Department: Astrofísica

Area: Astronomy and Astrophysics

Research group: Evolución de galaxias


Research field: Ciencias

Doctor by the Universidad de La Laguna with the thesis Restricciones observacionales a las teorías de formación de brazos en galaxias espirales 1989. Supervised by Dr. Mercedes Prieto Muñoz.

My scientific interests are Extragalactic Astronomy and astronomical instrumentation. My first works were on star formation in nearby galaxies, determining star formation rates, and star formation efficiencies in spiral arms and elliptical galaxies. One of the most relevant results of my first works, were that the star formation in the spiral arms of Grand Design galaxies is triggered by a density wave. However, this wave biases the initial mass function to a top-heavy one. Then, the star formation rate of massive stars is larger in the arms than the rest of the disk, but the total star formation rate, averaged over the whole disk, is similar. This discovery allowed explaining the different observational and apparently contradictory facts, in an epoch where it was generally assumed that the initial mass function was universal. In the last ten years, my research has concentrated in the evolution of galaxies via deep multiple wavelength surveys. I lead as P.I. the surveys OTELO and Lockman SpReSO, based on OSIRIS at the GTC telescope; and I was Co-I of the survey PEP in the far infrared, using the instrument PACS of the Herschel spatial observatory (ESA). OTELO is the deepest emission line imaging survey to date, obtained with the tunable filters of the instrument OSIRIS, an observing mode unique in 8-10m class telescopes. The scientific exploitation of OTELO in still under way, but the first results so far have allowed deriving the faintest luminosity functions of emitters to date. PEP photometry was obtained using the then largest spatial telescope, in a spectral domain inaccessible from ground based telescopes. Lockman SpReSO is a spectroscopic survey obtained using the multiple object observing mode of OSIRIS/GTC. Lockman SpReSO is deeper than VVDS and with advantages with respect to COSMOS and AEGIS. Lockman SpReSO provides a very deep (24.6 AB magnitude) magnitude limited survey of all optical counterparts (786) of Herschel sources in the central part (24 × 24 arcmin2) of the Lockman Hole field, that will be complemented in the near infrared with spectra from EMIR/GTC. Lockman SpReSO collects also spectra of reddened AGN and Submm galaxies. Regarding my favourites personal contributions in galaxy evolution, I would like to point out the discovery that Ly-α emitters are dusty and far infrared emitters, the existence of metallicity evolution in the gas of galaxies at redshifts as low as 0.4, and the discovery of a fundamental plane for star forming galaxies defined by mass, metallicity and star formation rate. Regarding astronomical instrumentation, I am the P.I. of OSIRIS instrument at the GTC, and Co-I of the instrument PACS of the Herschel mission. My role in PACS was to lead the development of the Signal Processing Unit. This is a subsystem of the maximum importance for the mission, since it preprocesses and lossless compresses the data. In this way, the data can be transferred to ground in spite of the limited bandwidth, and scarce down-link daily time. OSIRIS is successfully working at the GTC since July 2009. Up to 2017 OSIRIS was the only Spanish instrument at the GTC, generating hundreds of papers in international refereed journals. OSIRIS was part of the in-kind contribution for the entrance-fee of Spain in ESO