A quasar-anchored protocluster at z = 6.6 in the ASPIRE survey: II. an environmental analysis of galaxy properties in an overdense structure
We present in this paper (Paper II of the series) a 35 arcmin2 JWST/NIRCam imaging and wide-field slitless spectroscopy mosaic centered on J0305-3150, a luminous quasar at z = 6.61. The F356W grism data reveal 124 [O iii]+Hβ emitters at 5.3 < z < 7, 53 of which constitute a protocluster spanni...
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| Main Authors: | , , , , , , , , , , , , , , , , , , , , , , , |
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| Format: | Article (Journal) |
| Language: | English |
| Published: |
2025 March 10
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| In: |
The astrophysical journal
Year: 2025, Volume: 981, Issue: 2, Pages: 1-17 |
| ISSN: | 1538-4357 |
| DOI: | 10.3847/1538-4357/adb1bc |
| Online Access: | Verlag, kostenfrei, Volltext: https://doi.org/10.3847/1538-4357/adb1bc Verlag, kostenfrei, Volltext: https://dx.doi.org/10.3847/1538-4357/adb1bc |
| Author Notes: | Jaclyn B. Champagne, Feige Wang, Jinyi Yang, Xiaohui Fan, Joseph F. Hennawi, Fengwu Sun, Eduardo Bañados, Sarah E.I. Bosman, Tiago Costa, Melanie Habouzit, Xiangyu Jin, Hyunsung D. Jun, Mingyu Li, Weizhe Liu, Federica Loiacono, Alessandro Lupi, Chiara Mazzucchelli, Maria Pudoka, Sofía Rojas-Ruiz, Wei Leong Tee, Maxime Trebitsch, Haowen Zhang, Ming-Yang Zhuang, and Siwei Zou |
| Summary: | We present in this paper (Paper II of the series) a 35 arcmin2 JWST/NIRCam imaging and wide-field slitless spectroscopy mosaic centered on J0305-3150, a luminous quasar at z = 6.61. The F356W grism data reveal 124 [O iii]+Hβ emitters at 5.3 < z < 7, 53 of which constitute a protocluster spanning (10 cMpc)2 across 6.5 < z < 6.8. We find no evidence of any broad-line active galactic nucleus (AGN) in individual galaxies or stacking, reporting a median Hβ FWHM of 585 ± 152 km s−1; however, the mass-excitation diagram and “little red dot” color and compactness criteria suggest that there are a few AGN candidates on the outskirts of the protocluster. We fit the spectral energy distributions (SEDs) of the [O iii] emitters with Prospector and Bagpipes and find that none of the SED-derived properties (stellar mass, age, or star formation rate) correlate with proximity to the quasar. While there is no correlation between galaxy age and local galaxy density, we find modest correlations of local galaxy density with increasing stellar mass, decreasing 10-100 Myr star formation rate ratios, and decreasing nebular line equivalent widths. We further find that the protocluster galaxies are consistent with being more massive, being older, and hosting higher star formation rates than the field sample at the 3σ level, distributed in a filamentary structure that supports inside-out formation of the protocluster. There is modest evidence that galaxy evolution proceeds differently as a function of the density of local environment within protoclusters during the epoch of reionization, and the central quasar has little effect on the galaxy properties of the surrounding structure. |
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| Item Description: | Online verfügbar: 04. März 2025 Gesehen am 11.09.2025 |
| Physical Description: | Online Resource |
| ISSN: | 1538-4357 |
| DOI: | 10.3847/1538-4357/adb1bc |