mirror focal ratio: f/3
focal ratio: f/9
focus ratio: f/45
(Beijing-Faint Object Spectrograph and Camera)
HRS (High Resolution fiber-fed Spectrograph)
BFOSC (Beijing-Faint Object Spectrograph
Cassegrain focal ratio: f/9
CCD55-30-1-348 back, AIMO, CCD controller was made by Lick
CCD size: 1242×1152 pixel
Pixel scale: 0".457
Pixel size: 22.5 μm
Focal plane scale: 10.61”/mm
Fig. 2. Observing
mode of 2.16m BFOSC
For the imaging
The Johnson UBVRI and 385LP band and Z band
Fig. 3. The filter response functions of the broadband for 2.16m
In addition, we
have a series of interference narrow band filters of H-alpha, [OIII] and He
with radial velocities up to 20,000km/s.
Fig. 4. Filter
response functions of 2.16m BFOSC (narrow band)
For the spectrograph:
It has the long
slits (9'.4) and short slits(3″.5-4″.0) observing modes.
Table 1. The current parameters of BFOSC
The current thinned BFOSC CCD has high QE in the
blue band and a new CCD, which has high QE in the red band, will replace it.
Fig. 5. The QE of
the current BFOSC CCD
It also has the
slitless spectroscopic mode for the multi-object observations.
From the year of 2012, with the new facility, the mask observation mode
has been available. Usually 10-20 objects can be observed simultaneously.
OMR Low Resolution Spectrograph
The Optical-Mechanism Research Low Resolution Spectrograph (OMR) is
another low-intermediate resolution spectrograph in 2.16m telescopes, which is
also mounted on the Cassegrain focus. It is composed of spectrograph, CCD
camera, guiding camera, console and data collecting PC.
Fig. 6. OMR Low Resolution
HRS (High Resolution Fiber-fed Spectrograph)
High Resolution Fiber-fed Spectrograph
(HRS) is developed by the Nanjing Institute of Astronomical Optics &
Technology (NIAOT) in October, 2010 to satisfy the scientific requirement of extro-planets
survey, research of stellar abundances, research of stellar magnetic activity etc.
(see Fig. 7).
HRS can be switched between the
existing equipment and itself by the Cassegrain focal interface of the
telescope. The calibration system of HRS, the I2 cell with its heating system,
and the incoming Tip/Tilt system all mounted or will mount on this interface.
The main body of HRS is set in a protective box (see Fig. 8 and Fig. 9), in
which the temperature stability is better than 0.5°C during one week. Further
parameters of HRS please see table 4.
Ongoing improvement project for HRS:
phase schedule of HRS
(1) Add 1″.6 fiber
and Tip/Tilt system for HRS (which will be finished before March, 2014)
To satisfy the requirement for deferent
resolution observation and improve the efficiency for different seeing；
environmental control system for HRS
(which will be finished before September, 2014)
It is under construction, which could accurately
control the pressure, temperature, and humidity for HRS of the Xinglong 2.2m
telescope. The key components are delivered. The construction of the whole
system will be finished in the end of 2013.
astro-frequency comb (which will be finished before May, 2014)
requirement for an astro-frequency comb
High precision radial velocity measurement
to the I2 cell (Wilken et al. 2010)
Thousands of uniformly spaced lines with equal
Keeplines stable and reproducible for long time
(3) Progress of
the astro-frequency comb adjustment
An astro-frequency comb, which will greatly improve the precision of
HRS, had been developed by Peking University and shipped to Xinglong
Observatory. The comb was setup and the first spectrum simultaneously from the
comb and the flat lamp has been obtained during the engineering run.
Fig. 7. The light-path
Fig. 8. The
protective box for HRS
Fig. 9. HRS
adjusting by a laser lamp-house