NGC3379 is a bright, circular, well-studied galaxy. In addition, it is located next to two other similarly sized galaxies that can be studied in the same PFC field.
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The NGC3379 field on a McDonald 0.8-meter PFC image. I have 5 images of the N3379 field
made with this instrument:
% cd /home/sco/N3379/images_fixed (on old scohome) % gethead R*fits OBJECT INSFILTE EXPTIME Rsco2039.fits NGC3379 R 60.00 Rsco2040.fits NGC3379 R 600.00 Rsco2041.fits NGC3379 R 600.00 Rsco2042.fits NGC3379_B B 600.00 Rsco2043.fits NGC3379_V V 600.00 (Image shown above) |
The PFC CCD collection has been reduced in with CCDRED (iraf) and the processed images reside in $scohome/Red_PhaseI_Data/.
This file: /home/sco/N3379/S/README.Jun2018_N3379
I want to work on my N3379 images (I do all of this in: /home/sco/N3379)
Most of the work, through the stage of wcs calibrtion, is in: /home/sco/N3379/T2
============================================================================
STEP: Get the images (See file:///home/sco/sco/scohtm/scocodes/PFC_List/index.html#SEC_1)
I do all of this in ./images_raw
% object_fits_list /home/sco/sco/Red_PhaseI_Data/
List.1 = fullfits list of files
List.2 = list with file, target. and filter names
% object_unique_list.py List.2 List.SCO_objects
This makes: List.SCO_objects and I see 3 names I am interestin:
NGC3379_V (line 17)
NGC3379_B (line 29)
NGC3379 (line 139)
# Recall in my early days I included the filter in the OBJECT card
% fits_select NGC3379_V V > list.ALL
% fits_select NGC3379_B B >> list.ALL
% fits_select NGC3379 B >> list.ALL
% fits_select NGC3379 V >> list.ALL
% fits_select NGC3379 R >> list.ALL
# I can make a quicky listing:
% gethead @list.ALL INSFILTE OBJECT EXPTIME
Rsco2043.fits V NGC3379_V 600.00
Rsco2042.fits B NGC3379_B 600.00
Rsco2039.fits R NGC3379 60.00
Rsco2041.fits R NGC3379 600.00
Rsco2040.fits R NGC3379 600.00
I can pull the images:
% mkdir imgs_raw
% cd imgs_raw
% cp ../list.ALL .
% impuller list.ALL
Name = /home/sco/sco/Red_PhaseI_Data/apr_2004_p1/Rsco2043.fits
Name = /home/sco/sco/Red_PhaseI_Data/apr_2004_p1/Rsco2042.fits
Name = /home/sco/sco/Red_PhaseI_Data/apr_2004_p1/Rsco2039.fits
Name = /home/sco/sco/Red_PhaseI_Data/apr_2004_p1/Rsco2041.fits
Name = /home/sco/sco/Red_PhaseI_Data/apr_2004_p1/Rsco2040.fits
============================================================================
STEP: Remove bad cards from my original PFC images in ./imgs
mkdir images_fixed/
cd images_fixed/
ls -1 /home/sco/N3379/images_raw/R*fits >list.1
To get the list of all keywords:
% fitskw.sh /home/sco/N3379/images_raw/Rsco2040.fits > words.list
% cp words.list my_bad_cards
# Then I edit my_bad_cards to include only the words I DO NOT want
Here is what I usually use:
% cat my_bad_cards
ORIGIN
IRAF-TLM
COMMENTS
DARKTIME
POINT
PROGRAM
SSI
DSP
PREFLASH
CAMTEMP
DEWTEMP
CCDSEC
ORIGSEC
CCDSUM
INSTRTEM
WCSDIM
LTM1_1
LTM2_2
WAT0_001
WAT1_001
WAT2_001
TRIM
FIXPIX
OVERSCAN
ZEROCOR
LTV1
LTV2
CCDPROC
FLATCOR
COMMENT
INSFOCUS
*** Finally I correct the headers with:
% remove_fitslist_kwords list.1 my_bad_cards N
% ls
list.1 my_bad_cards Rsco2039.fits Rsco2040.fits Rsco2041.fits Rsco2042.fits Rsco2043.fits
============================================================================
STEP: Install wcs
NOTE: All of my wcsf_ codes read the local WCSF.DEFAULTS if present. Below
I show a good example for PFC images.
