TY - JOUR
T1 - The PAU survey: measurements of the 4000 Å spectral break with narrow-band photometry
AU - Renard, Pablo
AU - Siudek, Malgorzata
AU - Eriksen, Martin B.
AU - Cabayol, Laura
AU - Cai, Zheng
AU - Carretero, Jorge
AU - Casas, Ricard
AU - Castander, Francisco J.
AU - Fernandez, Enrique
AU - García-Bellido, Juan
AU - Gaztanaga, Enrique
AU - Hoekstra, Henk
AU - Joachimi, Benjamin
AU - Miquel, Ramon
AU - Navarro-Girones, David
AU - Padilla, Cristóbal
AU - Sanchez, Eusebio
AU - Serrano, Santiago
AU - Tallada-Crespí, Pau
AU - De Vicente, Juan
AU - Wittje, Anna
AU - Wright, Angus H.
N1 - Publisher Copyright:
© 2022 The Author(s) Published by Oxford University Press on behalf of Royal Astronomical Society.
PY - 2022/9/1
Y1 - 2022/9/1
N2 - The D4000 spectral break index is one of the most important features in the visible spectrum, as it is a proxy for stellar ages and is also used in galaxy classification. However, its direct measurement has always been reserved to spectroscopy. Here, we present a general method to directly measure the D4000 with narrow-band (NB) photometry; it has been validated using realistic simulations, and then evaluated with PAUS NBs, cross-matched with VIPERS spectra (iAB < 22.5, 0.562 < z < 0.967). We also reconstruct the D4000 with the SED-fitting code cigale; the use of PAUS NBs instead of broad-bands significantly improves the SED fitting results. For D4000n, the direct measurement has [SNR]∼ 4, but we find that for iAB < 21 all direct D4000 measurements have [SNR]> 3. The cigale D4000n has [SNR ]∼ 20, but underestimates the error by >50 per cent. Furthermore, the direct method recreates well the D4000-SFR relation, as well as the D4000-mass relation for blue galaxies (for red galaxies, selection effects impact the results). On the other hand, cigale accurately classifies galaxies into red and blue populations. We conclude that the direct measurement of D4000 with narrow-band photometry is a promising tool to determine average properties of galaxy samples, with results compatible with spectroscopy.
AB - The D4000 spectral break index is one of the most important features in the visible spectrum, as it is a proxy for stellar ages and is also used in galaxy classification. However, its direct measurement has always been reserved to spectroscopy. Here, we present a general method to directly measure the D4000 with narrow-band (NB) photometry; it has been validated using realistic simulations, and then evaluated with PAUS NBs, cross-matched with VIPERS spectra (iAB < 22.5, 0.562 < z < 0.967). We also reconstruct the D4000 with the SED-fitting code cigale; the use of PAUS NBs instead of broad-bands significantly improves the SED fitting results. For D4000n, the direct measurement has [SNR]∼ 4, but we find that for iAB < 21 all direct D4000 measurements have [SNR]> 3. The cigale D4000n has [SNR ]∼ 20, but underestimates the error by >50 per cent. Furthermore, the direct method recreates well the D4000-SFR relation, as well as the D4000-mass relation for blue galaxies (for red galaxies, selection effects impact the results). On the other hand, cigale accurately classifies galaxies into red and blue populations. We conclude that the direct measurement of D4000 with narrow-band photometry is a promising tool to determine average properties of galaxy samples, with results compatible with spectroscopy.
KW - Galaxies: evolution
UR - http://www.scopus.com/inward/record.url?scp=85134563404&partnerID=8YFLogxK
U2 - 10.1093/mnras/stac1730
DO - 10.1093/mnras/stac1730
M3 - Article
AN - SCOPUS:85134563404
SN - 0035-8711
VL - 515
SP - 146
EP - 166
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 1
ER -