The Most Luminous Known Fast Blue Optical Transient AT 2024wpp: Unprecedented Evolution and Properties in the X-Rays and Radio

Abstract We present X-ray (0.3–79 keV) and radio (0.25–203 GHz) observations of the most luminous fast blue optical transient (LFBOT) AT 2024wpp at z = 0.0868, spanning 2–280 days after first light. AT 2024wpp shows luminous ( L X ≈ 1.5 × 10 43 erg s −1 ), variable X-ray emission with a Compton hump peaking at δt ≈ 50 days. The X-ray spectrum evolves from a soft ( F ν ∝ ν −0.6 ) to an extremely hard state ( F ν ∝ ν 1.26 ) accompanied by a rebrightening at δt ≈ 50 days. The X-ray emission properties favor an embedded high-energy source shining through asymmetric expanding ejecta. We detect radio emission peaking at L 9 GHz ≈ 1.7 × 10 29 erg s −1 Hz −1 at δt ≈ 73 days. The spectral evolution is unprecedented: the early millimeter fluxes rise nearly an order of magnitude during δt ≈ 17–32 days, followed by a decline in spectral peak fluxes. We model the radio emission as synchrotron radiation from an expanding blast wave interacting with a dense environment ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mover accent="true"> <mml:mi>M</mml:mi> <mml:mo>̇</mml:mo> </mml:mover> <mml:mo>∼</mml:mo> <mml:mn>1</mml:mn> <mml:msup> <mml:mn>0</mml:mn> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>3</mml:mn> </mml:mrow> </mml:msup> <mml:mspace width="0.25em"/> <mml:msub> <mml:mi>M</mml:mi> <mml:mo>⊙</mml:mo> </mml:msub> <mml:mspace width="0.25em"/> <mml:msup> <mml:mi>yr</mml:mi> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>1</mml:mn> </mml:mrow> </mml:msup> </mml:math> for v w = 1000 km s −1 ). The inferred outflow velocities increase from Γ βc ≈ 0.07 c to 0.42 c during δt ≈ 32–73 days, indicating an accelerating blast wave. We interpret these observations as a shock propagating through a dense shell of radius ≈10 16 cm and then accelerating into a steep density profile ρ CSM ( r ) ∝ r −3.1 . All radio-bright LFBOTs exhibit similar circumstellar medium (CSM) density profiles ( ρ CSM ∝ r −3 ), suggesting similar progenitor processes. The X-ray and radio properties favor a progenitor involving super-Eddington accretion onto a compact object launching mildly relativistic disk wind outflows.

Authors

Publication Details

Journal
The Astrophysical Journal Letters
Published
2025-10-24
DOI
https://doi.org/10.3847/2041-8213/ae0b4d
Citations
4
Primary Topic
Gamma-ray bursts and supernovae
Type
article
Field-Weighted Citation Impact
4.62

Funders

Controls
|||
ALL TIME
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
article

The Most Luminous Known Fast Blue Optical Transient AT 2024wpp: Unprecedented Evolution and Properties in the X-Rays and Radio

Xiaoshan Huang, D. Tsuna, Andrew Siemion, Fabio De Colle et al.
4 citations
The Astrophysical Journal Letters
Gamma-ray bursts and supernovae
4.62
article

The Most Luminous Known Fast Blue Optical Transient AT 2024wpp: Unprecedented Evolution and Properties in the X-Rays and Radio

Xiaoshan Huang, D. Tsuna, Andrew Siemion, Fabio De Colle, Luigi F. Cruz, Itai Sfaradi, David R. DeBoer, W. V. Jacobson-Galán, Sofia Z. Sheikh, Collin T. Christy, K. D. Alexander, T. Laskar, Brian D. Metzger, Giulia Migliori, Natalie LeBaron, Wael Farah, Wenbin Lu, Daniel Kasen, G. C. Anupama, A. Hajela, Timothy J. Galvin, D. L. Coppejans, E. Berger, Brian W. Grefenstette, R. Chornock, Dan Milisavljevic, Nathaniel Roth, Alexander W. Pollak, Indrek Vurm, M. R. Drout, Paz Beniamini, James F. Steiner, R. Margutti, Huei Sears, Eli Wiston, A. J. Nayana, Olivia Aspegren
article en
4 citations

