J/ApJ/695/276 Search for megamasers in type-2 AGNs (Bennert+, 2009)
A search for H2O megamasers in high-z Type-2 active galactic nuclei.
Bennert N., Barvainis R., Henkel C., Antonucci R.
<Astrophys. J., 695, 276-286 (2009)>
=2009ApJ...695..276B 2009ApJ...695..276B
ADC_Keywords: Active gal. nuclei ; Galaxies, Seyfert ; Radio lines
Keywords: galaxies: active - galaxies: Seyfert - masers - quasars: general
Abstract:
We report a search for H2O megamasers in 274 SDSS type-2 active
galactic nuclei (AGNs; 0.3<z<0.83), half of which can be classified as
type-2 quasi-stellar objects (QSOs) from their [OIII]5007 luminosity,
using the Robert C. Byrd Green Bank Telescope (GBT) and the Effelsberg
100m radio telescope. Apart from the detection of the extremely
luminous water vapor megamaser SDSS J080430.99+360718.1, already
reported by Barvainis & Antonucci (2005ApJ...628...89B 2005ApJ...628...89B), we do not
find any additional line emission. This high rate of nondetections is
compared to the water maser luminosity function created from the 78
water maser galaxies known to date and its extrapolation toward the
higher luminosities of "gigamasers" that we would have been able to
detect given the sensitivity of our survey. The properties of the
known water masers are summarized and discussed with respect to the
nature of high-z type-2 AGNs and megamasers in general. In the
Appendix (tables 4 and 5), we list 173 additional objects (mainly
radio galaxies, but also QSOs and galaxies) that were observed with
the GBT, the Effelsberg 100m radio telescope, or Arecibo Observatory
without leading to the detection of water maser emission.
Description:
All sources were measured in the 616-523 line of H2O
(22.23508GHz rest frequency). The observations were carried out during
several runs at the GBT of the National Radio Astronomy Observatory
(NRAO) in 2005 January and June as well as at the Effelsberg 100m
radio telescope of the Max-Planck-Institut fur Radioastronomie (MPIR)
in 2005 November and December. For details of observations, see table 1.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 84 288 Details of observations: 274 SDSS type-2 AGNs
table2.dat 121 83 The 78 galaxies at D≥100kpc with known H2O masers
table4.dat 99 148 Details of observations: radio galaxies
table5.dat 99 26 Details of observations: miscellaneous sources
refs.dat 63 52 References for table 2
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See also:
VII/258 : Quasars and Active Galactic Nuclei (13th Ed.) (Veron+ 2010)
VII/260 : The SDSS-DR7 quasar catalog (Schneider+, 2010)
VII/113 : Catalogued Galaxies + QSOs observed in IRAS, V2 (IPAC, 1989)
J/ApJ/678/96 : Extragalactic H2O masers (Braatz+, 2008)
J/ApJ/658/1096 : H2O maser classification (Deacon+, 2007)
J/PASJ/59/1185 : Water maser in galactic IRAS sources (Sunada+, 2007)
J/ApJ/652/136 : Water maser emission in five AGNs (Kondratko+, 2006)
J/MNRAS/362/9 : Radio-loud AGN in SDSS (Best+, 2005)
J/AJ/128/1002 : SDSS candidate type II quasars. II (Zakamska+, 2004)
J/AJ/126/2125 : SDSS candidate type II quasars (Zakamska+, 2003)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 18 A18 --- SDSS Source identification (1)
20- 24 F5.3 --- z Heliocentric redshift (2)
26- 29 F4.2 [Lsun] L[OIII] Log of [OIII] luminosity (3)
31- 37 F7.2 mJy F20cm ? FIRST 20cm integrated flux (4)
39 A1 --- f_F20cm [n] 'n' if field not observed by FIRST survey
41- 48 F8.2 MHz nu Observed frequency
50- 53 F4.1 mJy rms Root mean square flux density
55- 59 I5 km/s vmin Minimum velocity covered by observation
61- 64 I4 km/s vmax Maximum velocity covered by observation
66- 68 F3.1 km/s dv Channel width
70- 79 A10 --- Tel Telescope used (G1)
81- 84 I04 --- Epoch Date of observation in MMYY format
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Note (1): Where the source position is given in the identification in the
format HHMMSS.ss+DDMMSS.s. Note that only in first object was
megamaser emission detected (Barvainis & Antonucci, 2005ApJ...628...89B 2005ApJ...628...89B)
Note (2): From Zakamska et al. (2003, Cat. J/AJ/126/2125) as measured from
the [OII]3727 emission line.
Note (3): From Zakamska et al. (2003, Cat. J/AJ/126/2125). A value >8.48
classifies the object as a type-2 QSO.
Note (4): From Zakamska et al. (2003, Cat. J/AJ/126/2125), if the object is
matched within 3". There is no entry if the object was not detected,
i.e. <1mJy.
