J/ApJS/279/22 Confirmed AGN type 1 & 2 from sp. in Kepler fields (Tsan+, 2025)
Infrared-selected active galactic nuclei in the Kepler fields.
Tsan T., Malkan M., Edelson R., Smith K., Stern D., Graham M.
<Astrophys. J. Suppl. Ser., 279, 22 (2025)>
=2025ApJS..279...22T 2025ApJS..279...22T
ADC_Keywords: Active gal. nuclei; Spectra, optical; Equivalent widths;
Redshifts; Infrared sources
Keywords: Active galactic nuclei ; Quasars ; Seyfert galaxies ;
Emission line galaxies ; Active galaxies
Abstract:
We utilized the Edelson & Malkan (2012, J/ApJ/751/52) and
Stern+ 2012ApJ...753...30S 2012ApJ...753...30S selection techniques and other methods to
identify active galactic nuclei (AGN) candidates that were monitored
during the Kepler prime and K2 missions. Subsequent to those
observations, we obtained 125 long-slit optical spectra with the Lick
3m telescope, 58 spectra with the Palomar 5m telescope, and three
spectra with the Keck 10m telescope to test these identifications. Of
these 186 AGN candidates, 105 were confirmed as Type 1 AGN and 35 as
Type 2 AGN, while the remaining 46 were found to have other
identifications (e.g., stars and normal galaxies). This indicated an
overall reliability of ∼75%, while the two main methods had much
higher reliability, 87%-96%. The spectra indicated redshifts out to
z=3.4. Then, we examined the AGN sample properties through the
Baldwin-Phillips-Terlevich diagram and compared the AGNs' spectral
energy distributions with those from the literature. We found that our
sample yielded the same AGN population as those identified through
other methods, such as optical spectroscopy.
Description:
We spectroscopically confirmed 186 AGN candidates using the Kast
spectrograph on the Lick 3.0m reflector, the Double Spectrograph
(DBSP) on the Palomar 5m reflector, and the Low-Resolution Imaging
Spectrograph (LRIS) on the Keck 10m reflector.
The spectroscopic observations spanned from 2011 to 2016. We observed
125 objects at Lick, 58 at Palomar, and 3 at Keck, mostly in clear
weather. The total integration times ranged from 300 to 1800s. The
Kast spectrograph operated at a spectral resolution of R∼2000 in the
red and 1500 in the blue, with slit widths of mostly 2". The
wavelength coverage extended from 300 to 800nm. DBSP on Palomar
performed at R∼800 with a 1" slit and covered wavelengths from 300 to
1000nm. Keck LRIS provided resolution ranging from R=1000 to 5000,
with slit widths of 0.7", 1.0", 1.5", and 8.7". The wavelength
coverage followed similarly to the previous two spectrographs:
300-900nm in the optical.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 171 186 Observed AGN candidates in Kepler Prime and K2
fields
table2.dat 355 186 Line measurements for the AGN candidates
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See also:
IX/30 : Second ROSAT PSPC Catalog (ROSAT, 2000)
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
V/133 : Kepler Input Catalog (Kepler Mission Team, 2009)
VII/260 : The SDSS-DR7 quasar catalog (Schneider+, 2010)
VII/258 : Quasars and Active Galactic Nuclei (13th Ed.) (Veron-Cetty+ 2010)
II/328 : AllWISE Data Release (Cutri+ 2013)
IV/34 : K2 Ecliptic Plane Input Catalog (EPIC) (Huber+, 2017)
J/ApJ/613/682 : AGN central masses (Peterson+, 2004)
J/ApJS/194/45 : QSO properties from SDSS-DR7 (Shen+, 2011)
J/ApJ/751/52 : AGN cand. from the WISE, 2MASS, RASS (W2R) (Edelson+, 2012)
J/MNRAS/423/600 : Type-1 low-z AGN emission properties (Stern+, 2012)
J/MNRAS/426/2703 : Type 1 AGN at low z. II. (Stern+, 2012)
J/MNRAS/431/836 : Type 1 AGN at low z. III. (Stern+, 2013)
J/ApJ/795/38 : Phot./sp. measurements for KA1858+4850 (Pei+, 2014)
J/ApJS/219/18 : LIRAS: LoCuSS IR AGN survey (Xu+, 2015)
J/MNRAS/476/2501 : AGN short time-scale optical variability (Aranzana+, 2018)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Seq [1/186] Sequential identifier, this work
5- 6 I2 h RAh Hour of Right Ascension (J2000)
8- 9 I2 min RAm Minute of Right Ascension (J2000)
11- 14 F4.1 s RAs Second of Right Ascension (J2000)
16- 16 A1 --- DE- [±] Sign of the Declination (J2000)
17- 18 I2 deg DEd [1/51] Degree of Declination (J2000)
20- 21 I2 arcmin DEm Arcminute of Declination (J2000)
23- 26 F4.1 arcsec DEs Arcsecond of Declination (J2000)
28- 34 A7 --- Camp Kepler Campaign(s)
36- 44 I9 --- KeplerID [2694186/248018164]? Kepler identifier (1)
46- 48 A3 --- EM12 Results of Edelson & Malkan
(2012, J/ApJ/751/52) technique (2)
50- 50 A1 --- S12 Results, Stern+ 2012ApJ...753...30S 2012ApJ...753...30S technique (3)
52- 56 A5 --- Type AGN Type (4)
58- 64 A7 --- Obs Observatory ("Keck", "Palomar" or "Lick")
66-171 A106 --- Comm Comment(s)
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Note (1): Kepler ID includes both the KIC (from Kepler Prime campaign:
https://archive.stsci.edu/kepler/help/search_help.html#ktc_kepler_id;
see V/133 and in Simbad, numbers from 1 to 13161029)
and the K2 ID:
https://archive.stsci.edu/k2/data_search/help/search_help.html#ktc_k2_id
(see IV/34 and in Simbad, numbers between
201000001 and 251809144).
