scholarly journals On the red supergiant problem

2020 ◽  
Vol 493 (4) ◽  
pp. 4945-4949 ◽  
Author(s):  
C S Kochanek
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Bayesian Approach ◽  
Mass Range ◽  
Mass Function ◽  
Initial Mass Function ◽  
Initial Mass ◽  
Maximum Mass ◽  
Upper Limit

ABSTRACT We examine the problem of estimating the mass range corresponding to the observed red supergiant (RSG) progenitors of Type IIP supernovae. Using Monte Carlo simulations designed to reproduce the properties of the observations, we find that the approach of Davies & Beasor significantly overestimates the maximum mass, yielding an upper limit of Mh/M⊙ = 20.5 ± 2.6 for an input population with Mh/M⊙ = 18. Our preferred Bayesian approach does better, with Mh/M⊙ = 18.6 ± 2.1 for the same input populations, but also tends to overestimate Mh. For the actual progenitor sample and a Salpeter initial mass function, we find $M_{\rm h}/\mathrm{M}_\odot = 19.01_{-2.04}^{+4.04}$ for the Eldridge & Tout mass–luminosity relation used by Smartt and Davies & Beasor, and $M_{\rm h}/\mathrm{M}_\odot = 21.28_{-2.28}^{+4.52}$ for the Sukhbold, Woosley & Heger mass–luminosity relation. Based on the Monte Carlo simulations, we estimate that these are overestimated by $(3.3\pm 0.8)\, \mathrm{M}_\odot$. The red supergiant problem remains.

scholarly journals System initial mass function of the 25 Ori group from planetary-mass objects to intermediate/high-mass stars

2019 ◽  
Vol 486 (2) ◽  
pp. 1718-1740 ◽  
Author(s):  
Genaro Suárez ◽  
Juan José Downes ◽  
Carlos Román-Zúñiga ◽  
Miguel Cerviño ◽  
César Briceño ◽  
...  
Keyword(s):  
Power Law ◽  
Near Infrared ◽  
Mass Range ◽  
Mass Function ◽  
Initial Mass Function ◽  
High Mass ◽  
Initial Mass ◽  
Formation Mechanisms ◽  
Stellar Association ◽  
Planetary Mass

Abstract The stellar initial mass function (IMF) is an essential input for many astrophysical studies but only in a few cases has it been determined over the whole cluster mass range, limiting the conclusions about its nature. The 25 Orionis group (25 Ori) is an excellent laboratory for investigating the IMF across the entire mass range of the population, from planetary-mass objects to intermediate/high-mass stars. We combine new deep optical photometry with optical and near-infrared data from the literature to select 1687 member candidates covering a 1.1° radius area in 25 Ori. With this sample we derived the 25 Ori system IMF from 0.012 to 13.1 M⊙. This system IMF is well described by a two-segment power law with Γ = −0.74 ± 0.04 for m < 0.4 M⊙ and Γ = 1.50 ± 0.11 for m ≥ 0.4 M⊙. It is also well described over the whole mass range by a tapered power-law function with Γ = 1.10 ± 0.09, mp = 0.31 ± 0.03 and β = 2.11 ± 0.09. The best lognormal representation of the system IMF has mc = 0.31 ± 0.04 and σ = 0.46 ± 0.05 for m < 1 M⊙. This system IMF does not present significant variations with the radii. We compared the resultant system IMF as well as the brown dwarf/star ratio of 0.16 ± 0.03 that we estimated for 25 Ori with that of other stellar regions with diverse conditions and found no significant discrepancies. These results support the idea that general star-formation mechanisms are probably not strongly dependent on environmental conditions. We found that the substellar and stellar objects in 25 Ori do not have any preferential spatial distributions and confirmed that 25 Ori is a gravitationally unbound stellar association.

