Hanle Faint Object Spectrograph Camera


INSTRUMENT DESCRIPTION

The beam from the telescope passes through an interface unit, the FASU (Filter and Spectral Lamp Unit), which is mounted between the instrument mount cube and the main instrument. The FASU contains two wheels, FASU-A and FASU-B (in the telescope converging beam) for narrow band filters and the calibration mirror. The interface unit also houses the calibration lamps for wavelength calibration and flat-fielding. Both wheels in the FASU have 5 slots each. After the beam has passed the FASU, it comes to focus on the aperture wheel which is located at the focal plane of the telescope. The aperture wheel has slots in which various slits can be mounted. The beam then passes through the collimator and forms a parallel beam. The filter wheel and the girsm wheel, each having eight slots, are placed in the parallel beam, in between the collimator and the camera. The parallel beam is imaged by the camera on the CCD. All HFOSC wheels have 8 positions.


PRESENT INSTRUMENT CONFIGURATION
  • Aperture Wheel
  • Position slit

    1

    134 l

    2

    1340 l

    3

    167 l

    4

    335 l

    5

    100 m

    6

    67 l

    7

    67 s

    8

    free

  • Filter Wheel
  • Position Filter/Grism

    1

    free

    2

    Gr. 14

    3

    Bes I

    4

    Bes R

    5

    Bes V

    6

    Bes B

    7

    Bes U

    8

    Gr. 11

  • Grism Wheel
  • Position Grism

    1

    focus pyramid

    2

    Gr. 8

    3

    Gr. 9

    4

    Gr. 7

    5

    Gr. 5

    6

    Gr. 17

    7

    Gr. 15

    8

    free

  • FASU-A
  • Position Filter

    1

    free

    2

    486.1

    3

    656.3

    4

    Cal-Mir

    5

    500.7

  • FASU-B
  • Position Filter

    1

    free

    2

    672.4

    3

    Halpha (broad)

    4

    372.7

    5

    free

SLITS AVAILABLE
Width Height

micron

arcsec

arcmin

67

0.77

11

100

1.15

2.1

100

1.15

11

134

1.54

10 (arcsec)

134

1.54

11

167

1.92

11

335

3.85

11

1340

15.41

11


GRISMS AVAILABLE

Grism #

Wavelength range

Resolution

nm

Gr. 5

520 - 1030

870

Gr. 7

380 - 800

1000

Gr. 8

580 - 920

1200

Gr. 9 (echelle)

330 - 1050

4000

Gr. 10 (cross disp)

330 - 650

230

Gr. 11 (cross disp)

370 - 740

390

Gr. 12

520 - 1040

205

Gr. 14

327 - 616

1320

Gr. 15

330 - 600

745

Gr. 17

760 - 1050

2640


FILTERS AVAILABLE

Bessell U

Bessell B

Bessell V

Bessell R

Bessell I

Bessell I_c

Bessell z

Halpha Broad(50)

372.7 (10)

486.1 (10)

500.7 (10)

656.3 (10)

672.4 (10)



CALIBRATION LAMPS:

Fe-Ar

Fe-Ne

Hg-Cd

Halogen (for flat-fielding)


ALSO AVAILABLE:

Focus Pyramid

Re-imaging optics for calibration sources (cal-mir)

Pinhole apertures

Hartmann masks


Last updated on: November 20, 2020