Muspelheim

Muspelheim is a numerical model for the spectral evolution of stars in the early Universe. These models can be used to analyze photometric and spectroscopic data on lensed, high-redshift stars, and to predict the ionizing or Lyman-Werner fluxes of early generations of stars.

The name of the model stems from Norse mythology, where the stars of the night sky are believed to be the sparks and glowing cinders from Muspelheim, the realm of fire.

Model files

Spectra

These files (zipped) contain rest-frame spectral energy distributions for stars at various ages.

10% solar tracks, 9-575 M☉, Szécsi et al. (2022): [v1.0] (60 Mb)
Pop III tracks, 10-1000 M☉, Yoon et al. (2012): [v1.0] (26 Mb)
Pop III tracks, 10-100 M☉, Windhorst al. (2018): [v1.0] (5 Mb)
Pop III tracks, 9-120 M☉, Murphy et al. (2021): [v1.0] (29 Mb)
Pop III tracks, 100-1000 M☉, Volpato et al. (2023): [v1.0] (6 Mb)

Magnitudes

These zipped archives contain AB magnitudes in a selection of JWST (NIRCam and MIRI) and HST filters for stars at the same selection ages for which spectra are available. Magnitudes have been computed at redshifts z=1-20, in redshifts increments of 1.0, but please don't be shy to reach out if you need higher redshift resolution, redshifts outside this range or predictions for different filters. All magnitudes are computed under the assumption of an ΩM=0.3, ΩΛ=0.7, H0=70 km s-1 Mpc-1 cosmology. At z≥5.8, all flux shortward of the Lyman-α limit is assumed to be absorbed by the neutral intergalactic medium. At lower redshifts, no absorption shortward of the Lyman-α limit is applied.

10% solar tracks, 9-575 M☉, Szécsi et al. (2022): [v1.0 NIRCam], [v1.0 MIRI], [v1.0 HST]
Pop III tracks, 10-1000 M☉, Yoon et al. (2012): [v1.0 NIRCam], [v1.0 MIRI], [v1.0 HST]
Pop III tracks, 10-100 M☉, Windhorst al. (2018):[v1.0 NIRCam], [v1.0 MIRI], [v1.0 HST]
Pop III tracks, 9-120 M☉, Murphy et al. (2021): [v1.0 NIRCam], [v1.0 MIRI], [v1.0 HST]
Pop III tracks, 100-1000 M☉, Volpato et al. (2023): [v1.0 NIRCam], [v1.0 MIRI], [v1.0 HST]

Ionizing fluxes

These zipped archives contain rest-frame H-, He- and He+-ionzing fluxes plus Lyman-Werner fluxes for stars at various ages.

10% solar tracks, 9-575 M☉, Szécsi et al. (2022): [v1.0]
Pop III tracks, 10-1000 M☉, Yoon et al. (2012): [v1.0]
Pop III tracks, 10-100 M☉, Windhorst al. (2018): [v1.0]
Pop III tracks, 9-120 M☉, Murphy et al. (2021): [v1.0]
Pop III tracks, 100-1000 M☉, Volpato et al. (2023): [v1.0]

How to acknowledge Muspelheim in a publication

If you use the Muspelheim models, please cite the primary Muspelheim publication Zackrisson et al. (2023, submitted, arXiv:2312.09289) along with references to the the stellar evolutionary tracks used for the specific Muspelheim models you are using.

Example: "The lensed star is analyzed using the Muspelheim SEDs of Pop III stars (Zackrisson et al. 2023) based on the stellar evolutionary tracks of Volpato et al. (2023)"

Reference for low-metallicity tracks (SMC; ∼10% solar):
Szécsi D., Agrawal P., Wünsch R., Langer N., 2022, A&A, 658, A125

References for Pop III tracks (metal-free):
Yoon S. C., Dierks A., Langer N., 2012, A&A, 542, A113
Windhorst R. A., et al., 2018, ApJS, 234, 41
Murphy L. J., et al., 2021, MNRAS, 501, 2745
Volpato G., et al. 2023, ApJ, 944, 40

Contact

Questions or comments about the Muspelheim models? Please get in touch!

Email:
erik.zackrisson [at]physics.uu.se