Low‐Mass Star Formation and the Initial Mass Function in IC 348

1998 ◽  
Vol 508 (1) ◽  
pp. 347-369 ◽  
Author(s):  
K. L. Luhman ◽  
G. H. Rieke ◽  
C. J. Lada ◽  
E. A. Lada
Keyword(s):  
Star Formation ◽  
Mass Function ◽  
Initial Mass Function ◽  
Initial Mass ◽  
Mass Star ◽  
Low Mass

scholarly journals An optical observational cluster mass function at z ∼ 1 with the ORELSE survey

2021 ◽  
Vol 502 (3) ◽  
pp. 3942-3954
Author(s):  
D Hung ◽  
B C Lemaux ◽  
R R Gal ◽  
A R Tomczak ◽  
L M Lubin ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Large Scale ◽  
Near Infrared ◽  
Function Analysis ◽  
Voronoi Tessellation ◽  
Cosmological Parameters ◽  
Mass Range ◽  
Mass Function ◽  
Cluster Mass ◽  
Theoretical Mass

ABSTRACT We present a new mass function of galaxy clusters and groups using optical/near-infrared (NIR) wavelength spectroscopic and photometric data from the Observations of Redshift Evolution in Large-Scale Environments (ORELSE) survey. At z ∼ 1, cluster mass function studies are rare regardless of wavelength and have never been attempted from an optical/NIR perspective. This work serves as a proof of concept that z ∼ 1 cluster mass functions are achievable without supplemental X-ray or Sunyaev-Zel’dovich data. Measurements of the cluster mass function provide important contraints on cosmological parameters and are complementary to other probes. With ORELSE, a new cluster finding technique based on Voronoi tessellation Monte Carlo (VMC) mapping, and rigorous purity and completeness testing, we have obtained ∼240 galaxy overdensity candidates in the redshift range 0.55 < z < 1.37 at a mass range of 13.6 < log (M/M⊙) < 14.8. This mass range is comparable to existing optical cluster mass function studies for the local universe. Our candidate numbers vary based on the choice of multiple input parameters related to detection and characterization in our cluster finding algorithm, which we incorporated into the mass function analysis through a Monte Carlo scheme. We find cosmological constraints on the matter density, Ωm, and the amplitude of fluctuations, σ8, of $\Omega _{m} = 0.250^{+0.104}_{-0.099}$ and $\sigma _{8} = 1.150^{+0.260}_{-0.163}$. While our Ωm value is close to concordance, our σ8 value is ∼2σ higher because of the inflated observed number densities compared to theoretical mass function models owing to how our survey targeted overdense regions. With Euclid and several other large, unbiased optical surveys on the horizon, VMC mapping will enable optical/NIR cluster cosmology at redshifts much higher than what has been possible before.

scholarly journals CHARACTERIZING THE BROWN DWARF FORMATION CHANNELS FROM THE INITIAL MASS FUNCTION AND BINARY-STAR DYNAMICS

2015 ◽  
Vol 800 (1) ◽  
pp. 72 ◽  
Author(s):  
Ingo Thies ◽  
Jan Pflamm-Altenburg ◽  
Pavel Kroupa ◽  
Michael Marks
Keyword(s):  
Binary Star ◽  
Mass Function ◽  
Initial Mass Function ◽  
Initial Mass ◽  
Brown Dwarf

scholarly journals Radial gradients in initial mass function sensitive absorption features in the Coma brightest cluster galaxies

2016 ◽  
Vol 465 (1) ◽  
pp. 192-212 ◽  
Author(s):  
Simon Zieleniewski ◽  
Ryan C. W. Houghton ◽  
Niranjan Thatte ◽  
Roger L. Davies ◽  
Sam P. Vaughan
Keyword(s):  
Mass Function ◽  
Initial Mass Function ◽  
Initial Mass ◽  
Cluster Galaxies ◽  
Brightest Cluster Galaxies ◽  
Absorption Features

scholarly journals Is the stellar initial mass function universal?

2016 ◽  
Vol 57 (2) ◽  
pp. 2.32-2.36 ◽  
Author(s):  
Ignacio Ferreras ◽  
Francesco La Barbera ◽  
Alexandre Vazdekis
Keyword(s):  
Mass Function ◽  
Initial Mass Function ◽  
Initial Mass ◽  
Stellar Initial Mass Function
Sign in / Sign up

Export Citation Format

Share Document