Instruments & Operations

 

 

News and Updates (click here for older news)

Nov 26, 2012

CAM/FW2 problems: We are currently experiencing some orientation-dependent mechanical issues with the CAMERA wheel as well as a faulty position sensor in filter wheel #2 (FW2) that contains the broadband filters. While software workarounds for these issues exist, should problems be encountered it may be necessary to interrupt observations to recover, including moving to zenith.

Updated lucichk to v4.26: Details can be found on the scriptcheck page.

Observation prep guidelines: Before submitting scripts to your partner coordinators, please ensure that

ANY variation from these basic recommendations should include contacting scienceops@lbto.org well in advance to discuss that program's specific needs.

Quick links to:

Summary Description of LUCI

LUCI 1 and 2 are a pair of infrared multi-mode instruments for the Large Binocular Telescope. In seeing-limited mode, each will have a 4 arc-minute square field of view and will be capable of long-slit and multi-slit spectroscopy as well as imaging in the near infrared zJHK bands from 0.85 to 2.4 microns. Each instrument also includes diffraction-limited optics covering a 30-arcsecond field of view for use with the adaptive secondary mirrors.

The LUCI team's webpage can be found here. On those pages can be found more detailed descriptions of the optical, mechanical, and electronic design.

Cameras (seeing-limited modes):

Filters:

LUCI1 Available Filters (March 2012)
Name
Center WL (microns)

FWHM (microns)

Trans (peak %)

Trans (avg %)
z
0.957
0.195
98.4
94.3
J
1.247
0.305
91.2
83.2
H
1.653
0.301
95.0
90.5
K
2.194
0.408
90.1
85.7
Ks
2.163
0.270
90.7
86.8
HKspec
1.950
0.981
95.0
86.3
zJspec
1.175
0.405
93.1
90.4
Br_gam
2.170
0.024
79.4
76.5
FeII
1.646
0.018
91.2
89.5
H2
2.124
0.023
87.9
84.9
HeI
1.088
0.015
65.2
64.6
J_high
1.303
0.108
95.9
93.3
J_low
1.199
0.112
95.4
93.3
OH_1060
1.065
0.009
68.6
66.8
OH_1190
1.193
0.010
80.4
78.0
P_beta
1.283
0.012
86.1
85.5
P_gam
1.097
0.010
81.1
80.0
Y1
1.007
0.069
67.3
64.2
Y2
1.074
0.065
94.2
89.5

Longslits:

Gratings:

The resolutions above are all derived using the N1.8 camera and an 0.5-arcsec (2-pixel) wide slit. Resolutions will double, and the wavelength range would be halved, if you use the N3.75 camera with an 0.25-arcsec (2-pixel for this camera) slit. This higher resolution spectroscopy mode has been commissioned, but spectrophotometric calibration is not complete.

The typical spectroscopic configuration will be with the 210_zJHK grating and the N1.8 camera, giving slightly less than a full single (z, J, H, or K) band across the detector. All of the gratings can be tilted over a small range so if your science requires a spectrum at the blue or red ends of the bandpass, this can be accommodated. The 200_H+K grating alows for simultaneous H- and K-band spectroscopy. The 150_Ks grating is blazed closer to the center of the Ks band and thus has a higher overall efficiency across the K band than the 210_zJHK grating.

Detector:

Guiding and Wavefront Sensing:

LUCI is connected to an Auto-Guiding and Wavefront sensing (AGw) unit. The guider has a fixed patrol field with respect to the LUCI field of view such that both rotate together on sky as the position angle is varied. The probe shadows the LUCI entrance window at low field angles, and emits thermal radiation visible in the K band. The apparent size of the probe is ~2 arcmin across, or about half the LUCI field of view, so you need to be careful in the selection of your guide stars. Guide stars should be in the range of 13 < R < 16.5 magnitude.

The AGw Patrol Field

AGw Patrol Field
A plot of the AGw guide probe patrol field (green) is shown at left, relative to the 4'x4' LUCIFER field of view (gray square) and the delivered focal plane at the left-front bent Gregorian focal station (outer 11 arcmin diameter circle). Click on the image for a full resolution jpeg, or you can download a PDF by clicking here.