A quick guide for GTC MOS spectral reduction using GTCMOS pipeline
Written by Divakara Mayya (ydm@inaoep.mx) Date: 16-Apr-2015
Summary
GTCMOS is an IRAF-based script that works directly on the files in the
GTC raw data directory. Contains automatic wavelength calibration
routines that transform the original spectral image into a
wavelength-calibrated longslit-like 2D image. Even the slanted slitlets
are aligned parallel to other slitlets. Sky spectra from any
object-free slitlet (or object-free part of a slitlet) can be used to
subtract sky from objects in any other slitlet.
THERE IS NO NECESSITY TO OBSERVE SKY FOR EACH SLITLET, which can save you as
much as 50% of observing time! In around 30 minutes you can get
wavelength-calibrated sky-subtracted 2D image, with minimum level of interaction.
Basic working knowledge of IRAF is expected.
This cookbook contains the sequence of commands that the user
can follow, which also guides users on the command syntax. Each task
contains a detailed IRAF-format help, with practical examples.
Introduction
- It is an IRAF-based pipeline. Installation instructions are
available in gtcmos.install file. Once you are in the IRAF environment
(i.e. with the cl> prompt), load GTCMOS package by typing
gtcmos . At anytime you can type phelp gtcmos for general
guidelines on the package or phelp taskname for help on
a particular task.
All gtcmos commands start with om for the OSIRIS-MOS
spectra and ol for OSIRIS-LONGSLIT spectra.
- The first command that you should use is omstart . This task joins
the 2 CCDs into a single file directly from the raw data
directory and stores the resultant file in the working directory,
A unique output filename is automatically given by the task.
This output file is the input for the subsequent tasks of GTCMOS.
All images in the raw data directory can be processed by a single command.
- omcombine combines multiple images of flat, bias, object or arclamp,
which is the logical second active task to execute.
- The package contains a few passive tasks, to handle the files.
They are omslits, omslice and omunlearn
( passive tasks do not create an output image, whereas an active
task always creates an output image).
-
Carries out bias subtraction ( omstart ) and flatfielding ( omreduce ).
-
The task omidentify automatically identifies the arc lamp lines for
all the slitlets. Even when an arclamp is not available (e.g. standard star), an approximate solution
(rms error 2 pixels = 4 Ang for R1000B for example) is obtained.
Users can improve the solution obtained by the
automatic routine by examining each solution individually using the task omreidentify .
- The task omreduce wavelength calibrates all the slitlet spectra one by one and puts them
back onto a 2D image at their original position. Corrects for tilts of
spectral lines, if asked to do so. The resultant 2D image looks similar
to a longslit image, except that there are gaps in the spatial direction.
- The task omskysub subtracts sky from the output of omreduce .
Various sky subtraction options are available.
- The task omextract extracts one 1-D spectrum for each slitlet, even
when the continuum spectrum is weak or absent. Alternatively, you can use the
"apall" task of IRAF, with which you can extract multiple spectra in each slitlet.
- Longslit spectra (i.e. stardard star spectra) can also be reduced using this package.
There are two special commands ( olreduce, oltilt ) for longslit spectra, while
MOS-specific commands like omstart, omcombine work for longslit as well.
- Read IRAF reduction manuals
if you are new to spectroscopic reductions.
Cookbook
vocl> gtcmos
+------------------- GTCMOS IRAF Package -------------------+
| Test release of Version 1.0, April 15, 2015 |
| Tested with IRAF v2.16 on Fedora |
| Developed by Divakara Mayya at INAOE, Puebla, Mexico |
| |
| Type help before using it for the first time |
| |
| User's guide is available at |
| file:///iraf/iraf/extern/gtcmos/html/mos_reduction.html |
| |
|Please contact ydm@inaoep.mx if you have questions/comments|
+-----------------------------------------------------------+
olreduce omextract omreidentify omslits
oltilt omidentify omskysub omstart
omcombine omreduce omslice omunlearn
gtcmos>
Tips:
- Should know to use IRAF and ds9 beforehand
- Run iraf in xgterm
- widen xgterm as much as possible
- For longslit spectrum (e.g. standard star) use "olreduce" instead of "omreduce"
gtcmos> lpar omstart
datadir = "../m81/MOS/GTC4-14AMEX/OB0001/bias" Data directory
(filein = "all") File Name
(mosaic = no) Mosaic the 2 CCDs (no==>list only)
(verify = no) Verify each file before mosaic?
