Echelle spectrum of QSO HE2217-2818

This UVES echelle spectrum QSO HE2217-2818 (U-magnitude = 16.5) is recorded in different orders (the individual horizontal lines) and altogether covers the wavelength interval between 330 - 450 nm (from the bottom to the top). It illustrates the excellent capability of UVES to work in the UV-band on even faint targets. Simultaneously with this observation, UVES also recorded the adjacent spectral region 465 - 660 nm in its other channel. The broad Lyman-alpha emission from ionized hydrogen associated with the powerful energy source of the QSO is seen in the upper half of the spectrum at wavelength 413 nm. At shorter wavelengths, the dark regions in the spectrum are Lyman-alpha absorption lines from intervening, neutral hydrogen gas located along the line-of-sight at different redshifts (the so-called Lyman-alpha forest) in the redshift interval z = 1.7 - 2.4. Note that since this exposure was done with the nearly Full Moon above the horizon, an underlying, faint absorption-line spectrum of reflected sunlight is also visible.

Herkunftsnachweis:

ESO

Über das Bild

ID:eso9944d
Typ:Simulation
Veröffentlichungsdatum:5. Oktober 1999
Dazugehörige Veröffentlichungen:eso9944
Größe:3000 x 2049 px

Über das Objekt

Name:QSO HE2217-2818, Spectrum
Typ:Early Universe : Galaxy : Activity : AGN : Quasar
Entfernung:z=2.4 (Rotverschiebung)
Kategorie:Cosmology
Quasars and Black Holes

Bildformate

Großes JPEG
3,8 MB

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Farben & Filter

SpektralbereichTeleskop
UltraviolettVery Large Telescope
UVES