Instruments

The WSO-UV is equipped with multipurpose instrumentation to carry out:

  • High resolution spectroscopy(R~55,000) of point sources by means of the far UV echelle spectrograph (VUVES), working in the range 1020-1800 Å, and the near UV echelle spectrograph (UVES), working in the range 1740-3100 Å.
  • Long-slit low resolution spectroscopy (R: 1500-4500) in the 1020-3200 Å range with the Long Slit Spectrograph (LSS).
  • Imaging and slitless spectroscopy (R~500) in the 1150-3200 Å range with field of view larger than 1 arcmin for UV sources with the Imaging and Slitless Spectrograph Instrument for Surveys (ISSIS).

The instruments VUVES, UVES, and LSS are grouped together under the same spectrographs unit, the World Space Observatory Ultraviolet Spectrographs (WUVS).

Instrumental compartment.

Optical bench

The WSO-UV telescope provides an accessible field of view of 30 arcmin on the telescope focal plane. The Instrumental Compartment (IC) consists of the (serially connected to each other) cylindrical insert and thermostabilised protective cover made of aluminum alloy. The IC insert is attached to the supporting frame of the Telescope Primary Mirror Unit (PMU) at 3 points. The IC thermal protective cover is attached to the bottom of the IC insert flange. The insert has been made the loading bearing structure. The Telescope loading is transferred to the transitional truss of the Navigator Service.

The optical bench (OB), used as reference plane for all the onboard instrumentation, is aligned and maintained in the correct position with respect to the primary mirror unit (PMU) using a three rods system. ISSIS is mounted on the upper basis of the optical bench, in the space available between the PMU and the OB itself, while the WUVS assembly (the three spectrographs UVES, VUVES and LSS) is mounted to the OB bottom basis. The Fine Guidance System (FGS), that uses three visible sensors placed at the vertex of an equilater triangle in the focal plane close to the spectrograph entrance slits, ensures a pointing stability better than 0.03 arcsec (1 sigma). Each of the focal science plane instruments has its own power supply and data handling unit in a service box mounted on the external side of the instrument compartment.

General view of the Focal Assembly (scientific instruments mounted on the OB) is shown in image below.