MOIRCS Service Mode OPEfile Generator

OBJECT's ID:!! USE capital letters, number, and/or underscore ("_") only !!
OBJECT keyword in FITS file:!! USE capital letters, number, and/or some symbols ("-","_") only !!
Right Ascension of Pointing Position (RA):In hhmmss.ss format.
Declination of Pointing Position (DEC):In ddmmss.s format.
Equinox:
Positon Angle (PA): -270 < PA < 270
Filter (FILTER01):
Each single-expousre time (EXPTIME):Typical values (for faint objects) would be 180 s for Y, 60 s for J, 25 s for H, 45 sec for Ks, 60 sec for MB, and 180s for NB, respectively.
NEXPOSURE:Typically between 1 and 6 (see the description below). Set 1 if not necessary.
Dithering number (DITHNUM): See details for description below.
DITHCENTER yes/no ?:

Yes No

Take an image before dither?
Dithering length (DITHLENGTH):Larger than 20 arcsec is recommended.
Use Autoguider? Yes No YJHKs and most NBs --> NO (recommended) / NB119 --> YES.

Do you accept non-photometric condition?

Yes No

Do you need photometric standards?

Yes No


Description About Each Parameters

OBJECT's ID
Use capital letters, numbers, and underscore ("_") only. Dash ("-") is not acceptable.
e.g. MOIRCS_1, MESSIER_3, COSMOS_F23_2, RXJ1234P5678
 
OBJECT keyword in FITS file
Use capital letters, numbers, and some symbols ("+","-","_", " ") only.
e.g. MOIRCS_1, MESSIER_3, COSMOS_F23-2, RXJ1234+5678
 
Right Ascension of Pointing Position (RA), Declination of Pointing Position (DEC)
In hhmmss.sss and ddmmss.ss format. Note that the pointing position lies between channel-1 and 2, because MOIRCS is the mosaic imager. If your target is single compact object and if you set the target coordinate as the pointing position, the target will jump between chip 1 and chip 2 by the dither, thus it may introduce any additional uncertainty. Shifting the pointing position so that the target can come on the center of chip-2 may make the better result. For detail, see Figure 1 of the MOIRCS homepage.
e.g. For pointing position at RA=12h34m56.78s Dec=12d34m56.7s, we use RA=123456.780 DEC=123456.70.
 
Position Angle (PA)
Should be -270 ≤ PA ≤ 270. For definition of the PA, please see Figure 2a of the MOIRCS homepage.
 
Filter (FILTER01)
All open-use filters are available for Service observation.
 
Each single-expousre time (EXPTIME)
The unit exposure time for each exposure set should appropriately be set. It should be larger than 2 seconds, and smaller than the maximum exposure time listed in the last column of Table 1 in the page. The maximum single exposure time above largely depends on the condition, as the sky level in near infrared changes drastically by hour-to-hour basis. If you do not have any special requirement and want to leave the summit observer for the suitable exposure setting, just set the "typical" values as written in the generator (180 for Y, 60 for J, 25 for H, 45 for Ks, 60 sec for MB, and 180 for NB filters) and explicitly write the request. Then they will set the appropriate exposure so that the sky level to 10000-20000 ADU (within ≤ 3% linearity range).
If your target is so bright that it could saturate under typical exposures, you can explicitly ask in the memo to keep the peak count of the object to be less than (for example) 25000 ADU etc. In such cases, it is highly recommended to submit the finding chart with a clear description so that the observer can easily recognize your target.
 
NEXPOSURE
You can consider the NEXPOSURE option to increase the observing efficiency (see the relevant page and/or "MOIRCS Observing Guide" for detail). The NEXPOSURE operation will take a set of exposure at each dither position in order to reduce overhead time by the dither. If you take 5-point dither exposure with NEXPOSURE=3 setting, you will get 3 frames at each dither position, and you will get 15 frames in total after the sequence. Keep in mind that telescope tracking is reasonably accurate for 2 to 3 minutes. The longer you stay at a dither position by NEXPOSURE, you will have higher chance to see the guiding error among the nexposure set. Typically, we use EXPTIME=180 with NEXPOSURE=1 for Y and NBs, EXPTIME=60 with NEXPOSURE=2 for J, EXPTIME=25 with NEXPOSURE=4 for H, and EXPTIME=45 with NEXPOSURE=3 for Ks and MBs. If you do not have any special requirement for the exposure setting, please just set the EXPTIME and NEXPOSURE as the values above. We then flexibly change the exposure time and NEXPOSURE option appropriately according to the condition of the observing night for maximum effeciency.
 
Dithering number (DITHNUM), DITHCENTER, Dithering length (DITHLENGTH)
The number of dither and the optional exposure at the center of the dither circle before the start of the sequence. For dither pattern please refer the MOIRCS website. As a default we use "DITHCENTER=YES". Note that the exposure by DITHCENTER=YES is NOT counted as a number of dither; i.e., you will get 10 frames if you set "DITHNUM=9 DITHCENER=YES". The maximum number allowed for DITHNUM is 9. Please copy the generated GETOBJECT command until your required total exposure time is achieved.
Note that the DITHANGLE in OPE file will be set 5 degrees for the first dither set. If you repeat GETOBJECT in the same setting several times, please change the DITHANGLE (and DITHLENGTH too if necessary) randomly in order not to trace the same dither pattern among each dither set.
DITHLENGTH should be (at least) larger than the diameter of the largest object in your field of view. At least larger than 15 arcsec is recommended for making good median sky. And also, it is important to take at least 7 frames per filter by the same reason.
See "Guide to Observing with MOIRCS" for more detail.
 
Use Autoguider?
The telescope can track target enough accurately without the Autoguider for about 3 minutes. Usually the AG is not necessary. However, the use of the autoguider is highly recommended for observation by the NB119, due to very dark sky by the filters. Note that the use of the autoguider will add some more overhead (~30 sec per dither).
The applicants who want to use AG tracking for NB119 filter must check the availability of the AG star (and put the info in the finding charts). Make sure that the AG probe does not vignette your field of view. You can find the AG-related information from here.
If your target goes up to high elevation (>75 deg), the open tracking sometimes become quite poor, and the AG tracking greatly helps better guiding. We might have to start the AG tracking for the fields at very high elevation, without regard to your request.
 
Do you accept non-photometric condition?
Choose "No" only if any of your scientific aims can only be achieved under photometric condition. If "No" we will go to other low-priority programs instead under poor condition. Instead, we may go back to your program again if there are next chances in better condition and if your target is still available at that time.
 
Do you need photometric standards?
Usually we take several standard star data considering various condition (target visibility, the position on the sky, weather condition etc.) during one service night. We choose one standard star under similar airmass value to target data. We take 3 shots in each chip with the filters used, and take the data on both channel. Typically two independent standard star data will be taken during one program, if condition is allowed. If you choose this option to "YES", please add 10 minutes per filter for the estimate of the observing time (< 4hr).
If "No" we do not take standard data. But if we take standards for other programs during the same night, we will also send the data.

Please copy and paste the generated form (in OPE file format) for each setting to one new text file. Put space between each output of the setting. Submit the text file.


Notes:

Any questions should be directed to Ichi Tanaka (ichi[]naoj.org: change [] to @).


Acknowledgement

IT would like to express special thanks to Dr. K.Aoki for initiating this web ope file generator.


Last Update: 2022-08-03