Mass Loss: Its Effect on the Evolution and Fate of High-Mass Stars

“Since massive stars have short lifetimes, their ultraviolet (UV) radiation (reprocessed in various forms) is the most observable tracer of star formation and is used to calculate the star formation rates (Kennicutt 1998, Kennicutt & Evans 2012).”

“Perhaps new open-source codes like MESA (Paxton et al. 2011) will facilitate this.”

“This single-star paradigm then permitted one to extend even further, to compute models for the collective radiative output of entire stellar populations as a function of age (e.g., codes like starburst99; Leitherer et al. 1999).”

“Later, estimates for the solar wind (Parker 1958) powered by hot gas pressure had such low mass-loss rates that winds would not matter much in stellar evolution.”

“Since massive stars have short lifetimes, their ultraviolet (UV) radiation (reprocessed in various forms) is the most observable tracer of star formation and is used to calculate the star formation rates (Kennicutt 1998, Kennicutt & Evans 2012).”

“They leave behind exotic corpses such as black holes, neutron stars, pulsars, magnetars, and all the bizarre high-energy phenomena that occur when compact objects remain bound in a binary system (e.g., Remillard & McClintock 2006).”

“The fact that GRB progenitors have shed most of their envelopes while still retaining a great deal of angular momentum (MacFadyen & Woosley 1999) would seem to strongly favor their origin in binary evolution with mass transfer to spin up the star, or even a merger.”

“…very massive, and they made the first SNe, the first stellar mass black holes, the first dust, ejected the first metals back into the ISM, enhanced or dominated reionization, and probably triggered the formation of the earliest generations of low-mass stars (Bromm & Larson 2004, Heger et al. 2003).”

“…from several young clusters suggest that, when corrected for obervational bias, the fraction of massive stars in binary systems whose orbital period is so short that the stars must exhange mass or merge is something like 3/4 (Kiminki & Kobulnicky 2012, Kobulnicky & Fryer 2007, Sana et al. 2012).”

“…ambiguous; the two most common explanations are enhanced radiative or eruptive mass loss (e.g., Langer et al. 1994; Maeder & Meynet 2000; Heger et al. 2003; Smith 2014) and interaction with and Roche lobe overflow onto a close binary companion (Woosley et al. 1994; Izzard et al. 2004; Yoon 2017).”

“Important targets for QUVIK are type IIn SNe (Schlegel 1990; Filippenko 1997; Smith 2014; Gal-Yam 2017), which show particularly strong and narrow-to-intermediate Balmer emission lines.”

“Enhanced mass loss in massive stars such as lumin-ious blue variables (LBVs) or Wolf-Rayet (WR) stars occurs in the years before explosion (see Smith 2014 for a review), but was not necessarily expected in RSGs, where there is not yet a consensus on mass loss rates.”

“LBVs show stellar outbursts and episodes of high mass loss during which the stars lose significant fractions of their initial mass (Humphreys & Davidson 1994; Smith 2014).”

“However, these constraints on the distance and reddening depend sensitively on assumptions about how the strengths of winds for various classes of evolved stars depend on luminosity, which is still often debated (Smith 2014).”

“LBVs have the highest mass-loss rates of any stars, and this can profoundly affect a massive star’s late-time evolution (Smith 2014).”

“Similar and additional arguments (Smith et al. 2010, 2011; Smith 2014) favoring an explosive scenario have also been given for the broader population of giant-eruption LBVs.”

“Both affect the time evolution of massive stars’ surface properties and their main-sequence lifetimes, which in turn set the total number of ionizing photons that a stellar population is predicted to produce (e.g., Levesque et al. 2012; Smith 2014).”

“The exact nature of the underlying physical process causing this timedependent mass loss remains the subject of debate, as well as how these processes inform the evolutionary path of the progenitor (e.g., Smith 2014).”

“These lines are indicative of interaction of fast SN ejecta with slow-moving H-rich CSM ejected shortly before (tens to thousands of years [73]) the SN explosion ([74], for a review of the ejecta-CSM interaction theory).”

“Stellar winds, binary interaction, and eruptions are among the prominent mechanisms (see, e.g., Smith 2014, for a review).”

“This arises from the numerical instability caused by the large density discontinuity at the interface of the bound CSM and the star, after fallback of the bound CSM starts to dominate the emission.”

“Instead, LBV-like eruptions (e.g., Humphreys & Davidson 1994; Vink 2012; Smith 2014, 2017b), like those seen in Eta Carinae, may be responsible for the precursor, given their comparable luminosities.”

“However, the nature of these progenitors is not fully clear, and other precursor 16 Miller Senior Fellow. channels have been proposed (see, e.g., Mauerhan & Smith (2012) in the case of the SN 1998S, or Smith (2014) for a larger review of this topic).”

