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)
  • Testing a double reionization scenario of the Universe

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.

Testing a double reionization scenario of the Universe

We have obtained an ultra-deep image taken with a narrow-band filter (FWHM = 11nm and central wavelength λc = 1.254 μm) designed on purpose by ourselves for the CIRCE nIR camera at GTC.

The data was supposed to reach a depth enough to detect LAEs (Luminous Lyman-α Emitters) at z=9.3 by the flux excess due to the Lyα emission.

The density of LAEs would help us to support or to reject the double reionization scenario predicted by the AMIGA model (Salvador-Solé 2015).

The ultra-deep image has been obtained within the Extended Groth Strip (EGS) field, and after17.6 hours on target we confirmed reaching a limiting AB magnitude ∼23 in the ALBA-NB filter.

As a complementary result, we have performed a scientific analysis of the identified galaxies, gathering the available ancillary information from the 3D-HST and CANDELS surveys.

Cabello et al. 2019, in prep.