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Herschel data for absolute beginners

Herschel Science Centre (ESAC)

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• This presentation contains a simple cookbook to search,

retrieve, analyse and reprocess Herschel data from the

Herschel Science Archive.

• Step 1: Register to be able to retrieve data from the

Herschel Science Archive

• Step 2: Search for your data

• Step 3: Retrieve your data

• Step 4: Look at your data

• Step 5: Decide whether you need to reprocess or not

• (Step 5b: Reprocess your data)

• Step 6: Analyse your data.

CONTENTS

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• Step 1: Register to be able to retrieve data from the Herschel

Science Archive• http://herschel.esac.esa.int/registration.shtml

• Step 2: Search for your data

• At the postcard gallery (web-based):• http://archives.esac.esa.int/hsa/aio/doc/postcardGallery.html

• With the Herschel Science Archive User Interface (java):• http://herschel.esac.esa.int/Science_Archive.shtml

• You can search by object name (SIMBAD/NED resolved), by

coordinates, by programme, by observer or by date.

STEPS 1 & 2: REGISTRATION AND SEARCH

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• Step 4: Look at your data

• Summary of basic instrumental characteristics

STEP 4: LOOK AT YOUR DATA

The Herschel Instruments:

Imaging Spectroscopy

PACS – Photodetector Array Camera and Spectrometer

70 & 160 μm or

100 & 160 μm

50 – 210 μmR ~ 1000 - 5000

SPIRE – Spectral and Photometric Imaging Receiver

250, 350 and 500 μm194 – 671 μmR ~ 20 - 1000

HIFI – Heterodyne Instrument for the Far Infrared

- 157 – 625 μmR = 106 - 107

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• Step 4: Look at the data

• The level2 data are fully calibrated images, spectra and cubes.

• The Level 2.5 data combines level2 maps of the same region.

STEP 4: LOOK AT YOUR PACS & SPIRE IMAGES

PACS Photo: 70 & 160 or 100 & 160 micronJy/pixel

SPIRE Photo: 250, 350 & 500 micronsJy/beam or MJy/sr

M31 Andromeda

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STEP 4: LOOK AT YOUR PACS SPECTRA

PACS Spec pointed: spectral cubes (5x5 spaxels) Jy vs micron

PACS Spec mapping: spectral cubes (small spaxels) Jy vs micron

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STEP 4: LOOK AT YOUR SPIRE SPECTRA

SPIRE spec pointed: full coverageJy vs GHz

SPIRE spec mapping: spectral cubesJy vs GHz

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STEP 4: LOOK AT YOUR HIFI SPECTRA

HIFI pointed: very high spectral resolutionDouble side-band (USB & LSB), K vs GHz

HIFI mapping: spectral cubes (level2.5)Double side-band (USB & LSB), K vs GHz

HIFI spectral scans: single spectra (level2.5)Single side-band (USB & LSB), K vs GHz

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• Step 5: Decide whether you need to reprocess or not

• This is a science-dependent question, in general all PACS data

and most spectroscopy needs reprocessing for science.

• More details: Data Products Known Issues:• http://herschel.esac.esa.int/twiki/bin/view/Public/DpKnownIssues?template=viewprint

• (Step 5b: Reprocess your data in HIPE) Not for this demo

STEPs 5: REPROCESS YOUR DATA (IF NEEDED)

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The Herschel Images

Filter λ μm

FWHM arcsec

“Pixel” size

arcsec

FluxUnits

Point-source Sensitivity mini-

scan5σ /1 h mJy

FITSFilename

Refs.

PACS–70 70 5.2 x 5.8 (slow scan) – 5.8 x 9.0 (fast scan) –

5.8 x 12.1 (fast scan, ||)

3.2 Jy/pixel 4.7 (slow scan) Level 2/2.5: hppppb

1, 2, 3

PACS-100 100 6.6 x 6.8 (slow scan) – 6.9 x 9.7 (fast scan) –

6.9 x 12.7 (fast scan, ||)

3.2 Jy/pixel 5.5 (slow scan) Level 2/2.5: hppppb

1, 2, 3

PACS-160 160 10.4 x 12.02 (slow scan) - 11.3 x 13.3 (fast scan) – 11.6 x 15.7 (fast scan, ||)

6.4 Jy/pixel 10.5 (slow scan) Level 2/2.5: hppppr

1, 2, 3

SPIRE-250 250 18.2 6 Jy/beam& MJy/sr

7.3 (slow scan ||) – 12.6 (fast scan ||)

Level 2/2.5: Hspirepsw

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SPIRE-350 350 24.9 10 Jy/beam& MJy/sr

6.0 (slow scan ||) – 10.5 (fast scan ||)

Level 2/2.5: hspirepmw

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SPIRE-500 500 36.3 14 Jy/beam& Mjy/sr

8.7 (slow scan ||) – 15.0 (fast scan ||)

Level 2/2.5: Hspireplw

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HERSCHEL IMAGING REFERENCE

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The Herschel Spectra:

Instrument Mode

Wavelengthsmicron/GHz

WaveFreq.Units

Flux Unit

Line flux Sensitivity 5σ /1 h W/m2

FITS FilenamesLevel 2 mostly

Refs.

