Identification of SDSS J141324.27+530527.0 as a New “Changing-look” Quasar with a “Turn-on” Transition

Abstract

We here report an identification of SDSS J141324+530527.0 (SBS 1411+533) at z = 0.456344 as a new "changinglook" 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 Hβ 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 Mg IIλ2800 emission and time scale argument (The invariability of [O III]λ5007 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 ∼ 5 − 9 × 10 7 M ⊙ black hole.

The Sloan Digital Sky Survey Reverberation Mapping Project: Accretion and Broad Emission Line Physics from a Hypervariable Quasar

“…Those changes are associated with factor of ∼ 10 variations in optical continuum luminosity on month to year timescales. Long known in nearby Seyferts (Tohline & Osterbrock 1976;Cohen et al 1986;Clavel et al 1989;Storchi-Bergmann et al 1995), this type of large amplitude, rapid variability is now found in higher luminosity quasars (LaMassa et al 2015;MacLeod et al 2016;Ruan et al 2016;Runnoe et al 2016;Gezari et al 2017;Wang et al 2018;Yang et al 2018;Stern et al 2018;MacLeod et al 2018;Trakhtenbrot et al 2019a). Evidence from short timescale variability of both the broad emission lines and continuum (e.g., LaMassa et al 2015), a lack of change in optical reddening (MacLeod et al 2016) or X-ray column , echoed midinfrared variability (from warm dust) following optical variability (Stern et al 2018), and spectro-polarimetry (Hutsemékers et al 2017) all imply that these objects undergo rapid changes in intrinsic accretion power on timescales much shorter than the 10 4−6 year inflow time expected for a standard thin disk.…”

“…The quasar SDSS J141324+530527 at z 0.456 was recently identified as a "turn-on" changing look object, in which the broad Hα and Hβ lines increased in strength during a large change in continuum luminosity in 2017 (Wang et al 2018). This object is included in the Sloan Digital Sky Survey Reverberation Mapping (SDSS-RM, RMID 017) campaign that intensively monitors 849 quasars with optical imaging and spectroscopy since 2014 (Shen et al 2015a).…”

Catalogues of active galactic nuclei from Gaia and unWISE data

“…These are AGNs that show optical spectral feature transitions involving appearance and disappearance of broad emission lines on time scales of years or decades. There are a few tens of known optical changing-look AGNs so far (e.g., Denney et al 2014;LaMassa et al 2015;Ruan et al 2016;MacLeod et al 2016;Gezari et al 2017;Yang et al 2018;Wang et al 2018a). The physical mechanisms responsible for the transitions are still not fully understood.…”

X-Ray Spectral Shape Variation in Changing-look Seyfert Galaxy SDSS J155258+273728

“…Disappearing or appearing broad Balmer emission lines have been known for many years in a number of local lowluminosity AGNs (e.g., Tohline & Osterbrock 1976;Cohen et al 1986;Denney et al 2014;Shappee et al 2014). With large-scale time-domain survey recent studies have identified a growing number of such cases in quasars with associated large, order-of-magnitude variations in the optical continuum on month to year timescales (LaMassa et al 2015;MacLeod et al 2016;Ruan et al 2016;Runco et al 2016;Runnoe et al 2016;Stern et al 2018;Wang et al 2018;Yang et al 2018;MacLeod et al 2019;Trakhtenbrot et al 2019;Sheng et al 2020). Their optical classification was caught to change between type 1.8-2 (narrow-line) to type 1 (broad-line) AGNs (or vice versa), and even from low-ionization nuclear emission-line region galaxies to broad-line quasars (Gezari et al 2017;Frederick et al 2019).…”