THE SIZE OF THE NARROW-LINE-EMITTING REGION IN THE SEYFERT 1 GALAXY NGC 5548 FROM EMISSION-LINE VARIABILITY
ASTROPHYSICAL JOURNAL, cilt.779, sa.2, 2013 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 779 Sayı: 2
- Basım Tarihi: 2013
- Doi Numarası: 10.1088/0004-637x/779/2/109
- Dergi Adı: ASTROPHYSICAL JOURNAL
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
- İstanbul Üniversitesi Adresli: Hayır
Özet
The narrow[O III] lambda lambda 4959, 5007 emission-line fluxes in the spectrum of the well-studied Seyfert 1 galaxy NGC5548 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 (n(e) similar to 10(5) 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 H beta emission-line light curves for the period 1988-2008.