2024-Mar 23: Fixed transient vertical stripes on detector bottom-right quadrant

This issue was fixed after months of troubleshooting and repair work with the help of T. Greffe from Caltech. Critical to fixing the issue were:

• Repairing and making new J15 and J16 cables that carry the video signal between the detector and the Archon controller.
• Reworking the custom-made PCB in the Archon controller.

2023-Dec 07: Transient vertical stripes in detector bottom-right quadrant

NIRC2 images are affected by intermittent vertical stripes on the bottom right quadrant when the detector is operated with the Archon controller. This issue may be originated in the Archon controller or in the cables between the Archon controller and the detector connector plate under the NIRC2 dewar. Troubleshooting is ongoing.

2023-Nov 23: Found an issue with the MCDS exposure time calculations (fixed on Nov 26)

We detected an issue with the software used to operate the new Archon controller. The exposure time calculations in MCDS mode were incorrect due to an undetected bug caused by last-minute modifications to the software. This issue was fixed on Nov 26. NIRC2 data taken on Nov 21,22, and 23 UT are affected by this issue. One can potentially generate the correct images from the individual frames, but it would not be easy.

2023-Nov 20: Science operations with upgraded detector electronics start

We have been working on replacing the obsolete NIRC2 detector electronics based on Transputers with a new STA Archon controller for the last year. The Archon controller was installed in parallel to the Transputers last February. We have been working during the day on the Archon controller while continued science operations with the Transputers at night. Today, we use the Archon controller for science operations for the first time.

2021-Nov 13: Alad (detector server) keywords available on vm-nirc2

Detector server keywords (alad) have been made available on the Linux VNC server vm-nirc2. This is an important step towards migrating as much of the NIRC2 operations software as possible away from waikoko. NIRC2 VNCs will include vm-nirc2 terminals, instead of waikoko terminals, by default. One can still open a waikoko terminal from the VNC pulldown menu, if needed.

2021-Jun 10: Sounds available on VNC server vm-nirc2

A new keyword service (nirc2plus) was created to support sounds on the VNC server (vm-nirc2). This keyword service can be used to make new high-level keywords which are not supported by the traditional NIRC2 keyword services (nirc2 and alad), such as PROGNAME.

2021-Apr 21: waikoko memory upgraded

The NIRC2 instrument host, waikoko, RAM was updated from upgraded from 512MB to 2GB.

2021-Jan 24: Detector lower-left quadrant noise improved

The lower-left quadrant of the NIRC2 Aladdin-3 detector has historically been noisy, with 1 of 8 channels particularly noisy. We noticed in early January a sudden improvement with no apparent reason.

2019-Nov 26: Vortex operation update

The software needed to operate the vortex coronagraph, QACITS, has been released on the new Linux-based VNC server (vm-nirc2 or simply nirc2.) The coronography section of the NIRC2 manual has been updated with a new section that contains a basic guideline on how to perform observations with vortex coronagraph at night.

2019-Nov 15: waikoko died and was replaced

The NIRC2 host (waikoko) crashed multiple times between Nov 14 and 15. It was replaced with a spare including the disks and SCSI boards from the faulty machine. NIRC2 was tested with the waikoko replacement and no issues were found.

2019-May 05: NIRC2 two-stage colhead replacement

The two NIRC2 cold heads were replaced as a preventative maintenance task during the March 2019 upgrade. The replacement 2-stage head started to malfunction about 1 month after the upgrade. We have replaced the malfunctioning head by a reburbished head provided by the manufacturer. The replaced head performs nominally.

2019-Mar 19: NIRC2 high-contrast imaging upgrade

New optical elements installed on NIRC2 by a team led by Keith Matthews (Caltech) as part of the NIRC2 high-contrast imaging upgrade led by Dimitri Mawet (Caltech). The project was funded with contributions from Jeff and Rebecca Steele. The following elements were installed on NIRC2:

• Vector Vortex Coronagraphic (VVC) mask optimized for L/M band (replaces previous VVC mask).
• VVC mask optimized for K band (replaces spare VVC mask).
• Pupil mask optimized for coronagraphy. New mask provides better blockage of the thermal emission from M2 spiders than regular NIRC2 pupil masks.
• Wollaston prism (H to L band). Half-wave plate not available yet. It will be installed in the future, once funds are made available.
• Field masks for imaging polarimetry and spectropolarimetry.

