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arXiv · 1707.03461

Galaxy properties from J-PAS narrow-band photometry

A. Mejía-Narváez·G. Bruzual·G. Magris C.·J. S. Alcaniz·N. Benítez·S. Carneiro·A. J. Cenarro·D. Cristóbal-Hornillos·R. Dupke·A. Ederoclite·A. Marín-Franch·C. Mendes de Oliveira·M. Moles·L. Sodre Jr.·K. Taylor·J. Varela·H. Vázquez Ramió
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Abstract

We study the consistency of the physical properties of galaxies retrieved from SED-fitting as a function of spectral resolution and signal-to-noise ratio (SNR). Using a selection of physically motivated star formation histories, we set up a control sample of mock galaxy spectra representing observations of the local universe in high-resolution spectroscopy, and in 56 narrow-band and 5 broad-band photometry. We fit the SEDs at these spectral resolutions and compute their corresponding the stellar mass, the mass- and luminosity-weighted age and metallicity, and the dust extinction. We study the biases, correlations, and degeneracies affecting the retrieved parameters and explore the r\^ole of the spectral resolution and the SNR in regulating these degeneracies. We find that narrow-band photometry and spectroscopy yield similar trends in the physical properties derived, the former being considerably more precise. Using a galaxy sample from the SDSS, we compare more realistically the results obtained from high-resolution and narrow-band SEDs (synthesized from the same SDSS spectra) following the same spectral fitting procedures. We use results from the literature as a benchmark to our spectroscopic estimates and show that the prior PDFs, commonly adopted in parametric methods, may introduce biases not accounted for in a Bayesian framework. We conclude that narrow-band photometry yields the same trend in the age-metallicity relation in the literature, provided it is affected by the same biases as spectroscopy; albeit the precision achieved with the latter is generally twice as large as with the narrow-band, at SNR values typical of the different kinds of data.

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A. Mejía-Narváez, G. Bruzual, G. Magris C., J. S. Alcaniz, N. Benítez, S. Carneiro, A. J. Cenarro, D. Cristóbal-Hornillos, R. Dupke, A. Ederoclite, A. Marín-Franch, C. Mendes de Oliveira, M. Moles, L. Sodre Jr., K. Taylor, J. Varela, H. Vázquez Ramió. 2017-07-11. Galaxy properties from J-PAS narrow-band photometry. https://doi.org/10.1093/mnras/stx1758

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