Data Challenge Session 2: 2D to 1D Extraction

This is the second of three planned splinter sessions on Roman slitless spectroscopy, and  builds upon AAS 245 (January 2025) Data Challenge Part-1, “Introduction to slitless spectroscopy with the Nancy Grace Roman Space Telescope”. Attendees  should bring laptops capable of running a Jupyter notebook in order to fully participate in the interactive challenge. Advance registration is necessary to download and install Jupyter notebooks in advance, and also for remote participation.  This series of data challenges are designed to be pedagogical and oriented towards newcomers.

While the first session focused on (1) foundations (2) introduction to Grism and (3) basic 1D spectral fitting, this session will emphasize  (1) prism spectroscopy and (2) the principles of 2D-to-1D spectral extraction.

We will begin with a short recap of the material and lessons from Data Challenge 1 before diving into the key differences between grism and prism modes on Roman’s Wide Field Instrument. Participants will then explore practical approaches to spectral extraction, including weighted versus unweighted methods, background subtraction, and optimal strategies for collapsing 2D spectra into 1D.

A major component of this session will be the introduction of a straightforward extraction tool developed specifically for these challenges. This tool is designed to convert 2D Roman-like spectra into 1D form and will serve as the primary method for this data challenge. The emphasis will be on usability and clarity, enabling participants to gain confidence with extraction workflows without requiring extensive technical setup.

We will feature a live demonstration of extracting spectra for individual objects using both grism and prism examples. This hands-on walkthrough will allow participants to see the process step by step and directly apply the techniques to the challenge material.

1. Introduction & Objectives 

2. Grism Refresher 

3. Understanding the Prism 

4. Principles of 2D to 1D Spectral Extraction 

5. Introduction to Tools for Spectral Extraction 

6. Demonstration: One Object at a Time