The spectral variability of quasar SDSS J030639.57+000343.1

TL;DR

This study analyzes spectral variability in a quasar, revealing a bluer-when-brighter trend and a proportional relationship between broad H-alpha luminosity and continuum brightness, with no Baldwin effect observed.

Contribution

First detailed spectral variability analysis of SDSS J030639.57+000343.1 using multi-epoch SDSS data, highlighting specific spectral and emission line behaviors.

Findings

Bluer-when-brighter spectral trend observed.

Broad H-alpha luminosity correlates with continuum luminosity.

No Baldwin effect detected for broad H-alpha.

Abstract

We compiled a sample of 60 quasars with spectroscopy on at least six epochs from the Sloan Digital Sky Survey (SDSS) to study the variabilities of the spectral shape, the continuum and the emission lines luminosity. In this paper, we present the results of SDSS J030639.57+000343.1. We found a strong anti-correlation between the continuum luminosity at $5100 \AA$ and the spectral index, implying a bluer-when-brighter trend. The luminosity of the broad $\rm H_\alpha$ line is proportion to the continuum luminosity at $5100 \AA$. Correspondingly, we did not find strong correlation between the equivalent width of broad $\rm H\alpha$ and the continuum luminosity, i.e. no baldwin effect of broad $\rm H\alpha$ in this source.