pysedm

Data Reduction Pipeline for the SEDmachine. Please have a look at the pysedm paper.

works in python 2.7+ and 3.x, but the 2.7+ might not be supported in the future.

Acknowledgements

This project was funded by the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (grant agreement n°759194 - USNAC, PI: Rigault).

Reference

If you are using a SEDM spectrum obtained since July 2018 (incl.) please cite the pysedm paper

Installation

pip install pysedm

or

git pull https://github.com/MickaelRigault/pysedm.git
cd pysedm
python setup.py install

Basic installation detailed here enables you to:

• load, visualize and use pysedm product objects (spectra, cubes, but also calibration objects)
• extract spectra from cubes.

Running a manual spectral extraction (from the shell)

Here is are some examples to use pysedm.

Open and display a Cube.

Say you have a cubefile name e3d_crr_date_fileid_ztfname.fits

import pysedm
# Load the cube
cube = pysedm.get_sedmcube('e3d_crr_date_fileid_ztfname.fits')
# See the cube and enable to clic on the cube to visualize spaxels:
cube.show(interactive=True)

what is going on? if you click on spaxels you see the spaxel spectra on the left. If you click once on "control" you will not replace the spectrum on the left but see new spaxel's spectra with a new color (colors match bewtween spaxel contours and spectra. Click once again on "control" to turns this off. If you drag your mouse on the IFU, the display spectrum will be the average of the rectangle defined by the draging. Click on "shift" to draw any polygon. Click again on "shift" to turns it off. Click on "option"and your dragging will define an aperture radius. Click on "escape" to clean everything switch back to original mode

You can directly display the cube without opening ipython by doing:

display_cube.py e3d_crr_date_id_ztfname.fits

Manual cube extraction.

You want to manually extract a spectrum from a cube e3d_crr_date_fileid_ztfname.fits (fileid is HH_MM_SS)

From your shell do (with date been YYYYMMDD):

extract_star.py DATE --auto FILE_ID --display

what is going on? (1) double click to locate the expected centroid of the target (creating the black cross) and (2) click and "shift" and draw a countour avoiding the host. The contours should be a ~5 spaxels large if possible. Finally (3) close the window to launch the PSF extraction. This will happen in your terminal

Flux Calibration if you want your extracted spectra to be flux calibrated, you need to have a fluxcal file in your DATE directory. You can also directly provide your favorite fluxcal file as an option to extract_star.py:

extract_star.py DATE --auto FILE_ID --display --tag manual --fluxcalsource your_favorite_fluxcal.fits

Some other important extract_star.py options:

• "--tag": provide a string, this string will be in the name. Useful to avoid overwriting existing files, i.e. --tag host
• "--observer": Your name, this will be stored in the header as "OBSERVER"
• "--vmin", "--vmax": lower and upper values (in percent) of the MLA spaxel plot (--vmax 80 to saturate the color at the 80% brightest spaxel signal)

Output Data

extract_star.py creates several files (see *_auto_*crr_date_fileid_ztfname.fits). Most interesting ones are:

• spec_auto...: extracted spectrum with formats .fits or .txt (and figures in .png/.pdf)

  

• psfprofile...: figure showing the quality of the PSF extraction

  

• adr_fit...: figure showing the quality of the ADR (i.e. target centroid as a function of wavelength)

  

Interactive 3D psf extraction (from notebook or any python code)

Starting with version 0.24.0 you can directly extract a point source from a SEDMCube.

Simply do:

import pysedm
cube = pysedm.get_sedmcube(CUBE_FILEPATH)
cube.extract_pointsource() # runs extractstars creating a cube.extractstar

Then, to get the flux calibrated spectrum, do:

spectrum = cube.extractstar.get_fluxcalibrated_spectrum()

And to see the validation plots:

• cube.extractstar.show_mla() ; centroid and spaxel used
• cube.extractstar.show_adr() ; adr fit quality
• cube.extractstar.show_psf() ; psf profile

pysedm in details:

See library details here

Dependencies

The following dependencies are automatically installed (if needed only):

• numpy, scipy, matpotlib, astropy (basic anaconda)

• propobject (pip install propobject) for the structure of the classes

• pyifu (pip install pyifu or see https://github.com/MickaelRigault/pyifu) cube and spectra object library

• psfcube (pip install psfcube or see https://github.com/MickaelRigault/psfcube) psfcube depends on Minuit (fitter) and modefit (structure), which are automatically installed if needed

See details here for additional dependencies you will need for full pipeline functionalities (like re-creating the wavelength solution etc.)