Near-IR narrow-band imaging with CIRCE at the Gran Telescopio Canarias: Searching for Ly alpha-emitters at z similar to 9.3
| Autor: | Cabello González, Cristina, Gallego Maestro, Jesús, Cardiel López, Nicolás, Pascual Ramírez, Sergio, Guzmán, R., Herrero, A., Manrique, A., Marín Franch, A., Mas Hesse, J. M., Rodriguez Espinosa, J. M., Salvador Solé, E. |
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| Rok vydání: | 2022 |
| Předmět: | |
| Zdroj: | E-Prints Complutense. Archivo Institucional de la UCM instname |
| Popis: | Context. Identifying very high-redshift galaxies is crucial for understanding the formation and evolution of galaxies. However, many questions still remain, and the uncertainty on the epoch of reionization is large. In this approach, some models allow a double-reionization scenario, although the number of confirmed detections at very high z is still too low to serve as observational proof. Aims. The main goal of this project is studying whether we can search for Lyman-alpha emitters (LAEs) at z similar to 9 using a narrow-band (NB) filter that was specifically designed by our team and was built for this experiment. Methods. We used the NB technique to select candidates by measuring the flux excess due to the Ly alpha emission. The observations were taken with an NB filter (full width at half minimum of 11 nm and central wavelength lambda(c)1.257 mu m) and the CIRCE near-infrared camera for the Gran Telescopio Canarias. We describe a data reduction procedure that was especially optimized to minimize instrumental effects. With a total exposure time of 18.3 h, the final NB image covers an area of similar to 6.7 arcmin(2), which corresponds to a comoving volume of 1.1 x 10(3) Mpc(3) at =9.3. Results. We pushed the source detection to its limit, which allows us to analyze an initial sample of 97 objects. We detail the different criteria we applied to select the candidates. The criteria included visual verifications in different photometric bands. None of the objects resembled a reliable LAE, however, and we found no robust candidate down to an emission-line flux of 2.9 x 10(-16) erg s(-1) cm(-2), which corresponds to a Ly alpha luminosity limit of 3 x 10(44) erg s(-1). We derive an upper limit on the Ly alpha luminosity function at similar to 9 that agrees well with previous constraints. We conclude that deeper and wider surveys are needed to study the LAE population at the cosmic dawn. |
| Databáze: | OpenAIRE |
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