2018-Jun 28: New VNCs for NIRC2

We have replaced the old NIRC2 VNCs running on the svncserver2 machine (old Sun-Fire-V240 with Solaris 10) by new VNCs running on a modern Linux 64-bit virtual machine (vm-nirc2). This upgrade includes wider VNC desktops; 1850x990 pix instead of 1264x990 pix, and faster response to mouse control commands such as changing the image contrast on the Quicklook Tool. The VNC startup script used for the old VNCs should also work for the new VNCs in the case of mainland observers. Waimea observers should use the new command start_all_vnc.sh nirc# from any local terminal in the observing room computers, where nirc# represents the assigned NIRC2 user account, e.g. nirc5.

2016-Mar 28: Updated distortion solution available for NIRC2 narrow camera

We are pleased to report that a new distortion solution for the NIRC2 narrow camera after the AO re-alignment work 2015 Apr. 13 is now available. You can access the new solution here. It uses methods similar to those used in the Yelda et al. 2010 analysis. Many thanks to M. Service and J. Lu et. al. for deriving the new solution.

2016-Mar 11: User manuals available for the vortex coronagraph

The L-band vortex coronagraph will be offered for shared-risk science in semester 2016B. Two user manuals are now available, one for using the vortex coronagraph, and another for the "Quadrant Analysis of Coronagraphic Images for Tip-tilt Sensing" (QACITS) software needed to perform real-time automatic pointing control.

2016-Jan 26: DVD writer no longer available for data backups

The Keck Observatory is phasing out the auto DVD writer sometimes used by observers for data backups. Options to launch the DVD autobackup gui are no longer available from the background menu. Because the Keck Observatory Archive (KOA) now ingests all raw data from every instrument at the observatory, observers are encouraged to use KOA to retrieve a copy of the data following your observing sessions. Instructions and links to possible methods of data backup including KOA, scp, and rsync are found at: BackingUp.

2015-Nov 17: NIRC2/AO re-alignment

Some alignment work was done on the K2 AO bench starting on April 13, 2015. We were able to eliminate the image elogation seen in L-band by rotating the wedge of the IR dichroic. We also improved the pupil alignment and reduced pupil nutation by making adjustments to the off-axis parabolas (OAPs) on the AO bench. All in all, things should be be better but this probably introduced some changes in the NIRC2 distortion. We are working on a new distortion solution for NIRC2, and will post updates when they are available.

2015-Mar 17: L-band vortex coronagraph installed

Two new vortex coronagraph masks (annular groove phase masks) have been installed in NIRC2. They are intalled in the slit mask stage (SLS), replacing the grids of holes used for focusing and distortion tests, which will no longer be available.

2014-Mar 05: DVD writer for data backups will be phased out

The Keck Observatory is phasing out the auto DVD writer sometimes used by observers for data backups. Although there is no time line for the removal of the DVD writer, we will no longer troubleshoot or maintain the DVD writer. Because the Keck Observatory Archive (KOA) now ingests all raw data from every instrument at the observatory, observers are encouraged to use KOA to retrieve a copy of the data following your observing sessions. Instructions and links to possible methods of data backup including KOA, scp, and rsync are found at: BackingUp.

KOA filename translator available

A script koa_translator, is available to convert the names of data files downloaded from KOA back to the original file names as they came out of the instrument.

2014-Feb 26: Cold heads replaced

After 17 years of service, both cold heads in NIRC2 were replaced on 2013 November 26. Performance has been excellent.

2013-Jan 01: New year, new web pages

The NIRC2 web pages have been reformatted and reorganized to conform to the Keck instrument page standards. Feedback is welcome.

2012-Sep 18: NIRC2 cooldown starts

NIRC2 was opened up and serviced Sep. 17. The lead screw for the camera stage was inspected. The preload on the nut was reduced by removing one of the two wave washers. Testing when warm under vacuum showed that the stage was moving freely. NIRC2 is now closed up and has been vacuum pumped for 24 hrs. The cold heads have been turned on and cool down has started at 16:02 HST Sep. 18.

