Supernovae at distances <40 Mpc
Xiaoran Ma, Xiaofeng Wang, Jun Mo, D. A. Howell, C. Pellegrino, Jujia Zhang, Chengyuan Wu, Shengyu Yan, Dongdong Liu, Iair Arcavi, Zhihao Chen, Joseph Farah, Estefania Padilla Gonzalez, Fangzhou Guo, D. Hiramatsu, Gaici Li, Han Lin, Jialian Liu, C. McCully, Megan Newsome, Hanna Sai, G. Terreran, Danfeng Xiang, Xinhan Zhang
Abstract
Context . This is the second paper of a series aiming to determine the birth rates of supernovae (SNe) in the local Universe. Aims . We aimed to estimate the SN rates in the local Universe and fit the delay-time distribution of type Ia SNe (SNe Ia) to put constraints on their progenitor scenarios. Methods . We performed a Monte Carlo simulation to estimate volumetric rates using the nearby SN sample introduced in Paper I. The rate evolution of core-collapse (CC) SNe closely follows the evolution of the cosmic star formation history, while the rate evolution of SNe Ia involves the convolution of the cosmic star formation history and a two-component delay-time distribution including a power law and a Gaussian component. Results . The volumetric rates of type Ia, Ibc, and II SNe are derived as 0.325 ± 0.040 −0.010 +0.016 , 0.160 ± 0.028 −0.014 +0.044 , and 0.528 ± 0.051 −0.013 +0.162 (in units of 10 −4 yr −1 Mpc −3 h 70 3 ), respectively. The rate of CCSNe (0.688 ± 0.078 −0.027 +0.0206 ) is consistent with previous estimates, which trace the star formation history. Conversely, the newly derived local SN Ia rate is larger than existing results given at redshifts 0.01 < z < 0.1, favoring an increased rate from the Universe at z ∼ 0.1 to the local Universe at z < 0.01. A two-component model effectively reproduces the rate variation, with the power law component accounting for the rate evolution at larger redshifts and the Gaussian component with a delay time of 12.63 ± 0.38 Gyr accounting for the local rate evolution. This delayed component, with its exceptionally long delay time, suggests that the progenitors of these SNe Ia were formed around 1 Gyr after the birth of the Universe, which could only be explained by a double-degenerate progenitor scenario. Comparison with the Palomar Transient Factory (PTF) sample of SNe Ia at z = 0.073 and the morphology of their host galaxies, reveals that the increased SN Ia rate at z < 0.01 is primarily due to the SNe Ia of massive E and S0 galaxies with old stellar populations. Based on the above results, we estimate the Galactic SN rate as 3.08 ± 1.29 per century.