% cat WCSF.DEFAULTS
15.0 R2maglim R2mag limit for initial 2-panel usno_identify run
red textcolor Color for text labeling for initial 2-panel usno_identify run
14 fontsize Text size for initial 2-panel usno_identify run
14.5 Vmag V mag limit for wcs_refine run
26.0 radius search radius (arcminutes) for usno catalog in wcs_refine run
10.0 circrad radius (pixels) for source labels in wcs_refine run
Blue magname name of USNO mag for final usno_look_wcs run
14.0 magmax mag limit for final usno_look_wcs run
5.0 skysiglev sky sigma threshold for imgcat0 run
SubStep1: Get rough estimates for CRPIX1,2 and CRVAL1,2
-------------------------------------------------------
% pwd
/home/sco/N3379
% mkdir local_red
% ls -1 /home/sco/N3379/images_fixed/*fits >list.1
% cat list.1
/home/sco/N3379/images_fixed/Rsco2039.fits
/home/sco/N3379/images_fixed/Rsco2040.fits
/home/sco/N3379/images_fixed/Rsco2041.fits
/home/sco/N3379/images_fixed/Rsco2042.fits
/home/sco/N3379/images_fixed/Rsco2043.fits
**** If we are running on PFC images of one galaxy (which we are) then
create the local file named "Default.RaDecName" that gives the
RAsex,DECsex,Name for the galaxy. The code "ds9_crpix_set" will
be used to set the X,Y,Ra,Dec
% cat Default.RaDecName
10:47:49.90 +12:34:57.0 N3379
NOTE: If the "Default.RaDecName" is not present, then you will be
queried for the [RAsex,DECsex,Name] for every image.
ALSO NOTE: The single source you mark in ds9_crpix_set does not have to
be the galaxy of interest. You just have to have an easily
identified target with known Ra,Dec.
% wcsf_rough list.1 N
*** I answer "Y" to the question about running usno_identify (although in the
case of pfc images I'll really be running the code: ds9_crpix_set
% ls
Default.RaDecName fits_review.pass0 list.0 list.1.codes S/
fits_review.params_used fits_review.pass0_Explain list.1 local_red/ WCSF.DEFAULTS
% ls local_red/ROUGHWCS/
Rsco2039.fits Rsco2040.fits Rsco2041.fits Rsco2042.fits Rsco2043.fits
SubStep2: Confirm and refine the rough wcs solution
----------------------------------------------------
The wcsf_viscat code lest you assess the quality of the rough wcs solutions
and fix up (using wcs_refine) most cases of poor solutions.
% ls
fits_review.params_used list.1 local_red/ S/ t0/ WCSF.DEFAULTS
% ls ./local_red/VISCAT
Rsco2039.fits Rsco2040.fits Rsco2041.fits Rsco2042.fits Rsco2043.fits
Rsco2039.png Rsco2040.png Rsco2041.png Rsco2042.png Rsco2043.png
Rsco2039-usno.cdfp Rsco2040-usno.cdfp Rsco2041-usno.cdfp Rsco2042-usno.cdfp Rsco2043-usno.cdfp
*** The refined (or confirmed) wcs images are in the VISCAT subdirectory along
with a png image of the field and a cdfp catalog of (some) sources in the image.
