A Preferential Attachment Model for the Stellar Initial Mass Function

Abstract

Accurate specification of a likelihood function is becoming increasingly difficult in many inference problems in astronomy. As sample sizes resulting from astronomical surveys continue to grow, deficiencies in the likelihood function lead to larger biases in key parameter estimates. These deficiencies result from the oversimplification of the physical processes that generated the data, and from the failure to account for observational limitations. Unfortunately, realistic models often do not yield an analytical form for the likelihood. The estimation of a stellar initial mass function (IMF) is an important example. The stellar IMF is the mass distribution of stars initially formed in a given cluster of stars, a population which is not directly observable due to stellar evolution and other disruptions and observational limitations of the cluster. There are several difficulties with specifying a likelihood in this setting since the physical processes and observational challenges result in measurable masses that cannot legitimately be considered independent draws from an IMF. This work improves inference of the IMF by using an approximate Bayesian computation approach that both accounts for observational and astrophysical effects and incorporates a physically-motivated model for star cluster formation. The methodology is illustrated via a simulation study, demonstrating that the proposed approach can recover the true posterior in realistic situations, and applied to observations from astrophysical simulation data.

References in corpus (13)

• The mass distribution and gravitational potential of the Milky Way
• Constraining the thick disc formation scenario of the Milky Way
• The Jeans mass and the origin of the knee in the IMF
• The statistical properties of stars and their dependence on metallicity: the effects of opacity
• A Tale of Three Cities: OmegaCAM discovers multiple sequences in the color-magnitude diagram of the Orion Nebula Cluster
• Hierarchical fragmentation in the Perseus molecular cloud: From the cloud scale to protostellar objects
• The Deaths of Very Massive Stars
• Cosmological constraints with weak lensing peak counts and second-order statistics in a large-field survey
• The Intrinsic Neptune Trojan Orbit Distribution: Implications for the Primordial Disk and Planet Migration
• The low-mass population in the young cluster Stock 8: Stellar properties and Initial Mass Function
• Preferential Attachment in Online Networks: Measurement and Explanations
• Preferential Attachment and Vertex Arrival Times
• Are Extreme Value Estimation Methods Useful for Network Data?