1. The SPIRE Point Source Catalog (SPSC) Status
Bernhard Schulz
on behalf of the SPSC Team
NHSC-IPAC Caltech

2. The SPSC Team NASA Herschel Science Center IPAC-Caltech Nanyao Lu
John Rector
Bernhard Schulz (PI)
David Shupe
Kevin Xu
Konkoly Observatory
Csaba Kiss
Gabor Marton
Erika Varga-Verebélyi
SPIRE ICC, Rutherford Appleton Labs,
STFC
Chris Pearson
SPIRE ICC, Cardiff University
Andreas Papageorgiou
Herschel Science Centre, ESAC-ESA
Tanya Lim
Ivan Valtchanov
Eötvös Loránd University Budapest
Sándor Pintér
Victor Tóth

3. SPIRE Scan Map Observations
6917 Scan Map Obs. Total
4204 Small Scan Obs.
1880 Large Scan Map Obs.
833 Parallel Mode Obs.
Red: Single Maps
Green: Galactic Plane overlapping maps
Blue: Other overlapping maps

4. Catalog Consolidation
Building the SPSC
Re-Processing
TwoPass Pipeline
Incl. Turn-around data
HSA
SpireCat
Postgres database
SPSC
Re-Processing
Local Pool
Source Extraction
STRN Map generation
Structure Noise Maps
Catalog Consolidation
Source Extraction
Detection
Photometry
Determine source extension
Pointing correction
Catalog Consolidation
Resolve source multiplicities
Error analysis
Catalog statistics
Flags
Local STRN extraction

5. Daophot Parameter Filter
Source Detection
point source map
ext. source map
Start
Level 1 context
Sussextractor
Daophot
Daophot Parameter Filter
Timeline Fitter Fixed
Timeline Fitter Free
Output Table
End

6. Structure Noise Calculation
The Lockman Hole (KPGT_dlutz_1)
Field G (KPOT_mjuvela_1)
The structure noise measures the fluctuation around a given point in the sky. This measure can be translated into the power spectrum of the neighbouring areas, but it gives local information instead of a general number. We use this quantity to describe the background noise in the close vicinity of each detected source.
For each pixel of the map the structure noise (NS) is calculated as the mean deviation of the pixel’s (green) flux with respect to the reference pixel (red). It is calculated as follows:
, where
and μ is the mean value of the di values.

9. SPSC Status 1 Data Reprocessing Pointing Source Extraction
Small and large scan maps complete since June 2015.
Parallel mode maps complete since Sept 2015.
Very few maps resisted reprocessing and are excluded for now.
Pointing
Corrections available for more than 1/3 of all maps from WISE catalog stacking.
Most observations have good pointing accuracy for SPIRE except a few due to Star Tracker issues.
Focus on combined maps that are destriped together.
Source Extraction
First test of production grade point source extraction procedure in August 2015.
Small and large scan maps  2.5 M source candidates in Sept 2015.
All combined maps (parallel and large)  5.7 M source candidates in Oct 2015.
All 8.2M source candidates ingested in relational Postgres database.

10. Database Schema (SpireCat)
Observation Table (observation)
Obs ID: Primary Key
List of all scan map observations
Source Table (source)
Source ID: Primary Key
Obs ID: Foreign Key
Group ID: Foreign Key
List of source detections with different algorithms
Catalog (catalog)
Group ID: Primary Key
List of groups of source detections belonging to the same source
Position Corrections (poscorr)
List of position offsets from WISE point source stacking
Large Galaxies (largegal)
Galaxy ID: Primary Key
List of encircling ellipses of galaxies >1’ from 2MASS Catalog
SSO Tracks
SSO ID: Primary Key
List of start and end positions and estimated fluxes in SPIRE filters
Structure Noise Table (strn)
List of structure noise numbers for each source position in SPIRE filters
linked by position
Postgres database with fast Q3C position indexing.
Relational Postgres database
Run Log (runlog)
(ObsID, SwVersion): Primary Key
Information about source extraction runs safeguarding ingestion into source table.
WISE W4 Sources (wisecat)
name: Primary Key
Catalog of WISE 22 mm sources with S/N>=3 and w4m>1 to support position corrections through stacking.
linked by
Source ID
linked by Obs ID
and Sw Version
position
Obs ID
linked by Group ID

11. SPSC Status 2 Uncertainties Quality Control
Structure noise maps were produced for all observations that have reprocessed maps and the list of specific values for each position is in the making.
Photometric accuracy, and completeness expressed as a function of structure noise still needs to be fully established through simulations by source injection.
Quality Control
Sources where positions of both timeline fits disagree with the Sussextractor position are flagged.
Sources where photometry substantially disagrees between methods are flagged.
A tool was developed that shows cutouts of maps around source detections from a source list.
Various statistics will be derived from the database to find parameters like semi-extended source thresholds etc.

