Four Years of Type Ia Supernovae Observed by TESS: Early-time Light-curve Shapes and Constraints on Companion Interaction Models

Abstract

We present 307 type Ia supernova (SN) light curves from the first 4 yr of the Transiting Exoplanet Survey Satellite 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 flux 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 β 1 of the early-time light curves is β 1 = 1.93 ± 0.57, and the mean rise time to peak is 15.7 ± 3.5 days. The underlying population distribution for β 1 may instead consist of a Gaussian component with mean 2.29, width 0.34, and a long tail extending to values less than 1.0. We find that the data can rarely distinguish between models with and without companion interaction models. Nevertheless, we find three high-quality light curves that tentatively prefer the addition of a companion interaction model, but the statistical evidence for the companion interactions 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 3σ 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 ⊙ (separations >5.7 × 1012 cm, 99.9% confidence level) and disfavor companions having Roche lobe radii >10 R ⊙ (separations >1.9 × 1012 cm, 95% confidence level). Lastly, we discuss the implications of our results for the intrinsic fraction of single degenerate progenitor systems.

Flight of the Bumblebee: the Early Excess Flux of Type Ia Supernova 2023bee Revealed by TESS, Swift, and Young Supernova Experiment Observations

“…These SNe at 49 and 32 Mpc, respectively, are also among the closest SNe Ia observed by either observatory. The only comparably close SNe Ia in this combined sample (e.g., Olling et al 2015;Fausnaugh et al 2021Fausnaugh et al , 2023, and other individual SNe discussed above) are SNe 2018fhw (Vallely et al 2019) and 2018hib (Fausnaugh et al 2021), at 74 and 66 Mpc, respectively. SN 2018hib did not have any indication of an early flux excess (Fausnaugh et al 2021).…”

“…Deckers et al (2022) did a systematic analysis on the SNe Ia sample with early coverage from ZTF, and finds that 3 out of 30 SNe Ia with z < 0.07 have detectable early excess, although there is large difference in data conditions such as S/N and cadence between the brightest SNe Ia sample and the ZTF sample. Fausnaugh et al (2023) did a systematic search for the early excess features in the early light curves of 74 SNe Ia in TESS Sectors 1-50, only found 3 tentative candidates, and none of them are robust detection with the BIC test. The brightest SNe Ia with early excesses also show a wide variety of excess flux morphology and brightness relative to the SN brightness, e.g., a 50% difference in excess flux brightness between SN 2018oh and SN 2023bee, as well as differences in their early colors between SN 2017cbv, SN 2021aefx, and SN 2023bee.…”

Strong Carbon Features and a Red Early Color in the Underluminous Type Ia SN 2022xkq

“…Fixing a = 2 results in t exp almost 2 days before the last nondetection and is unable to reproduce the shape of the first few days of the rising light curve. Surveys have found a = 2 to be roughly consistent with normal SNe Ia (Conley et al 2006;Hayden et al 2010;Ganeshalingam et al 2011;Zheng et al 2017;Miller et al 2020b;Fausnaugh et al 2023); however, those with low s BV (s BV < 0.8) have been observed to have systematically lower a values than normal SNe Ia (González-Gaitán et al 2012), so a value <2 is expected for SN 2022xkq.…”

From out of the Blue: Swift Links 2002es-like, 2003fg-like, and Early Time Bump Type Ia Supernovae

“…However, SN 2020tld lies well outside its host, so we assume A V = 0.01 ± 0.01 mag. Finally, the rising light-curve fits from Fausnaugh et al (2023) disfavor companion interaction, so we categorize SN 2020tld as a single SN Ia. There are no preexplosion images, nor postexplosion templates in Swift for SN 2020tld, so we do not include it in our figures or analysis.…”

“…TESS observed SN 2021zny, and the rising TESS light curve shows a small bump (Dimitriadis et al 2023;Fausnaugh et al 2023). However, Fausnaugh et al (2023) express some concerns over the veracity of this bump. They note similar light-curve variations at the light-curve peak.…”