---
DOAJ_listed: '1'
OA_place: publisher
OA_type: gold
PlanS_conform: '1'
_id: '23052'
abstract:
- lang: eng
  text: While bursty star formation in low-mass galaxies has been observed in local
    populations and reproduced in simulations, the dormant phase of the burst cycle
    has not been well studied beyond the local Universe due to observational limitations.
    We present a unique sample of 43 JWST PRISM spectra of low-mass galaxies (M⋆ <
    10^9.5 M⊙) at cosmic noon (1 < z < 3), uniformly selected on F200W magnitude and
    precise photometric redshifts enabled by 20-band JWST photometry from the UNCOVER
    and MegaScience surveys. The spectra reveal numerous strong Balmer breaks, which
    are negatively correlated with the galaxies’ Hα equivalent width. By comparing
    these observations to synthetic samples of spectra generated using a simple parameterization
    of bursty star formation histories, we show that star formation in low-mass galaxies
    at cosmic noon is likely dominated by burst cycles with long timescales (≳100
    Myr) and large deviations below the star-forming main sequence (≳0.8 dex). Our
    results suggest that galaxies in this population—at least those within our detection
    limits—should not be classified solely by their current star formation rates,
    but instead viewed as a unified population undergoing dynamic movement above and
    below the star-forming main sequence. The derived constraints demonstrate that
    long-timescale fluctuations are important for this class of galaxies, indicating
    that galaxy-scale gas cycles—rather than molecular-cloud-scale stochasticity—are
    the primary regulators of star formation variability in low-mass galaxies at cosmic
    noon.
acknowledgement: "A.M. acknowledges support from the National Science Foundation Graduate
  Research Fellowship under grant No. DGE-2444107. A.M. thanks Helena Treiber for
  helpful discussions. Support for this work was provided by The Brinson Foundation
  through a Brinson Prize Fellowship grant.\r\n\r\nThis work is based in part on observations
  made with the NASA/ESA/CSA James Webb Space Telescope obtained from the Space Telescope
  Science Institute, which is operated by the Association of Universities for Research
  in Astronomy, Inc., under NASA contract NAS 5–26555. Financial support for programs
  JWST-GO-1837, JWST-GO-2561, JWST-GO-4111, and JWST-GO-6405 is gratefully acknowledged
  and is provided by NASA through grants from the Space Telescope Science Institute,
  which is operated by the Associations of Universities for Research in Astronomy,
  Incorporated, under NASA contract NAS 5-03127. These observations are associated
  with programs JWST-GO-2561, JWST-ERS-1324, JWST-DD-2756, JWST-GO-4111, HST-GO-11689,
  HST-GO-13386, HST-GO/DD-13495, HST-GO-13389, HST-GO-15117, and HST-GO/DD-17231.
  Some of the data presented in this article were obtained from the Mikulski Archive
  for Space Telescopes (MAST) at the Space Telescope Science Institute. The specific
  observations analyzed can be accessed via doi:10.17909/grtw-hr67. Some of the data
  products presented herein were retrieved from the Dawn JWST Archive (DJA). DJA is
  an initiative of the Cosmic Dawn Center, which is funded by the Danish National
  Research Foundation under grant No. 140.\r\n\r\nFacilities: JWST - James Webb Space
  Telescope (NIRCam and NIRSpec), HST - Hubble Space Telescope satellite (WFC3 and
  ACS).\r\n\r\nSoftware: NumPy (https://numpy.org, C. R. Harris et al. 2020), Astropy
  (https://astropy.org, Astropy Collaboration et al. 2013, 2018, 2022), Matplotlib
  (https://matplotlib.org, J. D. Hunter 2007), SciPy (https://scipy.org, P. Virtanen
  et al. 2020)."
article_number: '257'
article_processing_charge: Yes
article_type: original
arxiv: 1
author:
- first_name: Abby
  full_name: Mintz, Abby
  last_name: Mintz
- first_name: David J.
  full_name: Setton, David J.
  last_name: Setton
- first_name: Jenny E.
  full_name: Greene, Jenny E.
  last_name: Greene
- first_name: Joel
  full_name: Leja, Joel
  last_name: Leja
- first_name: Bingjie
  full_name: Wang, Bingjie
  last_name: Wang
- first_name: Emilie
  full_name: Burnham, Emilie
  last_name: Burnham
- first_name: Katherine A.
  full_name: Suess, Katherine A.
  last_name: Suess
- first_name: Hakim
  full_name: Atek, Hakim
  last_name: Atek
- first_name: Rachel
  full_name: Bezanson, Rachel
  last_name: Bezanson
- first_name: Gabriel
  full_name: Brammer, Gabriel
  last_name: Brammer
- first_name: Sam E.
  full_name: Cutler, Sam E.
  last_name: Cutler
- first_name: Pratika
  full_name: Dayal, Pratika
  last_name: Dayal
- first_name: Robert
  full_name: Feldmann, Robert
  last_name: Feldmann
- first_name: Lukas J.
  full_name: Furtak, Lukas J.
  last_name: Furtak
- first_name: Karl
  full_name: Glazebrook, Karl
  last_name: Glazebrook
- first_name: Gourav
  full_name: Khullar, Gourav
  last_name: Khullar
- first_name: Vasily
  full_name: Kokorev, Vasily
  last_name: Kokorev
- first_name: Ivo
  full_name: Labbé, Ivo
  last_name: Labbé
- first_name: Jorryt J
  full_name: Matthee, Jorryt J
  id: 7439a258-f3c0-11ec-9501-9df22fe06720
  last_name: Matthee
  orcid: 0000-0003-2871-127X
- first_name: Michael V.
