adsabs/AstroCLIMB huggingface dataset:
Paper: The ODYSSEUS Survey. Motivation and First Results: Accretion, Ejection, and Disk Irradiation of CVSO 109
Authors: C. C. Espaillat, G. J. Herczeg, T. Thanathibodee, C. Pittman, N. Calvet, N. Arulanantham, K. France, Javier Serna, J. Hernández, Á. Kóspál, F. M. Walter, A. Frasca, W. J. Fischer, C. M. Johns-Krull, P. C. Schneider, C. Robinson, Suzan Edwards, P. Ábrahám, Min Fang, J. Erkal, C. F. Manara, J. M. Alcalá, E. Alecian, R. D. Alexander, J. Alonso-Santiago, Simone Antoniucci, David R. Ardila, Andrea Banzatti, M. Benisty, Edwin A. Bergin, Katia Biazzo, César Briceño, Justyn Campbell-White, L. Ilsedore Cleeves, Deirdre Coffey, Jochen Eislöffel, Stefano Facchini, D. Fedele, Eleonora Fiorellino, Dirk Froebrich, Manuele Gangi, Teresa Giannini, K. Grankin, Hans Moritz Günther, Zhen Guo, Lee Hartmann, Lynne A. Hillenbrand, P. C. Hinton, Joel H. Kastner, Chris Koen, K. Maucó, I. Mendigutía, B. Nisini, Neelam Panwar, D. A. Principe, Massimo Robberto, A. Sicilia-Aguilar, Jeff A. Valenti, J. Wendeborn, Jonathan P. Williams, Ziyan Xu, and R. K. Yadav
Figure caption: Wind profiles from lines of Si II (co-added), C II (co-added), Si III λ1206.5, and He I λ10830 (colors), normalized to the surrounding continuum. Each profile includes a co-added profile (thin black spectrum) that combines the Si II and C II lines to help guide the eye. Narrow absorption features near 0 km s−1 trace either interstellar or circumstellar material. All co-added profiles are combined in flux space.
Paper: The ODYSSEUS Survey. Motivation and First Results: Accretion, Ejection, and Disk Irradiation of CVSO 109
Authors: C. C. Espaillat, G. J. Herczeg, T. Thanathibodee, C. Pittman, N. Calvet, N. Arulanantham, K. France, Javier Serna, J. Hernández, Á. Kóspál, F. M. Walter, A. Frasca, W. J. Fischer, C. M. Johns-Krull, P. C. Schneider, C. Robinson, Suzan Edwards, P. Ábrahám, Min Fang, J. Erkal, C. F. Manara, J. M. Alcalá, E. Alecian, R. D. Alexander, J. Alonso-Santiago, Simone Antoniucci, David R. Ardila, Andrea Banzatti, M. Benisty, Edwin A. Bergin, Katia Biazzo, César Briceño, Justyn Campbell-White, L. Ilsedore Cleeves, Deirdre Coffey, Jochen Eislöffel, Stefano Facchini, D. Fedele, Eleonora Fiorellino, Dirk Froebrich, Manuele Gangi, Teresa Giannini, K. Grankin, Hans Moritz Günther, Zhen Guo, Lee Hartmann, Lynne A. Hillenbrand, P. C. Hinton, Joel H. Kastner, Chris Koen, K. Maucó, I. Mendigutía, B. Nisini, Neelam Panwar, D. A. Principe, Massimo Robberto, A. Sicilia-Aguilar, Jeff A. Valenti, J. Wendeborn, Jonathan P. Williams, Ziyan Xu, and R. K. Yadav
Figure caption: The wind profile from CVSO 109A, obtained from co-added C II and Si II lines (C II lines at 1334.5 and 1335.7 Å and Si II lines at 1260.422, 1264.738, 1526.707, 1533.431, 1194.5, 1197.394, 1193.290, and 1190.416 Å), compared with the wind from RU Lup, as seen with COS (data obtained from France et al. 2012). The wind from RU Lup starts at a lower velocity and extends to a higher velocity, while the wind absorption from CVSO 109A is narrower, has a faster minimum velocity, and is centered at −220 km s−1.
