Eric B. Ford

TL;DR: In this paper, the authors assess the performance of several MCMC samplers that use varying degrees of geometric information about the target distribution, and show that the right choice of sampler can improve sampling efficiencies by several orders of magnitude.

TL;DR: In this article, the authors used hierarchical Bayesian modeling and Hamiltonian Monte Carlo (HMMC) to estimate the number of planets per star as a function of orbital period and planet size with updated stellar properties from the Gaia Data Release 2.

TL;DR: In this paper, the effects of planetesimal disk interactions on planet pairs trapped in 2:1 mean motion resonance (MMR) were studied using planets of mass typical of the Kepler planet candidates (KPC).

Abstract: We present ALMA band 7 (345 GHz) continuum and $^{12}$CO(J = 3-2) observations of the circumstellar disk surrounding HD141569. At an age of about 5 Myr, the disk has a complex morphology that may be best interpreted as a nascent debris system with gas. Our $870\rm~\mu m$ ALMA continuum observations resolve a dust disk out to approximately $ 56 ~\rm au$ from the star (assuming a distance of 116 pc) with $0."38$ resolution and $0.07 ~ \rm mJy~beam^{-1}$ sensitivity. We measure a continuum flux density for this inner material of $3.8 \pm 0.4 ~ \rm mJy$ (including calibration uncertainties). The $^{12}$CO(3-2) gas is resolved kinematically and spatially from about 30 to 210 au. The integrated $^{12}$CO(3-2) line flux density is $15.7 \pm 1.6~\rm Jy~km~s^{-1}$. We estimate the mass of the millimeter debris and $^{12}$CO(3-2) gas to be $\gtrsim0.04~\rm M_{\oplus}$ and $\sim2\times 10^{-3}~\rm M_{\oplus}$, respectively. If the millimeter grains are part of a collisional cascade, then we infer that the inner disk ($<50$ au) has $\sim 160~\rm M_{\oplus}$ contained within objects less than 50 km in radius, depending on the planetesimal size distribution and density assumptions. MCMC modeling of the system reveals a disk morphology with an inclination of $53.4^{\circ}$ centered around a $\rm M=2.39~ M_{\odot}$ host star ($\rm Msin(i)=1.92~ M_{\odot}$). We discuss whether the gas in HD141569's disk may be second generation. If it is, the system can be used to study the clearing stages of planet formation.

TL;DR: In this paper , an improved FourIEr phase SpecTrum Analysis (FIESTA) is proposed to disentangle apparent velocity shifts due to a line deformation from a true Doppler shift.