Published in

American Astronomical Society, Astrophysical Journal, 2(912), p. 92, 2021

DOI: 10.3847/1538-4357/abefe0

Links

Tools

Export citation

Search in Google Scholar

Velocity-resolved Reverberation Mapping of Changing-look AGN NGC 2617

This paper is made freely available by the publisher.
This paper is made freely available by the publisher.

Full text: Download

Red circle
Preprint: archiving forbidden
Red circle
Postprint: archiving forbidden
Green circle
Published version: archiving allowed
Data provided by SHERPA/RoMEO

Abstract

Abstract NGC 2617 attracted a lot of attention after the detection of changes in its spectral type; the geometry and kinematics of the broad-line region (BLR) are still ambiguous. In this paper, we present the high cadence (∼2 days) reverberation mapping campaign of NGC 2617 from 2019 October to 2020 May undertaken at the Lijiang 2.4 m telescope. For the first time, the velocity-resolved reverberation signature of the object was successfully detected. Both Hα and Hβ show an asymmetrical profile with a peak in the velocity-resolved time lags. For both of the lines, the lag of the line core is longer than those of the relevant wings, and the peak of the velocity-resolved lags is slightly blueshifted. These characteristics are not consistent with the theoretical prediction of the inflow, outflow or Keplerian disk model. Our observations give the time lags of Hα, Hβ, Hγ, and He i, with a ratio of τ : τ : τ : τ He I = 1.27:1.00:0.89:0.20, which indicates a stratified structure in the BLR of the object. It is the first time that the lags of Hα and He i are obtained. Assuming a virial factor of f = 5.5 for the dispersion width of the line, the masses of the black holes derived from Hα and Hβ are and , respectively. Our observed results indicate the complexity of the BLR of NGC 2617.