🔬 Identifying Spectral Lines in MIRI JWST Data

This project focuses on analyzing the Mid-Infrared (MIR) Integral Field Unit (IFU) spectral cubes from the James Webb Space Telescope (JWST) MIRI instrument for the active galaxy NGC 7469. The goal is to extract, compare, and identify emission lines across different regions within the galaxy, providing insights into hidden astrophysical structures and conditions.

🌌 Project Overview

• Source: NGC 7469
• Category: Seyfert 1 Active Galaxy (AGN)
• Data Source: MAST JWST Archive
• Instrument: MIRI IFU Spectral Cubes

🗂️ Steps Involved

1️⃣ Basic Exploration I

• Identify object properties using NED and Simbad:
• Coordinates (RA, Dec)
• Distance
• Redshift (z)
• Category & sub-category
• Understand the role of MIR in revealing structures obscured in optical/NIR wavelengths

2️⃣ Data Download

1. Go to MAST Portal
2. Advanced Search:
   • Object Name: NGC 7469
   • Observation Type: science
   • Mission: JWST
   • Instrument: MIRI/IFU
   • Product Type: cube
3. Download all files containing c1006_ in their name

3️⃣ Region Creation

• Open ch1-short cube in DS9
• Create two circular regions (radius = 0.5 arcsec)
• Save as region1.reg and region2.reg (Format: DS9, Coordinate System: ICRS)

4️⃣ Basic Exploration II

• Compute pixel scale in parsecs using FITS header (CDELT1/CDELT2)
• Estimate physical size covered per pixel

5️⃣ Spectral Extraction & Comparison

• Extract region-wise spectra using Astropy and Photutils
• Visualize and compare spectra between regions
• Identify astrophysical differences (e.g., line strength variations, ionization signatures)

6️⃣ Channel-wise Analysis

• Inspect spectral variations from Channel 1 to Channel 4
• Distinguish between instrumental effects and real astrophysical properties

7️⃣ Emission Line Identification

• Detect key emission lines using Cubeviz or Matplotlib
• Tabulate line names, rest-frame wavelengths, and astrophysical significance

📊 Key Technologies Used

• JWST MIRI Calibrated FITS Cubes
• Astropy (FITS handling, WCS transformations)
• Photutils (Aperture extraction)
• DS9 (Region definition)
• Matplotlib & Pandas for visualization and data handling

✅ Expected Outcomes

• Extracted spectra for multiple regions of NGC 7469
• Comparative analysis of emission lines across regions
• Channel-wise insights into spectral variations
• Table of identified emission lines and their astrophysical roles

📝 Notes

• This project demonstrates how MIR data unveils hidden structures like dust-enshrouded star-forming regions and AGN features
• Results provide insight into the ionization state, density, and composition of the galaxy's ISM

🚀 How to Run

1. Install dependencies: pip install -r requirements.txt
2. Place region files and FITS cubes in the project directory
3. Run Identifying_spectral_lines_in_MIRI_JWST_data.ipynb to perform the full analysis