English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

A spectral-energy distribution (SED) model for Type Ia supernovae (SNe Ia) isa critical tool for measuring precise and accurate distances across a largeredshift range and constraining cosmological parameters. We present an improvedmodel framework, SALT3, which has several advantages over current modelsincluding the leading SALT2 model (SALT2.4). While SALT3 has a similarphilosophy, it differs from SALT2 by having improved estimation ofuncertainties, better separation of color and light-curve stretch, and apublicly available training code. We present the application of our trainingmethod on a cross-calibrated compilation of 1083 SNe with 1207 spectra. Ourcompilation is $2.5\times$ larger than the SALT2 training sample and hasgreatly reduced calibration uncertainties. The resulting trained SALT3.K21model has an extended wavelength range $2000$-$11000$ angstroms (1800 angstromsredder) and reduced uncertainties compared to SALT2, enabling accurate use oflow-$z$ $I$ and $iz$ photometric bands. Including these previously discardedbands, SALT3.K21 reduces the Hubble scatter of the low-z Foundation and CfA3samples by 15% and 10%, respectively. To check for potential systematicuncertainties we compare distances of low ($0.01<z<0.2$) and high ($0.4<z<0.6$)redshift SNe in the training compilation, finding an insignificant $2\pm14$mmag shift between SALT2.4 and SALT3.K21. While the SALT3.K21 model was trainedon optical data, our method can be used to build a model for rest-frame NIRsamples from the Roman Space Telescope. Our open-source training code, publictraining data, model, and documentation are available athttps://saltshaker.readthedocs.io/en/latest/, and the model is integrated intothe sncosmo and SNANA software packages.

SALT3: An Improved Type Ia Supernova Model for Measuring Cosmic Distances