The IC1613 dwarf irregular galaxy, composite image made with data from the WHT, GALEX and VLA telescopes. The UV-sources, most of them massive stars, are highlighted in blue while red traces the regions of ionized gas. Image credit: G. Pérez (SMM-IAC) and M. Garcia (IAC).
The Dragonfish Nebula as seen by the Spitzer Space Telescope. This is a composite picture made with images at different wavelengths: 3.6 microns (blue); 4.5 microns (green); and 8.0 microns (red). Image credit: NASA/JPL-Caltech/Univ. of Toronto
The Sagittarius dwarf irregular galaxy (SagDIG) holds the record of hosting the massive stars with less chemical enrichment of the Local Group: their content of elements different from H and He is only 5% Solar. This image was made with composite HST-ACS observations, and green marks the UV emission detected by GALEX.
The IC1613 dwarf irregular galaxy, composite image made with data from the WHT, GALEX and VLA telescopes. The UV-sources, most of them massive stars, are highlighted in blue while red traces the regions of ionized gas. Image credit: G. Pérez (SMM-IAC) and M. Garcia (IAC).
OUR PROJECTS:
The team of Massive Stars at the Centre for Astrobiology works to characterize different aspects of the physics and evolution of these objects, using advanced codes and extensive sets of spectroscopic observations across the electromagnetic spectrum.
Massive stars are fundamental agents of the Universe at galactic-scale. They are mighty sources that ionize and shape the interstellar medium. Their death as supernova can outshine entire galaxies and releases a wealth of metals synthesized in the stellar interior enriching the Universe. Either as basic ingredients or probes, massive stars are crucial to understanding a variety of phenomena in Astrophysics.
One of the pivotal open questions of the field is to understand the role of metallicity in the evolution and physics of massive stars. In order to provide reliable answers, large stellar samples in a variety of metallicity environments are needed. We are leading a unique effort to unveil hot massive stars in nearby dwarf irregular galaxies with poorer metal content than the Small Magellanic Cloud (SMC). This sample of stars is extremely useful to study high redshift galaxies and to infer the physics of the first stars of the Universe. We are also part of international consortia (e.g. the VLT-FLAMES Tarantula Survey) to perform large spectroscopic surveys on both Magellanic Clouds. On the high-metallicity end, we have assembled our own collection of data from the Milky Way and M33 resulting in a dataset that spans from the metal-rich to the extreme metal-poor regime.
Our group has a long record on spectroscopic studies of massive stars at infrared (IR) wavelengths. We are working to unveil and characterize the population of massive stars in the disk of the Milky Way obscured by heavy dust absorption, and use it to map the chemical composition of our Galaxy. We have also obtained unprecedented information of the clusters of massive stars close to the Galactic Center (Quintuplet and Arches clusters) from IR quantitative spectroscopy. We have lead HERSCHEL observing programs for massive stars in the far infrared and participate actively in SPICA, in an effort to identify and characterize diagnostics at the new spectroscopic windows opened by these missions.
The team’s expertise is well balanced between the technical, theoretical and observational aspects. Besides our deep involvement and F. Najarro's leadership within the Spica mission, we are members of the science teams supporting the construction of the WSO-FCU, MEGARA and WEAVE instruments, and ESA and NASA teams promoting the construction of a future large space telescope. We handle the codes that currently provide the best description of the atmospheres of hot massive stars, and keep working to improve CMFGEN. Finally, we have assembled a powerful database of photometric and spectroscopic observations (UV, optical and near-IR ranges, with some additional data in the far-IR and radio), built from our successful proposals to large facilities (HST, HERSCHEL, VLT, GTC, VLA).