On the episodic excursions of massive protostars in the Hertzsprung-Russell diagram

Abstract

Massive protostars grow and evolve under the effect of rapid accretion of circumstellar gas and dust, falling at high rates ($\ge 10^{-4}$-$10^{-3}{\mathrm{M}}_{\odot }\mathrm{y}{\mathrm{r}}^{-1}$). This mass infall has been shown, both numerically and observationally, to be episodically interspersed by accretion of dense gaseous clumps migrating through the circumstellar disc to the protostellar surface, causing sudden accretion and luminous bursts. Using numerical gravito-radiation-hydrodynamics and stellar evolution calculations, we demonstrate that, in addition to the known bloating of massive protostars, variable episodic accretion further influences their evolutionary tracks of massive young stellar objects (MYSOs). For each accretion-driven flare, they experience rapid excursions toward more luminous, but colder regions of the Hertzsprung-Russell diagram. During these excursions, which can occur up to the end of the pre-main-sequence evolution, the photosphere of massive protostars can episodically release much less energetic photons and MYSOs surreptitiously adopt the same spectral type as evolved massive (supergiants) stars. Each of these evolutionary loop brings the young high-mass stars close to the forbidden Hayashi region and might make their surrounding H II regions occasionally fainter, before they recover their quiescent, pre-burst surface properties. We interpret such cold, intermittent pre-main-sequence stellar evolutionary excursions and the dipping variability of HII regions as the signature of the presence of a fragmenting circumstellar accretion disc surrounding the MYSOs. We conjecture that this mechanism might equivalently affect young stars in the intermediate-mass regime.

arXiv commentAccepted to MNRAS

References in corpus (95)