2012-Sep 10: Here comes the PIG

A new startup script has been released for NIRC2, which will automatically launch some of the most often used tools and GUIs, including the PIG (program identification gui). The PIG is a new tool that allows you to easily flag which data are yours on split nights. An example of the PIG is shown (for NIRSPEC; it is used for all instruments). A single click allows you to change OBSERVER names and data directory. An edit field allows you to change OBSERVER, if the default (from the telescope schedule) is not what you want. Please use the PIG while observing. It is your friend.

2012-Sep 08: Service mission initiated

We have decided to warm up NIRC2 in order to take advantage of an opportune window in the schedule this month to fix the camera stage problem that we have been experiencing. The CCRs were turned off around noon today.  The dewar is expected to be ready to open for service Monday, 17 September. NIRC2 should be cooled and fully operational by Sep. 29.

2012-Sep 02: Camera stage difficulty

We have been experiencing some difficulty with moving the camera stage to the wide camera. As a precautionary measure, observers are strongly advised not to use the wide camera.We will attempt to trouble-shoot the problem when NIRC2 is off sky.

2012-Mar 23: Master flats and darks available

We now have a library of imaging flats and darks (some graciously provided by A. Kraus) available here. More can be added as they become available.

2012-Jan 01: More targets in the new year!

In the spirit of giving this holiday season, US Space Command recently increased the number of LGSAO targets that observers are permitted to submit for LGSAO observations. The new maximum per night is 130 total targets. For split nights, each half night observing team is allocated 65 targets.

2011-Sep 19: Service Mission Complete

NIRC2 has reached equilibrium operating temperatures. Cold head speeds are being tuned, but preliminary checks indicate that all systems are operating normally. More information on the newly installed filters is available the updated filters page.

2011-Sep 07: Filters Installation Completed

NIRC2 was opened up and serviced Sep. 05-06. Seven new filters were installed: z, Y, L-wide, Pa-gamma, He IA (10,830A), Br-alpha, and Br-alpha continuum. The L-undersize and a duplicate Br-gamma filter were removed. The cold heads were purged. NIRC2 is now closed up and has been vacuum pumped for 24 hrs. The cold heads have been turned on and cool down has started at 16:07 HST Sep. 07.

2011-Aug 30: Service Mission Begins

Warm up of NIRC2 has begun for the service mission led by PI Keith Matthews to install new filters. An L filter, a Y filter, which was procured with generous partial funding from M. Liu, and a number of narrow-band filters will be added. The extra Br-gamma filter and the L-undersize filter will be removed. NIRC2 will be opened and filters installed Sep. 6-8. NIRC2 should be cooled and fully operational by Sep. 16.

2011-Jan 03: More Efficient Data Acquisition Scripts Available

We have a new set of data acquisition scripts that improve on-sky observing efficiency by reducing delays in status checks and time waiting for data writing to complete. Some minor modifications were also made to quicklook to handle more rapid image exposures. The time saved by the new scripts is estimated to be about 15-45 minutes per night, depending on the nature of your program. Unfortunately, the new scripts have also been found to introduce a "side effect" that causes the detector (Alad) server to crash, on average, about once a night, which requires ~5 min to recover. We will continue to investigate these server crashes, but in the mean time if you wish to use the new scripts, please let your support astronomer know.

2010-Jun 17: NIRC2 Begins Full-Time VNC Operation

Starting with the June 2010 NIRC2 run, we ask all observers to start up their NIRC2 control software within VNC desktops. Virtual Network Computing (VNC) is a technology that allows windows to be shared with observers at other computers and has been used successfully for years at Keck to provide mainland observers with access to Keck instrument controls. By expanding the use of VNC to all observers, we will thus have a single startup procedure for observers to follow regardless of whether or not they will operate with mainland observers. Operating under VNC also makes it easier for support staff to assist observers with troubleshooting and allows our observing assistants to monitor the status of observations during the night. Your support astronomer will be happy to assist you with starting your NIRC2 software under VNC.

2010-Jun 09: Snappier Quicklook

To take advantage of the color-map speed up available when quicklook is run from within an 8-bit display, the VNC configuration has been changed to use an 8-bit (tan background) display for the center screen. Users will also notice that xterms have all been converted to black-and-white to accomodate this change. The primary advantage of this change will be experienced when users apply right-mouse-button color stretch to tease out faint features. The improvement should help with rapid cadence programs such as companion-search survey programs.

