Evidence to disfavour dual core system leading to double-peaked narrow emission lines
Abstract
In this manuscript, an interesting method is proposed to test dual core system for double-peaked narrow emission lines, through precious dual core system with double-peaked narrow Balmer lines in one system in main galaxy but with single-peaked narrow Balmer lines in the other system in companion galaxy. Under a dual core system, considering narrow Balmer (Hα and Hβ) emissions (fe,~α and fe,~β) from companion galaxy but covered by SDSS fiber for the main galaxy and narrow Balmer emissions (fc,~α and fc,~β) from the companion galaxy covered by SDSS fiber for the companion galaxy, the same flux ratios fe,~α/fc,~α=fe,~β/fc,~β can be expected, due to totally similar physical conditions of each narrow Balmer emission region. Then, the precious dual core system in SDSS J2219-0938 is discussed. After subtracting pPXF code determined stellar lights, double-peaked narrow Balmer emission lines are confirmed in the main galaxy with confidence level higher than 5σ, but single-peaked narrow Balmer emission lines in the companion galaxy. Through measured fluxes of emission components, fe,~α/fc,~α is around 0.82, different from fe,~β/fc,~β0.52, to disfavour a dual core system for the double-peaked narrow Balmer emission lines in SDSS J2219-0938.