JWST IFUs and Data Tool Development Plans

Tracy BeckJWST NIRSpec Instrument Scientist

Integral Field Spectroscopy… with JWST!

IFU Data Cube

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Integral Field Units – provide 3-D imaging spectroscopy of a small region of the sky – every image location has a (R~3000) spectrum associated with it!

JWST NIRSpec – 1-5m IFUWith a 3” x 3” field of view (0.”1 square spatial sampling)

JWST MIRI – 5-25m IFU spectra acquired with 4 IFUs. IFU spatial fields scale with wavelength. This “MRS” mode is MIRI’s ONLY R=3000 spectral capability!

STScI Sponsored Workshop - “IFUs in the Era of JWST”

• Oct 26-28, STScI hosted the first major international workshop on Integral Field Spectroscopy to take place in the US

• 60+ Astronomers and Instrument developers from four continents participated

• All talks are archived: https://webcast.stsci.edu/webcast/ (view the archive for the week of Oct. 25th)

• IFUs are in our Future!• ~15 IFUs presently in operation at ground-based telescopes• 2 IFUS on JWST, MIRI and NIRSpec• First-light IFU instruments planned for both TMT and e-ELT (the latter has 2)

IFU Data Analysis Tools

Science from IFU surveys is making an impact, but the results are often very slow in coming…

IFU Users are experts at “reinventing the wheel” – by necessity! Robust, widely adopted data analysis tools don’t exist for IFU data. Very Common Data Analysis for IFU sets:

• Basic Data cube addition/subtraction (some tools exist)• Automated profile/dispersion fitting for basic kinematic analysis (Does not Exist)• Make IFU velocity channel maps or movies for publication/presentation analysis (Does not Exist)

IFU Data Analysis ToolsIFU Users are experts at “reinventing the wheel” – by necessity!

Basic Data cube addition/subtraction – combine multiple 2-D image planes to form an average image, or 1-D spectra to make an average spectrum. Fit

continuum and subtract from an emission line, to make an emission line map. (Exists in some viewing tools – BASIC functionalities).

Very Common Data Analysis for IFU sets:

“Qfitsview” – one of themost popular 3-D cubevisualization tools

(work with images & spectra at the same time)

IFU Data Analysis ToolsVery Common Data Analysis for IFU sets:

Profile/dispersion fitting: Fit a Gaussian or line profile to an emission line, or cross-correlate a template to a spectrum, to derive kinematics in a target. (velocity, dispersion)

H emission H velocity H dispersion

z~2 galaxy From Forster-Schreiber et al. (2006)

Jet from a young star - Beck et al.

If a datacube “visualization tool” does not provide a means to

make publication quality figures, users will need to use a different environment to do that, and the tool won’t be widely adopted.

Make velocity channel maps or movies for publication and presentations

IFU Data Analysis ToolsIFU Users are experts at “reinventing the wheel” – by necessity! Very Common Data Analysis for IFU sets:

• Basic Data cube addition/subtraction (some tools exist)• Line Profile/dispersion fitting for basic kinematic analysis (Does NOT Exist)• Make velocity channel maps or movies for publication/presentations analysis (Does NOT Exist)

IFU Data will be more accessible and easier to work with and publish for all JWST users if we don’t have to start from ‘step 1’ for these very common data analysis

techniques

• IFU Data Analysis Framework document, by Bacon, Beck, Greenfield & Stiavelli (ESO / STScI collaboration)

ESO’s IFU Development Plans

• ESO - Development is very strongly linked to their complex 1’ x 1’ field of view IFU, “MUSE” (300 x 300 x 4200 size datacubes). First light 2012.

• Wrote requirements for an IFU cube analysis tool, and looked at available options

• Recent decision: work with NRAO to update/adapt the “CASA Viewer” that exists for radio data and is being further developed for ALMA

• ESO is a partner in ALMA, and so will be a strong contributor to the CASA Viewer development work

• We will keep all communication channels open for this development.– CASA Viewer has no capability for plug-in

expansion by users (or us) – STScI has no means of visibility into this

development.

C++ Backbone, viewer has Qt GUI interface

STScI IFU Development

• Goals –– Provide visualization and analysis tools that will

optimize IFU science return for non-expert users, to improve impact and usability of the JWST IFUs. (Incorporate existing visualization tools whenever possible).

– At the end of the day, our priorities MUST be for data visualization and analysis of JWST MIRI and NIRSpec IFU data products. (But we hope our efforts will be useful for others).

STScI IFU Development

• For the first time, in FY11 I officially have a small allotment (10%) of my functional work time dedicated to IFU development.

• Plan of action:– Create an internal “STScI IFU Working Group” (meet ~1x per

month – first meeting was in Nov. 2010).

– Work with STScI developers, get familiar with 3-D datasets and 3-D .fits structures, existing cube viewing/manipulation tools.

– Work to develop our STScI requirements on IFU datacube viewing and analysis tools.

– Complete an exercise similar to ESO – identify an existing tool that we might be able to expand upon and develop.