2010-Apr-23: MCDS Puzzle

We have discovered an unusual aspect of data collected with NIRC2 in multiple correlated double-sampling (MCDS) mode. The peculiarity is seen most easily in dark frames. Figure 1 shows a histogram, with the expected Gausian distribution, of pixel values across a NIRC2 dark. The dark shown in figure 1 was taken in single correlated double sampling (CDS) mode. Figure 2 shows a similar histogram of a dark taken in MCDS mode. Note the excess of zero-valued pixels.

We have checked darks going back seven years, and with varying numbers of samples, and we see the same effect in all these data. Therefore, we believe that this phenomenon has existed since NIRC2 commissioned and occurs for all MCDS frames, regardless of the number of samples sepcified. We will continue to look at this problem to see if we can determine the root cause, and to see if there is a significant effect on data quality resulting from this anomaly.

2010-Apr-02: K Glow in Wide Camera

Users of the wide camera, observing at Kp (or longward of Kp), please be aware that a 'glow' now appears in the lower right portion of the detector. See jpeg image. The fits file associated with this image can be downloaded by clicking here.

This effect began, we believe, around August, 2009, and may be the result of a new optic that was installed on the AO bench (a replacement IR dichroic) around that time. We are working to better characterize, and hopefully correct, this effect. The effect produces a less than 1% increase in flux in that area and may be removable by flat fielding.

2010-Feb 19: Keep it Linear

For observers who might be new to observing in the infrared: The harmful effects of over-exposing with NIRC2 are shown in figure 1. Note that, unlike a CCD (which will "flat top" if over-exposed), the correlated double sampling (CDS) mechanism inherent in IR readout systems, will result in a "roll over" phenomenon. In this example, the total DN reaches approximately 13000 at which point the measured signal begins decreasing.

2009-Sep 28: Filter curve data values are now available.

A spreadsheet containing the the data values for the passband curves that appear on the NIRC2 filters page is now available on that page. See Note #10.

2009-May 11: Dome flat instructions updated

Along with recommended integration times, the dome flat calibration instructions page has been update to include a step-by-step procedure. Please consult this procedure when taking flats unattended (e.g., morning dome flats).

2009-Jan 01: Fine pin-hole mask unavailable

Over the past 1-2 years, the NIRC2 slit stage has faulted on several occasions when driven to locations near its negative limit. For this reason, we are restricting use of that stage to exclude use of the fine pin-hole mask. All other positions for that mask (slits 10-through-160 for spectroscopy, coronagraphic spots 100 through 2000, and the coarse pin-hole mask) are available for use. We will continue to investigate this issue and apologize for the inconvenience.

2008-Nov 03: Fixed Pupil versus Vertical Angle Mode

Observers using vertical angle mode, who are intending a fixed pupil, for example users of aperture masking or angular differential imaging (ADI), should be aware that a tracking shift in the pupil plane of order 0.4 degrees occurs when an object being observed in vertical angle mode transits near zenith. This effect is likely related to the difference between true vertical and the as-built telescope Y axis, as the offset is equal to the difference between PARANG and PARANTEL. A correction equal to that difference must also be applied to recover absolute astrometry.

The following plot, graciously provided by Bruce Macintosh and Christian Marois, characterizes the jump.

>

The plot shows the shift in the pupil plane that occured during transit while tracking an object in vertical angle mode. The curve of the object's location in the images (somewhat quantized) is due to expected (vertical angle mode) field rotation (shown as stars). The jump between images 120 and 140 is due to the tracking shift and shows that this tracking mode, which does hold a constant vertical angle, also results in an image location jump in the frame of the pupil. The differences between PARANG and PARANTEL, as read from the image headers, are over-plotted on this same plot (shown as diamonds). This latter plot provides a second visualization of the difference between fixed-pupil and fixed-vertical-angle.

2008-Jul 07: Transputer Board Replaced

A problem with the NIRC2 detector readout system occurred on Wednesday night, June 18th, 2008. The root cause was traced to a failed transputer board in the detector system electronics rack. That board has been replaced and since that repair mission, NIRC2 has been in use on five science nights without a recurrence of the problem.

