J/ApJ/779/109 Long-term monitoring of NGC 5548 (Peterson+, 2013)
The size of the narrow-line-emitting region in the Seyfert 1 galaxy NGC 5548
from emission-line variability.
Peterson B.M., Denney K.D., De Rosa G., Grier C.J., Pogge R.W., Bentz M.C.,
Kochanek C.S., Vestergaard M., Kilerci-Eser E., Dalla Bonta E., Ciroi S.
<Astrophys. J., 779, 109 (2013)>
=2013ApJ...779..109P 2013ApJ...779..109P
ADC_Keywords: Active gal. nuclei ; Line Profiles
Keywords: galaxies: active; galaxies: individual: NGC 5548;
galaxies: nuclei; galaxies: Seyfert; quasars: emission lines
Abstract:
The narrow [OIII]λλ4959,5007 emission-line fluxes in the
spectrum of the well-studied Seyfert 1 galaxy NGC 5548 are shown to
vary with time. From this we show that the narrow-line-emitting region
has a radius of only 1-3pc and is denser (ne∼105/cm3) than
previously supposed. The [O III] line width is consistent with virial
motions at this radius given previous determinations of the black hole
mass. Since the [O III] emission-line flux is usually assumed to be
constant and is therefore used to calibrate spectroscopic monitoring
data, the variability has ramifications for the long-term secular
variations of continuum and emission-line fluxes, though it has no
effect on shorter-term reverberation studies. We present corrected
optical continuum and broad Hβ emission-line light curves for the
period 1988-2008.
Description:
For the first seven years of the International AGN Watch campaign
(1988-1989 to 1994-1995), we used published [OIII]λ5007
emission-line fluxes (Peterson et al. 1992ApJ...392..470P 1992ApJ...392..470P,
1994ApJ...425..622P 1994ApJ...425..622P, 1999, J/ApJ/510/659; Korista et al.
1995ApJS...97..285K 1995ApJS...97..285K). New measurements were made from International
AGN Watch data from Years 8 through 13 (Peterson et al.
2002ApJ...581..197P 2002ApJ...581..197P). These measurements are given in Table 1.
In addition to the International AGN Watch data, we employed data from
more recent monitoring campaigns that were undertaken by our group in
cooperation with others. We refer to these data sets by the internal
campaign names we used at MDM Observatory: AGN05 over 2005 March-April
(Bentz et al. 2007ApJ...662..205B 2007ApJ...662..205B), AGN07 over 2007 March-August
(Denney et al. 2010ApJ...721..715D 2010ApJ...721..715D), and AGN12 over 2012 January-April
(G. De Rosa et al., in preparation). We also used data from a campaign
undertaken by the Lick AGN Monitoring Program from 2008 February-May
(LAMP08; Bentz et al. 2009ApJ...705..199B 2009ApJ...705..199B).
Objects:
---------------------------------------------------
RA (ICRS) DE Designation(s)
---------------------------------------------------
14 17 59.51 +25 08 12.5 NGC 5548 = LEDA 51074
---------------------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 29 26 Unpublished AGN Watch spectroscopic measurements
table2.dat 19 72 [OIII] measurements from recent monitoring campaigns
table5.dat 22 1859 5100Å revised continuum light curve
table6.dat 22 1438 Revised Hβ emission-line light curve
sp/* . 26 Individual FIS optical spectra (3500-8000Å) of
NGC 5548, between 1995-Nov and 2000-Dec
--------------------------------------------------------------------------------
See also:
B/eso : ESO Science Archive Catalog (ESO, 1991-2015)
B/hst : HST Archived Exposures Catalog (STScI, 2007)
J/ApJS/199/8 : Interstellar column densities compilation (Gudennavar+, 2012)
J/ApJ/753/L2 : Reverberation mapping of AGNs (Assef+, 2012)
J/ApJ/716/993 : LAMP: reverberation mapping of H and He lines (Bentz+, 2010)
J/ApJ/698/895 : Variations in QSOs optical flux (Kelly+, 2009)
