Distant galaxies

Our group works to make some light in different topics which are listed bellow

  • On the properties, origin and evolution of  Low-Mass Star-Forming Galaxies (LMSFGs)
  • Searching for Ly-alpha emitters at z=9.3 with CIRCE at GTC

On the properties, origin and evolution of Low-Mass Star-Forming Galaxies (LMSFGs)

The study of distant galaxies is crucial for understanding the reionization process, the formation and evolution of galaxies, and the large-scale structure in the Universe. The lowmass star-forming galaxies (LMSFGs) are the most poorly know galaxies in the Universe due to the difficulty of detecting them. Moreover, their mass assembly is still not well understood and disagreements remain about the period of their dominant star-formation activity.

AIM: Our main goal is to observe a sample of low-mass galaxies at intermediate redshifts (0.7 < z < 1.5) to study their physical properties, the formation redshift and cosmic role of dwarf galaxies.

HOW: We are exploiting the Guaranteed Time (GT), spectral resolution and multiplex capabilities of both EMIR and MEGARA instruments installed on the 10.4m GTC telescope in La Palma. In order to better constrain the formation and the evolution of LMSFGs, we are carrying out a spectroscopic study in the near-infrared (0.9 – 2.5 µm) with EMIR as well as in the optical (3600 – 9600 Å) with MEGARA. These multiobject-spectrographs allow to configure and observe a large number of distant galaxies in real time.

Searching for Ly-alpha emitters at z=9.3 with CIRCE at GTC

Cabello et al. 2022, A&A 659, A116

In this project, we studied the feasibility of detecting Lyman-α Emitters (LAEs) at z = 9.3 using the near-IR camera CIRCE at the 10.4 m Gran Telescopio Canarias (GTC). For this work, the ALBA team designed a narrow-band filter (NB1257) with FWHM = 11nm and centered at 1257 nm that was manufactured by SCHOTT. As a result of the observations, we obtained a near-IR image of 18.3 hours which covers an area of ∼7 arcmin2 within the EGS cosmological field. After the source detection, no robust LAE candidate was selected down to an emission-line flux of 2.9 × 10−16 erg s−1 cm−2. Nonetheless, we derived an observational constraint of the Lyα luminosity function at z ∼ 9 that agrees well with the previous constraints. We conclude that wider and deeper observations are needed to address the scientific challenge of detecting the first galaxies of the Universe.