Update on SPIRE Photometer Pipeline

Transcription

1 Update on SPIRE Photometer Pipeline Kevin Xu NHSC/IPAC on behalf of the SPIRE ICC page 1

2 What s New in HIPE 9.1 Improved map-making, with destriper in standard processing Electrical crosstalk correction (significant for very bright sources) NaiveMapper has two options for estimating flux in a sky pixel: simple average (the only option before HIPE 9) inverse variance weighted mean Cooler Burps correction in user pipeline scripts New versions of two point source photometry tasks: Timeline Fitter Sussextractor Two new SPIRE Useful scripts : Photometer Bolometer Finder Photometer Calculate Ephemeris SSO Position page 2

3 Destriper Destriper (replacing the median baseline remover as pipeline default): Minimize map stripes by adjusting the baseline subtraction (median or polynomial) iteratively using the naïve mapper. Median Baseline Remover: Destriper: For more information, see the Destriper s webpage: page 3 3

4 What s New in HIPE 9.1 Improved map-making, with destriper in standard processing Electrical crosstalk correction (significant for very bright sources) NaiveMapper has two options for estimating flux in a sky pixel: simple average (the only option before HIPE 9) inverse variance weighted mean Cooler Burps correction in user pipeline scripts New versions of two point source photometry tasks: Timeline Fitter Sussextractor Two new SPIRE Useful scripts : Photometer Bolometer Finder Photometer Calculate Ephemeris SSO Position page 4

5 What s New in HIPE 9.1 Improved map-making, with destriper in standard processing Electrical crosstalk correction (significant for very bright sources) NaiveMapper has two options for estimating flux in a sky pixel: simple average (the only option before HIPE 9) inverse variance weighted mean Cooler Burps correction in user pipeline scripts New versions of two point source photometry tasks: Timeline Fitter Sussextractor Two new SPIRE Useful scripts : Photometer Bolometer Finder Photometer Calculate Ephemeris SSO Position page 5

6 SPIRE Naïve Mapper Two options: (1) No weighting: Flux of a sky pixel is the simple average of all signal samplings (by all detectors) in the pixel: f pixel = page 6 n " i n f i, error pixel = n # i ( f i " f pixel ) 2 n(n "1) (2) Inverse variance (of instrument noise) weighted: Flux of a sky pixel is the inverse variance weighted mean of all signal samplings in the pixel, the variance is calculated using the white noise of the detector with which a given sampling is taken: f pixel = n # i n # i f i /" i 2 1/" i 2 error pixel = % ' & n $ i n $ i ( f i " f pixel ) 2 /# i 4 ( 2 1/# i * ) 2 n $ " 1/# i 4 i Sky pixel f 5 f 4 f 3 f 1 f 2 signal samplings

7 SPIRE Naïve Mapper HIPE Command Line: Simple Average: mappsw=naivescanmapper(scans, array="psw", method=binaryweightstrategy) Inverse variance (of instrument white noise) weighted: mappsw=naivescanmapper(scans, array="psw", method=whitenoiseweight) page 7 7

8 What s New in HIPE 9.1 Improved map-making, with destriper in standard processing Electrical crosstalk correction (significant for very bright sources) NaiveMapper has two options for estimating flux in a sky pixel: simple average (the only option before HIPE 9) inverse variance weighted mean Cooler Burps correction in user pipeline scripts New versions of two point source photometry tasks: Timeline Fitter Sussextractor Two new SPIRE Useful scripts : Photometer Bolometer Finder Photometer Calculate Ephemeris SSO Position page 8

9 NHSC Webinar: New SPIRE Features in HIPE th Nov 2012, Pasadena Every time when SPIRE is switched on after a cooler recycle, the first ~6 h sees rapid drifts of the temperature and of the bias voltage. It causes abnormal drifts in detector timelines, which in turn cause stripes in maps observed during the cooler burp period. An example of stripes caused by cooler burp: In user pipeline, there is an optional module for the correction of this effect. page 9 Cooler Burp Resistor voltage After cooler recycle 1 (~40 h) Bias voltage After cooler recycle 2 (~40 h) bias drift ~10σ burp ~ 6h

10 What s New in HIPE 9.1 Improved map-making, with destriper in standard processing Electrical crosstalk correction (significant for very bright sources) NaiveMapper has two options for estimating flux in a sky pixel: simple average (the only option before HIPE 9) inverse variance weighted mean Cooler Burps correction in user pipeline scripts New versions of two point source photometry tasks: Sussextractor Timeline Fitter Two new SPIRE Useful scripts : Photometer Bolometer Finder Photometer Calculate Ephemeris SSO Position page 10

11 HIPE Command Line: Sussextractor (new algorithm): srclist = sourceextractorsussextractor(image=map,\ detthreshold=detectionthreshold, fwhm=fwhm[array], \ beamarea=area[array]) Timeline Fitter (old name: timelinesourcefittertask): result = sourceextractortimeline(input=scancontext, array=array, \ sourcepositionestimate=double1d([racentres[i], deccentres[i]]),\ rpeak=rpeak[array]) To learn more about these modules, see SPIRE Data Reduction Guide, Section 5.7 Recipe for SPIRE Photometry page 11

12 What s New in HIPE 9.1 Improved map-making, with destriper in standard processing Electrical crosstalk correction (significant for very bright sources) NaiveMapper has two options for estimating flux in a sky pixel: simple average (the only option before HIPE 9) inverse variance weighted mean Cooler Burps correction in user pipeline scripts New versions of two point source photometry tasks: Sussextractor Timeline Fitter Two new SPIRE Useful scripts : Photometer Bolometer Finder Photometer Calculate Ephemeris SSO Position page 12

13 new SPIRE Useful scripts : page 13

14 Bolometer Finder: A new (and better) version: See the following web page for details: page 14

15 Other News Improvement in pointing for data taken between Because of an error in the pointing model, Herschel data taken between suffered larger than normal pointing 5 errors (up to 8 ). Now new, improved pointing products are available for these observations in: ftp://ftp.sciops.esa.int/pub/msanchez/corrected_pointing_od320_761/. See the following twiki page on how to use them: New values for SPIRE beam profile solid angles (i.e. beam areas): New analyses of the SPIRE beam profile data, with background tilt subtraction and background source removal, lead to revised values for beam profile solid angles, which differ from the current official values by up to 6.7%. See the following twiki page for details: page 15

16 Anticipated Major Changes in HIPE 10 Level 1 timelines will be destriped (i.e. baseline removed). 5 Zero-level correction (i.e. realistic large-scale background level taken from the Planck Survey) will be available. Level 2 products will include: maps in units of Jy/beam (for point sources); maps in units of MJy/sr (for extended sources); maps corrected for proper motion (for solar system objects only). page 16