Finding well-hidden galaxies

Well-hidden galaxies can be discovered through the imprint their interstellar gas leave on the spectrum of an even more remote quasar. Interstellar clouds of gas in galaxies, located between the quasars and us on the same line of sight, absorb parts of the light emitted by the quasars. The resulting spectrum consequently presents dark ''valleys'' that can be attributed to well-known elements and possibly molecules. In this schematic representation, the VLT observes (D) the features associated with three systems, located at different distances (A, B, and C), and whose light is therefore shifted by different amounts. The quasar, which acts as a beacon, is the bright object at the left of the image.

Bildnachweis:

ESO

Über das Bild

ID:eso0813a
Typ:Illustration
Veröffentlichungsdatum:13. Mai 2008
Dazugehörige Veröffentlichungen:eso0813
Größe:914 x 691 px

Über das Objekt

Name:Spectrum
Typ:Unspecified : Galaxy
Unspecified : Nebula : Type : Interstellar Medium
Kategorie:Galaxies
Illustrations
Nebulae

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