(biasim = "") Bias image [empty means no Sub Bias]
(mode = "ql")
gtcmos> omstart ../m81/MOS/GTC4-14AMEX/OB0001/bias
Analyzing the following files
../m81/MOS/GTC4-14AMEX/OB0001/bias/0000652346-20140403-OSIRIS-OsirisBias[1] Bias 1049 2051 OPEN fOtelo911/42 OPEN 0. "2 2" 0.
../m81/MOS/GTC4-14AMEX/OB0001/bias/0000652347-20140403-OSIRIS-OsirisBias[1] Bias 1049 2051 OPEN fOtelo911/42 OPEN 0. "2 2" 0.
../m81/MOS/GTC4-14AMEX/OB0001/bias/0000652348-20140403-OSIRIS-OsirisBias[1] Bias 1049 2051 OPEN fOtelo911/42 OPEN 0. "2 2" 0.
../m81/MOS/GTC4-14AMEX/OB0001/bias/0000652349-20140403-OSIRIS-OsirisBias[1] 7ias 1049 2051 OPEN fOtelo911/42 OPEN 0. "2 2" 0.
../m81/MOS/GTC4-14AMEX/OB0001/bias/0000652350-20140403-OSIRIS-OsirisBias[1] 7ias 1049 2051 OPEN fOtelo911/42 OPEN 0. "2 2" 0.
../m81/MOS/GTC4-14AMEX/OB0001/bias/0000652351-20140403-OSIRIS-OsirisBias[1] Bias 1049 2051 OPEN fOtelo911/42 OPEN 0. "2 2" 0.
../m81/MOS/GTC4-14AMEX/OB0001/bias/0000652352-20140403-OSIRIS-OsirisBias[1] Bias 1049 2051 OPEN fOtelo911/42 OPEN 0. "2 2" 0.
../m81/MOS/GTC4-14AMEX/OB0001/bias/0000652353-20140403-OSIRIS-OsirisBias[1] Bias 1049 2051 OPEN fOtelo911/42 OPEN 0. "2 2" 0.
../m81/MOS/GTC4-14AMEX/OB0001/bias/0000652354-20140403-OSIRIS-OsirisBias[1] Bias 1049 2051 OPEN fOtelo911/42 OPEN 0. "2 2" 0.
../m81/MOS/GTC4-14AMEX/OB0001/bias/0000652355-20140403-OSIRIS-OsirisBias[1] Bias 1049 2051 OPEN fOtelo911/42 OPEN 0. "2 2" 0.
gtcmos> omstart ../m81/MOS/GTC4-14AMEX/OB0001/bias mosaic+
Analyzing the following files
../m81/MOS/GTC4-14AMEX/OB0001/bias/0000652346-20140403-OSIRIS-OsirisBias[1] Bias 1049 2051 OPEN fOtelo911/42 OPEN 0. "2 2" 0.
Running mosaic_2x2_v2 ../m81/MOS/GTC4-14AMEX/OB0001/bias/0000652346-20140403-OSIRIS-OsirisBias
Output stored as gtc14aob001_bias_346
../m81/MOS/GTC4-14AMEX/OB0001/bias/0000652347-20140403-OSIRIS-OsirisBias[1] Bias 1049 2051 OPEN fOtelo911/42 OPEN 0. "2 2" 0.
Running mosaic_2x2_v2 ../m81/MOS/GTC4-14AMEX/OB0001/bias/0000652347-20140403-OSIRIS-OsirisBias
Output stored as gtc14aob001_bias_347
../m81/MOS/GTC4-14AMEX/OB0001/bias/0000652348-20140403-OSIRIS-OsirisBias[1] Bias 1049 2051 OPEN fOtelo911/42 OPEN 0. "2 2" 0.
Running mosaic_2x2_v2 ../m81/MOS/GTC4-14AMEX/OB0001/bias/0000652348-20140403-OSIRIS-OsirisBias
Output stored as gtc14aob001_bias_348
../m81/MOS/GTC4-14AMEX/OB0001/bias/0000652349-20140403-OSIRIS-OsirisBias[1] 7ias 1049 2051 OPEN fOtelo911/42 OPEN 0. "2 2" 0.