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 16 A16 --- Name Source name
18- 25 A8 --- OName Other name
27 A1 --- f_Name [ad] Note for NGC 598 (1)
29- 30 I2 h RAh Hour of right ascension (J2000)
32- 33 I2 min RAm Minute of right ascension (J2000)
35- 38 F4.1 s RAs Second of right ascension (J2000)
40 A1 --- DE- Declination sign (J2000)
41- 42 I2 deg DEd Degree of declination (J2000)
44- 45 I2 arcmin DEm Arcminute of declination (J2000)
47- 48 I2 arcsec DEs Arcsecond of declination (J2000)
50- 54 I5 km/s cz ? Systemic velocity from NED
55 A1 --- f_cz [z] For SDSS J0804+3607, z=0.66
57- 63 F7.2 Mpc Dist ? Distance (2)
65- 68 F4.1 [Lsun] LFIR ? Far_infrared (FIR) luminosity
(log(LFIR/L☉)) (3)
69 A1 --- f_LFIR [bhi] lower limit or missing measurements (4)
71- 73 I3 K Tdust ? Dust temperature (4)(3)
75- 78 F4.1 [Lsun] LH2O H2O luminosity (log(LH2O/L☉),
using H0=75km/s/Mpc
79 A1 --- f_LH2O [cef] Note on LH2O computation (5)
81- 94 A14 --- Mtype Host galaxy morphological type from NED
95 A1 --- f_Mtype [j] Flag on Mtype (6)
97-108 A12 --- Otype Activity type from NED (7)
109 A1 --- f_Otype [g] Flag on Otype (8)
111-121 A11 --- Ref Reference(s) number(s); see refs.dat file
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Note (1): Flag as follows:
a = While the detection of two more masers has been claimed by Huchtmeier et
al. (1978A&A....64L..21H 1978A&A....64L..21H, 1988A&A...200...26H 1988A&A...200...26H), we list only the three
masers confirmed by Brunthaler et al. (2006A&A...457..109B 2006A&A...457..109B).
d = The maser luminosity refers to a brief flaring episode.
Note (2): Using H0=75km/s/Mpc. For the 53 of the 78 masers that were
included in Henkel et al. (2005A&A...436...75H 2005A&A...436...75H), we adapt the
distances from their table 4. For a few objects, we take distances
from the references listed in Column "Ref".
Note (3): For the determination of LFIR and Tdust (60/100um color
temperatures), see Wouterloot & Walmsley (1986A&A...168..237W 1986A&A...168..237W). The
IRAS fluxes were taken from Fullmer & Lonsdale (1989, Cat. VII/113)
and, for a few sources (NGC 262, NGC 598, IC 0184, NGC 4151, NGC 4258,
IRAS F19370-0131, NGC 6323, 3C 403, and AM 2158-380b), from NED.
Note (4): Flag as follows:
b = LFIR and Tdust are lower limits as there are no IRAS flux
measurements at 12 and 25um.
h = There is no IRAS flux measurement at 12um.
i = There is no IRAS flux measurement at 100um.
Note (5): Flag as follows:
c = Estimated from Figure 1 of Kondratko et al. (2006, Cat. J/ApJ/652/136)
using LH2O/L☉=0.023Stotal/(Jy.km/s)*D2/Mpc with
Stotal=Σ(1.06Speak*FWHM) (summed over the different
components).
e = We assume logLH2O/L☉=0.9 as total integrated single-dish flux
density when including NGC 2146 in Figures 1, 2, and 3.
f = Using H0=75km/s/Mpc, ΩΛ=0.73, and ΩM=0.27.
Note (6): j = Note that while NED lists "E/S0" as morphological
classification of the host galaxy according to Koekemoer et al.,
1995Natur.378..697K 1995Natur.378..697K, Falcke et al. (2000ApJ...530L..13F 2000ApJ...530L..13F) favor a
classification as a highly inclined spiral galaxy. We use the latter
in our statistics in Section 5.
Note (7): Types as follows:
Sy = Seyfert,
L = LINER,
LIRG = luminous-infrared galaxy,
SB = starburst,
NLRG = narrow-line radio galaxy,
RG = radio galaxy
Note (8):
g = Note that NED gives "Sy3" as classification, which corresponds to a LINER
(Veron-Cetty & Veron 1996, Cat. VII/258).
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Byte-by-byte Description of file: table[45].dat
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Bytes Format Units Label Explanations
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1- 23 A23 --- Name Source identification
25- 27 A3 --- Class NED Classification (for table 5 only)
29- 30 I2 h RAh NED Hour of Right Ascension (J2000)
32- 33 I2 min RAm NED Minute of Right Ascension (J2000)
35- 38 F4.1 s RAs NED Second of Right Ascension (J2000)
40 A1 --- DE- Sign of the NED Declination (J2000)
41- 42 I2 deg DEd NED Degree of Declination (J2000)
44- 45 I2 arcmin DEm NED Arcminute of Declination (J2000)
47- 48 I2 arcsec DEs NED Arcsecond of Declination (J2000)
50- 54 F5.3 --- z NED Heliocentric redshift
56- 63 F8.2 MHz nu Observed frequency
65- 68 F4.1 mJy rms Root mean square flux density
70- 74 I5 km/s vmin Minimum velocity covered by observation
76- 79 I4 km/s vmax Maximum velocity covered by observation
81- 83 F3.1 km/s dv Channel width
85- 94 A10 --- Tel Telescope used (G1)
96- 99 I04 --- Epoch Date of observation in MMYY format
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Byte-by-byte Description of file: refs.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Ref Reference number
4- 22 A19 --- BibCode Bibcode
24- 44 A21 --- Aut Author's name
46- 63 A18 --- Com Catalog reference in VizieR
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Gloval Notes:
Note (G1): Telescope as follows:
GBT = Robert C. Byrd Green Bank Telescope;
Arecibo = Arecibo Observatory;
Effelsberg = Effelsberg 100-m radio telescope.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 19-Apr-2011