Paper: The ODYSSEUS Survey. Motivation and First Results: Accretion, Ejection, and Disk Irradiation of CVSO 109
Authors: C. C. Espaillat, G. J. Herczeg, T. Thanathibodee, C. Pittman, N. Calvet, N. Arulanantham, K. France, Javier Serna, J. Hernández, Á. Kóspál, F. M. Walter, A. Frasca, W. J. Fischer, C. M. Johns-Krull, P. C. Schneider, C. Robinson, Suzan Edwards, P. Ábrahám, Min Fang, J. Erkal, C. F. Manara, J. M. Alcalá, E. Alecian, R. D. Alexander, J. Alonso-Santiago, Simone Antoniucci, David R. Ardila, Andrea Banzatti, M. Benisty, Edwin A. Bergin, Katia Biazzo, César Briceño, Justyn Campbell-White, L. Ilsedore Cleeves, Deirdre Coffey, Jochen Eislöffel, Stefano Facchini, D. Fedele, Eleonora Fiorellino, Dirk Froebrich, Manuele Gangi, Teresa Giannini, K. Grankin, Hans Moritz Günther, Zhen Guo, Lee Hartmann, Lynne A. Hillenbrand, P. C. Hinton, Joel H. Kastner, Chris Koen, K. Maucó, I. Mendigutía, B. Nisini, Neelam Panwar, D. A. Principe, Massimo Robberto, A. Sicilia-Aguilar, Jeff A. Valenti, J. Wendeborn, Jonathan P. Williams, Ziyan Xu, and R. K. Yadav
Figure caption: The FUV continuum spectrum of CVSO 109A. The full COS spectrum is shown in gray while the black filled circles are the average fluxes in 0.75 Å bins selected to exclude bright stellar and disk emission lines. A second-order polynomial fit is shown in red.
Paper: The ODYSSEUS Survey. Motivation and First Results: Accretion, Ejection, and Disk Irradiation of CVSO 109
Authors: C. C. Espaillat, G. J. Herczeg, T. Thanathibodee, C. Pittman, N. Calvet, N. Arulanantham, K. France, Javier Serna, J. Hernández, Á. Kóspál, F. M. Walter, A. Frasca, W. J. Fischer, C. M. Johns-Krull, P. C. Schneider, C. Robinson, Suzan Edwards, P. Ábrahám, Min Fang, J. Erkal, C. F. Manara, J. M. Alcalá, E. Alecian, R. D. Alexander, J. Alonso-Santiago, Simone Antoniucci, David R. Ardila, Andrea Banzatti, M. Benisty, Edwin A. Bergin, Katia Biazzo, César Briceño, Justyn Campbell-White, L. Ilsedore Cleeves, Deirdre Coffey, Jochen Eislöffel, Stefano Facchini, D. Fedele, Eleonora Fiorellino, Dirk Froebrich, Manuele Gangi, Teresa Giannini, K. Grankin, Hans Moritz Günther, Zhen Guo, Lee Hartmann, Lynne A. Hillenbrand, P. C. Hinton, Joel H. Kastner, Chris Koen, K. Maucó, I. Mendigutía, B. Nisini, Neelam Panwar, D. A. Principe, Massimo Robberto, A. Sicilia-Aguilar, Jeff A. Valenti, J. Wendeborn, Jonathan P. Williams, Ziyan Xu, and R. K. Yadav
Figure caption: The best-fit reconstructed Lyα profile of CVSO 109A (black, solid curve), with ± 1σ contours drawn based on the uncertainties in the model parameters (gray, shaded regions). The model was fit to “data points” constructed from fluorescent H2 emission line fluxes (red circles), which allowed us to trace the Lyα reaching the disk surface at wavelengths where the observed profile is attenuated by geocoronal emission and interstellar absorption. Since CVSO 109A shows detectable H2 emission lines from only four upper levels redward of the Lyα line center, the blue side of the reconstructed profile is less well constrained, as seen most clearly in the wide spread of possible H I outflow velocities.
