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Title: ON THE THREE-DIMENSIONAL STRUCTURE OF THE MASS, METALLICITY, AND STAR FORMATION RATE SPACE FOR STAR-FORMING GALAXIES

Abstract

We demonstrate that the space formed by the star formation rate (SFR), gas-phase metallicity (Z), and stellar mass (M {sub *}) can be reduced to a plane, as first proposed by Lara-Lopez et al. We study three different approaches to find the best representation of this 3D space, using a principal component analysis (PCA), a regression fit, and binning of the data. The PCA shows that this 3D space can be adequately represented in only two dimensions, i.e., a plane. We find that the plane that minimizes the {chi}{sup 2} for all variables, and hence provides the best representation of the data, corresponds to a regression fit to the stellar mass as a function of SFR and Z, M {sub *}= f(Z, SFR). We find that the distribution resulting from the median values in bins for our data gives the highest {chi}{sup 2}. We also show that the empirical calibrations to the oxygen abundance used to derive the Fundamental Metallicity Relation have important limitations, which contribute to the apparent inconsistencies. The main problem is that these empirical calibrations do not consider the ionization degree of the gas. Furthermore, the use of the N2 index to estimate oxygen abundances cannot bemore » applied for 12 + log(O/H) {approx}> 8.8 because of the saturation of the [N II] {lambda}6584 line in the high-metallicity regime. Finally, we provide an update of the Fundamental Plane derived by Lara-Lopez et al.« less

Authors:
; ;  [1]
  1. Australian Astronomical Observatory, P.O. Box 915, North Ryde, NSW 1670 (Australia)
Publication Date:
OSTI Identifier:
22167697
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal
Additional Journal Information:
Journal Volume: 764; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0004-637X
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ASTRONOMY; ASTROPHYSICS; CALIBRATION; ELEMENT ABUNDANCE; GALACTIC EVOLUTION; GALAXIES; HYDROGEN; NITROGEN IONS; OXYGEN; STAR EVOLUTION; STARS; THREE-DIMENSIONAL CALCULATIONS

Citation Formats

Lara-Lopez, Maritza A., Lopez-Sanchez, Angel R., and Hopkins, Andrew M., E-mail: mlopez@aao.gov.au. ON THE THREE-DIMENSIONAL STRUCTURE OF THE MASS, METALLICITY, AND STAR FORMATION RATE SPACE FOR STAR-FORMING GALAXIES. United States: N. p., 2013. Web. doi:10.1088/0004-637X/764/2/178.
Lara-Lopez, Maritza A., Lopez-Sanchez, Angel R., & Hopkins, Andrew M., E-mail: mlopez@aao.gov.au. ON THE THREE-DIMENSIONAL STRUCTURE OF THE MASS, METALLICITY, AND STAR FORMATION RATE SPACE FOR STAR-FORMING GALAXIES. United States. doi:10.1088/0004-637X/764/2/178.
Lara-Lopez, Maritza A., Lopez-Sanchez, Angel R., and Hopkins, Andrew M., E-mail: mlopez@aao.gov.au. Wed . "ON THE THREE-DIMENSIONAL STRUCTURE OF THE MASS, METALLICITY, AND STAR FORMATION RATE SPACE FOR STAR-FORMING GALAXIES". United States. doi:10.1088/0004-637X/764/2/178.
@article{osti_22167697,
title = {ON THE THREE-DIMENSIONAL STRUCTURE OF THE MASS, METALLICITY, AND STAR FORMATION RATE SPACE FOR STAR-FORMING GALAXIES},
author = {Lara-Lopez, Maritza A. and Lopez-Sanchez, Angel R. and Hopkins, Andrew M., E-mail: mlopez@aao.gov.au},
abstractNote = {We demonstrate that the space formed by the star formation rate (SFR), gas-phase metallicity (Z), and stellar mass (M {sub *}) can be reduced to a plane, as first proposed by Lara-Lopez et al. We study three different approaches to find the best representation of this 3D space, using a principal component analysis (PCA), a regression fit, and binning of the data. The PCA shows that this 3D space can be adequately represented in only two dimensions, i.e., a plane. We find that the plane that minimizes the {chi}{sup 2} for all variables, and hence provides the best representation of the data, corresponds to a regression fit to the stellar mass as a function of SFR and Z, M {sub *}= f(Z, SFR). We find that the distribution resulting from the median values in bins for our data gives the highest {chi}{sup 2}. We also show that the empirical calibrations to the oxygen abundance used to derive the Fundamental Metallicity Relation have important limitations, which contribute to the apparent inconsistencies. The main problem is that these empirical calibrations do not consider the ionization degree of the gas. Furthermore, the use of the N2 index to estimate oxygen abundances cannot be applied for 12 + log(O/H) {approx}> 8.8 because of the saturation of the [N II] {lambda}6584 line in the high-metallicity regime. Finally, we provide an update of the Fundamental Plane derived by Lara-Lopez et al.},
doi = {10.1088/0004-637X/764/2/178},
journal = {Astrophysical Journal},
issn = {0004-637X},
number = 2,
volume = 764,
place = {United States},
year = {2013},
month = {2}
}