Running mosaic_2x2_v2 ../m81/MOS/GTC4-14AMEX/OB0001/bias/0000652349-20140403-OSIRIS-OsirisBias
Output stored as gtc14aob001_bias_349
../m81/MOS/GTC4-14AMEX/OB0001/bias/0000652350-20140403-OSIRIS-OsirisBias[1] 7ias 1049 2051 OPEN fOtelo911/42 OPEN 0. "2 2" 0.
Running mosaic_2x2_v2 ../m81/MOS/GTC4-14AMEX/OB0001/bias/0000652350-20140403-OSIRIS-OsirisBias
Output stored as gtc14aob001_bias_350
../m81/MOS/GTC4-14AMEX/OB0001/bias/0000652351-20140403-OSIRIS-OsirisBias[1] Bias 1049 2051 OPEN fOtelo911/42 OPEN 0. "2 2" 0.
Running mosaic_2x2_v2 ../m81/MOS/GTC4-14AMEX/OB0001/bias/0000652351-20140403-OSIRIS-OsirisBias
Output stored as gtc14aob001_bias_351
../m81/MOS/GTC4-14AMEX/OB0001/bias/0000652352-20140403-OSIRIS-OsirisBias[1] Bias 1049 2051 OPEN fOtelo911/42 OPEN 0. "2 2" 0.
Running mosaic_2x2_v2 ../m81/MOS/GTC4-14AMEX/OB0001/bias/0000652352-20140403-OSIRIS-OsirisBias
Output stored as gtc14aob001_bias_352
../m81/MOS/GTC4-14AMEX/OB0001/bias/0000652353-20140403-OSIRIS-OsirisBias[1] Bias 1049 2051 OPEN fOtelo911/42 OPEN 0. "2 2" 0.
Running mosaic_2x2_v2 ../m81/MOS/GTC4-14AMEX/OB0001/bias/0000652353-20140403-OSIRIS-OsirisBias
Output stored as gtc14aob001_bias_353
../m81/MOS/GTC4-14AMEX/OB0001/bias/0000652354-20140403-OSIRIS-OsirisBias[1] Bias 1049 2051 OPEN fOtelo911/42 OPEN 0. "2 2" 0.
Running mosaic_2x2_v2 ../m81/MOS/GTC4-14AMEX/OB0001/bias/0000652354-20140403-OSIRIS-OsirisBias
Output stored as gtc14aob001_bias_354
../m81/MOS/GTC4-14AMEX/OB0001/bias/0000652355-20140403-OSIRIS-OsirisBias[1] Bias 1049 2051 OPEN fOtelo911/42 OPEN 0. "2 2" 0.
Running mosaic_2x2_v2 ../m81/MOS/GTC4-14AMEX/OB0001/bias/0000652355-20140403-OSIRIS-OsirisBias
Output stored as gtc14aob001_bias_355
gtcmos> imstat gtc14aob001_bias_*
# IMAGE NPIX MEAN STDDEV MIN MAX MIDPT
gtc14aob001_bias_346.fits 4327610 6.705 33.02 -1223. 3328. 7.369
gtc14aob001_bias_347.fits 4327610 6.732 34.12 -1223. 11968. 7.984
gtc14aob001_bias_348.fits 4327610 6.86 33.41 -1229. 6447. 8.153
gtc14aob001_bias_349.fits 4327610 6.918 33.26 -1229. 3141. 8.434
gtc14aob001_bias_350.fits 4327610 6.907 32.87 -1230. 1280. 7.578
gtc14aob001_bias_351.fits 4327610 6.934 37.11 -1229. 33230. 8.468
gtc14aob001_bias_352.fits 4327610 6.909 32.96 -1229. 2703. 7.501
gtc14aob001_bias_353.fits 4327610 6.944 34.12 -1229. 9904. 8.134
gtc14aob001_bias_354.fits 4327610 6.916 33.12 -1229. 4884. 8.027
gtc14aob001_bias_355.fits 4327610 6.929 34.67 -1228. 13979. 8.286
gtcmos> lpar omcomb
filein = "" Input File Name(s)
(fileout = "omcombine") File Name
(imtype = "obj") Image type [bias|obj|arc]
(combine = "median") Type of combine operation
(reject = "none") Type of rejection
(mode = "ql")
gtcmos> omcomb gtc14aob001_bias_* imtype=bias
# IMAGE NPIX MEAN STDDEV MIN MAX MIDPT
gtc14aob001_bias_346.fits 4327610 6.705 33.02 -1223. 3328. 7.369
gtc14aob001_bias_347.fits 4327610 6.732 34.12 -1223. 11968. 7.984
gtc14aob001_bias_348.fits 4327610 6.86 33.41 -1229. 6447. 8.153
gtc14aob001_bias_349.fits 4327610 6.918 33.26 -1229. 3141. 8.434
gtc14aob001_bias_350.fits 4327610 6.907 32.87 -1230. 1280. 7.578
gtc14aob001_bias_351.fits 4327610 6.934 37.11 -1229. 33230. 8.468
gtc14aob001_bias_352.fits 4327610 6.909 32.96 -1229. 2703. 7.501
gtc14aob001_bias_353.fits 4327610 6.944 34.12 -1229. 9904. 8.134
gtc14aob001_bias_354.fits 4327610 6.916 33.12 -1229. 4884. 8.027
gtc14aob001_bias_355.fits 4327610 6.929 34.67 -1228. 13979. 8.286
Feb 4 22:30: IMCOMBINE
combine = median, scale = none, zero = median, weight = none
blank = 0.