Paper: The ODYSSEUS Survey. Motivation and First Results: Accretion, Ejection, and Disk Irradiation of CVSO 109
Authors: C. C. Espaillat, G. J. Herczeg, T. Thanathibodee, C. Pittman, N. Calvet, N. Arulanantham, K. France, Javier Serna, J. Hernández, Á. Kóspál, F. M. Walter, A. Frasca, W. J. Fischer, C. M. Johns-Krull, P. C. Schneider, C. Robinson, Suzan Edwards, P. Ábrahám, Min Fang, J. Erkal, C. F. Manara, J. M. Alcalá, E. Alecian, R. D. Alexander, J. Alonso-Santiago, Simone Antoniucci, David R. Ardila, Andrea Banzatti, M. Benisty, Edwin A. Bergin, Katia Biazzo, César Briceño, Justyn Campbell-White, L. Ilsedore Cleeves, Deirdre Coffey, Jochen Eislöffel, Stefano Facchini, D. Fedele, Eleonora Fiorellino, Dirk Froebrich, Manuele Gangi, Teresa Giannini, K. Grankin, Hans Moritz Günther, Zhen Guo, Lee Hartmann, Lynne A. Hillenbrand, P. C. Hinton, Joel H. Kastner, Chris Koen, K. Maucó, I. Mendigutía, B. Nisini, Neelam Panwar, D. A. Principe, Massimo Robberto, A. Sicilia-Aguilar, Jeff A. Valenti, J. Wendeborn, Jonathan P. Williams, Ziyan Xu, and R. K. Yadav
Figure caption: The accretion-dominated Lyα and interstellar H I attenuation profile of CVSO 109A. The COS data are the gray histogram, the intrinsic Lyα emission line is the blue dashed line, and the pink solid line is the best-fit model of the stellar emission line and the interstellar absorption profile. The best-fit interstellar hydrogen column density is ﹩{\mathrm{log}}_{10}(N(﹩ H I)) = 20.32 ± 0.06.
Paper: The ODYSSEUS Survey. Motivation and First Results: Accretion, Ejection, and Disk Irradiation of CVSO 109
Authors: C. C. Espaillat, G. J. Herczeg, T. Thanathibodee, C. Pittman, N. Calvet, N. Arulanantham, K. France, Javier Serna, J. Hernández, Á. Kóspál, F. M. Walter, A. Frasca, W. J. Fischer, C. M. Johns-Krull, P. C. Schneider, C. Robinson, Suzan Edwards, P. Ábrahám, Min Fang, J. Erkal, C. F. Manara, J. M. Alcalá, E. Alecian, R. D. Alexander, J. Alonso-Santiago, Simone Antoniucci, David R. Ardila, Andrea Banzatti, M. Benisty, Edwin A. Bergin, Katia Biazzo, César Briceño, Justyn Campbell-White, L. Ilsedore Cleeves, Deirdre Coffey, Jochen Eislöffel, Stefano Facchini, D. Fedele, Eleonora Fiorellino, Dirk Froebrich, Manuele Gangi, Teresa Giannini, K. Grankin, Hans Moritz Günther, Zhen Guo, Lee Hartmann, Lynne A. Hillenbrand, P. C. Hinton, Joel H. Kastner, Chris Koen, K. Maucó, I. Mendigutía, B. Nisini, Neelam Panwar, D. A. Principe, Massimo Robberto, A. Sicilia-Aguilar, Jeff A. Valenti, J. Wendeborn, Jonathan P. Williams, Ziyan Xu, and R. K. Yadav
Figure caption: The H2 (1–7)R(3) emission line pumped by the core of the stellar or accretion Lyα emission line. The observed line width (FWHM shown in the upper left) indicates the average H2 emitting radius between 0.06–0.6 au, depending on the disk inclination (Section 6.5.2).
