In:
The Astrophysical Journal Supplement Series, American Astronomical Society, Vol. 263, No. 1 ( 2022-11-01), p. 10-
Abstract:
NGC 5548 is one of the active galactic nuclei (AGNs) selected for our long-term spectroscopic monitoring with the Lijiang 2.4 m telescope, aiming at investigating the origin and evolution of broad-line regions (BLRs), accurately measuring the mass of supermassive black holes (SMBHs), and understanding the structure and evolution of the AGN. We have performed five-season observations for NGC 5548 with the median sampling interval ranging from 1.25 to 3 days. The light curves of the 5100 Å continuum and broad emission lines are measured after subtracting contamination of the host galaxy starlight. The time lags of the broad He ii , He i , H γ , and H β lines with respect to the 5100 Å continuum are obtained for each season and their mean time lags over the five seasons are 0.69, 4.66, 4.60, and 8.43 days, respectively. The H γ and H β velocity-resolved lag profiles in the seasons of 2015, 2018, 2019, and 2021 are constructed, from which an “M-shaped” structure is found in 2015 but disappears after 2018. Our five-season reverberation mapping (RM) yields an average virial SMBH mass of M • /10 7 M ⊙ = 14.22, with a small standard deviation of 1.89. By combining the previous 18 RM campaigns and our five-season campaign for NGC 5548, we find that there exists a time lag of 3.5 yr between the changes in the BLR size and optical luminosity. In addition, we construct the BLR radius−luminosity relation and the virial relation for NGC 5548.
Type of Medium:
Online Resource
ISSN:
0067-0049
,
1538-4365
DOI:
10.3847/1538-4365/ac94d3
Language:
Unknown
Publisher:
American Astronomical Society
Publication Date:
2022
detail.hit.zdb_id:
2006860-8
detail.hit.zdb_id:
2207650-5
SSG:
16,12
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