Four years of Type Ia Supernovae Observed by TESS: Early Time Light Curve Shapes and Constraints on Companion Interaction Models

• Main Authors: Fausnaugh, M. M, Vallely, P. J, Tucker, M. A, Kochanek, C. S, Shappee, B. J, Stanek, K. Z, Ricker, George R, Vanderspek, Roland, Agarwal, Manan, Daylan, Tansu, Jayaraman, Rahul, Hounsell, Rebekah, Muthukrishna, Daniel
• Format: Journal Article
• Language: English
• Published: 21-07-2023
• Subjects: Physics - Astrophysics of Galaxies; Physics - High Energy Astrophysical Phenomena
• DOI: 10.48550/arxiv.2307.11815

We present 307 Type Ia supernova (SN) light curves from the first four years
of the TESS mission. We use this sample to characterize the shapes of the early
time light curves, measure the rise times from first light to peak, and search
for companion star interactions. Using simulations, we show that light curves
must have noise $<$10% of the peak to avoid biases in the early time light
curve shape, restricting our quantitative analysis to 74 light curves. We find
that the mean power law index $t^{\beta_1}$ of the early time light curves is
1.93$\pm$ 0.57 and the mean rise time to peak is 15.7 $\pm$ 3.5 days. We also
estimate the underlying population distribution and find a Gaussian component
with mean $\beta_1 = 2.29$, width 0.34, and a tail extending to values less
than 1.0. We use model comparison techniques to test for the presence of
companion interactions. In contrast to recent results in the literature, we
find that the data can rarely distinguish between models with and without
companion interactions, and caution is needed when claiming detections of early
time flux excesses. Nevertheless, we find three high-quality SN light curves
that tentatively prefer the addition of a companion interaction model, but the
statistical evidence is not robust. We also find two SNe that disfavor the
addition of a companion interaction model to a curved power law model. Taking
the 74 SNe together, we calculate 3$\sigma$ upper limits on the presence of
companion signatures to control for orientation effects that can hide
companions in individual light curves. Our results rule out common progenitor
systems with companions having Roche lobe radii $>$ 31 R$_{\odot}$ (99.9%
confidence level) and disfavor companions having Roche lobe radii $>$ 10
R$_{\odot}$ (95% confidence level). Lastly, we discuss the implications of our
results for the intrinsic fraction of single degenerate progenitor systems.