Monitoring of active galactic nuclei. IV. The Seyfert 1 galaxy NGC 4593

• Results of a five-month campaign of optical monitoring the Seyfert 1 galaxy NGC 4593 are presented. High resolution Halpha and Hbeta 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 Halpha 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 known so far

Subject headings

NATURVETENSKAP  -- Fysik -- Astronomi, astrofysik och kosmologi (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Astronomy, Astrophysics and Cosmology (hsv//eng)

Keyword

Experimental/ astronomical photometry

astronomical spectra

Seyfert galaxies

visible astronomical observations/ Seyfert 1 galaxy

NGC 4593

optical monitoring

active galactic nucleus

Hbeta spectral line

direct images

Johnson UBVRI bands

AD 1990 01 to 06

emission lines

optical continuum variations

Halpha line

light curves

Balmer lines

visible

low luminosity Seyfert galaxy

broad line region size

450 to 540 nm

620 to 720 nm

H/ A9850R Active and peculiar galaxies A9580J Photographic region astronomical observations A9850G Radiation and spectra of galaxies/ wavelength 4.5E-07 to 5.4E-07 m

wavelength 6.2E-07 to 7.2E-07 m/ H/el

Publication and Content Type

ref (subject category)

art (subject category)