Paper: The ODYSSEUS Survey. Motivation and First Results: Accretion, Ejection, and Disk Irradiation of CVSO 109
Authors: C. C. Espaillat, G. J. Herczeg, T. Thanathibodee, C. Pittman, N. Calvet, N. Arulanantham, K. France, Javier Serna, J. Hernández, Á. Kóspál, F. M. Walter, A. Frasca, W. J. Fischer, C. M. Johns-Krull, P. C. Schneider, C. Robinson, Suzan Edwards, P. Ábrahám, Min Fang, J. Erkal, C. F. Manara, J. M. Alcalá, E. Alecian, R. D. Alexander, J. Alonso-Santiago, Simone Antoniucci, David R. Ardila, Andrea Banzatti, M. Benisty, Edwin A. Bergin, Katia Biazzo, César Briceño, Justyn Campbell-White, L. Ilsedore Cleeves, Deirdre Coffey, Jochen Eislöffel, Stefano Facchini, D. Fedele, Eleonora Fiorellino, Dirk Froebrich, Manuele Gangi, Teresa Giannini, K. Grankin, Hans Moritz Günther, Zhen Guo, Lee Hartmann, Lynne A. Hillenbrand, P. C. Hinton, Joel H. Kastner, Chris Koen, K. Maucó, I. Mendigutía, B. Nisini, Neelam Panwar, D. A. Principe, Massimo Robberto, A. Sicilia-Aguilar, Jeff A. Valenti, J. Wendeborn, Jonathan P. Williams, Ziyan Xu, and R. K. Yadav
Figure caption: (Top panel) The two-component fit to the [O I] 6300 Å emission from CVSO 109A is illustrated. (Bottom panel) Emission profiles from H2 [1,4] 1489 Å (red) and [1,7] 1500 Å (gray) compared with [O I] 6300 Å (blue). The H2 emission lines have widths of ∼ 42–52 km s−1 and are consistent with a single component whereas the [O I] profiles are better fit with a two-component model with FWHM([O I])narrow = 19.8 km s−1 and FWHM([O I])broad = 47.1 km s−1.
Paper: The ODYSSEUS Survey. Motivation and First Results: Accretion, Ejection, and Disk Irradiation of CVSO 109
Authors: C. C. Espaillat, G. J. Herczeg, T. Thanathibodee, C. Pittman, N. Calvet, N. Arulanantham, K. France, Javier Serna, J. Hernández, Á. Kóspál, F. M. Walter, A. Frasca, W. J. Fischer, C. M. Johns-Krull, P. C. Schneider, C. Robinson, Suzan Edwards, P. Ábrahám, Min Fang, J. Erkal, C. F. Manara, J. M. Alcalá, E. Alecian, R. D. Alexander, J. Alonso-Santiago, Simone Antoniucci, David R. Ardila, Andrea Banzatti, M. Benisty, Edwin A. Bergin, Katia Biazzo, César Briceño, Justyn Campbell-White, L. Ilsedore Cleeves, Deirdre Coffey, Jochen Eislöffel, Stefano Facchini, D. Fedele, Eleonora Fiorellino, Dirk Froebrich, Manuele Gangi, Teresa Giannini, K. Grankin, Hans Moritz Günther, Zhen Guo, Lee Hartmann, Lynne A. Hillenbrand, P. C. Hinton, Joel H. Kastner, Chris Koen, K. Maucó, I. Mendigutía, B. Nisini, Neelam Panwar, D. A. Principe, Massimo Robberto, A. Sicilia-Aguilar, Jeff A. Valenti, J. Wendeborn, Jonathan P. Williams, Ziyan Xu, and R. K. Yadav
Figure caption: A comparison of the 2014 and 2020 disk and accretion profiles of CVSO 109A. The disk H2 profiles are nearly unchanged, while the C IV and underlying FUV continuum lines show significant temporal variability.