“Type IIn supernovae (SNe) are characterized by prominent and narrow-to-intermediate width Balmer emission lines in their spectra (Schlegel 1990; Filippenko 1997; Smith 2014; Gal-Yam 2017).”

“Moreover, it has been found that differences on a factor of two in the mass-loss rate considerably affects the final fate of a star (Meynet et al. 1994; Smith 2014).”

“The reliance upon the LBV phase for making WR stars from single stars is even more accute because of lowered O-star wind mass-loss rates (Fullerton et al. 2006; Bouret et al. 2005; Smith & Owocki 2006; Smith 2014).”

“The lack of broad hydrogen emission features also suggests SPIRITS 19q is not associated with a giant eruption from a luminous blue variable (LBV; e.g., Smith 2014).”

“10−5 M⊙yr −1; Smith 2014b), the polarization, in the optical bands, is higher in the shorter wavelength region.”

“It should also be stressed that the evolutionary models for massive stars are very uncertain at the post-main-sequence phases as they do not include any eruptive event, which means that the mass-loss rate recipes are poorly known (Smith 2014).”

“The CSM may be explained by an extraordinarily strong, steady wind Corresponding author: Alexandra Kozyreva sasha@mpa-garching.mpg.de that a massive star experiences during the few years prior to exploding (Smith 2014).”

“None of the stars in W3 are massive enough to have experienced significant mass loss over their lifetimes (see, e.g., Smith 2014), so the current masses are representative of the inital masses.”

“The properties of such wind inhomogeneities have an enormous impact on derived mass-loss rates (Hamann et al. 2008), and thus on our understanding of stellar evolution (Smith 2014).”

“However, the clumpiness of the medium is not expected to change the mass-loss rate by more than a factor of 3 (Smith 2014), much less than the discrepancy we note.”

“Assuming a wind velocity of 10 km s−1 (Smith 2014, for an RSG), the progenitor of SN2016gfy experienced an episode of enhanced mass loss 30–80 yr preceding the explosion.”

“Mass-loss has a great influence on the evolution of massive stars and the resultant core-collapse supernova (SN) types (e.g., Smith 2014).”

“The lives and deaths of massive stars are strongly influenced by the huge amount of mass loss they experience during their evolution in the form of radiation-driven stellar winds (Smith 2014).”

“Mass loss constitutes the most substantial property that drives massive stars throughout the diverse evolutionary channels (Smith 2014).”

“…growing observations of preexplosion mass losses or envelope in fl ation before the explosion in extra-galactic SNe ( Smith & McCray 2007; Immler et al. 2008; Miller et al. 2009; Ofek et al. 2013; Margutti et al. 2014; Smith 2014; Margutti et al. 2017; Yaron et al. 2017; Morozova et al. 2018 ) .”

“Such primordial dust grains may have formed in the expanding matter blown from red giant stars or AGB stars 14,109 .”

“Both SNe Ibn and their H-rich counterparts, SNe IIn, have CSM interaction signatures that point to pre-SN mass loss that is much stronger than normal massive-star winds (Smith 2014, 2017).”

“…range with a significant mass-loss rate have their envelopes stripped, leading to more compact progenitors and consequently nonType II SNe, such as Type Ib/c or IIb, although what fraction of the RSGs can have such substantial mass-loss rates is poorly understood (van Loon et al. 2005; Smith 2014).”

“While the physics of line-driven massloss is largely understood, the mechanisms driving the sporadic outbursts of stars like LBVs are not (see Smith 2014; Owocki 2015, for reviews).”

“Some Wolf–Rayet stars have reported momentum efficiencies 50» (Hamann et al. 1995), though inferred mass-loss rates may now be a factor of a few lower after accounting for clumping (e.g., Hamann & Koesterke 1998; Smith 2014).”

“…C T I O N The role of dynamics and mass-loss is interconnected with the evolutionary tracks of high-mass stellar binaries: during their lifetimes as stars to their eventual fate as supernovae and potential gravitational wave mergers (Belczynski, Kalogera & Bulik 2002; Sana et al. 2012; Smith 2014).”

“16 1 csm csm 16 1 w 1 ⎜ ⎟ ⎜ ⎟ ⎛ ⎝⎜ ⎞ ⎠⎟ ⎛ ⎝ ⎞ ⎠ ⎛ ⎝ ⎞ ⎠ ( ) This mass-loss rate is much higher than the typical mass-loss rate of Galactic red supergiants or Wolf–Rayet stars but is consistent with those required for luminous SNe-IIn (e.g., Kiewe et al. 2012; Taddia et al. 2013; Smith 2014).”

