Bibcode
Dietrich, M.; Kollatschny, W.; Alloin, D.; Aretxaga, I.; Axon, D.; de Bruyn, A. G.; Clavel, J.; Goad, M. R.; Gondhalekar, P.; van Groningen, E.; Horne, K.; Jackson, N.; Laurikainen, E.; Lawrence, A.; Masegosa, J.; Moles, M.; O'Brien, P.; del Olmo, A.; Penston, M. V.; Perea, J.; Perez, E.; Perez-Fournon, I.; Perry, J. J.; Peterson, B. M.; Robinson, A.; Rodriguez Espinosa, J. M.; Stirpe, G. M.; Tadhunter, C.; Terlevich, R.; Unger, S.; Wagner, S. J.; Wanders, I.; Williams, R.
Referencia bibliográfica
Astronomy and Astrophysics (ISSN 0004-6361), vol. 284, no. 1, p. 33-43
Fecha de publicación:
4
1994
Número de citas
26
Número de citas referidas
24
Descripción
Results of a five-month campaign of optical monitoring the Seyfert 1
galaxy NGC 4593 are presented. High resolution H-alpha and H-Beta
spectra and direct images in the Johnson U, B, V, R, and I bands were
obtained between January and June 1990. The emission lines and the
continuum showed strong variations on time scales of weeks to days. The
H-alpha line varied by more than 30% within only 5 days.
Cross-correlating the light curves of the Balmer lines with that of the
optical continuum gives a lag of around 4 days. Therefore, this low
luminosity Seyfert galaxy may have one of the smallest broad line
regions (BLRs) known so far.