Paper: Unresolved Binaries in the Intermediate Mass Range in the Pleiades Star Cluster  
Authors: Alina A. Malofeeva, Anton F. Seleznev, and Giovanni Carraro
Figure caption: Deviation of the unresolved binary system from the single star sequence as a function of the q value in a typical CMD in the Gaia EDR3 (Gaia Collaboration et al. 2021) photometric system. M1 = 1 M⊙.
Paper: Unresolved Binaries in the Intermediate Mass Range in the Pleiades Star Cluster  
Authors: Alina A. Malofeeva, Anton F. Seleznev, and Giovanni Carraro
Figure caption: The differences of monochromatic stellar magnitudes of a binary and its primary component for binary stars adopting the Planck approximation. M1 = 1M⊙. The dotted line corresponds to q = 0.1, dashed line–q = 0.2, dashed-with-one-dot line–q = 0.3, dashed-with-two-dots line–q = 0.4, and solid line–q = 0.5.
Paper: Unresolved Binaries in the Intermediate Mass Range in the Pleiades Star Cluster  
Authors: Alina A. Malofeeva, Anton F. Seleznev, and Giovanni Carraro
Figure caption: The diagram W2-(BP-K) vs. (H-W2)-W1 for the model cluster. (a) Blue points show the binary stars, black points show the single stars. The magenta region shows an area where the model does not have binary stars due to the lack of information on stellar magnitudes of objects with masses lower than 0.1 solar masses. (b) Lines of the deviation of the unresolved binary star from the single star sequence for different masses of the primary component. Different values of q are indicated by numbers and arrows.
Paper: Unresolved Binaries in the Intermediate Mass Range in the Pleiades Star Cluster  
Authors: Alina A. Malofeeva, Anton F. Seleznev, and Giovanni Carraro
Figure caption: (a) The diagram W2-(BP-K) vs. (H-W2)-W1 for the combined sample of Pleiades probable members. (b) Lines of the constant q values are over-imposed onto the Pleiades stars’ distribution. The black numbers are q values, the blue lines and numbers correspond to masses of primary components. The lines of the constant q values correspond to the Bressan et al. (2012) isochrone with ﹩\mathrm{log}t=8.1﹩.
Paper: Unresolved Binaries in the Intermediate Mass Range in the Pleiades Star Cluster  
Authors: Alina A. Malofeeva, Anton F. Seleznev, and Giovanni Carraro
Figure caption: The diagram W2-(BP-K)–(H-W2)-W1 for the counts of stars with different values of q. Lines of the constant q values are shown.
Paper: Unresolved Binaries in the Intermediate Mass Range in the Pleiades Star Cluster  
Authors: Alina A. Malofeeva, Anton F. Seleznev, and Giovanni Carraro
Figure caption: The distribution of the component mass ratio q and its approximation by a power law. Solid line–stars with 0 < q < 0.2 are considered as binaries; dashed line–stars with 0 < q < 0.2 are considered as singles.
Paper: Accurate Modeling of Grazing Transits Using Umbrella Sampling
Authors: Gregory J. Gilbert
Figure caption: Schematic illustration of a nongrazing transit geometry with the corresponding light curve approximated as a trapezoid. The transit depth, δ; transit duration, T; ingress/egress duration τ; midtransit time, t0; impact parameter, b; and fist through fourth contact points, tI–tIV, are indicated. Note that for this study, the transit duration, T, will always refer to the full first-to-fourth contact duration, T14, unless otherwise specified because this is the only duration that is defined for all grazing and nongrazing geometries. The approximation τ12 = τ34 (i.e., ingress and egress timescales are equal) is valid as long as eccentricities are not very large. Figure adapted from Winn (2010).
