Open AccessA first close look at the Balmer‐edge behaviour of the quasar big blue bump
Author(s) -
Kishimoto Makoto,
Antonucci Robert,
Blaes Omer
Publication year - 2003
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.2003.06934.x
Subject(s) - balmer series , physics , quasar , astrophysics , discontinuity (linguistics) , emission spectrum , flux (metallurgy) , wavelength , line (geometry) , spectral line , astronomy , optics , geometry , galaxy , mathematical analysis , materials science , mathematics , metallurgy
We have found for the first time a Balmer‐edge feature in the polarized flux spectrum of a quasar (Ton 202). The edge feature is seen as a discontinuity in the slope, rather than as a discontinuity in the absolute flux. As the polarized flux contains essentially no broad emission lines, it is considered to arise interior to the broad emission line region, showing the spectrum with all the emissions outside the nucleus scraped off and removed. Therefore, the polarized flux spectrum is likely to reveal features intrinsic to the big blue bump emission. In this case, the existence of the Balmer‐edge feature, seen in absorption in the shorter wavelength side, indicates that the big blue bump is indeed thermal and optically thick.