Identification of SDSSJ141324.27+530527.0 as A New "Changing-Look" Quasar with a "Turn-on" Transition

TL;DR

This paper reports the discovery of a new changing-look quasar, SDSSJ141324.27+530527.0, which transitioned from a Type-1.9/2 to Type-1 spectrum within 1-10 years, providing insights into quasar spectral variability.

Contribution

The study identifies a new changing-look quasar with a rapid spectral type transition, and discusses possible physical mechanisms behind this change, such as disk instability or viscous inflow.

Findings

Spectral transition observed within 1-10 years.

Obscuration change unlikely due to line invariability.

Possible cause linked to disk instability or inflow.

Abstract

We here report an identification of SDSSJ141324+530527.0 (SBS1411+533) at $z=0.456344$ as a new "changing-look" quasar with a "turn-on" spectral type transition from Type-1.9/2 to Type-1 within a rest frame time scale of 1-10 yr by a comparison of our new spectroscopic observation and the Sloan Digital Sky Survey (SDSS) archive data base. The SDSS DR7 spectrum taken in 2003 is dominated by a starlight emission from host galaxies redward of the Balmer limit, and has non-detectable broad H$\beta$ line. The new spectrum taken by us on June 1st, 2017 and SDSS DR14 spectrum taken on May 29, 2017 indicate that the object is of a typical quasar spectrum with a blue continuum and strong Balmer broad emission lines. In addition, an intermediate spectral type can be identified in the SDSS DR13 spectrum taken in 2015. The invariability of the line wing of MgII$\lambda2800$ emission and time scale argument (The invariability of [OIII]$\lambda$5007 line blue asymmetry) suggests that a variation of obscuration (an accelerating outflow) is not a favorable scenario. The time scale argument allows us to believe the type transition is possibly caused by either a viscous radial inflow or a disk instability around a $\sim5-9\times10^{7}M_\odot$ black hole.