Several efforts are underway to improve our preparedness should a similar problem occur in the future, including the configuration of a hot-swappable host computer system.

2008-Apr 28: IQ Repository Started

An Image Quality comparison page has been been generated for collecting observers' before and after experiences with NIRC2 since the upgrade of the AO Wave Front Controller.

2008-Apr 23: LGSAO Differential Tracking Available (Shared Risk)

As of April 24, 2008, an LGS mode which allows for differential motion between the laser and the tip-tilt reference is available for shared risk. Limiting rates and magnitudes for this new mode, as well as all other nonsidereal AO modes, are provided in a summary table. Contact Randy or Al for details.

2008-Feb 23: Astrometry Page Updated

The Astrometry Page has been revised, including new information related to the NIRC2 position angle.

2007-Oct 20: Astrometric Calibration: M15 added

The procedure for observing M15 for astrometric calibration has been added to the Astrometry Page. If you use the procedure, please consider contributing your calibration frames to the Observatory (via your Support Astronomer) for general use by the community.

2007-Sep 12: The answer is "14"

Since the commissioning of NGWFC, many have wondered: Under what conditions is it better to use NGS over LGS? Please see KAON 489 figure 14 for details, but the short answer is "When brighter than 14th and closer than 10 arcseconds, use NGS."

2007-Jul 17: Dewarp Utilities Posted

The IDL code to remove geometric distortion (graciously provided by Brian Cameron) has been added to the NIRC2 web page. Go to the Dewarp Utility Page.

2007-Jun 4: AO improved and characterized

Strehl-vs-magnitude and related performance statistics for the upgraded AO system have been characterized.

2007-Apr 4: AO improved

The NIRC2 Adaptive Optics feed has been upgraded. Performance improvement is still being quantified, but in the mean time, check out this snapshot of improved performance at J from Mike Liu's April 3rd SSC presentation.

2007-Mar 26: Astrometry discussed in Santa Cruz

At the CfAO Retreat held in Santa Cruz March 26th, an informal meeting was held by NIRC2 observers interested in precise astrometry. The collaboration has resulted in a report, recommended calibration fields, and a dewarp application. Once these are finalized they will appear on this page. In the mean time, email aconrad@keck.hawaii.edu if you desire preliminary versions of this material.

2007-Jan 17: New Web Page in the Works

Please check out the new NIRC2 home page. It is a work in progress, but comments are welcome.

2004-July 28: Zero Points updated

Based on photometric data gathered in April of 2004 the zero points have been updated. The values are included in the list of filters and in the NIRC2 manual. There was improvement in both the zero points and the background levels from the initial commissioning measurements, likely the result of cleaner optics on the AO bench.

2004-April 1: AO Enclosure has Silver Lining! AO Rotator Optics (K Mirror) Recoated with Silver

The three mirrors in the AO rotator were recoated with silver (2 of the 3 surfaces were previously Al.) and reinstalled in March 04. The rotator, which is often referred to as the K mirror, was subsequently realigned to the optical axis of the telescope and to the pupil of the optical system. One requirement of the realignment effort was to minimize the pupil nutation as a function of rotator angle, which has been a significant problem in the past. The realignment effort met the requirements and was deemed successful with the pupil nutation now only 10cm on the primary (peak to valley). These changes will have several likely benefits to NIRC2 observers,

• Improved throughput of the AO bench optics resulting in improved sensitivity.
• Lower thermal background from improved pupil mask performance.
• Lower thermal background from cleaner, silver coated mirrors.
• Better coronographic reduction of diffracted light due to the improved pupil mask performance.
• Improved background subtraction performance at L and M band ( no more "mottling" of the background).

2004 April 23: New Strehl Meter Available

An accurate and consistent method of measuring image quality on NIRC2 has been developed by Marcos van Dam, WMKO AO Scientist. The tool is available from the NIRC2 user interface menu and users are encouraged to give it a try. Instructions for its use are available as a web document.

2003-Sep 29: New Filters Installed

The NIRC2 dewar was warmed to ambient temperature and opened in late August of 2003, the first time since being delivered to WMKO in June of 2001. The primary purpose of the service mission was to install recently procured narrow-band filters. The successful effort was led by PI, Keith Mathews of CalTech. One prerequisite to going forth with the service efforts was the development of the Keck II AO enclosure into a clean "ish" room. The clean room project was led by Craig Nance. He and the summit facilities group worked hard to enable this important work on NIRC2 to be accomplished.

