arXiv subjects

Susana Sánchez

Publications and source records attributed to Susana Sánchez.

3 recordsLinked to original sources

arXiv2026

Advanced computing for reproducibility of astronomy Big Data Science, with a showcase of AMIGA and the SKA Science prototype

The Square Kilometre Array Observatory (SKAO) faces unprecedented technological challenges due to the vast scale and complexity of its data. This paper provides an overview of research by the AMIGA group to address these computing and reproducibility challenges. We present advancements in semantic data models, analysis services integrated into federated infrastructures, and the application to astronomy studies of techniques that enhance research transparency. By showcasing these astronomy work, we demonstrate that achieving reproducible science in the Big Data era is feasible. However, we conclude that for the SKAO to succeed, the development of the SKA Regional Centre Network (SRCNet) must explicitly incorporate these reproducibility requirements into its fundamental architectural design. Embedding these standards is crucial to enable the global community to conduct verifiable and sustainable research within a federated environment.

astro-ph.IM↗

arXiv2021

A diffuse tidal dwarf galaxy destined to fade out as a "dark galaxy"

We have explored the properties of a peculiar object detected in deep optical imaging and located at the tip of an HI tail emerging from Hickson Compact Group 16. Using multiband photometry from infrared to ultraviolet, we were able to constrain its stellar age to 58$^{+22}_{-9}$ Myr with a rather high metallicity of [Fe/H] = $-$0.16$^{+0.43}_{-0.41}$ for its stellar mass of M$_\star$ = 4.2$\times$10$^6$ M$_\odot$, a typical signature of tidal dwarf galaxies. The structural properties of this object are similar to those of diffuse galaxies, with a round and featureless morphology, a large effective radius (r$_{eff}$ = 1.5 kpc), and a low surface brightness (<$μ_{g}$>$_{eff}$ = 25.6 mag arcsec$^{-2}$). Assuming that the object is dynamically stable and able to survive in the future, its fading in time via the aging of its stellar component will make it undetectable in optical observations in just $\sim$2 Gyr of evolution, even in the deepest current or future optical surveys. Its high HI mass, M(HI) = 3.9$\times$10$^8$ M$_\odot$, and future undetectable stellar component will make the object match the observational properties of dark galaxies, that is, dark matter halos that failed to turn gas into stars. Our work presents further observational evidence of the feasibility of HI tidal features becoming fake dark galaxies; it also shows the impact of stellar fading, particularly in high metallicity systems such as tidal dwarfs, in hiding aged stellar components beyond detection limits in optical observations.

astro-ph.GA↗

arXiv2012

The AMIGA sample of isolated galaxies XI. A First Look at Isolated Galaxy Colors

The basic properties of galaxies can be affected by both nature (internal processes) or nurture (interactions and effects of environment). Deconvolving the two effects is an important current effort in astrophysics. Observed properties of a sample of isolated galaxies should be largely the result of internal (natural) evolution. It follows that nurture-induced galaxy evolution can only be understood through comparative study of galaxies in different environments. We take a first look at SDSS (g-r) colors of galaxies in the AMIGA sample involving many of the most isolated galaxies in the local Universe. This leads us to simultaneously consider the pitfalls of using automated SDSS colors. We focus on median values for the principal morphological subtypes found in the AMIGA sample (E/S0 and Sb-Sc) and compare them with equivalent measures obtained for galaxies in denser environments. We find a weak tendency for AMIGA spiral galaxies to be redder than objects in close pairs. We find no clear difference when we compare with galaxies in other (e.g. group) environments. However, the (g-r) color of isolated galaxies shows a Gaussian distribution as might be expected assuming nurture-free evolution. We find a smaller median absolute deviation in colors for isolated galaxies compared to both wide and close pairs. The majority of the deviation on median colors for spiral subtypes is caused by a color-luminosity correlation. Surprisingly isolated and non-isolated early-type galaxies show similar (g-r). We see little evidence for a green valley in our sample with most spirals redder than (g-r)=0.7 having spurious colors. The redder colors of AMIGA spirals and lower color dispersions for AMIGA subtypes -compared with close pairs- is likely due to a more passive star formation in very isolated galaxies.

astro-ph.CO↗