SDSS J083253.18+064316.7: One strange object with double-peaked narrow Hα but single-peaked narrow Hβ

Abstract

In this Letter, we first report one unique object SDSS J0832+0643 with particular features of narrow Balmer emission lines: double-peaked narrow Hα but single-peaked narrow Hβ. The particular features cannot be expected by currently proposed kinematic models for doublepeaked narrow emission lines, because the proposed kinematic models lead to similar line profiles of narrow Balmer emission lines. However, due to radiative transfer effects, the nonkinematic model can be naturally applied to well explain the particular features of narrow Balmer emission lines: larger optical depth in Hα than 10 leads to observed double-peaked narrow Hα, but smaller optical depth in Hβ around 2 leads to observed single-peaked narrow Hβ. Therefore, SDSS J0832+0643 can be used as strong evidence to support the non-kinematic model for double-peaked narrow emission lines.