Recent Talks

The faint glow produced by the stripped stars of the galaxies within clusters is shown to follow the dark matter distribution with extreme accuracy. In this contribution, we will show how the Intra-Cluster light can be used to trace the dark matter distribution of galaxy clusters just using deep imaging. This finding opens up the possibility of exploring the distribution of dark matter in hundreds of galaxy clusters and test the current LCDM paradigm.

The composition and nature of interstellar dust grains and the molecular composition of interstellar gas are important factors in understanding the chemistry and physics of the diffuse interstellar medium and its role in star formation and galaxy evolution. In this contribution we present the first results from two VLT surveys studying in detail the nature and properties of interstellar gas and dust in diffuse clouds.

The ESO diffuse interstellar band large exploration survey (EDIBLES) focusses on the atomic and molecular content of the diffuse ISM by probing the lines-of-sight towards ~120 bright OB stars. This survey provides a deep census of interstellar atomic and molecular abundances and diffuse interstellar band (DIB) absorptions in the diffuse/translucent ISM. The goal of EDIBLES is to `reverse-engineer' the physical properties of the carriers of the enigmatic unidentified diffuse interstellar bands as a contribution towards their identification. I will present the first results related to DIB profiles, interstellar hydrides, and the C60 fullerene.

The large interstellar polarisation survey (LIPS) is a medium-resolution spectropolarimetry study with FORS2 (and WHT) to measure the wavelength-dependent polarisation of starlight by aligned interstellar dust grains in ~100 lines-of-sight (a large fraction overlapping with EDIBLES). We investigate the variations (evolution) of dust grains through a parametrised Serkowski-law fitting of these curves. The polarisation spectra are combined with UV extinction curves and modelled simultaneously with a physical dust grain model. We present the first observational results in terms of the Serkowski-parameters as well as the dust modelling of a sub-set of the targets, in particular our study of “single-cloud” sightlines.

Together, EDIBLES and LIPS provide a new comprehensive examination of the molecules and dust properties in a statistically large sample of Galactic sightlines.

Diffuse Interstellar Bands (DIBs) are non-stellar weak absorption features of unknown origin found in the spectra of different astronomical objects when they are viewed through one or several clouds of Interstellar Medium. Galaxies other than ours offer the opportunity of study the behavior of DIBs under physical (e.g. radiation field) and chemical (e.g. metallicity and relative abundances) different to those typically found in the Milky Way. This can in turn, put further constrains on the nature of the agents creating these features. Because of their weakness, studies targeting extragalactic DIBs are relatively scarce.  This is a research that will certainly blossom at the E-ELT era. However, we can already start paving the way.

In this talk, we will illustrate how MUSE can help us in this quest. I will use as examples some results on two highly reddened systems. In the first one, AM 1353-272, we established a gradient of DIB strength in a galaxy at more than 150 Mpc (Monreal-Ibero et al. 2015, A&A, 576, 3). In the second one, The Antennae Galaxy, we measured the strength of the l5780 and l5797 DIBs in more than 100 independent line of sights, thus mapping these DIBs in a system outside the Local Group for the first time (Monreal-Ibero et al. 2017, A&A, 615, 33). The distribution of DIB strength was compared with that of atomic hydrogen, molecular gas, and PAHs as traced by the emission in the mid-infrared. In both cases, DIB strength correlates well with extinction, similar to results for the Milky Way.

In 1988 I joined the quest find exoplanets with the radial velocity method. At the time, exoplanet research was virtually unknown, and no extra-solar planets had been discovered. Since then, we have discovered several thousand extra-solar planets found mostly via the radial velocity and transit methods.

Planets with masses as low as the Earth and even in the habitable zone of low mass stars have been detected. We have also taken the first steps to characterize these new worlds in terms of their masses, radii, densities, internal structure and atmospheric composition. This was unforeseen thirty years ago. In my talk I will review the expectations we had when we first started searching for extra-solar planet, he surprises along the way, and what to expect in the future from extra-solar planet research.

Series: XXX Canary Islands Winter School of Astrophysics: Big Data in Astronomy
Topic: Supervised learning: classification and regression
Lecture 4

Series: XXX Canary Islands Winter School of Astrophysics: Big Data in Astronomy
Topic: Supervised learning: classification and regression
Lecture 3

Series: XXX Canary Islands Winter School of Astrophysics: Big Data in Astronomy
Topic: Deep learning
Lecture 4

Series: XXX Canary Islands Winter School of Astrophysics: Big Data in Astronomy
Topic: Data challenges and solutions in forthcoming surveys
Lecture 4

Series: XXX Canary Islands Winter School of Astrophysics: Big Data in Astronomy
Topic: General overview on the use of machine learning techniques in astronomy
Lecture 4

Series: XXX Canary Islands Winter School of Astrophysics: Big Data in Astronomy
Topic: Machine learning methods for non-supervised classification and dimension reduction techniques
Lecture 4