SubStep3: Build image catalogs
------------------------------
% cat WCSF.DEFAULTS
15.0 R2maglim R2mag limit for initial 2-panel usno_identify run
red textcolor Color for text labeling for initial 2-panel usno_identify run
14 fontsize Text size for initial 2-panel usno_identify run
14.5 Vmag V mag limit for wcs_refine run
26.0 radius search radius (arcminutes) for usno catalog in wcs_refine run
10.0 circrad radius (pixels) for source labels in wcs_refine run
Blue magname name of USNO mag for final usno_look_wcs run
14.0 magmax mag limit for final usno_look_wcs run
10.0 skysiglev sky sigma threshold for imgcat0 run
% wcsf_imgcat list.1 N
The results are placed into the archive directory: local_red/IMGCAT0
The basic files ade in this step:
Rsco2040.fits - the images analyzed (just a copy)
Rsco2040_bkg1.fits - background map
Rsco2040_sigma.fits - image of the noise distribution
Rsco2040_detsig.fits - detection significance map
Rsco2040_label0.fits - connected (and labeled) pixel map
Rsco2040.cat0 - ascii catalog file
Rsco2040.cdfp - cdfp file of sources (has Ra,Dec for all catalog sources)
Rsco2040.table,params,parlab - table file of simple image parameters
SubStep4: Use catalog sources to make final wcs solution
--------------------------------------------------------
% pwd
/home/sco/N3379/T2
% ls
Default.RaDecName list.1 local_red/ S/ WCSF.DEFAULTS
% wcsf_final list.1 Y N
After this I have:
% ls local_red/WCS
Rsco2039.fits Rsco2040.fits Rsco2041.fits Rsco2042.fits Rsco2043.fits
*** Each PFC image is now wcs-calibrated with around 300 stars
In Jul2018 I revised some of the ZP calibration reduction steps to make a more seamless reduction flow. Most of the deatils are dissussd in the documentation for the the main tool used in this process: photcal_fitslist. The steps really come down to this:
% photcal_fitslist ./S/list.1 ps1 N # First pass to collect stars # gri photometry is collected from the PS1 webtool % photcal_fitslist ./S/list.1 ps1 N # Second pass to compute ZP values
The primary upgrades concerned how to more easily change the set of sources used to compute the ZP values. I made changes to the zpstars routine to make it simpler to change the aperture sizes and resultant photometry (via (usno_look_wcs and (mido.sh). I upgraded a lot of my documenation on how to use the gri of PanSTARRS (PS1) for this work, and the results are summarized in the table below:
% gethead ./local_red/ZP/*.fits INSFILTE ZPSEC ZPERR NUMZP Rsco2039.fits R -8.79392 0.007837 74 Rsco2040.fits R -8.86507 0.002382 96 Rsco2041.fits R -8.90970 0.004795 66 Rsco2042.fits B -9.82242 0.008243 59 Rsco2043.fits V -9.30222 0.018677 50
With a photometric zeropoint available, we can compute calibrated photometry. One of the most valuable quantities is a measure of the night sky surface brightness of the image calibrated to some standard system. In addition, we'd like to know the state of the moon at the time the image was taken (was it up?, what was the phase?, what is the angular separation of the moon and the image position on the sky?). In thsi section we instal all of this information in the image headers.
% skyprops_fitslist ./S/list.0 NFor each image we'll mark clear sky area with a ds9 box region and compute mean sky surface brightness via he routine skysb_stats). The moon properties will be installed in the FITS headers using skymoon.
After processing the NGC3379 images I find:
% gethead ./local_red/CAT/*.fits INSFILTE SKYSB SKYSBERR Image filterm.e. Rsco2039.fits R 20.54326 0.009656 Rsco2040.fits R 20.48375 0.007863 Rsco2041.fits R 20.68311 0.003766 Rsco2042.fits B 21.96543 0.006386 Rsco2043.fits V 20.99785 0.003754 These images were taken in mid solar cycle (between max-min). I am unsure of the weather conditions for this night. These calibrated images are on scohome in: /home/sco/N3379/T2/local_red/CAT
I have two basic codes that make viewing and initial measurements of FITS images very easy. They are ds9_imstats and ds9_profiles. As a brief intro to the surface photometry used here, I describe in the ds9_profiles webdoc a quick look at profiles in the NGC3379 field.