J/ApJ/613/682 : AGN central masses & broad-line region sizes (Peterson+, 2004)
J/A+A/422/925 : Profile variability in lines of NGC 5548 (Shapovalova+ 2004)
J/ApJS/143/257 : AGN emission line properties (Kuraszkiewicz+, 2002)
J/A+A/371/79 : NGC 5548 UBVRI phot. & Halpha, Hbeta fluxes (Dietrich+, 2001)
J/PAZh/27/942 : Nuclear activity of NGC 5548 (Doroshenko+, 2001)
J/ApJ/549/155 : [OIII] emission in a sample of AGNs (Nagao+, 2001)
J/ApJ/510/659 : Size and Structure of AGN in NGC 5548 (Peterson+, 1999)
J/ApJS/112/315 : Spectroscopic parameters of Seyfert nuclei (Ho+ 1997)
J/A+A/320/405 : NGC 5548 continuum light curve (Sergeev+ 1997)
J/A+A/314/43 : NGC 5548 Profile variability (Kollatschny+ 1996)
J/ApJS/98/477 : Optical spectral atlas of Seyfert nuclei (Ho+ 1995)
http://www.astronomy.ohio-state.edu/~agnwatch : International AGN Watch
home page
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 11 A11 "YYYY-MMM-DD" Date UT date of the observation
13- 19 A7 --- SpID Name of the spectrum in the International
AGN Watch archive (1)
21- 24 F4.2 10-16W/m2 FOIII [4.4/5.6] Measured observed-frame
[OIII]λ5007 flux
in 10-13erg/s/cm2
26- 29 F4.2 10-16W/m2 e_FOIII [0.2/0.24] FOIII uncertainty
--------------------------------------------------------------------------------
Note (1): Name of the spectrum as it appears in the International AGN Watch
archive (see http://www.astronomy.ohio-state.edu/~agnwatch), where the
prefix "n5" refers to the galaxy, the following digits are the four
least significant figures in the Julian Date of observation, and the
final letter indicates the origin of the data (see Table 2 of Peterson
et al. 2002ApJ...581..197P 2002ApJ...581..197P: a=1.8m Perkins Telescope+Ohio State CCD
Spectrograph or h=2.1m Guillermo Haro Observatory Telescope+B&C
Spectrograph).
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 7 F7.1 d JD Julian Date of observation; JD-2400000
9- 12 F4.2 10-16W/m2 FOIII [3.6/5.3] Observed-frame [OIII]λ5007
emission-line flux in 10-13erg/s/cm2
14- 17 F4.2 10-16W/m2 e_FOIII [0.1/0.4] FOIII uncertainty
19 I1 --- Ref [1/4] Reference for each spectrum (1)
--------------------------------------------------------------------------------
Note (1): Reference as follows:
1 = AGN05 (Bentz et al. 2007ApJ...662..205B 2007ApJ...662..205B);
2 = AGN07 (Denney et al. 2010ApJ...721..715D 2010ApJ...721..715D);
3 = LAMP08 (Bentz et al. 2009ApJ...705..199B 2009ApJ...705..199B);
4 = AGN12 (G. De Rosa et al., in preparation).
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 F9.3 d JD Julian Date of the observation; JD-2400000
11- 16 F6.3 10-17W/m2/nm F5100 Observed-frame AGN flux (1)
18- 22 F5.3 10-17W/m2/nm e_F5100 Uncertainty in F5100
--------------------------------------------------------------------------------
Note (1): At rest wavelength 5100Å in units of 10-15erg/s/cm2/Å.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table6.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 F9.3 d JD Julian Date of the observation; JD-2400000
11- 16 F6.3 10-16W/m2 FHb Observed-frame Hβ emission-line flux (1)
18- 22 F5.3 10-16W/m2 e_FHb Uncertainty in FHb
--------------------------------------------------------------------------------
Note (1): Corrected for the Hβ narrow component
in units of 1e-13erg/s/cm2.
--------------------------------------------------------------------------------
History:
* 06-May-2015: From electronic version of the journal.
Spectra downloaded from
http://www.astronomy.ohio-state.edu/~agnwatch/n5548/spectra/Optical/
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 06-May-2015