“…indicating little mass loss, and those of Type IIL/b SNe have some of their H envelopes intact, the Ib/Ic SNe are thought to originate from stripped-envelope progenitors that experienced significant mass loss either through strong stellar winds or binary interactions (see review by Smith 2014).”

“This can give independent clues about the progenitor, especially for Type IIn SNe, which is under debate and possibly diverse (for reviews see Smith 2014, 2017).”

“Direct observations of mass loss during the final stages, the last months to years before the explosion, are complicated and poorly understood (Smith 2014).”

“Recent observations support that mass loss in luminous blue variables (LBV) is important, and such strong LBV mass losses are seen in lowmetallicity dwarf galaxies and are relatively insensitive to metallicity (Smith 2014; Neill et al. 2011).”

“…their CSM would power their unusual LCs; studying the 2 properties of the ejecta and CSM would provide important information, e.g., the masses of the ejecta and the CSM, the mass-loss rate and mass-loss history of the SN progenitors, and so on (see Smith 2014 for a review and references therein).”

“Pre iously, strong mass loss was invok to remove the surface layers, bu a downward revision of the empirical mass-loss rates led to the recog ition that steady stellar winds ar insufficient for the mass rem val [61].”

“For massive stars, the main sequence phase is followed by the red supergiant phase, which is dominated by slow, dense winds, with velocities of ∼ 10–20 km s−1 and mass loss rates of ∼ 0.5–2.0 × 10−5 M yr−1 (Smith 2014).”

“LBVs play a key role in the mass budget of very massive stars (Smith 2014) and regulate their final compact remnant masses, which in some cases can be a massive black hole (Groh et al. 2019a).”

“Such mass-loss reductions have dramatic consequences for predictions of stellar evolution and feedback models (e.g., Smith 2014).”

“The importance of investigating massive stars, especially dusty massive stars, comes from the observed phenomenon of episodic mass loss, which complicates modeling the evolution of these objects (Smith 2014).”

“If the SNR resulted from a the SN Ib/c, the progenitor may be a single, massive Wolf-Rayet star whose massive winds have removed the bulk of the stellar envelope, or a lower-mass star whose envelope has been stripped away by a binary companion (Smith 2014; Dessart et al. 2015; Yoon et al. 2017).”

“However, some progenitors appear to exhibit mass-loss rates as high as 10−4– 10−3 M yr−1 (Smith 2014).”

“…break down in the presence of a binary companion (Heger et al. 2003; Eldridge et al. 2008; Yoon et al. 2010; Smith et al. 2011; Sana et al. 2012; Smith 2014; Yoon 2015; Yoon et al. 2017; Ouchi & Maeda 2017; Eldridge et al. 2018; Fang et al. 2019; Zapartas et al. 2019, 2021; Chen et al. 2023;…”

“In particular, episodic mass loss in massive, cool supergiants remains poorly understood (e.g., Smith 2014), both in terms of the physical mechanisms that drive it and critical properties such as the frequency, possible duration, and mass-loss rates of the most extreme events; an extended massloss…”

“10−5 M yr−1 (e.g., Vink et al. 2001; Smith 2014).”

“At all redshifts, single and binary massive metal-poor stars are thought to be the progenitors to many explosive transients, including gravitational wave sources (e.g., Smartt 2009; Smith 2014; Spera et al. 2015).”

“While historically, massive star evolution was thought to be dominated by single-star wind mass loss, there is now strong evidence that ∼ 10% of massive stars undergo substantial and even eruptive mass loss a few years prior to core collapse (see e.g., Smith 2014, and references therein).”

“M M 10 yr 4 1 for a stellar wind velocity of v w = 25 km s − 1 , which is at least an order of magnitude higher than typical RSG mass-loss rates ( N. Smith 2014; E. R. Beasor et al. 2020 ) .”

“Massive stars can lose a substantial amount of their birth mass through stellar winds [135, 136], eruptions [136, 137], and interaction with a companion star [138, 139].”

“…poorly understood: it could be due to winds (Heger et al. 1997; Puls et al. 2008), episodic ejection (Smith & Owocki 2006; Pastorello et al. 2007; Shiode & Quataert 2014), or binary interactions, including commonenvelope formation and ejection (see the reviews by Taam & Sandquist 2000; Smith 2014).”

“Such mass-loss rate is consistent with a low-luminosity RSG (L≈ 104.5–105 Le) based on the standard observational prescriptions of de Jager et al. (1988; see, e.g., Figure 3 of Smith 2014).”

“, [43,44], and references therein).”

“These late phases of evolution of massive stars are very un- ★ E-mail: jmackey@cp.dias.ie (JM) certain because some key physical processes are poorly constrained and poorly modelled, namely convection, mass loss, rotation, and interaction with a companion (for a review, see Smith 2014).”