SN 2023gpw: Exploring the diversity and power sources of hydrogen-rich superluminous supernovae
Year: 2025
Type: article
Abstract: We present our observations and analysis of SN 2023gpw, a hydrogen-rich superluminous supernova (SLSN II) with broad emission lines in its post-peak spectra. Unlike previously observed SLSNe II, its light curve suggests an abrupt drop during a solar conjunction between ∼80 and ∼180 d after the light curve peak, which is possibly analogous to a normal hydrogen-rich supernova (SN). Spectra taken at and before the peak show hydrogen and helium “flash” emission lines attributed to early interaction with a dense confined circumstellar medium (CSM). A well-observed ultraviolet excess appears as these lines disappear, also as a result of CSM interaction. The blackbody photosphere expands roughly at the same velocity throughout the observations, indicating little or no bulk deceleration. This velocity is much higher than what is seen in spectral lines, suggesting asymmetry in the ejecta. The high total radiated energy (≳9 × 10 50 erg) and aforementioned lack of bulk deceleration in SN 2023gpw are difficult to reconcile with a neutrino-driven SN simply combined with efficient conversion from kinetic energy to emission through interaction. This suggests an additional energy source, such as a central engine. While magnetar-powered models qualitatively similar to SN 2023gpw exist, more modeling work is required to determine if they can reproduce the observed properties in combination with early interaction. The required energy might alternatively be provided by accretion onto a black hole created in the collapse of a massive progenitor star.
Source: Astronomy and Astrophysics
Institutions: Aalto University, California Institute of Technology, Aarhus University, Northwestern University, Institute of Space Sciences, Osservatorio Astronomico di Padova, National Institute for Astrophysics, Liverpool John Moores University, Stockholm University, Trinity College Dublin, Arturo Prat University, Institut d'Estudis Espacials de Catalunya, Infrared Processing and Analysis Center
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,865
Funders: National Science Foundation, California Institute of Technology, Northwestern University, Aarhus Universitet, University of Warwick, European Commission, Trinity College Dublin, Weizmann Institute of Science, Academy of Finland, Aarhus Universitets Forskningsfond, Generalitat de Catalunya, Ministerio de Ciencia e Innovación, Istituto Nazionale di Astrofisica, Stockholms Universitet, Instituto de Astrofísica de Canarias, HORIZON EUROPE Framework Programme, Deutsches Elektronen-Synchrotron, Horizon 2020, Agencia Estatal de Investigación, Institut National de Physique Nucléaire et de Physique des Particules, HORIZON EUROPE European Research Council
Awards: Unveiling the origins of white-dwarf explosions, G1855990336, G2064873908, G2262748287, G2309174360, G2601397997, Exploring & Exploiting the Dynamic Optical Sky, G3005324705, G300979063, G3439265645, G3480869486, G3681454997, G4042783231, G4144370461, G4212629114, G425668148, G430777504, G434337789, Studying Exotic and extReme EruptioNs AnD Explosions (SERENADE), G4823672097, Opticon RadioNet Pilot, G5080475149, G5421974903, G617610489, G6513613686, G7432173962, G7685115895, G8421397835
OpenAlex ID: W4414788940