The Size of the Narrow-Line Emitting Region in the Seyfert 1 Galaxy NGC 5548 from Emission-Line Variability
Sep 5, 201311 pages
Published in:
- Astrophys.J. 779 (2013) 109
e-Print:
- 1309.1468 [astro-ph.CO]
Report number:
- NSF-KITP-13-244
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Abstract: (IOP)
The narrow [O III] 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 1-3 pc and is denser (ne ~ 105 cm–3) 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.Note:
- 11 pages, 5 figures, 6 tables. Accepted for publication in ApJ
- galaxies: active
- galaxies: individual (NGC 5548)
- galaxies: nuclei
- galaxies: Seyfert
- quasars: emission lines
References(6)
Figures(5)
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