Bibcode
Cid Fernandes, R.; Pérez, E.; García Benito, R.; González Delgado, R. M.; de Amorim, A. L.; Sánchez, S. F.; Husemann, B.; Falcón Barroso, J.; Sánchez-Blázquez, P.; Walcher, C. J.; Mast, D.
Bibliographical reference
Astronomy and Astrophysics, Volume 557, id.A86, 15 pp.
Advertised on:
9
2013
Journal
Citations
190
Refereed citations
177
Description
Aims: Fossil record methods based on spectral synthesis
techniques have matured during the past decade, and their application to
integrated galaxy spectra has fostered substantial advances in the
understanding of galaxies and their evolution. Yet, because of the lack
of spatial resolution, these studies are limited to a global view,
providing no information about the internal physics of galaxies.
Methods: Motivated by the CALIFA survey, which is gathering integral
field spectroscopy (IFS) over the full optical extent of 600 galaxies,
we have developed an end-to-end pipeline that: (i) partitions the
observed datacube into Voronoi zones in order to, when necessary and
taking due account of correlated errors, increase the signal-to-noise
ratio; (ii) extracts rest-framed spectra, including propagated errors
and bad-pixel flags; (iii) feeds the spectra into the starlight spectral
synthesis code; (iv) packs the results for all galaxy zones into a
single FITS or HDF5 file; (v) performs a series of post-processing
operations, including zone-to-pixel image reconstruction and unpacking
the spectral and stellar population properties derived by starlight into
multidimensional time, metallicity, and spatial coordinates. This paper
provides an illustrated description of the whole pipeline and its many
products. Using data for the nearby spiral NGC 2916 as a showcase, we go
through each of the steps involved and present a series of ways of
visualizing and analyzing this manifold. These include 2D maps of
properties such as the velocity field, stellar extinction, mean ages and
metallicities, mass surface densities, and star formation rates on
different time scales and normalized in different ways, as well as 1D
averages in the temporal and spatial dimensions, which lead to
evolutionary curves and radial profiles of physical properties.
Projections of the stellar light and mass growth onto radius-age
diagrams are introduced as a means of visualizing galaxy evolution in
time and space simultaneously, something which can also be achieved in
3D with snapshot cuts through the (x,y,t) cubes. Results: The
results vividly illustrate the richness both of the combination of IFS
data with spectral synthesis and of the insights on galaxy physics
provided by the variety of diagnostics and semi-empirical constraints
obtained. Additionally, they give a glimpse of what is to come from
CALIFA and future IFS surveys.
Related projects
Traces of Galaxy Formation: Stellar populations, Dynamics and Morphology
We are a large, diverse, and very active research group aiming to provide a comprehensive picture for the formation of galaxies in the Universe. Rooted in detailed stellar population analysis, we are constantly exploring and developing new tools and ideas to understand how galaxies came to be what we now observe.
Ignacio
Martín Navarro