Paper: Accurate Modeling of Grazing Transits Using Umbrella Sampling
Authors: Gregory J. Gilbert
Figure caption: Light-curve model illustrating how the transit shape changes as a function on impact parameter, b. This model is for a warm Neptune orbiting a Sun-like star with model parameters r = 0.05, P = 13.0 days, R⋆ = R⊙, M⋆ = M⊙, and u = (0.4, 0.25). Warm colored, solid lines indicate grazing or near-grazing transits (informally defined here as b ≳ 0.8), while cool-colored, dashed lines indicate nongrazing transits. As b increases, transit duration decreases (due to the shorter transit chord) and transit depth decreases (due to stellar limb darkening). There is little change in the transit shape between 0 ≤ b ≲ 0.5, making differences between low impact parameters difficult to resolve. The transit depth and duration both change more rapidly above b ≳ 0.5. At b = 1 − r = 0.95, the transit morphology switches from “U-shaped” to “V-shaped,” providing a diagnostic avenue for distinguishing grazing from nongrazing transits, although the effects of limb darkening blur this transition somewhat.
Paper: Accurate Modeling of Grazing Transits Using Umbrella Sampling
Authors: Gregory J. Gilbert
Figure caption: Distribution of rp/R⋆ and b for cumulative Kepler object of interest (KOI) planet candidates. Left panel: joint 2D distribution of rp/R⋆ and b. Each point represents an individual validated or candidate planet. The red shaded region highlights planets inferred to orbit on a grazing trajectory. There is a suspicious pile-up of planets near b ≈ 1.25 at the b = 1 − r boundary, hinting that the radius and impact parameter measurements derived for these planets may not be reliable. Nonisotropic structure in the distribution among planets on nongrazing trajectories—particularly near b = 0—suggests that measurements for these planets should be approached with some skepticism as well. Right panel: fraction of planets inferred to be on grazing trajectories as a function of radius ratio. The red line plots the relation f = 2r/(1 + r), which is the geometric upper limit on how many planets are expected to be on grazing orbits, ignoring any reduced detection efficiencies for grazing transits. For planets with physically plausible radii (rp ≲ 2RJ), the observed fraction of grazing transits is in line with expectations, but for supergiant planets, an overabundance of KOIs are found on grazing trajectories, again suggesting that their radius and impact parameter measurements may be unreliable.
Paper: Accurate Modeling of Grazing Transits Using Umbrella Sampling
Authors: Gregory J. Gilbert
Figure caption: Impact parameters reported by Kepler DR22 (Mullally et al. 2015) vs. DR25 (Thompson et al. 2018). Plotted values correspond to best-fit point estimates. Each point indicates a single KOI reported in both catalogs, so points should cluster around the line b22 = b25. The high degree of scatter in the actual data indicates that results are inconsistent and therefore unreliable. While there is some correspondence of values where b ≳ 0.7, in a substantial fraction of cases, one catalog reports b ≈ 0 while the other reports b ≈ 1. A pile-up of reported values near b = 0 can be seen in both catalogs, indicating that results are inaccurate. Because r and b are correlated for stars with nonnegligible limb darkening, any mis-measurement of b will propagate through to a mis-measurement of r.
Paper: Accurate Modeling of Grazing Transits Using Umbrella Sampling
Authors: Gregory J. Gilbert
Figure caption: Simulated light-curve photometry for a Jupiter-sized planet on a circular orbit around a Sun-like star with various impact parameters. The orbital period was adjusted to maintain a consistent transit duration of T = 3 hr. The solid colored lines show the true underlying model while the gray points have additive Gaussian noise. The low S/N of the transit makes the orbital trajectory (grazing vs. nongrazing) ambiguous. Top panel: b = 0.22, placing the planet on a nongrazing trajectory, corresponding to model J-22 in Table 1. Middle panel: b = 0.85, a near-grazing trajectory (model J-85). Bottom panel: b = 1.0, a grazing trajectory (model J-100).