• Grids of stellar models with rotation - I. Models from 0.8 to 120 Msun at solar metallicity (Z = 0.014)
• PLUTO: a Numerical Code for Computational Astrophysics
• Using FU Orionis Outbursts to Constrain Self-Regulated Protostellar Disk Models
• On the Formation of Massive Stars
• The Formation of Massive Star Systems by Accretion
• Gravitational Instabilities in Circumstellar Disks
• The Effective Temperature Scale of Galactic Red Supergiants: Cool, But Not As Cool As We Thought
• The PLUTO Code for Adaptive Mesh Computations in Astrophysical Fluid Dynamics
• On the formation of massive stars
• Evolution of Massive Protostars with High Accretion Rates
• Modeling Collapse and Accretion in Turbulent Gas Clouds: Implementation and Comparison of Sink Particles in AMR and SPH
• Radiation-Hydrodynamic Simulations of Collapse and Fragmentation in Massive Protostellar Cores
• A spectroscopic survey on the multiplicity of high-mass stars
• Episodic accretion in magnetically layered protoplanetary discs
• The burst mode of accretion and disk fragmentation in the early embedded stages of star formation
• The Origin of Episodic Accretion Bursts in the Early Stages of Star Formation
• Non-steady Accretion in Protostars
• Evolution of Massive Protostars via Disk Accretion
• Episodic accretion at early stages of evolution of low mass stars and brown dwarfs: a solution for the observed luminosity spread in HR diagrams?
• H II regions: Witnesses to massive star formation
• Formation of Massive Primordial Stars: Intermittent UV Feedback with Episodic Mass Accretion
• Variable protostellar accretion with episodic bursts
• Limiting Accretion onto Massive Stars by Fragmentation-Induced Starvation
• Fragmentation of Massive Protostellar Disks
• Global Models for the Evolution of Embedded, Accreting Protostellar Disks
• Mid-Infrared Extinction Mapping of Infrared Dark Clouds II. The Structure of Massive Starless Cores and Clumps
• An extraordinary outburst in the massive protostellar system NGC6334I-MM1: quadrupling of the millimeter continuum
• 2-D simulations of FU Orionis disk outbursts
• Formation of massive stars by growing accretion rate
• Fundamental properties of core-collapse Supernova and GRB progenitors: predicting the look of massive stars before death
• Radiation hydrodynamics with Adaptive Mesh Refinement and application to prestellar core collapse. I Methods
• On the Reliability of Stellar Ages and Age Spreads Inferred from Pre-Main Sequence Evolutionary Models
• Massive planets in FU Orionis discs: implications for thermal instability models
• Magnetic fields during the early stages of massive star formation - I. Accretion and disk evolution
• On the existence of accretion-driven bursts in massive star formation
• A Keplerian-like disk around the forming O-type star AFGL 4176
• An Unstable Truth: How Massive Stars get their Mass
• Observations on the Formation of Massive Stars by Accretion
• Supersonic Gas Streams Enhance the Formation of Massive Black Holes in the Early Universe
• The Origin and Formation of the Circumstellar Disk
• Decoupling of Magnetic Fields in Collapsing Protostellar Envelopes and Disk Formation and Fragmentation
• G11.92-0.61 MM1: A Keplerian disc around a massive young proto-O star
• Neon Abundances in B-Stars of the Orion Association: Solving the Solar Model Problem?
• Infall-Driven Protostellar Accretion and the Solution to the Luminosity Problem
• B fields in OB stars (BOB): low-resolution FORS2 spectropolarimetry of the first sample of 50 massive stars
• Stellar irradiated discs and implications on migration of embedded planets II: accreting-discs
• A search for ionized jets towards massive young stellar objects
• Forming spectroscopic massive proto-binaries by disk fragmentation
• The structure of disks around intermediate-mass young stars from mid-infrared interferometry. Evidence for a population of group II disks with gaps
• Simulating the Formation of Massive Protostars: I. Radiative Feedback and Accretion Disks
• Supersonic turbulence, filamentary accretion,and the rapid assembly of massive stars and disks
• Fu Ori outbursts and the planet-disc mass exchange
• Radiation Magnetohydrodynamics In Global Simulations Of Protoplanetary Disks
• A Keplerian disk around Orion Source I, a ~15 Msun YSO
• A near-IR spectroscopic survey of massive jets towards EGOs
• On the simultaneous evolution of massive protostars and their host cores
• Filament Fragmentation in High-Mass Star Formation
• The ALMA early science view of FUor/EXor objects - V: continuum disc masses and sizes
• Self-consistent evolution of accreting low-mass stars and brown dwarfs
• Radio outburst from a massive (proto)star. When accretion turns into ejection
• A Pulsed, Precessing Jet in Cepheus A
• Radiation-hydrodynamical simulations of massive star formation using Monte Carlo radiative transfer: I. Algorithms and numerical methods
• Jet formation from massive young stars: Magnetohydrodynamics versus radiation pressure
• Radiation hydrodynamics integrated in the code PLUTO
• Burst occurrence in young massive stellar objects
• Evidence of magnetic field decay in massive main-sequence stars
• Gravitational fragmentation and formation of giant protoplanets on tens-of-au orbits
• Variable accretion in the embedded phase of stellar evolution
• The ALMA view of W33A: A Spiral Filament Feeding the Candidate Disc in MM1-Main
• The Darkest Shadows: Deep Mid-Infrared Extinction Mapping of a Massive Protocluster
• A spectroscopic investigation of the O-type star population in four Cygnus OB associations. I. Determination of the binary fraction
• Radiation-hydrodynamical simulations of massive star formation using Monte Carlo radiative transfer II. The formation of a 25 solar-mass star
• Massive star formation by accretion I. Disc accretion
• A grid of 1D low-mass star formation collapse models
• First Core Properties: From Low- to High-mass Star Formation
• Stellar parameters and H$\alpha$ line profile variability of Be stars in the BeSOS survey
• A high-mass protobinary system with spatially resolved circumstellar accretion disks and circumbinary disk
• The effect of accretion on the pre-main-sequence evolution of low-mass stars and brown dwarfs
• The circumstellar disk response to the motion of the host star
• The Impact of Feedback in Massive Star Formation. II. Lower Star Formation Efficiency at Lower Metallicity
• Self-gravitating disc candidates around massive young stars
• Dense gas in IRAS 20343+4129: an ultracompact HII region caught in the act of creating a cavity
• Proper motions of collimated jets from intermediate-mass protostars in the Carina Nebula
• Trigonometric distance and proper motions of H2O maser bowshocks in AFGL 5142
• Massive star formation by accretion II. Rotation: how to circumvent the angular momentum barrier?
• Tracers of Discs and Winds around Intermediate and High Mass Young Stellar Objects
• Line-driven ablation of circumstellar discs: III. Accounting for and analyzing the effects of continuum optical depth
• Impact of initial models and variable accretion rates on the pre-main-sequence evolution of massive and intermediate-mass stars and the early evolution of HII regions
• YSO jets in the Galactic Plane from UWISH2: V - Jets and Outflows in M17
• The nature of very low luminosity objects (VeLLOs)
• A very young, compact bipolar H${}_2$O maser outflow in the intermediate-mass star-forming LkH$\alpha$ 234 region
• Investigating the temporal domain of massive ionized jets - I. A pilot study
• Connecting low- and high-mass star formation: the intermediate-mass protostar IRAS 05373+2349 VLA 2
• IRAS 22150+6109 - a young B-type star with a large disc
• New eruptive variable in the massive star-forming region associated with IRAS 18507+0121 source

Cited by in corpus (17)

• Sub-arcsecond (sub)millimeter imaging of the massive protocluster G358.93-0.03: Discovery of 14 new methanol maser lines associated with a hot core
• M17 MIR: A massive protostar with multiple accretion Outbursts
• ALMA View of the Infalling Envelope around a Massive Protostar in S255IR SMA1
• Evolution of dust in protoplanetary disks of eruptive stars
• The Extraordinary Outburst in the Massive Protostellar System NGC6334I-MM1: Strong Increase in Mid-Infrared Continuum Emission
• Parameter study for the burst mode of accretion in massive star formation
• ALMA observations of the Extended Green Object G19.01$-$0.03: I. A Keplerian disc in a massive protostellar system
• On the ALMA observability of nascent massive multiple systems formed by gravitational instability
• The role of magnetic fields in the formation of multiple massive stars
• Episodic accretion and mergers during growth of massive protostars
• Disk fragmentation around a massive protostar: a comparison of two three-dimensional codes
• The burst mode of accretion in massive star formation with stellar inertia
• A rotating fast bipolar wind and disk system around the B[e]-type star MWC 922
• Periodic 6.7 GHz $\mathrm{C}{\mathrm{H}}_3\mathrm{OH}$ maser emission in G353.273+0.641: First candidate for a pulsating high-mass protostar
• Infrared observations of the flaring maser source G358.93-0.03 -- SOFIA confirms an accretion burst from a massive young stellar object
• Understanding Accretion Outbursts in Massive Protostars through Maser Imaging
• Identifying the Mechanisms of Water Maser Variability During the Accretion Burst in NGC6334I