Preliminary characterization has produced filter wavelength information that is now available on the NIRC2 filter page. Full characterization of the transmission profiles is yet to be completed.

2003-Jan 25: Status Display modification

Just a small note: the parameter previously labeled "#Fowler" has been changed to read "# reads". This is the number of reads done in "MCDS" mode (sampmode 3).

The "Move Tel." command on the Quicklook image display has been broken for some time. This command is located under the "Tel" menu, and allows you to click on a starting point and an ending point and move the telescope so that a star at the first point moves onto the second point. The symptoms before were failure to move properly in the medium and narrow field cameras.

A bug in the software was found that was hard-wiring the pixel scale to that of the wide-field camera. This has been fixed, so that the plate scale gets properly read from the FITS image keyword. Telescope movement in all three cameras was confirmed, and moving the telescope using an image from one camera while a different camera was currently in use was also verified.

You can still, of course, use one of the other telescope move commands, including "mov", "pxy", etc.

2002-Dec-14: Revised Manual

A revised version of the manual (V1.1) has been placed on the Web. This updates various sections, most notably spectroscopy.

2002-Oct-28: Subarray Minimum Integration Time Problem-Fixed!

Recent observers have found that some subarray sizes would crash the alad server software that controls the NIRC2 detector. This would occur with a subset (about 10%) of the subarrays when the minimum integration time for that subarray was chosen using "tint 0". This problem has been tracked down and fixed. It occurred because of a rounding error that was implemented so that the integration time printed by "tint" did not have 20 decimal places in it.

Currently the tint value is set with full precision, and the tint command prints it out to 4 decimal places.

2002-Oct-27: Quicklook Modifications

NIRC2's Quicklook image display evolved from the NIRSPEC version of the tool, and it has shown this. Some recent modifications have been made to make it more NIRC-2-like, such as removing the menu item "Show SCAM PA". (SCAM is NIRSPEC's slit-viewing guider.) Also, when you select a new display scaling, you no longer have to remember to then select "Redisplay" from the "Disp" menu.

Like NIRSPEC's version, the NIRC-2 "Move Tel" command does not work reliably. We have added debugging lines to the code to try to track down this problem, but meanwhile you may want to rely on the command-line command "mov" to move a target from one (x,y) position to another.

Update, 2002-Dec-25: A bug causing failure of the "Move Tel" command was found and fixed during December engineering. (see above).

Work on the Strehl calculator proceeds. It now gets the pixel scale and filter bandpass information from the image headers, rather then requiring the observer to type this in each time. We will be adding better theoretical PSFs in the future, using the correct NIRC-2 pupil mask where appropriate.

Guide Star Offset Planning Tool

Because of the unique nature of the Field Steering Mirrors (FSMs)  a graphical planning tool was developed in order to avoid the problems associated with exceeding FSM limits. This tool allows the user to find the optimum position angle for a given guide star offset. Other features include display of a dither pattern box, the ability to place the object on a particular pixel on the NIRC2 detector, and compass rose display. The tool is available on-line using ION, IDL On the Net, which was recently installed on the Keck public web server. Please report any problems or suggestions associated with using this tool.

This tool was deprecated in 2017 due to lack of support of ION. Please refer to the AO Guide Star Tool, which contains the same information.

Planned Procurement of NIRC2 Filters

Because NIRC-2 currently has a somewhat limited inventory of filters, observers may wish to know what may be in store for the future. We are providing a list of filters that have been ordered, and will hopefully make their way into the NIRC-2 filter wheels. Note, however, that there is no guarantee that all of these filters will get successfully made and delivered to the NIRC-2 team at Caltech.

2002-Mar-12: New Dither Functionality

Some new functionality has been added into the "bxy*" and "dither" commands. Giving an argument "n=#" to these commands will take "#" exposures at each dither position. This allows for multiple images to be taken without the excess overheads of opening and closing AO loops. Note that increasing the number of coadds will accomplish a similar goal, with even less overhead, although there will only be a single data file containing the coadded data, rather than "#" independent files.

