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Evolution of galaxies across cosmic time

 

Galaxies have progressively formed through a complex combination of gas accretion, star formation, and merging with other galactic units. The Evolution of galaxies research line aims to unveil the physical mechanisms responsible for the most significant transformations in these objects. The team that makes up the research line is strongly involved in the development of forefront instrumentation (FRIDA, GTCAO, HARMONI, WEAVE) and has an important role in the scientific exploitation and development of international projects (SDSS, EUCLID, LSST, WEAVE).

 

 Specific goals 2020 - 2023:

  •  Identify the sources that reionized the universe one billion years after the Big Bang. Detect and study the first galaxies and quasars. Advance in our understanding of the nature and reality of dark matter. Investigate the low surface brightness universe to test dark matter predictions and galaxy formation theories.
  • Study the physics of active galactic nuclei and supernovae feedback and their connection with galaxy evolution from the observational and theoretical point of view. Explore the multiwavelength nature of feedback and investigate its impact on the host galaxies using data from GTC/EMIR & FRIDA and ALMA. Run the largest hydrodynamical cosmological simulations to date by developing star formation and feedback prescriptions that are designed to work at low resolution.
  • Study the physics of star formation and the conditions of the interstellar medium over the history of the Universe and under different physical conditions. Survey the star formation history, and the structural, kinematic and chemical properties of the various components of nearby galaxies to probe models of galaxy formation and evolution in a cosmological context. Get ready for resolved stellar population studies beyond what currently possible, exploiting future instruments on ELTs, JWST and other major facilities.
  • Explore different gas accretion mechanisms necessary for galaxies to keep forming stars. Image from the first time Intergalactic Medium gas flows funnelling gas into local galaxies
    using GTC/MEGARA and WHT/WEAVE. Investigate the role of major/minor mergers and secular processes in galaxy evolution.
  • Exploit unsupervised artificial intelligence to go beyond state-of-the-art data analysis techniques and get ready for big-data spectro-photometric surveys such as LSST, EUCLID,
    J-PAS and WFIRST. Improve the link between observations and theory by extracting and interpreting information from simulations of galaxies in a cosmological context spanning most of the Universes life.

 

Specific Scientific Outputs:

2016

  • An international scientific team in which the IAC participates has discovered that the largest galaxies in the universe are developing in cosmic clouds of cold gas. The finding, published in the journal Science, has been possible using radio telescopes in Australia and the US. 
  • Observations made with the Atacama Large Millimeter Array (ALMA) of the central region of NGC 1068, a prototypical Seyfert type 2 galaxy, have allowed to resolve for the first time the torus of dust and gas in the center of this active galaxy. The study, which has IAC participation, has been published in The Astrophysical Journal Letters.
  • A team of IAC researchers have obtained the deepest image of a galaxy from the ground with the GTC. The image is ten times deeper than any other made with ground-based telescopes and allows us to observe the faint stellar halo of one of our neighboring galaxies, which supports the presently accepted model of galaxy formation (published in The Astrophysical Journal).
  • A statistical correlation has been found between the size of the spiral galaxies' bulb and the number of "tidal dwarf" satellite galaxies (remnants of the interaction between host galaxies), which reinforces the models without dark matter (study published in The Astrophysical Journal).
  • IAC scientists have participated in the study of a "tadpole" galaxy observed with the Hubble Space Telescope, whose results reveal how cosmic gas triggers the birth of stars in galaxies. This process, which is very difficult to observe, would thus explain the formation of galaxies like the Milky Way (published in The Astrophysical Journal).
  • A new Einstein ring has been discovered by an IAC PhD student during the analysis of images of the Sculptor dwarf galaxy. Its physical properties has been later analyzed with the OSIRIS spectrograph in the GTC (study published in MNRAS Letters).  
  • Two new methods have been developed based on the properties of the RR Lyrae variable stars to used them as probes of the first star formation events in galaxies and to study the early formation history of the Milky Way stellar halos (Martínez-Vázquez et al., 2016; Fiorentino et al. 2017).
  • An IAC team has obtained the first measurements of dynamic mass for an Ultra Diffuse Galaxy in the Virgo galaxy cluster (Beasley et al., 2016).
  • New stellar population models based on empirical stellar libraries have been published covering the wavelength range from 0.16 to 50 microns (Vazdekis et al., 2016). 

 

2017

  • IAC researchers have participated in a study that has observed, for the first time, the interstellar dust of one of the most distant galaxies known, thanks to observations made with ALMA (published in The Astrophysical Journal Letters).
  • A study led by the IAC has used the microlensing effect on quasars to estimate the number of intermediate mass primordial black holes in galaxies. The results suggest that the gravitational waves detected by the LIGO experiment came from black holes generated in the collapse of stars and not in the origin of the Universe (published in The Astrophysical Journal Letters).
  • A scientific team led by the IAC has detected and measured a set of super bubbles expanding in the interstellar medium of the interacting galaxies "Antennae". The team has used the GHaFaS instrument, which can obtain a velocity map of an entire galaxy using the emission of ionized hydrogen, in the WHT and a method of analysis developed by themselves (study published in MNRAS).
  • A scientific team led by the IAC has found a precise way to measure the rate of star formation in galaxies using the range of radio frequencies between 1 and 10 GHz (published in The Astrophysical Journal).
  • An international team led by IAC researchers has discovered one of the brightest distant non-active galaxies so far known. The discovery of BG1429+1202, 11.4 billion light-years away, has been possible thanks to the effect of gravitational lens produced by a massive elliptical galaxy in the line of sight to the object. The results, published in The Astrophysical Journal Letters, are part of the BELLS GALLERY project, based on the analysis of 1.5 million spectra of SDSS galaxies.
  • Deep spectroscopic observations of the galaxy group Abell 2151, made with AF2/WYFFOS at the WHT, allowed the identification of 360 galaxy members of the cluster. The study suggests that reddening of bright galaxies is independent of the environment, unlike for the population of dwarf galaxies (published in MNRAS).
  • An algorithm developed by the IAC researcher Sebastian Hidalgo to analyze data on star formation in the Universe has been selected to run in the global computing event "Global Azure Bootcamp 2017".
  • Images obtained with the infrared camera CIRCE installed in the GTC allow us to reveal the morphology of the host galaxy of a powerful active galactic nucleus. The study shows for the first time that the host galaxy of one of these active "Narrow Line Seyfert 1" galactic nuclei is an elliptical galaxy (study published in MNRAS Letters).
  • The HST "ISLAndS" project, which has obtained 111 orbits with the Hubble Space Telescope to study a representative sample of six spherical galaxies of M31, has made it possible to obtain the star formation history of these galaxies with a temporal resolution of ~ 1 Gigayear at old ages (Monelli et al. 2016; Skillman et al. 2017).

 

Previous results (2012 - 2015)

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