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Home Astronomy research Software Infrastructure: MESA FLASH-X STARLIB MESA-Web starkiller-astro My instruments White dwarf pulsations: 12C(α,γ) & overshooting Probe of 12C(α,γ)16O Impact of 22Ne Impact of ν cooling Variable white dwarfs MC reaction rates Micronovae Novae White dwarf supernova: Stable nickel production Remnant metallicities Colliding white dwarfs Merging white dwarfs Ignition conditions Metallicity effects Central density effects Detonation density Tracer particle burning Subsonic burning fronts Supersonic fronts W7 profiles Massive stars: Pop III with HST/JWST Rotating progenitors 3D evolution to collapse MC reaction rates Pre-SN variations Massive star supernova: Yields of radionuclides 26Al & 60Fe 44Ti, 60Co & 56Ni SN 1987A light curve Constraints on Ni/Fe An r-process Effects of 12C +12C Neutron Stars and Black Holes: Black Hole spectrum Mass Gap with LVK Compact object IMF He burn neutron stars Neutrino Emission: Neutrino emission from stars Identifying the Pre-SN Neutrino HR diagram Pre-SN Beta Processes Pre-SN neutrinos Stars: Hypatia catalog SAGB stars Nugrid Yields I He shell convection BBFH at 40 years γ-rays within 100 Mpc Iron Pseudocarbynes Pre-Solar Grains: C-rich presolar grains SiC Type U/C grains Grains from massive stars Placing the Sun SiC Presolar grains Chemical Evolution: Radionuclides in 2020s Zone models H to Zn Mixing ejecta Thermodynamics, Opacities & Networks Radiative Opacity Skye EOS Helm EOS Five EOSs Equations of State 12C(α,γ)16O Rate Proton-rich NSE Reaction networks Bayesian reaction rates Verification Problems: Validating an astro code Su-Olson Cog8 Mader RMTV Sedov Noh Software Instruments AAS Journals 2024 AAS YouTube 2024 AAS Peer Review Workshops 2024 ASU Energy in Everyday Life 2024 MESA Classroom Outreach and Education Materials Other Stuff: Bicycle Adventures Illustrations Presentations Contact: F.X.Timmes my one page vitae, full vitae, research statement, and teaching statement. |
Resolving The Peak Of The Black Hole Mass Spectrum (2022)
Gravitational wave (GW) detections of binary black hole (BH) mergers have begun to sample the cosmic BH mass distribution. The evolution of single stellar cores predicts a gap in the BH mass distribution due to pair-instability supernova (PISN). Determining the upper and lower edges of the BH mass gap can be useful for interpreting GW detections from merging BHs. In this article We use MESA to evolve single, non-rotating, massive helium cores with a metallicity of $Z = 10^{-5}$ until they either collapse to form a BH or explode as a PISN without leaving a compact remnant. We calculate the boundaries of the lower BH mass gap for S-factors in the range S(300 keV) = (77,203) keV b, corresponding to the $\pm 3\sigma$ uncertainty in our high resolution tabulated $^{12}$C($\alpha$,$\gamma$)$^{16}$O reaction rate probability distribution function. We extensively test the temporal and mass resolution to resolve the theoretical peak of the BH mass spectrum across the BH mass gap. We explore the convergence with respect to convective mixing and nuclear burning, finding that significant time resolution is needed to achieve convergence. We also test adopting a minimum diffusion coefficient to help lower resolution models reach convergence. We establish a new lower edge of the upper mass gap as M$_{\rm lower}$ $\simeq$ 60$^{+32}_{-14}$ M$_{\odot}$ from the $\pm 3\sigma$ uncertainty in the $^{12}$C($\alpha$,$\gamma$)$^{16}$O rate. We explore the effect of a larger 3-$\alpha$ rate on the lower edge of the upper mass gap, finding M$_{\rm lower}$ $\simeq$ 69$^{+34}_{-18}$ M$_{\odot}$. We compare our results with BHs reported in the Gravitational-Wave Transient Catalog. Observing Intermediate-mass Black Holes and the Upper Stellar-mass gap with LIGO and Virgo (2022) In this article we probe the mass function of intermediate-mass black holes (IMBHs) wherein we also include BHs in the upper mass gap ∼60 - 130 M$_{\odot}$. Employing the projected sensitivity of the upcoming LIGO and Virgo fourth observing (O4) run, we perform Bayesian analysis on quasi-circular non-precessing, spinning IMBH binaries (IMBHBs) with total masses 50 - 500 M$_\odot$, mass ratios 1.25, 4, and 10, and dimensionless spins up to 0.95, and estimate the precision with which the source-frame parameters can be measured. We find that, at 2$\sigma$, the mass of the heavier component of IMBHBs can be constrained with an uncertainty of ∼10 - 40% at a signal-to-noise ratio of 20. Focusing on the stellar-mass gap with new tabulations of the $^{12}$C($\alpha$,$\gamma$)$^{16}$O reaction rate and its uncertanties, we evolve massive helium core stars using MESA, to establish the lower and upper edge of the mass gap as ∼59$^{+34}_{-13}$ M$_{\odot}$ and ∼139$^{+30}_{-14}$ M$_{\odot}$ respectively, where the error bars give the mass range that follows from the ±3$\sigma$ uncertainty in the $^{12}$C($\alpha$,$\gamma$)$^{16}$O nuclear reaction rate. We find that high resolution of the tabulated reaction rate and fine temporal resolution are necessary to resolve the peak of the BH mass spectrum. We then study IMBHBs with components lying in the mass gap and show that the O4 run will be able to robustly identify most such systems. Finally, we re-analyse GW190521 with a state-of-the-art aligned-spin waveform model, finding that the primary mass lies in the mass gap with 90% credibility. |
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