Images Median Zero
gtc14aob001_bias_346.fits 8.1591 0.
gtc14aob001_bias_347.fits 8.1569 0.0022
gtc14aob001_bias_348.fits 8.293 -0.1339
gtc14aob001_bias_349.fits 8.3533 -0.1942
gtc14aob001_bias_350.fits 8.3566 -0.1975
gtc14aob001_bias_351.fits 8.3313 -0.1722
gtc14aob001_bias_352.fits 8.3415 -0.1824
gtc14aob001_bias_353.fits 8.3533 -0.1942
gtc14aob001_bias_354.fits 8.3401 -0.181
gtc14aob001_bias_355.fits 8.3295 -0.1704
Output image = omcombine, ncombine = 10
gtcmos> imrename omcombine gtc14aob001_bias_master
gtcmos> omstart ../m81/MOS/GTC4-14AMEX/OB0001/object
Analyzing the following files
../m81/MOS/GTC4-14AMEX/OB0001/object/0000652265-20140403-OSIRIS-OsirisMOS[1] M81-MOS1 1049 2051 OPEN OPEN Sloan_r OPEN 10. "2 2" 0.
../m81/MOS/GTC4-14AMEX/OB0001/object/0000652266-20140403-OSIRIS-OsirisMOS[1] M81-MOS1 1049 2051 OPEN OPEN Sloan_r OPEN 60. "2 2" 0.
../m81/MOS/GTC4-14AMEX/OB0001/object/0000652267-20140403-OSIRIS-OsirisMOS[1] M81-MOS1 1049 2051 R1000B OPEN OPEN OPEN 1308. "2 2" 0.
../m81/MOS/GTC4-14AMEX/OB0001/object/0000652268-20140403-OSIRIS-OsirisMOS[1] M81-MOS1 1049 2051 R1000B OPEN OPEN OPEN 1308. "2 2" 0.
../m81/MOS/GTC4-14AMEX/OB0001/object/0000652269-20140403-OSIRIS-OsirisMOS[1] M81-MOS1 1049 2051 R1000B OPEN OPEN OPEN 1308. "2 2" 0.
gtcmos> omstart ../m81/MOS/GTC4-14AMEX/OB0001/object mosaic+ biasim=gtc14aob001_bias_master
Analyzing the following files
../m81/MOS/GTC4-14AMEX/OB0001/object/0000652265-20140403-OSIRIS-OsirisMOS[1] M81-MOS1 1049 2051 OPEN OPEN Sloan_r OPEN 10. "2 2" 0.
Running mosaic_2x2_v2 ../m81/MOS/GTC4-14AMEX/OB0001/object/0000652265-20140403-OSIRIS-OsirisMOS
Bias subtracted output stored as gtc14aob001_object_265
../m81/MOS/GTC4-14AMEX/OB0001/object/0000652266-20140403-OSIRIS-OsirisMOS[1] M81-MOS1 1049 2051 OPEN OPEN Sloan_r OPEN 60. "2 2" 0.
