Dynamical properties and star formation history of a low-mass quenched galaxy at Cosmic Noon
Fuente:
arXiv
Guardado en:
| Autores principales: | , , , , , , , , , , , , , , |
|---|---|
| Formato: | Preprint |
| Publicado: |
2026
|
| Materias: | |
| Acceso en línea: | |
| Etiquetas: |
Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
|
| _version_ | 1866914233230295040 |
|---|---|
| author | Ito, K. Valentino, F. Baker, W. M. Brammer, G. Gottumukkala, R. Kakimoto, T. Lagos, C. D. P. Onodera, M. Pensabene, A. Scarpe, G. Tanaka, M. Whitaker, K. E. Reddy, N. A. Sanders, R. L. Shapley, A. E. |
| author_facet | Ito, K. Valentino, F. Baker, W. M. Brammer, G. Gottumukkala, R. Kakimoto, T. Lagos, C. D. P. Onodera, M. Pensabene, A. Scarpe, G. Tanaka, M. Whitaker, K. E. Reddy, N. A. Sanders, R. L. Shapley, A. E. |
| contents | We present the spectroscopic confirmation and in-depth analysis of AURORA-LQG1, a low-mass quiescent galaxy at $z_{\rm spec}=2.0834$ with $\log(M_\star/M_\odot)=9.6$ observed with medium-resolution JWST/NIRSpec spectroscopy. The deep medium-resolution spectrum enables the measurement of its stellar velocity dispersion ($σ_\star = 95_{-33}^{+38}\,{\rm km\,s^{-1}}$), the smallest value recorded among spectroscopically confirmed quiescent galaxies at $z\sim2$. Coupled with a compact size ($0.41\pm0.03\, {\rm kpc}$), it yields a dynamical mass estimate of $\log(M_{\rm dyn}/M_\odot)=9.75_{-0.38}^{+0.29}$. Its star formation history suggests that half of the stellar mass was in place $\sim1\,{\rm Gyr}$ before the observed epoch, with quenching occurring $\sim0.2\,{\rm Gyr}$ prior to $z=2.08$. These results confirm that AURORA-LQG1 is genuinely quenched, rather than in a temporary phase of suppressed star formation rate. AURORA-LQG1 is consistent with the mass fundamental plane at $z\sim2$, previously constrained only by massive quiescent systems. Compared with more massive counterparts at the same epoch observed with NIRSpec grating spectroscopy, the time since quenching for AURORA-LQG1 is among the shortest observed. The galaxy resides in a possible dense group-scale ($\sim50$ kpc) environment containing one companion with tentative spectroscopic redshift and five companion candidates, and it is embedded in a known protocluster on Mpc scales. A potential environmental influence on its evolution could explain the outside-in quenching suggested by the positive gradient of size with wavelength. This study demonstrates that deep JWST/NIRSpec spectroscopy enables low-mass quiescent galaxies at Cosmic Noon to be characterized with a level of detail long reserved for massive systems, offering valuable new insights into how quenching operates in these underexplored low-mass systems. [Abridged] |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2601_01722 |
| institution | arXiv |
| publishDate | 2026 |
| record_format | arxiv |
| spellingShingle | Dynamical properties and star formation history of a low-mass quenched galaxy at Cosmic Noon Ito, K. Valentino, F. Baker, W. M. Brammer, G. Gottumukkala, R. Kakimoto, T. Lagos, C. D. P. Onodera, M. Pensabene, A. Scarpe, G. Tanaka, M. Whitaker, K. E. Reddy, N. A. Sanders, R. L. Shapley, A. E. Astrophysics of Galaxies We present the spectroscopic confirmation and in-depth analysis of AURORA-LQG1, a low-mass quiescent galaxy at $z_{\rm spec}=2.0834$ with $\log(M_\star/M_\odot)=9.6$ observed with medium-resolution JWST/NIRSpec spectroscopy. The deep medium-resolution spectrum enables the measurement of its stellar velocity dispersion ($σ_\star = 95_{-33}^{+38}\,{\rm km\,s^{-1}}$), the smallest value recorded among spectroscopically confirmed quiescent galaxies at $z\sim2$. Coupled with a compact size ($0.41\pm0.03\, {\rm kpc}$), it yields a dynamical mass estimate of $\log(M_{\rm dyn}/M_\odot)=9.75_{-0.38}^{+0.29}$. Its star formation history suggests that half of the stellar mass was in place $\sim1\,{\rm Gyr}$ before the observed epoch, with quenching occurring $\sim0.2\,{\rm Gyr}$ prior to $z=2.08$. These results confirm that AURORA-LQG1 is genuinely quenched, rather than in a temporary phase of suppressed star formation rate. AURORA-LQG1 is consistent with the mass fundamental plane at $z\sim2$, previously constrained only by massive quiescent systems. Compared with more massive counterparts at the same epoch observed with NIRSpec grating spectroscopy, the time since quenching for AURORA-LQG1 is among the shortest observed. The galaxy resides in a possible dense group-scale ($\sim50$ kpc) environment containing one companion with tentative spectroscopic redshift and five companion candidates, and it is embedded in a known protocluster on Mpc scales. A potential environmental influence on its evolution could explain the outside-in quenching suggested by the positive gradient of size with wavelength. This study demonstrates that deep JWST/NIRSpec spectroscopy enables low-mass quiescent galaxies at Cosmic Noon to be characterized with a level of detail long reserved for massive systems, offering valuable new insights into how quenching operates in these underexplored low-mass systems. [Abridged] |
| title | Dynamical properties and star formation history of a low-mass quenched galaxy at Cosmic Noon |
| topic | Astrophysics of Galaxies |
| url | https://arxiv.org/abs/2601.01722 |