Temporal variations of the Balmer line profiles in the spectrum of the Seyfert 1 galaxy Arakelian 120

Abstract

view Abstract Citations (26) References (13) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Temporal variations of the Balmer line profiles in the spectrum of the Seyfert 1 galaxy Arakelian 120. Foltz, C. B. ; Peterson, B. M. ; Cariotti, E. R. ; Byard, P. L. ; Bertram, R. ; Lawrie, D. G. Abstract Observations of the emission-line strengths and the Hα and Hβ line profiles in the spectrum of the Seyfert 1 galaxy Arakelian 120 have been obtained with the Ohio State University image-dissector scanner. Comparison of these data with observations of comparable resolution and quality obtained with the Lick Observatory image-dissector scanner show that a dramatic change occurred in the Hβ profile between 1976 November and 1981 January. A change of the same sense is observed in Hα to a lesser extent, implying that the Balmer decrement of the component which has apparently brightened is less steep than that of the total line emission. The changes in the emission-line profiles were accompanied by decreases in both the Hα and Hβ equivalent widths and in the [O III] λ5007/Hβ flux ratio. The latter variations imply that the broad lines have increased in strength in response to an increase in the luminosity of the continuum source. Publication: The Astrophysical Journal Pub Date: November 1981 DOI: 10.1086/159396 Bibcode: 1981ApJ...250..508F Keywords: Astronomical Spectroscopy; Balmer Series; H Lines; Seyfert Galaxies; Spectral Line Width; Temporal Distribution; Galactic Nuclei; H Alpha Line; H Beta Line; Astrophysics full text sources ADS | data products NED (5) SIMBAD (4)