First Look at z > 1 Bars in the Rest-frame Near-infrared with JWST Early CEERS Imaging
Abstract
Stellar bars are key drivers of secular evolution in galaxies and can be effectively studied using rest-frame near-infrared (NIR) images, which trace the underlying stellar mass and are less impacted by dust and star formation than rest-frame UV or optical images. We leverage the power of JWST CEERS NIRCam images to present the first quantitative identification and characterization of stellar bars at z > 1 based on rest-frame NIR F444W images of high resolution (~1.3 kpc at z ~ 1-3). We identify stellar bars in these images using quantitative criteria based on ellipse fits. For this pilot study, we present six examples of robustly identified bars at z > 1 with spectroscopic redshifts, including the two highest-redshift bars at z ~ 2.136 and 2.312 quantitatively identified and characterized to date. The stellar bars at z ~ 1.1-2.3 presented in our study have projected semimajor axes of ~2.9-4.3 kpc and projected ellipticities of ~0.41-0.53 in the rest-frame NIR. The barred host galaxies have stellar masses ~1 × 1010 to 2 × 1011 M ⊙ and star formation rates of ~21-295 M ⊙ yr-1, and several have potential nearby companions. Our finding of bars at z ~ 1.1-2.3 demonstrates the early onset of such instabilities and supports simulations where bars form early in massive dynamically cold disks. It also suggests that if these bars at lookback times of 8-11 Gyr survive out to present epochs, bar-driven secular processes may operate over a long time and have a significant impact on some galaxies by z ~ 0.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- March 2023
- DOI:
- 10.3847/2041-8213/acacfb
- arXiv:
- arXiv:2210.08658
- Bibcode:
- 2023ApJ...945L..10G
- Keywords:
-
- Galaxy bars;
- Barred spiral galaxies;
- Galaxy structure;
- Galaxy evolution;
- 2364;
- 136;
- 622;
- 594;
- Astrophysics - Astrophysics of Galaxies
- E-Print:
- 16 pages, 5 figures. Accepted for Publication in Astrophysical Journal Letters