Popovic, BrodieScolnic, DanielVincenzi, MariaSullivan, MarkBrout, DillonChen, RebeccaPatel, UtsavPeterson, Erik R.Kessler, RichardKelsey, LisaSanchez, Bruno O.Bailey, Ava ClaireWiseman, PhilToy, Marcus2025-02-272025-02-272024-03-18B. Popovic, D. Scolnic, M. Vincenzi, M. Sullivan, D. Brout, R. Chen, U. Patel, E.R. Peterson, R. Kessler, L. Kelsey, B.O. Sanchez, A.C. Bailey, P. Wiseman, M. Toy. 2024. "Amalgame: cosmological constraints from the first combined photometric supernova sample" Monthly Notices of the Royal Astronomical Society, Volume 529, Issue 3, pp.2100-2115. https://doi.org/10.1093/mnras/stae4200035-87111365-2966https://hdl.handle.net/2144/49871Future constraints of cosmological parameters from Type Ia supernovae (SNe Ia) will depend on the use of photometric samples, those samples without spectroscopic measurements of the SNe Ia. There is a growing number of analyses that show that photometric samples can be utilized for precision cosmological studies with minimal systematic uncertainties. To investigate this claim, we perform the first analysis that combines two separate photometric samples, SDSS and Pan-STARRS, without including a low-redshift anchor. We evaluate the consistency of the cosmological parameters from these two samples and find they are consistent with each other to under 1σ. From the combined sample, named Amalgame, we measure ΩM = 0.328 ± 0.024 with SN alone in a flat ΛCDM model, and ΩM = 0.330 ± 0.018 and w = $-1.016^{+0.055}_{-0.058}$ when combining with a Planck data prior and a flat wCDM model. These results are consistent with constraints from the Pantheon+ analysis of only spectroscopically confirmed SNe Ia, and show that there are no significant impediments to analyses of purely photometric samples of SNe Ia. The data and results are made available at https://github.com/bap37/AmalgameDR.2100-2115en© 2024 The Author(s). Published by Oxford University Press on behalf of Royal Astronomical Society. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.https://creativecommons.org/licenses/by/4.0/Astronomical and space sciencesAstronomy & astrophysicsAstronomical sciencesParticle and high energy physicsSpace sciencesArticle10.1093/mnras/stae4200000-0002-8012-6978 (Popovic, Brodie)0000-0002-4934-5849 (Scolnic, Daniel)0000-0001-8788-1688 (Vincenzi, Maria)0000-0001-9053-4820 (Sullivan, Mark)0000-0001-5201-8374 (Brout, Dillon)0000-0003-0313-0487 (Kelsey, Lisa)0000-0002-3073-1512 (Wiseman, Phil)0000-0001-6882-0230 (Toy, Marcus)1005248