| Autor: |
Chayan Mondal, Kanak Saha, Rogier A. Windhorst, Rolf A. Jansen |
| Jazyk: |
angličtina |
| Rok vydání: |
2023 |
| Předmět: |
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| Zdroj: |
The Astrophysical Journal, Vol 946, Iss 2, p 90 (2023) |
| Druh dokumentu: |
article |
| ISSN: |
1538-4357 |
| DOI: |
10.3847/1538-4357/acc110 |
| Popis: |
We estimate the UV continuum slope ( β ) of 465 galaxies (with luminosities of 0.028–3.3 ${L}_{z=0.5}^{* }$ ) in the Great Observatories Origins Survey Northern field in the redshift range z = 0.40–0.75. We use two AstroSat/UVIT (N242W, N245M) bands, two Hubble Space Telescope (F275W, F336W) bands, and a KPNO ( U ) band to sample the UV continuum slope of selected galaxies between 1215 and 2600 Å. The mean (median) and 1 σ scatter in the observed β are found to be −1.33 ± 0.07 ( − 1.32) and 0.60 within the considered redshift range. We do not find any significant evolution in the mean β within our redshift window. Our measurements add new data points to the global β – z relation in the least-explored redshift regime, further reinforcing the gradual reddening of galaxy UV continuum with cosmic time. We notice no strong consistent trend between β and M _1500 for the entire luminosity range −21 < M _1500 < − 15 mag. However, the majority of the most-luminous galaxies ( M _1500 < − 19 mag) are found to have relatively redder slopes. Using UVIT, we detect galaxies as faint as M _1500 = − 15.6 mag (i.e., 0.028 ${L}_{z=0.5}^{* }$ ). The faintest galaxies ( M _1500 > − 16 mag) tend to be redder, which indicates they were less actively forming stars during this cosmic time interval. Our study highlights the unique capability of UVIT near-UV imaging to characterize the rest-frame far-UV properties of galaxies at redshift z ∼ 0.5. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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