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Supernovae and Stellar Transients

Understanding the transient universe

This group studies the physics driving the explosion mechanism of supernovae and other stellar transients, and also focuses on improving the understanding of supernovae as cosmological distance indicators.

Behind the explosions and beyond our galaxy

Supernovae are very energetic explosions and the end-point of stellar evolution. They trigger star formation and are the main drivers of chemical enrichment of the interstellar medium (ISM) in galaxies. By doing a continuous follow-up of these phenomena, we are able to understand the main classes of supernovae, explore sub-classes and other extreme events. In addition, the environment in which they explode contains valuable information about their stellar evolution, which gets imprinted in their light curves. Furthermore, IFS of supernova remnants is also used to study the after-math of these explosions by measuring the chemical composition and dynamics.

A subset of these stellar transients, known as Type Ia supernovae (SNe Ia), are excellent distance indicators, providing a competitive method to test the current standard cosmological model of the Universe. However, the physics that drives the explosion mechanism of SNe Ia, together with the stellar progenitors of these phenomena, are still not well understood and remain as some of the most important unanswered questions in astrophysics today.

Focus

Our main research lines are:

  • Characterize the local environment of SN host galaxies using integral field spectroscopy (IFS). We lead the PMAS/PPak Integral-field Supernova Hosts Compilation (PISCO) and the All-weather MUse Supernova Integral-field of Nearby Galaxies (AMUSING), which have put together observations of more than 1500 SN hosts.
  • Study the family of peculiar subluminous (91bg-like) type Ia SNe, their progenitors, environments, and explosion mechanisms.
  • Develop type II SN cosmology and prepare forecasts for the LSST from simulations using different cadences, providing independent measurements of the local expansion rate of the Universe.
  • Type Ia SN cosmology in the near infrared (NIR). Currently compiling NIR observations of ZTF discovered SNe Ia in the Hubble flow (z>0.01) to put independent constraints on the Hubble constant (H0).
  • Constrain on the local growth of structure, parameterized by fσ8, using NIR observations of nearby SNe Ia. Reconstruct the distribution of dark matter and the panorama of our supercluster Laniakea, to test the standard and other alternative cosmological models.

We are members of several international collaborations that are obtaining most of the photometric and spectroscopic observations of transient objects, such as the extended Public ESO Spectroscopic Survey of Transient Objects + (ePESSTO+), the Nordic-optical-telescope Un-biased Transient Survey (NUTS2), the Carnegie Supernova Pproject (CSP) and the Precision Observations of Infant SUpernova Explosions (POISE), the Global Supernova Project (GSP), the Electromagnetic counterparts of gravitational wave sources at the Very Large Telescope (ENGRAVE), and the Keck Infrared Transient Survey (KITS).

We are also members of other international collaborations aiming in using type Ia supernovae (SNe Ia) for cosmological analyses: the Dark Energy Survey (DES), the Dark Energy Spectroscopic Instrument (DESI), the Nancy Grace Roman Space Telescope supernova Science Investigation Team (SIT), the Dark Energy Science Collaboration (DESC) of the Legacy Survey of Space and Time (LSST).

Senior institute members involved

Meet the senior researcher who participates in this research line.

  • Lluís Galbany

    More theory and observations