Substellar Science with the Euclid Space Mission

Euclid is a space mission led by the European Space Agency (ESA) to conduct a deep, single-epoch survey of 15,000 deg2 of sky with visible and near-infrared photometry and spectroscopy, and 40 deg2 multi-epoch very deep surveys.

Its primary science goal is to investigate the geometry of the dark universe by mapping the distribution and shapes of galaxies.The unprecedented combination of sensitivity, areal coverage, spatial resolution, data homogeneity and spectral information will naturally be of tremendous benefit to other areas of astrophysics.

Two Euclid Independent Legacy Science (ILS) programs have been designated by ESA to develop and pursue independent science programs that capitalize on the unique data products of the Euclid surveys.In this proposal the PI of the Euclid Ultracool Dwarf (UCD) ILS team lays out an Advanced ERC project aimed at mining the Euclid surveys for pushing the frontier of knowledge in substellar science.The first challenge of the project is to identify, based on Euclid data, an unprecedented large number (>1,000,000) of very low mass (VLM) stars and Substellar-mass Objects (SMOs), including hard to find objects such as halo brown dwarfs and young free-floating planetary-mass objects.

Specific pipelines will be developed to extract the utmost information from Euclid for faint infrared objects.The second challenge is to discover very low-mass binaries and giant planets around VLM stars and SMOs using custom-made image analysis, astrometric monitoring and spectral fitting techniques.The third challenge is to combine the information gathered from harnessing the previous two challenges to determine the VLM stellar and substellar luminosity function, infer the most likely low-mass end of the Initial Mass Function (IMF), and explore its degree of universality in different components of the Milky Way.