  full_name: Maseda, Michael V.
  last_name: Maseda
- first_name: Tim B.
  full_name: Miller, Tim B.
  last_name: Miller
- first_name: Ikki
  full_name: Mitsuhashi, Ikki
  last_name: Mitsuhashi
- first_name: Themiya
  full_name: Nanayakkara, Themiya
  last_name: Nanayakkara
- first_name: Richard
  full_name: Pan, Richard
  last_name: Pan
- first_name: Sedona H.
  full_name: Price, Sedona H.
  last_name: Price
- first_name: John R.
  full_name: Weaver, John R.
  last_name: Weaver
- first_name: Katherine E.
  full_name: Whitaker, Katherine E.
  last_name: Whitaker
- first_name: Belinda
  full_name: Wu, Belinda
  last_name: Wu
citation:
  ama: 'Mintz A, Setton DJ, Greene JE, et al. Taking a break at cosmic noon: Continuum-selected
    low-mass galaxies require long burst cycles. <i>The Astrophysical Journal</i>.
    2026;998(2). doi:<a href="https://doi.org/10.3847/1538-4357/ae328c">10.3847/1538-4357/ae328c</a>'
  apa: 'Mintz, A., Setton, D. J., Greene, J. E., Leja, J., Wang, B., Burnham, E.,
    … Wu, B. (2026). Taking a break at cosmic noon: Continuum-selected low-mass galaxies
    require long burst cycles. <i>The Astrophysical Journal</i>. IOP Publishing. <a
    href="https://doi.org/10.3847/1538-4357/ae328c">https://doi.org/10.3847/1538-4357/ae328c</a>'
  chicago: 'Mintz, Abby, David J. Setton, Jenny E. Greene, Joel Leja, Bingjie Wang,
    Emilie Burnham, Katherine A. Suess, et al. “Taking a Break at Cosmic Noon: Continuum-Selected
    Low-Mass Galaxies Require Long Burst Cycles.” <i>The Astrophysical Journal</i>.
    IOP Publishing, 2026. <a href="https://doi.org/10.3847/1538-4357/ae328c">https://doi.org/10.3847/1538-4357/ae328c</a>.'
  ieee: 'A. Mintz <i>et al.</i>, “Taking a break at cosmic noon: Continuum-selected
    low-mass galaxies require long burst cycles,” <i>The Astrophysical Journal</i>,
    vol. 998, no. 2. IOP Publishing, 2026.'
  ista: 'Mintz A, Setton DJ, Greene JE, Leja J, Wang B, Burnham E, Suess KA, Atek
    H, Bezanson R, Brammer G, Cutler SE, Dayal P, Feldmann R, Furtak LJ, Glazebrook
    K, Khullar G, Kokorev V, Labbé I, Matthee JJ, Maseda MV, Miller TB, Mitsuhashi
    I, Nanayakkara T, Pan R, Price SH, Weaver JR, Whitaker KE, Wu B. 2026. Taking
    a break at cosmic noon: Continuum-selected low-mass galaxies require long burst
    cycles. The Astrophysical Journal. 998(2), 257.'
  mla: 'Mintz, Abby, et al. “Taking a Break at Cosmic Noon: Continuum-Selected Low-Mass
    Galaxies Require Long Burst Cycles.” <i>The Astrophysical Journal</i>, vol. 998,
    no. 2, 257, IOP Publishing, 2026, doi:<a href="https://doi.org/10.3847/1538-4357/ae328c">10.3847/1538-4357/ae328c</a>.'
  short: A. Mintz, D.J. Setton, J.E. Greene, J. Leja, B. Wang, E. Burnham, K.A. Suess,
    H. Atek, R. Bezanson, G. Brammer, S.E. Cutler, P. Dayal, R. Feldmann, L.J. Furtak,
    K. Glazebrook, G. Khullar, V. Kokorev, I. Labbé, J.J. Matthee, M.V. Maseda, T.B.
    Miller, I. Mitsuhashi, T. Nanayakkara, R. Pan, S.H. Price, J.R. Weaver, K.E. Whitaker,
    B. Wu, The Astrophysical Journal 998 (2026).
das_tickbox: '1'
date_created: 2026-10-04T22:01:56Z
date_published: 2026-02-20T00:00:00Z
date_updated: 2026-10-12T08:21:05Z
day: '20'
ddc:
- '520'
department:
- _id: JoMa
doi: 10.3847/1538-4357/ae328c
external_id:
  arxiv:
  - '2506.16510'
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fulldoi: https://doi.org/10.3847/1538-4357/ae328c
has_accepted_license: '1'
intvolume: '       998'
issue: '2'
language:
- iso: eng
month: '02'
oa: 1
oa_version: Published Version
publication: The Astrophysical Journal
publication_identifier:
  eissn:
  - 1538-4357
  issn:
  - 0004-637X
publication_status: published
publisher: IOP Publishing
quality_controlled: '1'
researchdata_availability: no
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status: public
supplementarymaterial: yes
title: 'Taking a break at cosmic noon: Continuum-selected low-mass galaxies require
  long burst cycles'
tmp:
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