91̽»¨

Skip to main content
Department Of Physics text logo
  • Research
    • Our research
    • Our research groups
    • Our research in action
    • Research funding 91̽»¨
    • Summer internships for undergraduates
  • Study
    • Undergraduates
    • Postgraduates
  • Engage
    • For alumni
    • For business
    • For schools
    • For the public
  • Support
91̽»¨
An image of the GOODS-South field as observed by JWST. More than 45,000 galaxies are visible here.

An image of the GOODS-South field as observed by JWST. More than 45,000 galaxies are visible here. In this image, blue, green, and red were assigned to Webb’s NIRCam (Near-Infrared Camera) data at 0.9, 1.15, and 1.5 microns; 2.0, 2.77, and 3.55 microns; and 3.56, 4.1, and 4.44 microns (F090W, F115W, and F150W; F200W, F277W, and F335M; and F356W, F410M, and F444W), respectively.

Credit: NASA, ESA, CSA, B. Robertson (UC Santa Cruz), B. Johnson (Center for Astrophysics, Harvard & Smithsonian), S. Tacchella (Univers

Dr Jacopo Chevallard

Postdoctoral Research Assistant

Research theme

  • Astronomy and astrophysics

Sub department

  • Astrophysics

Research groups

  • Galaxy formation and evolution
jacopo.chevallard@physics.ox.ac.uk
Telephone: 01865 273467
Denys Wilkinson Building, room 463
  • About
  • Publications

Overview of the JWST Advanced Deep Extragalactic Survey (JADES)

The Astrophysical Journal: Supplement Series American Astronomical Society 283:1 (2026) 6

Authors:

Daniel J Eisenstein, Chris Willott, Stacey Alberts, Santiago Arribas, Nina Bonaventura, Andrew J Bunker, Alex J Cameron, Stefano Carniani, Stephane Charlot, Emma Curtis-Lake, Francesco D’Eugenio, Pierre Ferruit, Giovanna Giardino, Kevin Hainline, Ryan Hausen, Peter Jakobsen, Benjamin D Johnson, Roberto Maiolino, Bernard J Rauscher, Marcia Rieke, George Rieke, Hans-Walter Rix, Brant Robertson, Daniel P Stark, Jacopo Chevallard, Gareth C Jones

Abstract:

We present an overview of the James Webb Space Telescope (JWST) Advanced Deep Extragalactic Survey (JADES), an ambitious program of infrared imaging and spectroscopy in the GOODS-S and GOODS-N deep fields, designed to study galaxy evolution from high redshift to cosmic noon. JADES uses about 770 hr of Cycle 1 guaranteed time largely from the Near-Infrared Camera (NIRCam) and Near-Infrared Spectrograph (NIRSpec) instrument teams. In GOODS-S, in and around the Hubble Ultra Deep Field and Chandra Deep Field South, JADES produces a deep imaging region of ∼42 arcmin2 with over 100 hr of exposure time spread over nine NIRCam filters, including two medium-band filters. This is extended at medium depth in GOODS-S and GOODS-N with NIRCam imaging of ∼167 arcmin2, averaging 25 hr of exposure over 8–10 filters. In both fields, we conduct extensive NIRSpec multiobject spectroscopy, including two deep pointings of 55 hr exposure time, 14 medium pointings of ∼12 hr, and 15 shallower pointings of ∼4 hr, targeting over 5000 Hubble Space Telescope– and JWST-detected faint sources with five low-, medium-, and high-resolution dispersers covering 0.6–5.3 μm. Finally, JADES extends redward via coordinated parallels with the JWST Mid-Infrared Instrument, featuring ∼10 arcmin2 with 43 hr of exposure at 7.7 μm and thrice that area with 1.4–6.8 hr of exposure at 12.8 and 15 μm. For nearly 30 yr, the GOODS-S and GOODS-N fields have been developed as the premier deep fields on the sky; JADES is now providing a compelling start on JWST's legacy in these fields.

JADES: the chemical enrichment pattern of distant galaxies – α enhancement, silicon depletion, and iron enhancement

Monthly Notices of the Royal Astronomical Society (2026) stag123

Authors:

Yuki Isobe, Roberto Maiolino, Xihan Ji, Francesco D’Eugenio, Charlotte Simmonds, Jan Scholtz, Ignas Juodžbalis, Aayush Saxena, Joris Witstok, Chiaki Kobayashi, Irene Vanni, Stefania Salvadori, Kuria Watanabe, Stephanie Monty, Vasily Belokurov, Anna Feltre, William McClymont, Sandro Tacchella, Mirko Curti, Hannah Übler, Stéphane Charlot, Andrew J Bunker, Jacopo Chevallard, Emma Curtis-Lake, Nimisha Kumari, Pierluigi Rinaldi, Brant Robertson, Christina C Williams, Chris Willott

Abstract:

We present gas-phase abundances of carbon (C), α-elements (O, Ne, Si, and Ar) and iron (Fe) obtained from stacked spectra of high-z star-forming galaxies with the deep Near Infrared Spectrograph medium-resolution data from the James Webb Space Telescope Advanced Deep Extragalactic Survey. Our 564 sources at z = 4–7 have a median stellar mass of log (M*/M⊙) = 8.46 and a median star-formation rate of log (SFR/M⊙ yr−1) = 0.30, placing them close to the star-formation main sequence. We find that the stacked spectrum of all our 564 sources has relatively low [C/O] = −0.70, moderate [Ne/O] = −0.09, and low [Ar/O] = −0.28 values at a low gas-phase metallicity of 12 + log (O/H) = 7.71 (Z ∼ 0.1 Z⊙), suggesting dominant yields of core-collapse supernovae evolved from massive stars. The detection of a weak Si iii] emission line in our stacked spectrum provides a silicon-to-oxygen abundance ratio of [Si/O] = −0.63, which is lower than that of stars in the Milky Way disc and lower than expected by chemical evolution models, suggesting silicon depletion onto dust grains. Likewise, this Si/O value is lower than that we newly derive for two individual z > 6 galaxies (GN-z11 and RXCJ2248) with negligible dust attenuation. By performing spectral stacking in bins of M*, SFR, specific SFR (sSFR), and ultra-violet (UV) continuum slope βUV, we identify [Fe iii] line detections in the high-sSFR bin and the blue-βUV bin, both of which exhibit supersolar Fe/O ratios, while their C/O, Ar/O, and Si/O ratios are comparable to those of the all-sources stack. Our findings 91̽»¨ a chemically young gas composition with rapid dust depletion in the general population of high-z star-forming galaxies, while raising the possibility of anomalous, selective Fe/O enhancement at the very early epoch of star formation.

On the origins of oxygen: ALMA and JWST characterise the multi-phase, metal-enriched, star-bursting medium within a ‘normal’ z > 11 galaxy

The Open Journal of Astrophysics Maynooth University 9 (2026)

Authors:

Joris Witstok, Renske Smit, William M Baker, Pierluigi Rinaldi, Kevin N Hainline, Hiddo SB Algera, Santiago Arribas, Tom JLC Bakx, Andrew J Bunker, Stefano Carniani, Stéphane Charlot, Jacopo Chevallard, Mirko Curti, Emma Curtis-Lake, Daniel J Eisenstein, Kasper E Heintz, Jakob M Helton, Gareth C Jones, Roberto Maiolino, Michael V Maseda, Pablo G Pérez-González, Clara L Pollock, Brant E Robertson, Aayush Saxena, Jan Scholtz, Irene Shivaei, Fengwu Sun, Sandro Tacchella, Hannah Übler, Darach Watson, Chris J Willott, Zihao Wu

Abstract:

The unexpectedly high abundance of galaxies at z > 11 revealed by JWST has sparked a debate on the nature of early galaxies and the physical mechanisms regulating their formation. The Atacama Large Millimeter/submillimeter Array (ALMA) has begun to provide vital insights on their gas and dust content, but so far only for extreme ‘blue monsters’. Here we present new, deep ALMA observations of JADES-GS-z11-0, a more typical (sub- L * ) z > 11 galaxy that bridges the discovery space of JWST and the Hubble Space Telescope. These data confirm the presence of the [O III] 88 μ m line at 4.5 σ significance, precisely at the redshift of several faint emission lines previously seen with JWST/NIRSpec, while the underlying dust continuum remains undetected ( F ν < 9.0 μ J y ), implying an obscured star formation rate (SFR) of SFR IR ≲ 6 M ⊙ y r − 1 and dust mass of M dust ≲ 1.0 × 10 6 M ⊙ (all 3 σ ). The accurate ALMA redshift of z [O III] = 11.1221 ± 0.0006 ( ≳ 5 × refined over NIRSpec) helps confirm that redshifts measured purely from the Lyman- α break, even spectroscopically, should properly take into account the effects of potential damped Lyman- α absorption (DLA) systems to avoid systematic overestimates of up to Δ z ≈ 0.5 . The [O III] 88 μ m luminosity of L [O III] = ( 1.1 ± 0.3 ) × 10 8 L ⊙ , meanwhile, agrees well with the scaling relation for local metal-poor dwarfs given the SFR measured by NIRCam, NIRSpec, and MIRI. The spatially resolved MIRI and ALMA emission also underscores that JADES-GS-z11-0 is likely to consist of two low-mass components that are undergoing strong bursts of star formation yet are already pre-enriched in oxygen ( ∼ 30 % solar), only 400 Myr after the Big Bang.

