J/A+A/371/79 NGC 5548 UBVRI phot. and Halpha, Hbeta fluxes (Dietrich+, 2001)
A spectroscopic and photometric study of short-timescale variability
in NGC 5548
Dietrich M., Bender C.F., Bergmann D.J., Bills T.E., Bochkarev N.G.,
Burenkov A.N., Gaskell C.M., Gutzmer D.D., Grove R., Hiller M.E.,
Huchra J.P., Klimek E.S., Lund C., Merkulova N.I., Pebley S., Poulsen M.A.,
Pronik V.I., Sergeev S.G., Sergeev E.A., Shapovalova A.I., Vlasyuk V.V.,
Wilkes B.
<Astron. Astrophys. 371, 79 (2001)>
=2001A&A...371...79D 2001A&A...371...79D
ADC_Keywords: Galaxies, Seyfert ; Photometry, UBVRI ; Spectroscopy
Keywords: galaxies: active - galaxies: Seyfert galaxies -
galaxies: individual (NGC 5548)
Abstract:
Results of a ground-based optical monitoring campaign on NGC 5548 in
June 1998 are presented. The broad-band fluxes (U, B, V), and the
spectrophotometric optical continuum flux Fλ (5100Å)
monotonically decreased in flux while the broad-band R and I fluxes
and the integrated emission-line fluxes of Hα and Hβ
remained constant to within 5%. On June 22, a short continuum flare
was detected in the broad band fluxes. It had an amplitude of about
∼18% and it lasted only ≃90 min. The broad band fluxes and the
optical continuum Fλ (5100Å) appear to vary simultaneously
with the EUV variations. No reliable delay was detected for the broad
optical emission lines in response to the EUVE variations. Narrow
Hβ emission features predicted as a signature of an accretion
disk were not detected during this campaign. However, there is
marginal evidence for a faint feature at λ≃4962Å with
FWHM≃6Å redshifted by Δv≃1100km/s with respect to
Hβnarrow.
Objects:
----------------------------------------------------------
RA (2000) DE Designation(s)
----------------------------------------------------------
14 17 59.7 +25 08 13 NGC 5548
----------------------------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1a.dat 81 178 log of the photometric observations. The flux of
the broad band fluxes is given in units
of [10-15erg/s/cm2^/Å]
table2a.dat 83 84 log of the spectroscopic observations
table3a.dat 58 56 Emission line and continuum flux measurements.
--------------------------------------------------------------------------------
See also:
J/ApJ/510/659 : Size and Structure of AGN in NGC 5548 (Peterson+, 1999)
Byte-by-byte Description of file: table1a.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 A10 "YYYY/MM/DD" Date Observation date
12- 23 F12.4 d HJD Heliocentric Julian date of observation
25 A1 --- Code [DQ] Code (G1)
27- 31 F5.2 10-17W/m2/nm Umag ? U magnitude
33- 36 F4.2 10-17W/m2/nm e_Umag ? rms uncertainty on Umag
38- 42 F5.2 10-17W/m2/nm Bmag ? B magnitude
44- 47 F4.2 10-17W/m2/nm e_Bmag ? rms uncertainty on Bmag
49- 53 F5.2 10-17W/m2/nm Vmag V magnitude
55- 58 F4.2 10-17W/m2/nm e_Vmag rms uncertainty on Vmag
60- 64 F5.2 10-17W/m2/nm Rmag ? R magnitude
66- 69 F4.2 10-17W/m2/nm e_Rmag ? rms uncertainty on Rmag
71- 75 F5.2 10-17W/m2/nm Imag ? I magnitude
77- 80 F4.2 10-17W/m2/nm e_Imag ? rms uncertainty on Imag
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table2a.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 A10 "YYYY/MM/DD" Date Observation date
12- 24 F13.5 d Middle Julian date of middle of observation
26- 27 A2 --- Code Code (G1)
29- 32 I4 s Tint Integration time
34- 37 I4 0.1nm linf Lower limit of spectroscopic range
38 A1 --- --- [-]
39- 42 I4 0.1nm lsup Upper limit of spectroscopic range
44- 47 F4.2 arcsec Aper1 Aperture
49 A1 --- --- [x]
51- 55 F5.2 arcsec Aper2 Aperture
57- 59 I3 deg PA Position angle
62- 64 F3.1 arcsec Seeing Seeing
66- 69 F4.2 0.1nm Res ? Resolution
70 A1 --- --- [-]
71 I1 0.1nm Res2 ? Upper limit of resolution when interval
74- 83 A10 --- Filename Filename of the observation
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table3a.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 A10 "YYYY/MM/DD" Date Observation date
12- 22 F11.3 d HJD Heliocentric Julian date of observation
24- 25 A2 --- Code Code (G1)
27- 31 F5.2 10-17W/m2/nm Fl5100 ? Continuum flux (1)
33- 36 F4.2 10-17W/m2/nm e_Fl5100 ? rms uncertainty on Fl5100 (1)
38- 42 F5.2 10-16W/m2 FHbeta ? Hβ emission line flux (2)
44- 47 F4.2 10-16W/m2 e_FHbeta ? rms uncertainty on FHbeta (2)
49- 53 F5.2 10-16W/m2 FHalpha ? Hα emission line flux (2)
55- 58 F4.2 10-16W/m2 e_FHalpha ? rms uncertainty on FHalpha (2)
--------------------------------------------------------------------------------
Note (1): Wavelength range 5185Å-5195Å. In units of 10-15erg/s/cm2^/Å
Note (2): In units of 10-13erg/s/cm2^
--------------------------------------------------------------------------------
Global notes:
Note (G1):
Table 1: Overview of observations; the aperture size is given in arcsec
-------------------------------------------------------------------------------
Source Code Tel. Photometry Aperture Spectroscopy
[m] U B V R I Aperture
-------------------------------------------------------------------------------
Mt. Hopkins Observatory C 1.5 --- --- --- --- --- 3x4.6
Crimean Astrophysical Obs. D 1.25 15 15 15 15 15 ---
Calar Alto Observatory G 2.2 --- --- --- --- --- 2.06x2.61
Special Astrophysical Obs. L1 1.0 --- --- --- --- --- 8x6.6,8x19.8
Special Astrophysical Obs. L2 6.0 --- --- --- --- --- 2x6
Univ. of Nebraska 0.4m Q 0.4 --- --- 8 --- --- ---
Shajn reflector, Crimean Obs. W 2.6 --- --- --- --- --- 3x11
-------------------------------------------------------------------------------
--------------------------------------------------------------------------------
Acknowledgements: Matthias Dietrich
(End) Patricia Bauer [CDS] 09-Mar-2001