High-rate spectroscopic active galactic nucleus monitoring at the Wise Observatory. I. Markarian 279

Journal Article · Wed Feb 28 23:00:00 EST 1990 · Astrophysical Journal; (USA)

DOI:https://doi.org/10.1086/168445· OSTI ID:6917425

Maoz, D; Netzer, H; Leibowitz, E; Brosch, N; Laor, A ^[1]

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1. Tel Aviv Univ. (Israel) Wise Observatory (Israel)

Spectrophotometric monitoring of a sample of AGNs has achieved a temporal sampling rate of once every 3-4 days, over a period of 5-7 months. By observing each object simultaneously with a nearby field star, in a long-slit spectroscopy mode, accurate flux measurements were obtained even during bad weather and full moon. Results for the Seyfert 1 galaxy MrK 279 are discussed. This object brightened by 20-50 percent in H-alpha, H-beta, and the optical continuum during the period of observation. The high sampling rate and small error allow the determination, through cross-correlation, of the lag in the emission-line response to the continuum brightening. A lag of 12 days is observed. The size of the broadline region (BLR) is estimated to be 12 + or - 3 light days in this object; the results rule out, at the 95 percent significance level, a BLR of 21 light-days or larger. This result is in conflict with the standard photoionization model of AGNs, which predicts a BLR size larger by an order of magnitude. 27 refs.

• OSTI ID: 6917425
• Journal Information: Astrophysical Journal; (USA), Journal Name: Astrophysical Journal; (USA) Vol. 351; ISSN ASJOA; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

640105* -- Astrophysics & Cosmology-- Galaxies
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BALMER LINES
CHARGE-COUPLED DEVICES
COSMIC RADIO SOURCES
EMISSION SPECTRA
GALAXIES
GALAXY NUCLEI
IONIZATION
MARKARIAN GALAXIES
MATHEMATICAL MODELS
MONITORING
PHOTOIONIZATION
PHOTOMETRY
SAMPLING
SEMICONDUCTOR DEVICES
SEYFERT GALAXIES
SPECTRA
SPECTROSCOPY
VARIATIONS