# Main sequence of star forming galaxies beyond the Herschel confusion limit

**Authors:** W. J. Pearson, L. Wang, P. D. Hurley, K. Małek, V. Buat, D. Burgarella, D. Farrah, S. J. Oliver, D. J. B. Smith, F. F. S. van der Tak  
**arXiv:** [1804.03482](https://arxiv.org/abs/1804.03482)  
**Date:** 2018-04-10  
**Summary page:** https://www.summarizepaper.com/en/paper/1804.03482v1/

## Key points

- Study focuses on the main sequence (MS) of star-forming galaxies in deep far-infrared (FIR) cosmological surveys
- Source confusion is a challenge in accurately examining individual galaxy properties
- Latest de-blended Herschel photometry used to address source confusion limitation
- De-blending tool XID+ and SED modeling tool CIGALE combined to generate flux density priors and extract flux densities from SPIRE maps
- SEDs, stellar mass (M*), and star formation rates (SFRs) derived using extracted flux densities and multi-wavelength data
- SFR-M* plane populated over redshift range of 0.2 ≤ z < 6.0
- No significant evidence of high-mass turn-over in the MS found
- Simple two-parameter power law model best fits the data: log(SFR) = α[log(M*) - 10.5] + β

## Summary

This study focuses on the main sequence (MS) of star-forming galaxies in deep far-infrared (FIR) cosmological surveys. These surveys are often affected by source confusion, which makes it challenging to examine the properties of individual galaxies accurately. To address this limitation, the authors of this study utilize the latest de-blended Herschel photometry, which reaches approximately 10 times deeper than the 5σ confusion limit in SPIRE. This enables more reliable measurements of star formation rates (SFRs), especially for fainter galaxies, and consequently a more accurate determination of the MS. The researchers develop a pipeline that combines the spectral energy distribution (SED) modeling and fitting tool CIGALE with the de-blending tool XID+. They generate flux density priors in the Herschel SPIRE bands using CIGALE and then use XID+ to extract flux densities from SPIRE maps. By combining these extracted flux densities with multi-wavelength data, they constrain SEDs and derive stellar mass (M*) and SFRs. Using these M* and SFR values, they populate the SFR-M* plane over a redshift range of 0.2 ≤ z < 6.0. The analysis reveals no significant evidence of a high-mass turn-over in the MS. Instead, they find that a simple two-parameter power law model best fits their data: log(SFR) = α[log(M*) - 10.5] + β.