A fundamental plane for field star-forming galaxies
Context. Star formation rate (SFR), metallicity, and stellar mass are
among the most important parameters of star-forming (SF) galaxies
characterizing their formation and evolution. They are known to be
related to each other both at low and high redshift in the
mass-metallicity, mass-SFR, and metallicity-SFR relations. <BR /> Aims:
We demonstrate the existence of a plane in a 3D parameter space defined
by the axes SFR [log (SFR)(M<SUB>ȯ</SUB> yr<SUP>-1</SUP>)] , gas
metallicity [12 + log (O/H)], and stellar mass [log
(M<SUB>star</SUB>/M<SUB>ȯ</SUB>)] of SF galaxies. <BR /> Methods:
We used SF galaxies from the “main galaxy sample” of the
Sloan Digital Sky Survey-Data Release 7 (SDSS-DR7) in the redshift range
0.04 < z < 0.1 and r-magnitudes between 14.5 and 17.77.
Metallicities, SFRs, and stellar masses were taken from the
Max-Planck-Institute for Astrophysics-John Hopkins University (MPA-JHU)
emission-line analysis database. <BR /> Results: From a final sample of
32 575 galaxies, we find for the first time a fundamental plane for
field galaxies relating the SFR, gas metallicity, and stellar mass for
SF galaxies in the local universe. One of the applications of this plane
would be to estimate stellar masses from SFR and metallicity. High
redshift data from the literature at redshift ~0.85, 2.2, and 3.5, do
not show evidence of evolution in this fundamental plane.
Appendix A is only available in electronic form at <A
href="http://www.aanda.org">http://www.aanda.org</A>