Running mosaic_2x2_v2 ../m81/MOS/GTC4-14AMEX/OB0001/object/0000652266-20140403-OSIRIS-OsirisMOS
Bias subtracted output stored as gtc14aob001_object_266
../m81/MOS/GTC4-14AMEX/OB0001/object/0000652267-20140403-OSIRIS-OsirisMOS[1] M81-MOS1 1049 2051 R1000B OPEN OPEN OPEN 1308. "2 2" 0.
Running mosaic_2x2_v2 ../m81/MOS/GTC4-14AMEX/OB0001/object/0000652267-20140403-OSIRIS-OsirisMOS
Bias subtracted output stored as gtc14aob001_object_267
../m81/MOS/GTC4-14AMEX/OB0001/object/0000652268-20140403-OSIRIS-OsirisMOS[1] M81-MOS1 1049 2051 R1000B OPEN OPEN OPEN 1308. "2 2" 0.
Running mosaic_2x2_v2 ../m81/MOS/GTC4-14AMEX/OB0001/object/0000652268-20140403-OSIRIS-OsirisMOS
Bias subtracted output stored as gtc14aob001_object_268
../m81/MOS/GTC4-14AMEX/OB0001/object/0000652269-20140403-OSIRIS-OsirisMOS[1] M81-MOS1 1049 2051 R1000B OPEN OPEN OPEN 1308. "2 2" 0.
Running mosaic_2x2_v2 ../m81/MOS/GTC4-14AMEX/OB0001/object/0000652269-20140403-OSIRIS-OsirisMOS
Bias subtracted output stored as gtc14aob001_object_269
gtcmos> omslits gtc14aob001_object_269
36 slitlets found in gtc14aob001_object_269
## ix1 ix2 x_cen y_mos y_CCD stype
1 312 392 352.16351348683 960.42809724925 948.39095873527 rectangular
2 406 422 413.97124290466 674.67596244812 663.72045919895 circular
3 544 623 583.80621672308 1041.9322213566 1033.9488301492 rectangular
....................................................................
....................................................................
35 1874 1889 1881.7553126431 1140.20518784 1121.2656933055 rectangular
36 1897 1974 1935.7530967888 1091.816709784 1071.6622651062 rectangular
## ix1 ix2 x_cen y_mos y_CCD stype
You man open the pre-image in ds9 and load the slitlets region file gtc14aob001_object_269_slits.reg
Pre-image after joining the CCDs with slitlet numbers overlaid as a ds9 reg file
Raw spectra after joining the CCDs with slitlet numbers overlaid as a ds9 reg file
gtcmos> hselect gtc14aob001_object_*.fits "$I EXPTIME BIASSUB" expr+
gtc14aob001_object_265.fits 10. gtc14aob001_bias_master
gtc14aob001_object_266.fits 60. gtc14aob001_bias_master
gtc14aob001_object_267.fits 1308. gtc14aob001_bias_master
gtc14aob001_object_268.fits 1308. gtc14aob001_bias_master
gtc14aob001_object_269.fits 1308. gtc14aob001_bias_master
Note the image has a new keyword BIASSUB containing the name of the bias image
Make sure bias="" when you don't want to subtract bias.
gtcmos> omcomb gtc14aob001_object_267,gtc14aob001_object_268,gtc14aob001_object_269 imtype=obj
# IMAGE NPIX MEAN STDDEV MIN MAX MIDPT
gtc14aob001_object_267 4327610 1090. 4966. -17.35 64465. 404.
gtc14aob001_object_268 4327610 1082. 5003. -21.96 64463. 403.
gtc14aob001_object_269 4327610 1060. 4937. -19.78 64465. 400.3
Feb 4 23:11: IMCOMBINE
combine = median, scale = median, zero = none, weight = none
blank = 0.
Images Median Scale
gtc14aob001_object_267 274.5 1.000
gtc14aob001_object_268 269.18 1.020
gtc14aob001_object_269 268.22 1.023
Output image = omcombine, ncombine = 3
gtcmos> imrename omcombine gtc14aob001_object_abc
Result of combining 3 spectra with slitlet numbers overlaid as a ds9 reg file
gtcmos> omstart ../m81/MOS/GTC4-14AMEX/OB0001/arc
Analyzing the following files
../m81/MOS/GTC4-14AMEX/OB0001/arc/0000652314-20140403-OSIRIS-OsirisCalibrationLamp[1] ArcLamp_HgAr 1049 2051 R1000B OPEN OPEN OPEN 3.6 "2 2" 0.