Paper: Accurate Modeling of Grazing Transits Using Umbrella Sampling
Authors: Gregory J. Gilbert
Figure caption: Corner plots of the posteriors from four identical MCMC runs of model J-85 using our fiducial ﹩\{\mathrm{ln}r,b\}﹩ basis. See Section 3.2 and Table 1 for details of the model setup. The only difference between the runs was the random seed for the Markov Chains. Despite their identical setups, each run produces a remarkably different posterior geometry. Panel A: the sampler appears to fully explore the posterior region, with most samples consistent with a nongrazing geometry and a smaller fraction extending into the grazing regime. There is a “dog leg” feature at b ≈ 1 where the geometry transitions from nongrazing to grazing, and there is a strong degeneracy between ﹩\mathrm{ln}r﹩ and b for grazing transits. Panel B: the sampler fails to explore the grazing regime entirely, giving the illusion of a well-behaved posterior. Panel C: the sampler extends to high impact parameters, but catches at the boundary between grazing and nongrazing geometries, producing a sharp spike at b ≈ 1. Panel D: the samples pile up at b ≈ 1, leading to a bimodal posterior distribution that barely explores the grazing regime at all. Increasing the length, the tuning phase, and/or the sampling phase does not reliably fix these issues.
Paper: Accurate Modeling of Grazing Transits Using Umbrella Sampling
Authors: Gregory J. Gilbert
Figure caption: Planet–star overlap area at midtransit as a function of impact parameter, b, for planet-to-star radius ratio r = 0.05. The plot is restricted to show only the grazing regime, i.e., 1 − r < b < 1 + r. The solid black line shows the exact geometric solution derived by Mandel & Agol (2002) and presented in this paper as Equation (A1). Even though the full geometry is quite complicated, the resultant curve is well approximated by a simple linear function (dashed red line).
Paper: Accurate Modeling of Grazing Transits Using Umbrella Sampling
Authors: Gregory J. Gilbert
Figure caption: Posterior distributions of ﹩\mathrm{ln}\lambda ﹩, γ, and ﹩\mathrm{ln}r﹩ for transit geometries restricted to the grazing regime for a near-grazing transit of a warm Jupiter orbiting a Sun-like star (model J-85). The effects of the biasing potential have been removed. See Table 1 for ground-truth simulation parameters and Figure 5 for the simulated photometry. The two parameterizations produce comparable posterior distributions, although the new λ − γ basis performs ∼20% more efficiently. Note that for the left panel, λ and γ were not basis parameters, but were computed after the fact from samples of r and b. A detailed discussion of the model parameterization is presented in Section 3.
Paper: Accurate Modeling of Grazing Transits Using Umbrella Sampling
Authors: Gregory J. Gilbert
Figure caption: Schematic illustration of the umbrella sampling method, inspired by Smith et al. (2017). The method is designed to facilitate sampling from multimodal target distributions (shaded gray region in all panels). Top left: the target distribution (emphasized with a thick black line) has a low-probability valley, which will create a bottleneck for standard sampling techniques. In order to ensure sampling from the full posterior space, we split the problem into three windows, each assigned a bias function, ψi. Top right: after sampling independently from each window, we have three biased subdistributions πi. Bottom left: removing the effect of the bias functions, ψi produces three unbiased subdistributions with unknown offsets between one another. Bottom right: calculating the window weights, zi, and recombining all subdistributions πi into a single joint posterior recovers the true target distribution. See Section 4.1 for a detailed discussion.
Paper: Accurate Modeling of Grazing Transits Using Umbrella Sampling
Authors: Gregory J. Gilbert
Figure caption: Our umbrella bias functions, ψ(γ). The solid blue line is the nongrazing umbrella (ψN). The dashed orange line is the transition umbrella (ψT). The dotted red line is the grazing umbrella (ψG). We have opted to use tent biases because these are simple to perform calculations with, but because umbrella sampling is insensitive to the particular choice of bias functions—provided that windows overlap—many other functional forms would perform just as well.