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Confirmation of the Remarkable Compactness of Massive Quiescent Galaxies at z ~ 2.3: Early-Type Galaxies Did not Form in a Simple Monolithic Collapse
Open accessAbstract
Using deep near-infrared spectroscopy, Kriek et al. found that ~45% of massive galaxies at z ∼ 2.3 have evolved stellar populations and little or no ongoing star formation. Here we determine the sizes of these quiescent galaxies using deep, high-resolution images obtained with HST /NIC2 and laser guide star (LGS)-assisted Keck/adaptive optics (AO). Considering that their median stellar mass is 1.7 × 10 11 M ☉ , the galaxies are remarkably small, with a median effective radius r e = 0.9 kpc. Galaxies of similar mass in the nearby universe have sizes of ≈5 kpc and average stellar densities that are 2 orders of magnitude lower than the z ∼ 2.3 galaxies. These results extend earlier work at z ∼ 1.5 and confirm previous studies at z > 2 that lacked spectroscopic redshifts and imaging of sufficient resolution to resolve the galaxies. Our findings demonstrate that fully assembled early-type galaxies make up at most ~10% of the population of K -selected quiescent galaxies at z ∼ 2.3, effectively ruling out simple monolithic models for their formation. The galaxies must evolve significantly after z ∼ 2.3, through dry mergers or other processes, consistent with predictions from hierarchical models.
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Cited by
AN ULTRA-DEEP NEAR-INFRARED SPECTRUM OF A COMPACT QUIESCENT GALAXY AT z= 2.2
Kriek, M., van Dokkum, P. G., Labbé, I., Franx, M., Illingworth, G. D., Marchesini, D., & Quadri, R. F. (2009) · The Astrophysical Journal · doi:10.1088/0004-637x/700/1/221 · Cited by 992
Self-citationTheoretical Challenges in Galaxy Formation
Naab, T., & Ostriker, J. P. (2017) · Annual Review of Astronomy and Astrophysics · doi:10.1146/annurev-astro-081913-040019 · Cited by 722
Bezanson, R., van Dokkum, P. G., Tal, T., Marchesini, D., Kriek, M., Franx, M., & Coppi, P. (2009) · The Astrophysical Journal · doi:10.1088/0004-637x/697/2/1290 · Cited by 538
Self-citationRodriguez-Gomez, V., Pillepich, A., Sales, L. V., Genel, S., Vogelsberger, M., Zhu, Q., Wellons, S., Nelson, D., Torrey, P., Springel, V., et al. (2016) · Monthly Notices of the Royal Astronomical Society · doi:10.1093/mnras/stw456 · Cited by 478
Bell, E. F., van der Wel, A., Papovich, C., Kocevski, D., Lotz, J., McIntosh, D. H., Kartaltepe, J., Faber, S. M., Ferguson, H., Koekemoer, A., et al. (2012) · The Astrophysical Journal · doi:10.1088/0004-637x/753/2/167 · Cited by 304
Metadata
- Authors
- van Dokkum, P. G., Franx, M., Kriek, M., Holden, B., Illingworth, G. D., Magee, D., Bouwens, R., Marchesini, D., Quadri, R., Rudnick, G., Taylor, E. N., & Toft, S.
- Venue
- The Astrophysical Journal
- Publisher
- American Astronomical Society
- Published
- 2008-03-19
- Volume
- 677
- Issue
- 1
- Pages
- L5-L8
- ISSN
- 0004-637X (ISSN-L)
- 1538-4357
- OpenAlex
- W2112633422
- Cited by
- 732
- References
- 0
- FWCI
- 32.42
- Type
- journal article
- Language
- en
- Open access
- bronze
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- CoChat. (2026). Citation check: Confirmation of the Remarkable Compactness of Massive Quiescent Galaxies at z ~ 2.3: Early-Type Galaxies Did not Form in a Simple Monolithic Collapse. https://app.cochat.ai/papers/10.1086/587874
- The paper
- van Dokkum, P. G., Franx, M., Kriek, M., Holden, B., Illingworth, G. D., Magee, D., Bouwens, R., Marchesini, D., Quadri, R., Rudnick, G., Taylor, E. N., & Toft, S. (2008). Confirmation of the Remarkable Compactness of Massive Quiescent Galaxies at z ~ 2.3: Early-Type Galaxies Did not Form in a Simple Monolithic Collapse. The Astrophysical Journal. https://doi.org/10.1086/587874
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Contains information from the Semantic Scholar Academic Graph Datasets, made available under the ODC Attribution License (ODC-BY 1.0).
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