6df workshsopatnf may 30th 20021 6df: observing, data reduction & dataflow q.a.parker macquarie...

6dF workshsop ATNF May 30th 2002 1

6dF: Observing, data reduction & dataflow6dF: Observing, data reduction & dataflow

Q.A.Parker

Macquarie University/AAO


TalkTalk outlineoutline

Brief summary of observing procedure

6dF data reduction with 6dFdr & runzDataflow


Current 6dF observing team:Current 6dF observing team:

Malcolm Hartley (observing management) Paul Cass (6dFdr) Ken Russell Fred Watson Dionne James (Bessell BOM programme) Will Saunders (post commissioning

development, observing) Other 6dfsag members/qap as required


Standard 6dF Observing processStandard 6dF Observing process

Selection of `tiles’ from latest tiling run sufficient to cover night/run

Consistent directory structure and field naming conventions ensures no confusion of input files, configure files etc for each nights observations

Potential targets cross-checked against SCOS image thumbnails to remove contaminants prior to configuration

.fld files created for each `cleaned’ tile pointing – includes merging in of suitable Tycho-2 guide stars

6dfconfigure run on .fld files for given field plate (takes into account broken fibres etc)


Standard 6dF .fld file structureStandard 6dF .fld file structure*comment line - 6dF field configuration file (an ascii file)LABEL target field number 1 xyz clusterUTDATE 2002 05 27EQUINOX J2000.0CENTRE 12 43 23.30 -10 34 10.0* end of required header info* these are fiducial star positionsF1 12 40 20.55 -10 30 11.4 F 9 12.0 1 brightest starF2 12 38 10.31 -09 59 58.9 F 9 13.5 1 fiducial star* these are target object positionsNGC1002 12 41 30.55 -10 31 56.9 P 2 15.0 1 galaxy targetic3082 12 40 18.40 -10 32 21.5 P 2 17.0 1 galaxy targetPHR1232 12 32 26.5 -09 58 26.4 P 2 16.6 1 galaxy target.. etc up to 200 say* these are checked blank sky positions*sky-1 12 40 10.20 -10 32 21.5 S 5 99.9 1 blank sky (checked)sky-2 12 39 11.5 -09 58 45.6 S 5 99.9 1 blank sky (checked).. etc up to 20 (say)


Observing process cont.Observing process cont.

Once field configuration has been tested the output configuration (.sds file) is input to the robot configure software

Configuration typically takes an hour for a full 150 fibre field If possible first 2 fields will have been prepared earlier in the afternoon

with the first ready to go before the end of astronomical twilight Availability of two field plates enables one to be configured whilst the

other is being observed 20-30 minutes are needed to mount each fibred 6dF field plate in the

telescope, take dome flat-fields and arc frames and for acquiring the field on the sky.

Acquire both 600V (1 hr) and 316R (0.5hr) observations for each field 5 fields per night have been achieved during the winter lunations and 3

are possible in the summer lunations


6dF R-theta robot and field plate


Data acquisition via 6dF CICADAData acquisition via 6dF CICADA

CICADA has been customised for 6dF in the following ways:

A 6dF instrument configuration plug-in added

An interface to the UK Schmidt TEL_CONTROL built as a TCS plug-in

A FITS plug-in written to insert 6dF BINTABLE extensions describing the 6dF instrument configuration


6dF commissioning data frame6dF commissioning data frame

Night sky lines

Blue region Red region

Emission lines


6dFdr:6dFdr: creating 1-D calibrated spectracreating 1-D calibrated spectra

Directly analogous to 2dFdr – has same basic functionality and very similar GUI

Specifically modified to work with 6dF data frames by Jeremy Bailey (AAO)

After some development now offers a relatively stable platform for reduction on standard 6DFGRS data almost as a `black box’

Care needs to be taken with the observations to ensure trouble free processing through the 6dfdr package


Running 6dFdrRunning 6dFdr Requires at least 1 Flat field frame, 1 arc frame and 3 or

more data frames 6dfdr runs on Starlink sdf files so need to convert from

cicada output fits images (tool available e.g. fits2ndf) Once 6dfdr is launched simply a question of going to

`setup’ menu & select prefix identifying frames in the run Select the Flat field - reduce it - check tram line fitting is

o.k. Select the Arc - reduce Arc Select data frames – reduce data frames Combine the individual reduced data frames Plot spectra from combined reduced frames to check o.k. Exit 6dfdr and cleanup all unwanted files


316R data316R data


RUNZ: RUNZ: semi-automated Z determinationssemi-automated Z determinations

Modified version of the code developed principally by Will Sutherland for the 2dFGRS.

Offers a convenient mechanism for interactive redshift estimation from 1-D 6dfdr reduced spectra

Some extra functionality offered by WS/QAP Currently need to reduce the 600V and 316R data separately

though are plans to splice the 2 slightly overlapping regions together after attempting flux-calibration

Still needs modifications to make it run more smoothly with 6dfdr reduced data (was developed for and works better with a wider wavelength coverage than 600V and 316R provide alone).


Can autofit to selected lines…Can autofit to selected lines…


6dF WWW interface & form of data product6dF WWW interface & form of data product

The www interface will provide access to the reduced survey data in the form of object parameters for each object together with their associated reduced 6dF spectra. For each observed object we would provide a minimum of:

object ID & position (J2000 ra,dec) + optional l,b 2MASS J,H,K photometry (with errors), DENIS I-band magnitude (with error) classification/spectral type (e.g. galaxy, AGN, stellar contaminant etc) redshift, z error, optical magnitude structural image information from the SCOS optical parameter lists fully reduced 1-D spectra Basic ancillary information for each entry such as date of observation,

grating, 6dF field plate, fibre number etc


Higher dispersion 600V dataHigher dispersion 600V data

Additionally the velocity dispersions from the 600V data would include most of the above parameters plus measurements (with errors) of: velocity dispersion & line indices, galaxy diameters, distance estimates peculiar velocities.

The www interface would permit all (or a selection) of the object parameters to be down-loaded including an option to down-load the associated 1-D spectra. The interface would also permit direct access to the raw/partially processed image frames via a suitable query system and survey field map.

It is estimated that 3 months of software effort would be required to produce such aninterface based On PERL scripts.


Dataflow to DatabaseDataflow to Database

Final details still to be sortedInvolves assimilation of reduced

spectra AND redshift/peculiar velocity results into the current master results catalogue

Results catalogue contains observed objects from the master input catalogue


WFAU 6dF involvement includes:WFAU 6dF involvement includes:

Involvement in survey data products management commissioning support (qap - done) help with target catalogue construction (mar/qap

done) archival of survey data products community access to the data products via

development of suitable www interface keen scientific interest in survey exploitation (Andy

Taylor, Dan Burkey, Andy Lawrence) PhD student (started Oct 2000)


Data and Data and information information flow in the flow in the 6DFGRS6DFGRS

6df workshsopatnf may 30th 20021 6df: observing, data reduction & dataflow q.a.parker macquarie...

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