of GN-z11: Lyman- α emission and possible enhanced nitrogen abundance in a z = 10.60 luminous galaxy
International audienceWe present JADES JWST/NIRSpec spectroscopy of GN-z11, the most luminous candidate z >â10 Lyman break galaxy in the GOODS-North field with M UV =ââ21.5. We derive a redshift of z =â10.603 (lower than previous determinations) based on multiple emission lines in our low and medium resolution spectra over 0.7â
ââ
5.3âÎŒm. We significantly detect the continuum and measure a blue rest-UV spectral slope of ÎČ =ââ2.4. Remarkably, we see spatially extended Lyman- α in emission (despite the highly neutral intergalactic medium expected at this early epoch), offset 555 km s â1 redwards of the systemic redshift. From our measurements of collisionally excited lines of both low and high ionisation (including [O II ] λ 3727, [Ne III ] λ 3869, and C III ] λ 1909), we infer a high ionisation parameter (log U âŒââ2). We detect the rarely seen N IV ] λ 1486 and N III ] λ 1748 lines in both our low and medium resolution spectra, with other high ionisation lines seen in the low resolution spectrum, such as He II (blended with O III ]) and C IV (with a possible P-Cygni profile). Based on the observed rest-UV line ratios, we cannot conclusively rule out photoionisation from an active galactic nucleus (AGN), although the high C III ]/He II and N III ]/He II ratios are compatible with a star formation explanation. If the observed emission lines are powered by star formation, then the strong N III ] λ 1748 observed may imply an unusually high N / O abundance. Balmer emission lines (H Îł , H ÎŽ ) are also detected, and if powered by star formation rather than an AGN, we infer a star formation rate of âŒ20 â 30 M â yr â1 (depending on the initial mass function) and low dust attenuation. Our NIRSpec spectroscopy confirms that GN-z11 is a remarkable galaxy with extreme properties seen 430 Myr after the Big Bang