J/ApJ/930/110 ASAS-SN light curves of SDSS AGNs (Yuk+, 2022)
Variability selected active galactic nuclei from ASAS-SN survey: constraining
the low luminosity AGN population.
Yuk H., Dai X., Jayasinghe T., Fu H., Mishra H.D., Kochanek C.S.,
Shappee B.J., Stanek K.Z.
<Astrophys. J., 930, 110 (2022)>
=2022ApJ...930..110Y 2022ApJ...930..110Y
ADC_Keywords: Active gal. nuclei; Photometry, UBV; Spectra, optical; Surveys
Keywords: Active galactic nuclei ; Low-luminosity active galactic nuclei ;
Surveys
Abstract:
Low luminosity active galactic nuclei (LLAGN) probe accretion physics
in the low Eddington regime can provide additional clues about galaxy
evolution. AGN variability is ubiquitous and thus provides a reliable
tool for finding AGN. We analyze the All-Sky Automated Survey for
SuperNovae light curves of 1218 galaxies with g<14mag and Sloan
Digital Sky Survey spectra in search of AGN. We find 37 objects that
are both variable and have AGN-like structure functions, which is
about 3% of the sample. The majority of the variability selected AGN
are LLAGN with Eddington ratios ranging from 10-4 to 10-2. We thus
estimate the fraction of LLAGN in the population of galaxies as 2%
down to a median Eddington ratio of 2x10-3. Combining the BPT line
ratio AGN diagnostics and the broad-line AGN, up to ∼60% of the AGN
candidates are confirmed spectroscopically. The BPT diagnostics also
classified 10%-30% of the candidates as star-forming galaxies rather
than AGN.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 55 13250 ASAS-SN photometry of AGN candidates
table2.dat 70 37 Data of AGN candidates from ASAS-SN light curves
--------------------------------------------------------------------------------
See also:
II/366 : ASAS-SN catalog of variable stars (Jayasinghe+, 2018-2020)
V/154 : Sloan Digital Sky Surveys (SDSS), Release 16 (DR16) (Ahumada+, 2020)
J/ApJS/112/315 : Spectroscopic parameters of Seyfert nuclei (Ho+ 1997)
J/ApJ/698/895 : Variations in QSOs optical flux (Kelly+, 2009)
J/ApJ/690/20 : Models of the AGN and black hole populations (Shankar+, 2009)
J/ApJ/713/970 : Low-resolution SED templates for AGNs & gal. (Assef+, 2010)
J/ApJ/728/26 : QSO selection based on phot. variability (Macleod+, 2011)
J/ApJ/746/L22 : Dual AGNs in the nearby Universe (Koss+, 2012)
J/ApJ/753/106 : Quasar variability with SDSS and POSS imaging (MacLeod+, 2012)
J/ApJ/825/72 : Study of gal. & AGNs in z>1 clusters (Alberts+, 2016)
J/ApJ/817/119 : Spitzer variability survey of Bootes field (Kozlowski+, 2016)
J/ApJ/856/93 : SDSS-IV MaNGA: kinematic galaxy pairs (Fu+, 2018)
J/ApJ/896/10 : NSA low-mass gal. with long-term PTF obs. (Baldassare+, 2020)
http://asas-sn.osu.edu/photometry : ASAS-SN online photometry database
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 24 A24 --- Name Name of the object
26- 26 A1 --- Filt Filter ("V" or "g")
28- 40 F13.5 d HJD Heliocentric Julian date
42- 47 F6.3 mag mag [12.26/16.7] Magnitude in Filter
49- 55 F7.5 mag e_mag [0/0.6] Uncertainty in mag
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 24 A24 --- Name Name of the object
26- 28 A3 --- AGN Known AGN?
30- 35 F6.4 --- z [0.0018/0.09] Redshift from SDSS
37- 51 A15 --- Morph Morphology from NED
53- 57 F5.2 [Lsun] logL [7.82/11.48] Log of the V-band (unless flagged)
luminosity
59 A1 --- f_logL a: g-band luminosity
61- 63 F3.1 [Msun] logMBH [5.7/9.5] Central supermassive black hole mass
(see Section 5.3)
65- 70 E6.2 --- REdd [0.0002/0.02] Eddington ratio (see Section 5.3)
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 19-Mar-2024