Light-bending matter in the distant Universe

This photo shows the unusual object HE 1104-1805, a gravitational lens (`cosmic mirage') in the southern constellation of Crater (the Cup) with two images of the same quasar and also the distant galaxy responsible for this effect.

This image was obtained by combining a series of exposures made at La Silla during the night of April 14 - 15, 1997, with the ESO/MPI 2.2-m telescope and the infrared detector IRAC 2b . The total exposure time was 6480 seconds in the near-infrared J-band, where the lensing galaxy is quite faint (J = 19.0 +- 0.2), but still sufficiently above the limiting magnitude of the combined image (J = 22) to be easily measurable.

The left panel shows the result of conventional image processing of the data (with seeing of about 0.8 arcsec). Only the two quasar images may be discerned.

In the right panel, however, the images have been simultaneously treated (deconvolved) by means of new software developed for this programme, cf. http://vela.astro.ulg.ac.be/imaproc. The resulting angular resolution is now 0.27 arcsecond, i.e. approaching that of the Hubble Space Telescope (0.13 arcsec in the J-band and 0.23 arcsec in the K-band with HST + NICMOS).

Now the lensing galaxy is clearly visible between the two quasar images. It is closer to the strongest of the two (`A'; upper); this is unusual and indicates the presence of more mass in the lensing system that what is directly observable. It may therefore be that dark (invisible) matter plays an important role in this gravitational lens.

Herkunftsnachweis:

ESO

Über das Bild

ID:eso9719a
Typ:Beobachtung
Veröffentlichungsdatum:25. Juli 1997
Dazugehörige Veröffentlichungen:eso9719
Größe:538 x 278 px

Über das Objekt

Name:HE 1104-1805
Typ:Early Universe : Galaxy : Type : Gravitationally Lensed
Early Universe : Galaxy : Activity : AGN : Quasar
Entfernung:z=2.319 (Rotverschiebung)
Kategorie:Cosmology
Galaxies
Quasars and Black Holes

Bildformate

Großes JPEG
64,1 KB

Bildschirm-Hintergrundbilder

1024x768
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1280x1024
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1920x1200
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2048x1536
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Farben & Filter

SpektralbereichWellenlängeTeleskop
Infrarot
K
2.2 μmHubble Space Telescope
NICMOS
Infrarot
J
1.25 μmHubble Space Telescope
NICMOS
OptischMPG/ESO 2.2-metre telescope

Endnoten: The right image was taken using the, the left image is from HST NICMOS data.