../m81/MOS/GTC4-14AMEX/OB0001/arc/0000652315-20140403-OSIRIS-OsirisCalibrationLamp[1] ArcLamp_Ne 1049 2051 R1000B OPEN OPEN OPEN 2.1 "2 2" 0.
gtcmos> omstart ../m81/MOS/GTC4-14AMEX/OB0001/arc mosaic+
Analyzing the following files
../m81/MOS/GTC4-14AMEX/OB0001/arc/0000652314-20140403-OSIRIS-OsirisCalibrationLamp[1] ArcLamp_HgAr 1049 2051 R1000B OPEN OPEN OPEN 3.6 "2 2" 0.
Running mosaic_2x2_v2 ../m81/MOS/GTC4-14AMEX/OB0001/arc/0000652314-20140403-OSIRIS-OsirisCalibrationLamp
Output stored as gtc14aob001_arc_314
../m81/MOS/GTC4-14AMEX/OB0001/arc/0000652315-20140403-OSIRIS-OsirisCalibrationLamp[1] ArcLamp_Ne 1049 2051 R1000B OPEN OPEN OPEN 2.1 "2 2" 0.
Running mosaic_2x2_v2 ../m81/MOS/GTC4-14AMEX/OB0001/arc/0000652315-20140403-OSIRIS-OsirisCalibrationLamp
Output stored as gtc14aob001_arc_315
Arc spectra after "summing" HgAr and Ne lamps
gtcmos> lpar omidentify
filarc = "gtc14aob001_arcs" Comparison arc file [auto|arcfile]
(coordli = "DEFAULT") Line id coordinate list
(cursor = "gtcinputs$identify2.cursor") Cursor file for indentify
(mode = "ql")
gtcmos> omidentify gtc14aob001_arcs
identify gtc14aob001_arcs_1[41,*]
identify gtc14aob001_arcs_2[9,*]
.............................
.............................
identify gtc14aob001_arcs_35[8,*]
identify gtc14aob001_arcs_36[39,*]
Dispersion solution from this automatic identificacion can be improved by manually identifying bad matches
To do that run identify gtc14aob001_arcs_36 section=mid col
On the graphic terminal all the identified lines are shown as a fast video.
Don't bother about it. You will only see the identification of the last slitlet.
Result of autoidentification of arc spectral lines of the last slitlet
gtcmos> ls *.rms
identify.rms
The file "identify.rms" contains residual of all lines identified in each of the slitlets.
After examining this file, you may decide to rerun identify gtc14aob001_arcs_# section="mid col"
gtcmos> page identify.rms
Wed 23:28:25 04-Feb-2015
Features identified in image gtc14aob001_arcs_1.
Pixel Fit User Residual Fwidth Wt Label
1 219.77 4046.5704 4046.563 0.00735675 4.00 1 HgI
2 399.10 4358.2962 4358.328 -0.0317851 4.00 1 HgI
3 957.70 5461.0573 5460.735 0.32227432 4.00 1 HgI
4 1110.96 5790.7551 5790.663 0.09208835 4.00 1 HgI
5 1139.01 5852.159 5852.488 -0.3289591 4.00 1 NeI
6 1180.96 5944.5444 5944.834 -0.2895656 4.00 1 NeI
..........................................................
..........................................................
..........................................................
gtcmos> lpar omreduce
filnam = "gtc14a_mos1abc" File Name
filarc = "auto" Comparison arc file [auto|gtc14a_p1arc_m_HgArNe
(filflat = "") Master Flat file [gtc14a_p1_m_flat_b or empty]
(dlam = INDEF) Wavelength interval in Ang/pixel
(pixref = INDEF) Pixel at which lambda=lamref [INDEF=middle]
(lamref = INDEF) Lambda in Ang at pixref
(tilt_slit = no) Correct for Slit tilt?
(fiducial = no) Retain fiducial stars?
(checksky = no) Improve lambda calibration by checking a skylin
(lamsky = 5577.838) Lambda of a sky line in Ang
(slitrej = "") Slitlet numbers to reject
(mode = "ql")
gtcmos> omreduce gtc14aob001_object_abc filarc=gtc14aob001_arcs
1 rectangular gtc14aob001_object_abc[312:392,*] 960.42809724925 948.39095873527 352.16351348683 312 392
3 rectangular gtc14aob001_object_abc[544:623,*] 1041.9322213566 1033.9488301492 583.80621672308 544 623
..........................................................