PACS line B2A/R1:103-220 μm B3A/R1: 51-73 μm

B2B/R1: 71-105 μm

μm Jy B2A: 1.7 x 10-6 - 8.010-8

hps3dpX[B/R] (spec. cubes)Rebinned: 5 x 5 x N. (freq.)

Projected: 24 x 23 x N. (freq.)

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PACS range B2A/R1:103-220 μm B3A/R1: 51-73 μm

B2B/R1: 71-105 μm

μm Jy B2A: > 1.7 x 10-6 - 8.010-8

hps3dpXs[B/R] (spec. cubes)Rebinned: 5 x 5 x N. (freq.)

Projected: 24 x 23 x N. (freq.)

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SPIRE FTS pointed

SSW: 194 – 313 μmSLW: 303 – 671 μm

GHz Jy 1.5 – 2.1 x 10-7 hspireanapod (binary table, two tables, SSW and SLW)

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SPIRE FTS mapping

SSW: 194 – 313 μmSLW: 303 – 671 μm

GHz Jy 1.5 – 2.1 x 10-7 hspireanapodSxW (cubes)SSW: 10 x 10 x 1951 (freq.)

SLW: 5 x 5 x 1810 (freq.)

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HIFI pointed bands 1-5: 488-114 GHzBands 6-7: 1430-1900

GHz

GHz K <6 % (bands 1,2,3,4)< 10% (band 5)

< 30% (bands 6,7)

hhifi[hrs/wbs][h/v] (binary tables)

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HIFI spectral scan

bands 1-5: 488-114 GHzBands6-7:1430-1900GHz

GHz K <6 % (bands 1,2,3,4)< 10% (band 5)

< 30% (bands 6,7)

Level 2.5: mydecon/hhifiX[h/v]WBS: 2 x 34649 (freq.)

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HIFI mapping bands 1-5: 488-114 GHzBands6-7:1430-1900GHz

GHz K <6 % (bands 1,2,3,4)< 10% (band 5)

< 30% (bands 6,7)

Level 2.5: hhifiX[h/v] [lsb/usb] HRS: 5 x 29 x 3826 (cubes)WBS: 5 x 29 x 1128 (cubes)

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HERSCHEL SPECTRA REFERENCE

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HERSCHEL REFERENCE LINKS

• Herschel Science Centre webpage

• http://herschel.esac.esa.int

• Herschel Observing log

• http://herschel.esac.esa.int/logrepgen/observationlist.do

• Herschel Publications tool

• http://herschel.esac.esa.int/hpt/publicationlist.do

• Herschel Science Archive

• http://herschel.esac.esa.int/Science_Archive.shtml

• Herschel Interactive Processing Environment (HIPE)

• http://herschel.esac.esa.int/hipe/

• Herschel data reduction youtube video tutorials

• http://www.youtube.com/user/hipeacademy

• Any questions? Let us know..

• http://herschel.esac.esa.int/esupport/

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Thank youAny questions?

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• Step 1: Search “Fomalhaut” in SIMBAD

• Step 2: Search for it at the Herschel Postcard Gallery

• Step 3: Look at the images with ds9 or Aladin

• Step 4: With ds9 or Aladin retrieve near-IR images from the 2MASS Survey

and compare with the Herschel ones.

• Step 5: With ds9 or Aladin blink all images from near-IR to 500 microns.

• Step 6: With ds9 make a RGB color composite with the images.

• Step 7: Calculate apparent sizes of the source in arcsec and in AUs at the

different Herschel wavelengths

• Step 8: compare result with Acke et al. (2012)

• http://esoads.eso.org/abs/2012A%26A...540A.125A

HERSCHEL IMAGE ANALYSIS TUTORIAL

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• From parallax to parsec:

• Distance(parsec) = 1./AngularSize(arcsec)

• From angular size to physical size

• Distance (AU) = Distance (parcsec) * AngularSize (arcsec)

HERSCHEL IMAGE ANALYSIS TUTORIAL

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• http://mmi-forum.wikispaces.com/home

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