Data Products

Several data outputs are produced by caesar{} at the end of the processing if corresponding options are activated in the configuration file:

ROOT Output

If saveToFile option is enabled, a ROOT file is produced with different stored objects (depending on the activated options):

  • ROOT TTree (named SourceInfo) with caesar Source objects, containing summary parameters plus detailed information at pixel level (see Source API section);

  • ROOT TTree (named ConfigInfo) with a list of configuration options used in the run;

  • ROOT TTree (named PerformanceInfo) with a list of run parameters (runtimes at different stages, used memory, etc);

    • Input map, stored as a caesar Image object (see Image API section)

    • Background, noise and significance maps, stored as caesar Image objects (see Image API section)

    • Residual map, stored as a caesar Image object (see Image API section)

    • Segmentation and saliency maps, stored as a caesar Image object (see Image API section)

DS9 Output

If saveDS9Region option is enabled, two ds9 region files are produced with the list of catalogued source islands and fitted components, respectively reported as labeled polygon or ellipse regions, each with a series of tags assigned (e.g. compact/point-like vs extended, real vs spurious, etc).

Ascii Output

If saveToCatalogFile option is enabled, two tabular ascii files are produced with a series of summary parameters for each catalogued source islands and fitted components, respectively.

Table format for source islands is described below:

Col No.

Name

Unit

Description

1

name

Source name assigned by finder

2

iauName

Source name in IAU notation

3

nPix

Number of pixels in island

4

nComp

Number of fitted components (=0 if fit not performed or failed)

5

nNested

Number of nested sources found in island

6-7

(x,y)

Source x,y position

8-9

(xw,yw)

Source x,y position weighted by pixel fluxes

10-11

(x_wcs,y_wcs)

deg

Source x,y sky position

12-13

(xw_wcs,yw_wcs)

deg

Source x,y sky position weighted by pixel fluxes

14-15

(xmin,xmax)

Source pixel min, max x coord.

16-17

(ymin,ymax)

Source pixel min, max y coord.

18-19

(xmin_wcs,xmax_wcs)

deg

Source pixel min, max x sky coord.

20-21

(ymin_wcs,ymax_wcs)

deg

Source pixel min, max y sky coord.

22

nu

GHz

Frequency value extracted from image header

23

Ssum

Jy/beam

Sum of island pixel brightness

24

Smax

Jy/beam

Max pixel brightness in island

25-26

(S,Serr)

Jy/beam

Source fitted flux brightness (not corrected by beam area) and its error

27

npix_beam

Number of pixels in beam

28

bkg_sum

Jy/beam

Background summed over island pixels

29

rms_sum

Jy/beam

Background noise summed over island pixels

30

F1

Source morph. flag {1=COMPACT,2=POINT-LIKE, 3=EXTENDED,4=COMPACT-EXTENDED}

31

F2

Sourceness flag{1=REAL,2=CANDIDATE,3=FAKE}

32

F3

Boolean flag indicating if source was tagged as good (true) or bad (false) in finding process

33

F4

Source depth level flag (nested source if >0)

Table format for source components is described below:

Col No.

Name

Unit

Description

1

name

Source name assigned by finder

2

nPix

Number of pixels in island

3

compId

Component id

4

iauName

Source name in IAU notation

5-6

(x,y)

Component x,y position

7-8

(xerr,yerr)

Component x,y position errors

9-10

(x_wcs,y_wcs)

deg

Component x,y sky position

11-12

(xerr_wcs,yerr_wcs)

deg

Component x,y sky position errors

13

nu

GHz

Frequency value extracted from image header

14-15

(Speak,Speak_err)

Jy/beam

Component peak brightness and error

16-17

(S,Serr)

Jy/beam

Component brightness (not corrected by beam area) and error

18-19

(S_i,Serr_i)

Jy/beam

Island brightness (not corrected by beam area) and error

20

npix_beam

Number of pixels in beam

21-23

(a,b,theta)

Component ellipse pars

24-26

(a_err,b_err,theta_err)

Component ellipse par errors

27-29

(a_wcs,b_wcs,theta_wcs)

“,”,deg

Component ellipse pars in sky coords

30-32

(a_err_wcs,b_err_wcs,theta_err_wcs)

“,”,deg

Component ellipse par errors in sky coords

33-35

(bmaj,bmin,pa)

“,”,deg

Beam ellipse pars in sky coords

36-38

(a_deconv_wcs,b_deconv_wcs,theta_deconv_wcs)

“,”,deg

Component ellipse par in sky coords, deconvolved by beam

39

E/E_beam

Ratio of fitted and beam ellipse eccentricities

40

A/A_beam

Ratio of fitted and beam ellipse areas

41

psi

deg

Rotation angle between fit and beam ellipse

42

bkg_sum

Jy/beam

Background summed over island pixels

43

rms_sum

Jy/beam

Background noise summed over island pixels

44-45

(chi2,ndf)

Source island fit chisquare and degrees of freedom

46

F1

Source fit quality flag {0=BAD,1=LOW,2=MEDIUM,3=HIGH}

47

F2

Component sourceness flag {1=REAL,2=CANDIDATE,3=FAKE}

48

F3

Component morph. flag {1=COMPACT,2=POINT-LIKE,3=EXTENDED, 4=COMPACT-EXTENDED}

FITS Output

If saveToFITSFile option is enabled, a series of FITS image files are produced (if corresponding options are activated):

  • Input map

  • Background, noise and significance maps

  • Residual map

  • Saliency map