Two-Dimensional Radiation-Hydrodynamic Simulations of Luminous Red Novae
arXiv:2508.09257 · doi:10.3847/2041-8213/ae1ae7
Abstract
Luminous Red Novae (LRNe) are transients associated with mass ejection during stellar mergers and common envelope evolution (CEE). LRNe have the potential to illuminate the poorly understood phases of binary evolution leading up to the CEE, during the mass ejection phase, and in the immediate aftermath. However, the mechanism responsible for powering LRN light curves and the origin of their observed diversity remain open questions. Here, we perform two-dimensional moving-mesh radiation-hydrodynamic simulations of LRNe that take into account hydrogen and helium recombination and relevant opacities. We study a typical high-mass stellar merger, which dynamically ejects 2 with a characteristic velocity of 410 km/s. This ejecta collides with 2.7 of equatorially concentrated circumbinary material (CBM) left behind from a prior phase of non-conservative runaway mass transfer. We find that the resulting light curve is composed of a short, blue peak followed by a redder, predominantly shock-powered plateau with luminosities reaching up to erg/s and durations up to 200 days. These luminosities are significantly higher, and the durations much longer, than those produced by a simple spherical ejection of the same mass. They also depend in a complex way on the radial distribution of the CBM and the viewing angle. The shock is embedded in the ejecta and its observational signatures during the optically-thick phase are largely hidden. Our results are broadly compatible with observations of the brightest extragalactic LRNe and pave the way for the transformation of LRNe into powerful probes of binary evolution.
arXiv commentAccepted to ApJL. 6 figures and 1 table in the main text, 28 pages. Added tabulated EOS and opacities, viewing-angle dependent light curves from raytracing, illumination by central merger remnant, and comparison to observed events. Movies will become available in the journal once published
References in corpus (66)
- SciPy 1.0--Fundamental Algorithms for Scientific Computing in Python
- Modules for Experiments in Stellar Astrophysics (MESA)
- Low Temperature Opacities
- Common Envelope Evolution: Where we stand and how we can move forward
- Rosseland and Planck Mean Opacities for Protoplanetary Discs
- V1309 Scorpii: merger of a contact binary
- Type II Supernovae: Model Light Curves and Standard Candle Relationships
- How mergers magnetise massive stars
- Radiation Magnetohydrodynamic Simulations of Protostellar Collapse: Protostellar Core Formation
- Radiation Magnetohydrodynamic Simulations of Protostellar Collapse: Non-Ideal Magnetohydrodynamic Effects and Early Formation of Circumstellar Disks
- Main-sequence stellar eruption model for V838 Mon
- The role of mass transfer and common envelope evolution in the formation of merging binary black holes
- Stellar Collisions and the Interior Structure of Blue Stragglers
- Identification of the Long-Sought Common-Envelope Events
- Equations and Algorithms for Mixed Frame Flux-Limited Diffusion Radiation Hydrodynamics
- It has to be cool: on supergiant progenitors of binary black hole mergers from common-envelope evolution
- Eruptions of the V838 Mon type: stellar merger versus nuclear outburst models
- Cool and Luminous Transients from Mass-Losing Binary Stars
- TESS: A Relativistic Hydrodynamics Code on a Moving Voronoi Mesh
- Binary Stellar Mergers with Marginally-Bound Ejecta: Excretion Disks, Inflated Envelopes, Outflows, and their Luminous Transients
- Luminous Red Novae: Stellar Mergers or Giant Eruptions?
- Structure and evolution of high-mass stellar mergers
- Shock-powered light curves of luminous red novae as signatures of pre-dynamical mass loss in stellar mergers
- Common Envelope ejection for a Luminous Red Nova in M101
- Lessons from the Onset of a Common Envelope Episode: the Remarkable M31 2015 Luminous Red Nova Outburst
- Massive-Star Mergers and the Recent Transient in NGC4490: A More Massive Cousin of V838 Mon and V1309 Sco
- Pre-explosion spiral mass loss of a binary star merger
- Shocks in nova outflows. I. Thermal emission
- Evolution of V838 Monocerotis during and after the 2002 eruption
- CASTRO: A New Compressible Astrophysical Solver. II. Gray Radiation Hydrodynamics
- Violent Stellar Merger Model for Transient Events
- Companion-launched jets and their effect on the dynamics of common envelope interaction simulations
- CASTRO: A New Compressible Astrophysical Solver. III. Multigroup Radiation Hydrodynamics
- Submillimeter-wave emission of three Galactic red novae: cool molecular outflows produced by stellar mergers
- Burying a Binary: Dynamical Mass Loss and a Continuous Optically-Thick Outflow Explain the Candidate Stellar Merger V1309 Scorpii
- Rayleigh-Taylor Instability in a Relativistic Fireball on a Moving Computational Grid
- On the triple peaks of SNHunt248 in NGC 5806
- The transitional gap transient AT 2018hso: new insights on the luminous red nova phenomenon
- The effect of binding energy and resolution in simulations of the common envelope binary interaction
- Remarkable changes in the near-infrared spectrum of the nova-like variable V4332 Sgr
- Simulating the formation of Carinae's surrounding nebula through unstable triple evolution and stellar merger-induced eruption
- Light Curve Model for Luminous Red Novae and Inferences about the Ejecta of Stellar Mergers
- On rapid binary mass transfer -- I. Physical model
- Progenitor, Precursor and Evolution of the Dusty Remnant of the Stellar Merger M31-LRN-2015
- MASTER OT J004207.99+405501.1/M31LRN 2015 Luminous Red Nova in M31: Discovery, Light Curve, Hydrodynamics, Evolution
- 2D radiation-hydrodynamic simulations of supernova ejecta with a central power source
- Luminous Red Nova AT 2019zhd, a new merger in M 31
- V838 Monocerotis: the central star and its environment a decade after outburst
- Efficiently jet-powered radiation in intermediate-luminosity optical transients (ILOTS)
- Explaining Two Recent Intermediate Luminosity Optical Transients (ILOTs) by a Binary Interaction and Jets
- The Evolution of Luminous Red Nova AT 2017jfs in NGC 4470
- Kinematics of Mass Loss from the Outer Lagrange Point L2
- Interaction of a Supernova with a Circumstellar Disk
- Three-Dimensional Simulations of Magnetar-Powered Superluminous Supernovae
- Observations of the luminous red nova AT 2021biy in the nearby galaxy NGC 4631
- Supernova explosions interacting with aspherical circumstellar material: implications for light curves, spectral line profiles, and polarization
- An Extension of the Athena++ Framework for General Equations of State
- Polarimetric evolution of V838 Mon
- Common Envelope Evolution of Massive Stars
- Moving-mesh radiation-hydrodynamic simulations of wind-reprocessed transients
- Merger Precursor: Year-long Transients Preceding Mergers of Low-mass Stripped Stars with Compact Objects
- Panchromatic evolution of three luminous red novae: Forbidden hugs in pandemic times -- IV
- Common envelopes in massive stars III. The obstructive role of radiation transport in envelope ejection
- The effect of relativistic precession on light curves of tidal disruption events
- Journey to the center of the common envelope evolution. Inner dynamics of the post-dynamical inspiral
- Bright common envelope formation requires jets