Perley, Daniel A and Ho, Anna Y Q and McGrath, Zoë and Camilo, Michael and Sevilla, Cassie and Chen, Ping and Schroeder, Genevieve and Govreen-Segal, Taya and Bochenek, Aleksandra and Qin, Yu-Jing and Gillanders, James H and Amend, Benjamin and Anderson, Joseph P and Andreoni, Igor and Aryan, Amar and Bellm, Eric C and Bloom, Joshua S and de Boer, Thomas and Carney, Jonathan and Caiazzo, Ilaria and Chambers, Ken C and Charalampopoulos, Panos and Chen, Ting-Wan and Chen, Tracy X and Coughlin, Eric R and Coughlin, Michael and Dennefeld, Michel and Dimitriadis, Georgios and Fremling, Christoffer and Frostig, Danielle and Gal-Yam, Avishay and Galbany, Lluís and Gangopadhyay, Anjashay and Ghendrih, Melzie and Graham, Matthew J and Gromadzki, Mariusz and Groom, Steven L and Gutiérrez, Claudia P and Hinds, K-Ryan and Huber, Mark E and Inserra, Cosimo and Kaiser, Benjamin C and Kasliwal, Mansi M and Koivisto, Niilo E and Lin, Chien-Cheng and Liu, Chang and Lowe, Thomas B and Magnier, Eugene and Mahabal, Ashish A and Milligan, Andrew and Minguez, Paloma and Mo, Geoffrey and Müller-Bravo, Tomás E and Nicholl, Matt and Pessi, Priscila J and Pignata, Giuliano and Purdum, Josiah and Rehemtulla, Nabeel and Rich, R Michael and Sahu, Anwesha and Singh, Avinash and Smartt, Stephen J and Smith, Ian A and Sollerman, Jesper and Srinivasaragavan, Gokul and Srivastav, Shubham and Stein, Robert D and Schulze, Steve and Tweddle, Jack W and Wainscoat, Richard and Wise, Jacob L and Yan, Lin and Young, David R (2026) AT 2024wpp : An Extremely Luminous Fast Ultraviolet Transient Powered by Accretion onto a Black Hole. Monthly Notices of the Royal Astronomical Society: stag678. ISSN 0035-8711
Full text not available from this repository.Abstract
We present the discovery of AT 2024wpp (‘Whippet’), a fast and luminous 18cow-like transient. At a redshift of z = 0.0868, revealed by Keck Cosmic Web Imager spectroscopy of its faint star-forming host, it is the fourth-nearest example of its class to date. Rapid identification of the source in the Zwicky Transient Facility data stream permitted ultraviolet-through-optical observations to be obtained prior to peak, allowing the first determination of the peak bolometric luminosity (2 × 1045 erg s−1), maximum photospheric radius (1015 cm), and total radiated energy (1051 erg) of an 18cow-like object. We present results from a comprehensive multiwavelength observing campaign, including a far-UV spectrum from the Cosmic Origins Spectrograph on the Hubble Space Telescope and deep imaging extending >100 days post-explosion from the Very Large Telescope, Hubble Space Telescope, Very Large Array, and Atacama Large Millimetre Array. We interpret the observations under a model in which a rapidly-accreting central engine blows a fast (∼ 0.2 c) wind into the surrounding medium and irradiates it with X-rays. The high Doppler velocities and intense ionization within this wind prevent identifiable spectroscopic features from appearing in the ejecta or in the surrounding circumstellar material. Weak H and He signatures do emerge in the spectra after 35 days in the form of double-peaked narrow lines. Each peak is individually narrow (full width δv ∼ 3000 km s−1) but the two components are separated by Δv ∼ 6600 km s−1, indicating stable structures of denser material, possibly representing streams of tidal ejecta or an ablated companion star.