..........................................................
35 rectangular gtc14aob001_object_abc[1874:1889,*] 1140.20518784 1121.2656933055 1881.7553126431 1874 1889
36 rectangular gtc14aob001_object_abc[1897:1974,*] 1091.816709784 1071.6622651062 1935.7530967888 1897 1974
On the graphic window, gaussian fit to the selected "lamsky" line is shown.
Gaussian profile fit to the 5577.838 line
Wavelength calibrated and "longslit-like" output is stored with _wl suffix.
Note that the fiducial spectra are eliminated with fiducial-
Wavelength calibrated and "longslit-like" output
Skylines of different slitlets are aligned using the values of dlam, pixref and lamref.
Tilt of slanted slitlets (and all other slitlets) can be corrected with tilt_slit+ option.
This option is relatively slower (takes around 10 seconds for each slitlet)
gtcmos> omreduce gtc14aob001_object_abc filarc=gtc14aob001_arcs tilt_slit+
Wavelength calibrated and "longslit-like" output with tilt_slit+
Each individual slitlets are cut and stored (without wavelength calibration)
gtcmos> splot gtc14aob001_object_abc_wl
Image line/aperture to plot (0:) (1480):
Splot cuts through various slitlets
Note the position of skylines (eg. 5577, 6300) which exactly coincide
independent of the original slitlet y-position. Thanks to this feature of the
pipeline, sky slitlets for each object slitlet is needed only in case of variable
backgound (when observing large nearby galaxies).
gtcmos> lpar omskysub
filnam = "gtc15aob1_object_av_wl" File Name
(skytype = "same") Sky type [same, skyslits, pair]
(method = "median") Method of obtaining sky spectrum [median, perce
(percent = 20.) Percentile value for sky [1-50]
(normali = no) Normalize the sky spectrum before subtration?
(skyslit = "1,10,30") Sky slitlet numbers
(mode = "ql")
gtcmos>
gtcmos> omskysub gtc14aob001_object_abc_wl skyslit="1,13,26,31"
Sky subtracted and "longslit-like" output
gtcmos> lpar omextract
filnam = "gtc14a_mos1abc" File Name
slitno = "all" Slit numbers to slice [all, #]
(nfind = 1) Number of apertures to be found automatically
(lamline = INDEF) Dispersion line
(referen = "") List of aperture reference images
(interac = no) Run task interactively?
(extras = yes) Extract sky, sigma, etc.?
(llimit = INDEF) Lower aperture limit relative to center
(ulimit = INDEF) Upper aperture limit relative to center
(ylevel = 0.1) Fraction of peak or intensity for automatic wid
(t_funct = "legendre") Trace fitting function
(t_order = 5) Trace fitting function order
(backgro = "none") Background to subtract
(mode = "ql")
gtcmos> omextract
gtcmos> omstart ../m81/MOS/GTC4-14AMEX/OB0001/stds mos-
Analyzing the following files
../m81/MOS/GTC4-14AMEX/OB0001/stds/0000652303-20140403-OSIRIS-OsirisLongSlitSpectroscopy[1] Ross640 1049 2051 OPEN OPEN Sloan_r OPEN 1. "2 2" 0.
../m81/MOS/GTC4-14AMEX/OB0001/stds/0000652304-20140403-OSIRIS-OsirisLongSlitSpectroscopy[1] Ross640 1049 2051 OPEN OPEN Sloan_r OPEN 1. "2 2" 2.52
../m81/MOS/GTC4-14AMEX/OB0001/stds/0000652305-20140403-OSIRIS-OsirisLongSlitSpectroscopy[1] Ross640 1049 2051 R1000B OPEN OPEN OPEN 10. "2 2" 2.52
../m81/MOS/GTC4-14AMEX/OB0001/stds/0000652306-20140403-OSIRIS-OsirisLongSlitSpectroscopy[1] Ross640 1049 2051 R1000B OPEN OPEN OPEN 100. "2 2" 2.52
gtcmos> omstart ../m81/MOS/GTC4-14AMEX/OB0001/stds mos+ biasim=gtc14aob001_bias_master
Analyzing the following files
../m81/MOS/GTC4-14AMEX/OB0001/stds/0000652303-20140403-OSIRIS-OsirisLongSlitSpectroscopy[1] Ross640 1049 2051 OPEN OPEN Sloan_r OPEN 1. "2 2" 0.
