Supernovae at distances <40 Mpc

I. Catalogues and fractions of supernovae in a complete sample

¹ Department of Physics, Tsinghua University, Beijing 100084, China
² Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210023, China
³ Las Cumbres Observatory, 6740 Cortona Drive Suite 102, Goleta, CA 93117-5575, USA
⁴ Department of Physics, University of California, Santa Barbara, CA 93106-9530, USA
⁵ Yunnan Observatories, Chinese Academy of Sciences, Kunming 650216, China
⁶ International Centre of Supernovae, Yunnan Key Laboratory, Kunming 650216, PR China
⁷ School of Physics and Astronomy, Tel Aviv University, Tel Aviv 69978, Israel
⁸ Center for Astrophysics | Harvard & Smithsonian, 60 Garden Street, Cambridge, MA 02138-1516, USA
⁹ The NSF AI Institute for Artificial Intelligence and Fundamental Interactions, USA
¹⁰ School of Physics and Information Engineering, Jiangsu Second Normal University, Nanjing 211200, China
¹¹ Key Laboratory of Space Astronomy and Technology, National Astronomical Observatories, Chinese Academy of Sciences, 20A Datun Road, Beijing 100101, China
¹² School of Astronomy and Space Science, University of Chinese Academy of Sciences, Beijing 101408, China
¹³ Beijing Planetarium, Beijing Academy of Sciences and Technology, Beijing, 100044, China

^★ Corresponding author: wang_xf@mail.tsinghua.edu.cn

Received: 21 October 2024
Accepted: 29 March 2025

Abstract

Context. This is the first paper in a series aiming to determine the fractions and birth rates of various types of supernovae (SNe) in the local Universe.

Aims. In this paper, we aim to construct a complete sample of SNe in the nearby Universe and provide more precise measurements of subtype fractions.

Methods. We carefully selected our SN sample at a distance of less than 40 Mpc mainly from wide-field surveys conducted over the years from 2016 to 2023.

Results. The sample contains a total of 211 SNe, including 109 SNe II, 69 SNe Ia, and 33 SNe Ibc. With the aid of sufficient spectra, we obtained relatively accurate subtype classifications for all SNe in this sample. After corrections for the Malmquist bias, this volumelimited sample yielded fractions of SNe Ia, SNe Ibc, and SNe II of 30.4_−11.5^+3.7 %, 16.3_−7.4^+3.7 %, and 53.3_−18.7^+9.5 %, respectively. In the SN Ia sample, the fraction of the 91T-like subtype becomes relatively low (~5.4%), while that of the 02cx-like subtype shows a moderate increase (~6.8%). In the SN Ibc sample, we find significant fractions of broadlined SNe Ic (~18.0%) and SNe Ibn (~8.8%). The fraction of the 87A-like subtype was determined to be ~2.3%, indicating rare explosions from blue supergiant stars. We find that SNe Ia show a double peak number distribution in S0- and Sc-type host galaxies, which may serve as straightforward evidence for the presence of “prompt” and “delayed” progenitor components that give rise to SN Ia explosions. Several subtypes of SNe such as 02cx-like SNe Ia, broadlined SNe Ic, and SNe IIn (and perhaps SNe Ibn) are found to occur preferentially in less massive spiral galaxies (i.e., with stellar mass <0.5×10¹⁰ M_ʘ), thus favoring their associations with young stellar progenitors. Moreover, the 02cx-like subtype shows a trend of exploding in the outer skirt of their hosts, which is suggestive of metal-poor progenitors.