The JADES Origins Field: A New JWST Deep Field in the JADES Second NIRCam Data Release

The Astrophysical Journal: Supplement Series American Astronomical Society 281:2 (2025) 50

Authors:

Daniel J Eisenstein, Benjamin D Johnson, Brant Robertson, Sandro Tacchella, Kevin Hainline, Peter Jakobsen, Roberto Maiolino, Nina Bonaventura, Andrew J Bunker, Alex J Cameron, Phillip A Cargile, Emma Curtis-Lake, Ryan Hausen, Dávid Puskás, Marcia Rieke, Fengwu Sun, Christopher NA Willmer, Chris Willott, Stacey Alberts, Santiago Arribas, William M Baker, Stefi Baum, Rachana Bhatawdekar, Stefano Carniani, Jacopo Chevallard, Gareth C Jones, Aayush Saxena

Abstract:

We summarize the properties and initial data release of the JADES Origins Field (JOF), the longest single pointing yet imaged with the James Webb Space Telescope (JWST). This field falls within the GOODS-S region about 8′ southwest of the Hubble Ultra Deep Field (HUDF), where it was formed initially in Cycle 1 as a parallel field of HUDF spectroscopic observations within the JWST Advanced Deep Extragalactic Survey (JADES). This imaging was greatly extended in Cycle 2 program 3215, which observed the JOF for 5 days in six medium-band filters, seeking robust candidates for z > 15 galaxies. This program also includes ultradeep parallel NIRSpec spectroscopy (up to 91 hr on source, summing over the dispersion modes) on the HUDF. Cycle 3 observations from program 4540 added 20 hr of NIRCam slitless spectroscopy and F070W imaging to the JOF. With these three campaigns, the JOF was observed for 380 open-shutter hours with NIRCam using 15 imaging filters and two grism bandpasses. Further, parts of the JOF have deep 43 hr MIRI observations in F770W. Taken together, the JOF is one of the most compelling deep fields available with JWST and a powerful window into the early Universe. This paper presents the second data release from JADES, featuring the imaging and catalogs from the year 1 JOF observations.

JADES reveals a large population of low-mass black holes at high redshift

Monthly Notices of the Royal Astronomical Society 91̽»¨ University Press 545:1 (2025) staf1979

Authors:

Sophia Geris, Roberto Maiolino, Yuki Isobe, Jan Scholtz, Francesco D’Eugenio, Xihan Ji, Ignas Juodžbalis, Charlotte Simmonds, Pratika Dayal, Alessandro Trinca, Raffaella Schneider, Santiago Arribas, Rachana Bhatawdekar, Andrew J Bunker, Stefano Carniani, Stéphane Charlot, Jacopo Chevallard, Emma Curtis-Lake, Benjamin D Johnson, Eleonora Parlanti, Pierluigi Rinaldi, Brant Robertson, Sandro Tacchella, Hannah Übler

Abstract:

James Webb Space Telescope (JWST) has revealed a large population of active galactic nuclei (AGNs) in the distant Universe, which are challenging our understanding of early massive black hole (BH) seeding and growth. We expand the exploration of this population to lower luminosities by stacking 600 NIRSpec grating spectra from the JWST Advanced Deep Extragalactic Survey (JADES) at , in bins of redshift, [O iii]5007 luminosity and equivalent width, UV luminosity, and stellar mass. In multiple stacks, we detect a broad component of H without a counterpart in [O iii], implying that it is not due to outflows but traces the broad-line region of a large population of low-luminosity AGNs not detected in individual spectra. The detection, in some stacks, of high [O iii]4363/H , typical of AGNs, further confirms the detection of a large population of AGNs. We infer that the stacks probe BHs with masses of a few times accreting at rates 0.02–0.1, i.e. a low-mass and dormant parameter space poorly explored by previous studies on individual targets. We identify populations of BHs that fall within the scatter of the local scaling relation, indicating that there is a population of high-z BHs that are not overmassive relative to their host galaxies. Yet, on average, the stacks are still overmassive relative the local relation, with some of them 1–2 dex above it. We infer that the BH mass function at is consistent with models in which BHs evolve through short bursts of super-Eddington accretion.

Pagination

  • Current page 1
  • Page 2
  • Page 3
  • Page 4
  • Page 5
  • Page 6
  • Page 7
  • Page 8
  • Page 9
  • …
  • Next page Next
  • Last page Last

Footer 91̽»¨

  • Contact us
  • Giving to the Dept of Physics
  • Work with us
  • Media

User account menu

  • Log in

Follow us

FIND US

Clarendon Laboratory,

Parks Road,

91̽»¨,

OX1 3PU

CONTACT US

Tel: +44(0)1865272200

Department Of Physics text logo

© 91̽»¨ - Department of Physics

Cookies | Privacy policy | Accessibility statement

  • Home
  • Research
  • Study
  • Engage
  • Our people
  • News & Comment
  • Events
  • Our facilities & services
  • About us
  • Giving to Physics