Running mosaic_2x2_v2 ../m81/MOS/GTC4-14AMEX/OB0001/stds/0000652303-20140403-OSIRIS-OsirisLongSlitSpectroscopy
Bias subtracted output stored as gtc14aob001_stds_303
../m81/MOS/GTC4-14AMEX/OB0001/stds/0000652304-20140403-OSIRIS-OsirisLongSlitSpectroscopy[1] Ross640 1049 2051 OPEN OPEN Sloan_r OPEN 1. "2 2" 2.52
Running mosaic_2x2_v2 ../m81/MOS/GTC4-14AMEX/OB0001/stds/0000652304-20140403-OSIRIS-OsirisLongSlitSpectroscopy
Bias subtracted output stored as gtc14aob001_stds_304
../m81/MOS/GTC4-14AMEX/OB0001/stds/0000652305-20140403-OSIRIS-OsirisLongSlitSpectroscopy[1] Ross640 1049 2051 R1000B OPEN OPEN OPEN 10. "2 2" 2.52
Running mosaic_2x2_v2 ../m81/MOS/GTC4-14AMEX/OB0001/stds/0000652305-20140403-OSIRIS-OsirisLongSlitSpectroscopy
Bias subtracted output stored as gtc14aob001_stds_305
../m81/MOS/GTC4-14AMEX/OB0001/stds/0000652306-20140403-OSIRIS-OsirisLongSlitSpectroscopy[1] Ross640 1049 2051 R1000B OPEN OPEN OPEN 100. "2 2" 2.52
Running mosaic_2x2_v2 ../m81/MOS/GTC4-14AMEX/OB0001/stds/0000652306-20140403-OSIRIS-OsirisLongSlitSpectroscopy
Bias subtracted output stored as gtc14aob001_stds_306
gtcmos> olreduce gtc14aob001_stds_306 filarc=auto
Emperical relation used to obtain the following spline3 order=1 coefficients
266.3072428 513.395714 1300.0320254 2164.274617
Running dispcor to resample linearly. Takes around 5 minutes.
Wavelength reference:
gtc14aob001_stds_306_arc_emp
gtcmos> oltilt gtc14aob001_stds_306_wl
160 2021
160 [160:179,*]929.90561136949 2.0770128333659 5561.998 5549.271 943.65949846209
180 [180:199,*]930.78042541532 2.0770128333659 5562.358 5551.088 943.65949846209
200 [200:219,*]931.45350743848 2.0770128333659 5562.718 5552.486 943.65949846209
220 [220:239,*]932.2715091247 2.0770128333659 5563.078 5554.185 943.65949846209
...............................................................................
...............................................................................
1970 [1970:1989,*]931.13622485389 2.0770128333659 5557.378 5551.827 943.65949846209
1990 [1990:2009,*]930.4751793476 2.0770128333659 5556.938 5550.454 943.65949846209
2010 [2010:2029,*]929.70002766142 2.0770128333659 5556.498 5548.844 943.65949846209
Tilt-corrected spectra stored as gtc14aob001_stds_306_wl_tlt
gtcmos> twodspe
twodspec> apextract
apextract> apall gtc14aob001_stds_306_wl_tlt interac+ extras+ lower=-8 upper=8 b_sampl="-50:-40,40:50" t_funct=legendre t_order=5 backgro=median
Find apertures for gtc14aob001_stds_306_wl_tlt? (yes):
Number of apertures to be found automatically (1):
Resize apertures for gtc14aob001_stds_306_wl_tlt? (yes):
Edit apertures for gtc14aob001_stds_306_wl_tlt? (yes):
Extraction plot
apextract> splot gtc14aob001_stds_306_wl_tlt.ms
Image band to plot (1:) (1):
Extracted standard star spectrum
Use standard and sensfunc to obtain the sensitivity curve and then run
fluxcalib gtc14aob001_object_abc_wl to get flux and wavelength calibrated 2D spectrum
use apall with appropriate parameters to extract individual 1D spectrum
Last updated on 6 February 2015 ydm@inaoep.mx