Moore, T. and Gillanders, J. H. and Nicholl, M. and Huber, M. E. and Smartt, S. J. and Srivastav, S. and Stevance, H. F. and Chen, T.-W. and Chambers, K. C. and Anderson, J. P. and Fulton, M. D. and Oates, S. R. and Angus, C. and Pignata, G. and Erasmus, N. and Gao, H. and Herman, J. and Lin, C.-C. and Lowe, T. and Magnier, E. A. and Minguez, P. and Ngeow, C.-C. and Sheng, X. and Sim, S. A. and Smith, K. W. and Wainscoat, R. and Yang, S. and Young, D. R. and Zeng, K.-J. (2025) SN 2023zaw : The Low-energy Explosion of an Ultrastripped Star. Astrophysical Journal Letters, 980 (2): L44. ISSN 2041-8205
Full text not available from this repository.Abstract
Most stripped-envelope supernova progenitors are thought to be formed through binary interaction, losing hydrogen and/or helium from their outer layers. Ultrastripped supernovae are an emerging class of transient that are expected to be produced through envelope stripping by a neutron star companion. However, relatively few examples are known, and the outcomes of such systems can be diverse and are poorly understood at present. Here we present spectroscopic observations and high-cadence, multiband photometry of SN 2023zaw, a rapidly evolving supernova with a low ejecta mass. SN 2023zaw was discovered in a nearby spiral galaxy at D = 39.7 Mpc. It has significant Milky Way extinction, E(B − V)MW = 0.21, and significant (but uncertain) host extinction. Bayesian evidence comparison reveals that nickel is not the only power source and that an additional energy source is required to explain our observations. Our models suggest that an ejecta mass of Mej ∼ 0.07 M⊙ and a synthesised nickel mass of MNi ∼ 0.007 M⊙ are required to explain the observations. We find that additional heating from a central engine, or interaction with circumstellar material, can power the early light curve.