Note (2): In the EM12 column, "W2R" refers to candidates drawn from
EM12 WISE/2MASS/ROSAT sample, while "W2" indicates selection
based only on WISE/2MASS.
Note (3): y = candidates that satisfy the WISE color criterion W1-W2≥0.8.
Note (4): AGN type as follows:
Ty 1 = Type 1 AGN (105 occurrences)
Ty 2 = Type 2 AGN (35 occurrences)
Star = 32 occurrences
Other = 14 occurrences
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- Seq [1/186] Sequential identifier, this work
5- 10 F6.4 --- zspec [0/3.33]? Spectroscopic redshift
12- 17 F6.4 --- e_zspec [0.0001/0.005]? Uncertainty in zspec
19- 99 A81 --- Features Spectral Features
101- 104 F4.1 [10-7W] logL-bCIV [44/45.1]? Log, luminosity, broad [CIV],
erg/s (1)
106- 110 F5.1 0.1nm EW-bCIV [23.8/266]? Equivalent width, broad [CIV]
(1)
112- 116 I5 km.s-1 FWHM-bCIV [2510/10060]? FWHM, broad [CIV] (1)
118- 121 F4.1 [10-7W] logL-bCIII [42.3/45]? Log, luminosity, broad CIII],
erg/s (1)
123- 127 F5.1 0.1nm EW-bCIII [22.8/243.2]? Equivalent width, broad
CIII] (1)
129- 133 I5 km.s-1 FWHM-bCIII [2910/10800]? FWHM, broad CIII] (1)
135- 138 F4.1 [10-7W] logL-bMgII [41/44.2]? Log, luminosity, broad [MgII],
erg/s (1)
140- 144 F5.1 0.1nm EW-bMgII [2.6/194]? Equivalent width, broad [MgII]
(1)
146- 150 I5 km.s-1 FWHM-bMgII [1210/11800]? FWHM, broad [MgII] (1)
152- 155 F4.1 [10-7W] logL-bHb [40.5/44]? Log, luminosity, broad
Hβ, erg/s (1)
157- 161 F5.1 0.1nm EW-bHb [4/644.5]? Equivalent width, broad
Hβ (1)
163- 167 I5 km.s-1 FWHM-bHb [1060/21250]? FWHM, broad Hβ (1)
169- 172 F4.1 [10-7W] logL-Hb [39/42]? Log, luminosity, Hβ, erg/s
(1)
174- 177 F4.1 0.1nm EW-Hb [1.7/61.2]? Equivalent width, Hβ (1)
179- 182 I4 km.s-1 FWHM-Hb [270/1010]? FWHM, Hβ (1)
184- 187 F4.1 [10-7W] logL-bHa [40.8/43.5]? Log, luminosity, broad
Hα, erg/s (1)
189- 193 F5.1 0.1nm EW-bHa [42.8/958]? Equivalent width, broad
Hα (1)
195- 198 I4 km.s-1 FWHM-bHa [1130/6280]? FWHM, broad Hα (1)
200- 203 F4.1 [10-7W] logL-Ha [39/42]? Log, luminosity, Hα], erg/s
205- 209 F5.1 0.1nm EW-Ha [2/260.1]? Equivalent width, Hα
211- 213 I3 km.s-1 FWHM-Ha [190/970]? FWHM, Hα
215- 355 A141 --- Comment Comment
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Note (1): broad components are defined as FWHM>1000km/s.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 23-Feb-2026