We analyze 143 Type Ia supernovae (SNe Ia) observed in H band (1.6–1.8 μm) and find that SNe Ia are intrinsically brighter in H band with increasing host galaxy stellar mass. We find that SNe Ia in galaxies more massive than 1010.43 M⊙ are 0.13 ± 0.04 mag brighter in H than SNe Ia in less massive galaxies. The same set of SNe Ia observed at optical wavelengths, after width–color–luminosity corrections, exhibit a 0.10 ± 0.03 mag offset in the Hubble residuals. We observe an outlier population (|ΔHmax| > 0.5 mag) in the H band and show that removing the outlier population moves the mass threshold to 1010.65 M⊙ and reduces the step in H band to 0.08 ± 0.04 mag, but the equivalent optical mass step is increased to 0.13 ± 0.04 mag. We conclude that the outliers do not drive the brightness–host-mass correlation. Less massive galaxies preferentially host more higher-stretch SNe Ia, which are intrinsically brighter and bluer. It is only after correction for width–luminosity and color–luminosity relationships that SNe Ia have brighter optical Hubble residuals in more massive galaxies. Thus, finding that SNe Ia are intrinsically brighter in H in more massive galaxies is an opposite correlation to the intrinsic (pre-width–luminosity correction) optical brightness. If dust and the treatment of intrinsic color variation were the main driver of the host galaxy mass correlation, we would not expect a correlation of brighter H-band SNe Ia in more massive galaxies.
Ponder, Kara A., et al. "Are Type Ia Supernovae in Rest-frame H Brighter in More Massive Galaxies?." The Astrophysical Journal, vol. 923, no. 2, Dec. 2021. https://doi.org/10.3847/1538-4357/ac2d99
Ponder, Kara A., Wood-Vasey, W. Michael, Weyant, Anja, Barton, Nathan T., Galbany, Lluís, Liu, Shu, Garnavich, Peter, & Matheson, Thomas (2021). Are Type Ia Supernovae in Rest-frame H Brighter in More Massive Galaxies?. The Astrophysical Journal, 923(2). https://doi.org/10.3847/1538-4357/ac2d99
Ponder, Kara A., Wood-Vasey, W. Michael, Weyant, Anja, et al., "Are Type Ia Supernovae in Rest-frame H Brighter in More Massive Galaxies?," The Astrophysical Journal 923, no. 2 (2021), https://doi.org/10.3847/1538-4357/ac2d99
@article{osti_1863783,
author = {Ponder, Kara A. and Wood-Vasey, W. Michael and Weyant, Anja and Barton, Nathan T. and Galbany, Lluís and Liu, Shu and Garnavich, Peter and Matheson, Thomas},
title = {Are Type Ia Supernovae in Rest-frame H Brighter in More Massive Galaxies?},
annote = {We analyze 143 Type Ia supernovae (SNe Ia) observed in H band (1.6–1.8 μm) and find that SNe Ia are intrinsically brighter in H band with increasing host galaxy stellar mass. We find that SNe Ia in galaxies more massive than 1010.43 M⊙ are 0.13 ± 0.04 mag brighter in H than SNe Ia in less massive galaxies. The same set of SNe Ia observed at optical wavelengths, after width–color–luminosity corrections, exhibit a 0.10 ± 0.03 mag offset in the Hubble residuals. We observe an outlier population (|ΔHmax| > 0.5 mag) in the H band and show that removing the outlier population moves the mass threshold to 1010.65 M⊙ and reduces the step in H band to 0.08 ± 0.04 mag, but the equivalent optical mass step is increased to 0.13 ± 0.04 mag. We conclude that the outliers do not drive the brightness–host-mass correlation. Less massive galaxies preferentially host more higher-stretch SNe Ia, which are intrinsically brighter and bluer. It is only after correction for width–luminosity and color–luminosity relationships that SNe Ia have brighter optical Hubble residuals in more massive galaxies. Thus, finding that SNe Ia are intrinsically brighter in H in more massive galaxies is an opposite correlation to the intrinsic (pre-width–luminosity correction) optical brightness. If dust and the treatment of intrinsic color variation were the main driver of the host galaxy mass correlation, we would not expect a correlation of brighter H-band SNe Ia in more massive galaxies.},
doi = {10.3847/1538-4357/ac2d99},
url = {https://www.osti.gov/biblio/1863783},
journal = {The Astrophysical Journal},
issn = {ISSN 0004-637X},
number = {2},
volume = {923},
place = {United States},
publisher = {IOP Publishing},
year = {2021},
month = {12}}
Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States); SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States)
Sponsoring Organization:
European Commission (EC); National Aeronautics and Space Administration (NASA); National Science Foundation (NSF); USDOE Office of Science (SC), High Energy Physics (HEP)
Grant/Contract Number:
AC02-05CH11231; AC02-76SF00515
OSTI ID:
1863783
Alternate ID(s):
OSTI ID: 1867889
Journal Information:
The Astrophysical Journal, Journal Name: The Astrophysical Journal Journal Issue: 2 Vol. 923; ISSN 0004-637X