12. Catalog Entries
ObsID Cross Reference
Object ID
Array Name RA
DEC s
D RA
D DEC
Position
Errors
Offsets l
Position Information
Source ID
Object ID
Observ. ID
unique
Flags
Extended Source
SSO Contamination
Map Edge
Large Galaxy
Variability
STRN Category
Cirrus Category ?
Catalog entries aim to provide the best position and flux values for a given object, based on the source extractions from one or several observations (maps).
Flux s
Instr.
N of M Det.
M Det.
Flags
Quality
Noise
# of detections
Flux Information
Quality Info

13. SPSC Status 3 Additional Data for Flags Catalog Consolidation
A list of nearby galaxies supplied by NED will be used to flag sources within these regions.
A list with tracks of known Solar System Objects in the SPIRE maps will be used to flag potential conflicts.
The structure noise category will be set based on the corresponding table.
The other planned flags will be derived from local information.
Catalog Consolidation
Currently we focus on the CCDPs.
The first procedure that creates the catalog entries by linking all source detections indistinguishable by position and wavelength, has been tested successfully.
A first catalog of the representative dataset sources (~170000) was created as a test bed for those CCDPs that fill the rest of the catalog columns.
A first skeleton catalog was produced end of 2015 with (2.8, 2.1, 0.8)M objects/groups for 250, 350, 500 micron respectively.
Documentation
Initial documents were SPSC Implementation Plan and the SPSC Feasibility Study.
We produced and are maintaining the SPSC Work-Packages Document and the SPSC Database Primer, that contain most information relevant to the project at this time.
Final documentation will be in form of an Explanatory Supplement and a refereed paper.

14. Remaining Issues Pointing Extended source discrimination
Only about one third of the corrections from WISE stacking are reliable so far.
Extended source discrimination
Investigation using machine learning for source classification
Combined Observations
There are many shallow Level 2 maps that overlap, that would provide better and more reliable source detections if combined first as Level 2.5.
Some naming inconsistencies exist that need fixing.
Old HIPE 13 and 14 bugs
Reprocessing was performed using HIPE 12.1 processed Level 0 data with HIPE and for some combined maps with HIPE
A number of issues were fixed and deglitching and destriping were improved in HIPE 14 RC2.
Catalog Column Derivation Procedures
Taking more time to develop.

15. Conclusion We have generated a first skeleton catalog.
Working on CCDPs for catalog columns and quality assessment.
First catalog version expected spring 2016.
Consider splitting into high quality catalog for science use and source list with lower photometric accuracy for obs. planning.
Some quality issues regarding pointing, and source extraction can only be fixed in a second round.

16. End

17. Appendix

18. Coverage Estimates
SPIRE observed a total area of 4723 deg^2 equivalent to ~11.4% of the sky.
Back-of-the-spreadsheet-calculation!
Duplicate coverage was only corrected for considering parallel mode.
Included increase over nominal areas.
Include turnaround data.
Removing turnaround data will decrease the covered area to ~10.8% of the sky.
Depending on the detection threshold we can expect a total of about 3 Million sources in all three bands for a 30 mJy threshold.
All scan maps
squ. deg
fraction
of all sky
Total
4723
11.4%
SpirePacsParallel
2515
53%
6.1%
SpirePhotoLargeScan
2001
42%
4.8%
SpirePhotoSmallScan
208 4%
0.5%
Without Calibration
squ. deg
# diff
fraction
of all sky
Total
4516
208
96%
10.9%
Parallel Mode
2439 76
54%
5.9%
Large Map
1899
102
42%
4.6%
SmallMap
178 30 4%
0.4%
Especially the Galactic Plane will make point source detection and discrimination very difficult.
Excluding +/- 2 deg around the Galactic Plane will reduce the area coverage by ~20%.
Exclude Galactic Plane
of all SPIRE
GalLat thresh. [deg] 2
# diff
fraction
of all sky
Total
3650
866
81%
8.8%
Parallel Mode
1598
841
44%
3.9%
Large Map
1882 17
52%
4.6%
SmallMap
170 8 5%
0.4%

19. Optimal Timeline Fitter Parameters
Core Area
Background Annulus
Timeline Fitter set to use readouts from central region and background annulus to fit Gaussian PSF model.
Allow background level to vary.
Choose annulus to begin after 2nd Airy ring and cover area only slightly larger than core area.
In second run allow elliptical fit and tilted background to distinguish extended sources.
PSW
PMW
PLW
Core radius [“] 22 30 42
Inner radius [“] 70 98
140
Outer radius [“] 74
103
147
PSF
Core Area
Background Annulus

20. Source Extraction Parameters
PSW
PMW
PLW
Sussex-tractor
Daophot
Timeline Fitter
Remarks
fwhm
17.6
23.9
35.2 x
FWHM in arcsec
pixSize 6 10 14
N/A
Pixel size in arcsec
detThreshold 3
S/N detection threshold
rpeak 22 30 42
Radius of central source aperture in arcsec
prfSize 5
Size of Sussextractor PRF in pixels
innerArcsec
Inner radius of background annulus in arcsec
outerArcsec 33 45 63
Outer radius of background annulus in arcsec
maxIter
400
Maximum number of iterations
rBackground[0] 70 98
140
rBackground[1] 74
103
147

21. Source Extraction per ObsID (spscRunObsid.py)
Start
Load next Observation
PNG Map Overplots
Post Processing
Source Table
Run Table
End
Level 2.5 exists?
yes no
Combine Level 1 scans
Copy maps from L2.5
Copy maps from L2
Copy Level 1 scans
point source maps
ext. source maps
Level 1 scans
Source Extractor
List of linked
observations
First ObsID?
ObsID List
End of List?

22. Source Extractor (spscExtract.py)
source list 1
TL Fixed Par.
point source map
ext. source map
Start
Level 1 context
Sussextractor
Daophot
Daophot Param.
Daophot Parameter Filter
source list 2
Timeline Fitter Fixed
Timeline Fitter Free
TL Free Par.
Output Table
End