Evidence for a fundamental stellar upper mass limit from clustered star formation, and some implications therof

By Pavel Kroupa, C. Weidner. Proceedings of the International Astronomical Union, 2005

157 citations recorded by the source corpus.

Theoretical considerations lead to the expectation that stars should not have masses larger than about $m_{\rm max*}=60$–$120M_\odot$, while the observational evidence has been ambiguous. Only very recently has a physical stellar mass limit near $150M_\odot$ emerged thanks to modern high-resolution observations of local star-burst clusters. But this limit does not appear to depend on metallicity, in contradiction to theory. Important uncertainties remain though. It is now also emerging that star-clusters limit the masses of their constituent stars, such that a well-defined relation between the mass of the most massive star in a cluster and the cluster mass, $m_{\rm max}={\cal F}(M_{\rm ecl}) \le m_{\rm max*}\approx 150M_\odot$, exists. One rather startling finding is that the observational data strongly favour clusters being built-up by consecutively forming more-massive stars until the most massive stars terminate further star-formation. The relation also implies that composite populations, which consist of many star clusters, most of which may be dissolved, must have steeper composite IMFs than simple stellar populations such as are found in individual clusters. Thus, for example, $10^5$ Taurus–Auriga star-forming groups, each with 20 stars, will ever only sample the IMF below about $1M_\odot$. This IMF will therefore not be identical to the IMF of one cluster with $2\times 10^6$ stars. The implication is that the star-formation history of a galaxy critically determines its integrated galaxial IMF and thus the total number of supernovae per star and its chemical enrichment history. Galaxy formation and evolution models that rely on an invariant IMF would be wrong.

Subfields: Astronomy and Astrophysics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/f98db7369238c1a2badec3f56260b3ce6af0f1c6

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

In Instrumentation

Citations in the corpus

Methanol Masers: Reliable Tracers of the Early Stages of High-Mass Star Formation (2005, background): “11−0.12 (Menten et al. 2005), which has been modeled as a nonmagnetic isothermal filament (Johnstone et al. 2003).”
The Formation of the First Stars. II. Radiative Feedback Processes and Implications for the Initial Mass Function (2007, background): “…hand, the dust couples the pressure of the UV continuum radiation to the gas very effectively, and it remains to be determined whether this limits the final mass of the star; e.g., Yorke & Sonnhalter (2002) find that it does, whereas Krumholz et al. (2005a) have not found evidence that it does.”
Protostellar Turbulence Driven by Collimated Outflows (2007, background): “Crutcher (2005) reviewed the available observational data on other regions of cluster/massive star formation and concluded that their magnetic fields, when detected, appear to have strengths not far from the critical values as well.”
EMU: Evolutionary Map of the Universe (2011, background): “However, the snapshot surveys missed an entirely new class of optically thick HII regions known as hypercompact HII (HCHII) regions (kurtz 2005), and missed a diffuse component (kurtz et al. 1999, Longmore et al. 2009) in which many UCHII regions are embedded.”
Slow Star Formation in Dense Gas: Evidence and Implications (2006, background): “Subject headinggs: ISM: clouds — stars: formation”
Hierarchical fragmentation and differential star formation in the Galactic ‘Snake’: infrared dark cloud G11.11−0.12 (2014, background): “P1-SMA1 is in a “warm core” phase because it has not yet reached the hot core phase defined by Cesaroni (2005): temperature> 100 K, size< 0.1 pc, mass 10 − 1000M⊙, and luminosity> 104 L⊙.”
OUTFLOW FEEDBACK REGULATED MASSIVE STAR FORMATION IN PARSEC-SCALE CLUSTER-FORMING CLUMPS (2009, background): “In practice, the mass accretion rate onto any individual star will be reduced relative to the characteristic free-fall rate by several factors, such as the turbulence, magnetic fields, protostellar outflows, and radiative feedback.”
STAR FORMATION IN DISK GALAXIES. I. FORMATION AND EVOLUTION OF GIANT MOLECULAR CLOUDS VIA GRAVITATIONAL INSTABILITY AND CLOUD COLLISIONS (2008, methodology): “The mean mass surface density, Σc, of Galactic GMCs was derived by Solomon et al. (1987) to have a median value of about 200 M⊙ pc −2.”
ATLASGAL — towards a complete sample of massive star forming clumps ⋆ (2014, background): “…(>8 M and 103 L ) play an important role in many astrophysical processes, from the formation of the first solid material in the early Universe (Dunne et al. 2003) to their substantial influence upon the evolution of their host galaxies and future generations of star formation (Kennicutt 2005).”
The Destruction of Cosmological Minihalos by Primordial Supernovae (2008, background): “It is generally held that the broad I-fronts of black holes and quasars exert positive feedback on structure formation because H2 formation is promoted in their partially ionized outer layers (e.g., Ricotti et al. 2001).”