The "n=#" argument can be placed anywhere, e.g. "bxy5 n=3 1.3" will take three exposures at each of five dither positions in a 1.3 x 1.3 arcsec box. ("1.3" is the step size, not the size of the entire pattern.) Similarly, "bxy4 1.2 2.7 n=4" will take four exposures in each of four positions in a 2.4 x 5.4 arcsec rectangular pattern.

New "bxy4" dither pattern

A new 4-position dither pattern has been released on NIRC-2. Basically this is a "bxy5" pattern with the central position removed. See above for enhanced functionality of this and other "bxy" commands.

2001-Oct-10: NIRC2 Commissioning Progress, Early Science Use

NIRC2 is expected to be fully commissioned and available for semester 2002A. In addition, the instrument will be offered for pre-commissioned use to NIRSPEC/AO observers for semester 2001B on a "shared risk" basis. The imaging modes of NIRC2 have performed as exepected during the initial testing of the instrument and it generally meets or exceeds design specifications. The test results have been positive enough to allow for early use of the instrument. The NIRC2 PI's and observatory staff are offering observers scheduled for NIRSPEC/AO the option of using NIRC2 for their imaging programs. NIRSPEC/AO observers will not be able to switch back and forth between instruments during the night due to complications of the AO calibration

Commissioning is still not complete, and not all observing modes have been adequately tested. Also, Keck staff are still receiving training on the instrument. Thus, the early shared risk use of NIRC2 will have limitations applied. The spectroscopy mode of instrument is not fully tested and will not be supported in 2001B, especially since those planning spectroscopy programs will likely choose to stick with NIRSPEC. The coronography modes will also not be available during the pre-commissioned use of NIRC2. With it's three cameras, NIRC2 offers field of view advantages over the NIRSPEC SCAM detector with choices of 10, 20, and 40 arcsec FOV. NIRC2 has fewer optics in the path and is expected to have better sensitivity in most situations. Please see NIRC2 specifications and a comparison of NIRC2 to NIRSPAO for more information on the trade-offs between the two instruments.

2001-Jul 29: NIRC2 First Light!

The Near InfraRed Camera Two, Keck II's instrument designed to take full advantage of the Adaptive Optics Facility, successfully achieved "First Light" on 29 July 2001. This event signaled the transition from the installation phase to the commissioning phase of NIRC2. Integration of the instrument with KeckII and the adaptive optics facility has been successful thus far. See NIRC2 specifications for initial performance measurements. If the commissioning process continues at it's current pace, NIRC-2 will be available in the first semester of 2002 for general use. NIRC2's first run took place 29 July through 3 August, 2001. Below are a sampling of images demonstrating the capability of NIRC-2 and Keck II Adaptive Optics system. Click on the thumbnail for a larger image.

M8 in J,H,K	Neptune in K

2001-Jul 29: NIRC-2 Installation in Keck II AO Room Complete

The NIRC-2 dewar, detector electronics, and ancillary equipment installation was completed and functioning by 29 July 2001. Below is a chronology of events leading up to this point, with pictures included.

• 17 April 2001: Pre-Ship Review, Pasadena, CA
• 11 July 2001: NIRC-2 dewar, D82, lifted from dome floor to Keck II AO enclosure.

NIRC-2 being lowered into Keck II AO enclosure.

PI Keith Matthew's of CalTech prepares NIRC-2 for placement, Bob Goodrich assists.

• 12 July 2001: Closed Cycle Refrigeration, CCR, system started, NIRC-2 cool down started.
• 13 July 2001: Detector electronics powered up.
• 16 - 21 July 2001: Dewar cool down progression, operability of instrument checked out.
• 24 July 2001: First images of AO internal light source images. Optical alignment with AO system.
• 27 July 2001: Alignment with telescope pupil.

NIRC2 workers imaged at K (2.2 microns) with NIRC2's pupil imaging capability. Perhaps it is the first use of a 10 meter telescope to image human beings. From left to right, Randy Campbell, Keith Matthews, Eiichi Egami, James Larkin.

• 28 July 2001: NIRC-2 permanent mounting installed.
• 29 July 2001: Final Alignment verification.
• 29 July 2001: "First Light" from the night sky.