Abstract

Abstract We present X-ray (0.3–79 keV) and radio (0.25–203 GHz) observations of the most luminous fast blue optical transient (LFBOT) AT 2024wpp at z = 0.0868, spanning 2–280 days after first light. AT 2024wpp shows luminous ( L X ≈ 1.5 × 10 43 erg s −1 ), variable X-ray emission with a Compton hump peaking at δt ≈ 50 days. The X-ray spectrum evolves from a soft ( F ν ∝ ν −0.6 ) to an extremely hard state ( F ν ∝ ν 1.26 ) accompanied by a rebrightening at δt ≈ 50 days. The X-ray emission properties favor an embedded high-energy source shining through asymmetric expanding ejecta. We detect radio emission peaking at L 9 GHz ≈ 1.7 × 10 29 erg s −1 Hz −1 at δt ≈ 73 days. The spectral evolution is unprecedented: the early millimeter fluxes rise nearly an order of magnitude during δt ≈ 17–32 days, followed by a decline in spectral peak fluxes. We model the radio emission as synchrotron radiation from an expanding blast wave interacting with a dense environment ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mover accent="true"> <mml:mi>M</mml:mi> <mml:mo>̇</mml:mo> </mml:mover> <mml:mo>∼</mml:mo> <mml:mn>1</mml:mn> <mml:msup> <mml:mn>0</mml:mn> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>3</mml:mn> </mml:mrow> </mml:msup> <mml:mspace width="0.25em"/> <mml:msub> <mml:mi>M</mml:mi> <mml:mo>⊙</mml:mo> </mml:msub> <mml:mspace width="0.25em"/> <mml:msup> <mml:mi>yr</mml:mi> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>1</mml:mn> </mml:mrow> </mml:msup> </mml:math> for v w = 1000 km s −1 ). The inferred outflow velocities increase from Γ βc ≈ 0.07 c to 0.42 c during δt ≈ 32–73 days, indicating an accelerating blast wave. We interpret these observations as a shock propagating through a dense shell of radius ≈10 16 cm and then accelerating into a steep density profile ρ CSM ( r ) ∝ r −3.1 . All radio-bright LFBOTs exhibit similar circumstellar medium (CSM) density profiles ( ρ CSM ∝ r −3 ), suggesting similar progenitor processes. The X-ray and radio properties favor a progenitor involving super-Eddington accretion onto a compact object launching mildly relativistic disk wind outflows.

The Astrophysical Journal LettersVol. 993(1)
National Science Foundation, National Aeronautics and Space Administration, Alfred P. Sloan Foundation, Research Corporation for Science Advancement, California Institute of Technology, Breakthrough Prize Foundation, National Radio Astronomy Observatory, Flatiron Health, University of Leicester, Tata Institute of Fundamental Research, Nuclear Safety and Security Commission, Korea Astronomy and Space Science Institute, National Astronomical Observatory of Japan, Goddard Space Flight Center, Science and Technology Facilities Council, Dirección General de Asuntos del Personal Académico, Universidad Nacional Autónoma de México, National Institutes of Natural Sciences, Astrophysics Science Division, U.S. Naval Observatory
Openalex Percentile: Top 5%
Gamma-ray bursts and supernovae
4.62
DOIOpen Access PDFOpenAlex
AI Navigator

Ask Laika to Summarize, Analyze, and Connect papers live on the map.

Summarize Papers & Methodologies

Extract key findings, datasets, and comparative methods across publications.

Benchmark Rankings & Visual Analytics

Rank top research institutions, authors, funders, topics, and journals by Field-Weighted Citation Impact (FWCI) and paper volume with instant charts.

Connect Distant Disciplines

Bridge topological clusters on the map to find hidden collaborative intersections.