An algorithm for the relative scaling of spectra

• A method is described for the automatic relative scaling of spectra in which one or more lines with constant flux are present. The algorithm takes into account differences in spectral resolution, flux factors, and spectral shifts. It was developed for the relative calibration of series of optical spectra obtained in variability studies of active galactic nuclei but it also can be used for other purposes, e.g., the subtraction of an underlying stellar continuum in AGN with a template spectrum. Tests show that a high degree of accuracy is obtained, and that the method is superior to scaling the spectra by eye or measuring narrow-band fluxes

Subject headings

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

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

Keyword

Application

Experimental/ astronomical spectra

astronomical techniques

galactic nuclei

quasars

visible astronomical observations/ astronomical spectra relative scaling algorithm

visible

constant flux spectral lines

forbidden O III lines

H beta

galactic nuclei spectral variations

forbidden S II lines

underlying stellar continuum subtraction

Fe II lines

AGN broad-line regions

narrow emission lines scaling

automatic relative scaling

spectral resolution

flux factors

spectral shifts

relative calibration

optical spectra

active galactic nuclei

template spectrum

473.0 to 536.0 nm

forbidden O 2+ lines

forbidden S + lines

Fe + blends

H emission line/ A9575F Astronomical spectroscopy A9850G Radiation and spectra of galaxies A9850R Active and peculiar galaxies A9850E Galactic structure

content and morphology A9870J Quasars A9580J Photographic region astronomical observations A9575M Astronomical data and image processing/ wavelength 4.73E-07 to 5.36E-07 m/ O/el

S/el

Fe/el

H/el

Publication and Content Type

ref (subject category)

art (subject category)