adsabs/AstroCLIMB huggingface dataset:
Paper: The Primary Flare Following a Stellar Collision in a Galactic Nucleus
Authors: Yuval Brutman, Elad Steinberg, Shmuel Balberg
Figure caption: Kinetic energy deposition rates of gas streams colliding at the antipodal points with respect to the DC. The SMBH mass and stellar masses are 4 × 106 M ⊙ and 1 M ⊙, respectively, while the magnitude and orientation of v CM are varied. The DCs are set at r 0 = 1014 cm (top panel) or at r 0 = 1015 cm (bottom panel). The impact parameter in the DCs is set at b = 0 or b = R ⊙; the dashed red curves display a crude model that includes mass that has not directly participated in the collision for a b = R ⊙ case (see Section 2.2).
Paper: The Primary Flare Following a Stellar Collision in a Galactic Nucleus
Authors: Yuval Brutman, Elad Steinberg, Shmuel Balberg
Figure caption: A two-parameter survey of the late-time power-law dependence of ﹩\beta \equiv d\,{\rm{ln}}\,{\dot{Q}}_{{\rm{kin}}}/d\,{\rm{ln}}\,t﹩ assumed for the stream–stream collisions. The two parameters are ﹩|{{\boldsymbol{v}}}_{{\rm{CM}}}|﹩ (in units of v typ) and the angle θ. All calculations are for stellar collisions of two stars of mass m = M ⊙ with b = 0 at a distance of r 0 = 1014 cm from an M • = 4 × 106 M ⊙ SMBH.
Paper: The Primary Flare Following a Stellar Collision in a Galactic Nucleus
Authors: Yuval Brutman, Elad Steinberg, Shmuel Balberg
Figure caption: Snapshots with density maps of two RICH simulations. Top panel: a head-on DC between two Sunlike stars at a distance of 1014 cm from an SMBH with mass of M • = 4 × 106 M ⊙. Bottom panel: a similar DC, but the centers of the stars are shifted in the x–y plane by an impact parameter of b = R ⊙. In both simulations, the green dot in the inset indicates the location of the SMBH (the origin).
Paper: The Primary Flare Following a Stellar Collision in a Galactic Nucleus
Authors: Yuval Brutman, Elad Steinberg, Shmuel Balberg
Figure caption: The principal setup for the model of the ejecta following a stellar collision. The ejected mass is assumed to explode spherically and homologously in its rest frame (panel (A)), which has a velocity ﹩{{\boldsymbol{v}}}_{{\rm{cm}}}﹩ in the SMBH rest frame. There exists a symmetry with respect to the ﹩{v}_{\mathrm{cm}}\unicode{8210}\hat{z}﹩ plane for any two points on opposite sides of the plane defined by ﹩{{\boldsymbol{v}}}_{{\rm{cm}}}﹩ and the ﹩\hat{z}﹩-axis. As a result, every mass element in the ejecta will collide with another element that is symmetric to it as their Keplerian paths coincide at the antipodal point to the collision (panel (B)).
Paper: Indication of Sharp and Strong Phase Transitions from NICER Observations
Authors: Zidu Lin, Andrew. W. Steiner
Figure caption: The line from Equation (1) compared with distributions of (R 1.34, R 2.0) in 3P, 4L, and CEFT15unif (left panel) and with the distributions of (R 1.34, R 2.0) in CSS and NICER observations (right panel). The dotted–dashed black lines are described in Equation (1) with M 1 = 1.34 M ⊙ and M 2 = 2.0 M ⊙. The black and red solid contour curves in the left panel represent 95% confidence interval of the (R 1.34, R 2.0) based on 3P and 4L EoSs. The green contour represents the 95% confidence interval of the prior distribution of (R 1.34, R 2.0) based on EoSs published in S. Huth et al. (2022), which are CEFT EoSs up to 1.5 saturation density and extended with EoSs parametrized using speed of sound. The shaded light yellow band represents the uncertainty of the linear regression line due to the uncertainty of low-density CEFT below two saturation densities (see detailed discussion in C. Drischler et al. 2021). The upper and lower dashed blue lines represent a band of threshold with ﹩{D}_{{\rm{L}}}^{\mathrm{Th}}=0.9﹩ km, beyond which one may claim beyond-standard EoS models are observed (see detailed discussion about the ﹩{D}_{{\rm{L}}}^{\mathrm{Th}}﹩ in text). The colored distribution in the right panel represents the strength of normalized probability distribution of (R 1.34, R 2.0) based on two NICER measurements (T. E. Riley et al. 2019, 2021). The red dots represent a selected ensemble of CSS realizations that have similar R 1.34 but very different R 2.0.
Paper: Indication of Sharp and Strong Phase Transitions from NICER Observations
Authors: Zidu Lin, Andrew. W. Steiner
Figure caption: The distribution of {D L} in 3P (black solid), 4L (black dashed), CEFT15unif (blue dashed), and in NICER observations (red solid line). The five red dots represent a selected ensemble of CSS realizations that have D L > 1.5 km that lie well beyond the distribution of {D L} in 3P and 4L. The blue vertical dotted–dashed line represents ﹩{D}_{{\rm{L}}}^{\mathrm{Th}}=0.9﹩ km. The data of selected EoS models are described in Zenodo: doi:10.5281/zenodo.13700330.
Paper: Indication of Sharp and Strong Phase Transitions from NICER Observations
Authors: Zidu Lin, Andrew. W. Steiner
Figure caption: We present the EoS, M–R curves, the D L, and the transition pressure locations for 29 EoSs with first-order phase transitions that have D L > 1.5 km. The red solid EoS and M–R curves in the top panels correspond to the five red points in Figure 2. The corresponding D L of these EoSs are presented in the lower left panel. In the lower right panel, the blue dot, orange triangle, green square, and red star represent the central pressure of the 1.4 M ☉ NS, the transition pressure of the first first-order phase transition, the transition pressure of the second first-order phase transition, and the central pressure of the 2.0 M ☉ NS of each EoS.
Paper: Indication of Sharp and Strong Phase Transitions from NICER Observations
Authors: Zidu Lin, Andrew. W. Steiner
Figure caption: We present the correlation between two NS radii in three different pairs—R 1.47 vs. R 1.42 (top left), R 2.01 vs. R 1.42 (top right), and R 2.18 vs. R 1.42 (bottom) based on the 3P model. The Pearson correlation between the NS radii is 0.99 (top left), 0.67 (top right), and 0.54 (bottom), respectively. The solid thick, solid thin, and dashed thin contours correspond to the 1σ, 2σ, and 3σ contours of the density distribution.
Paper: The Primary Flare Following a Stellar Collision in a Galactic Nucleus
Authors: Yuval Brutman, Elad Steinberg, Shmuel Balberg
Figure caption: Light curves for example cases, as noted in the legend. The red and green curves correspond to the scenarios shown in Figure 4.
Paper: The Distribution of Planet Radius in Kepler Multiplanet Systems Depends on Gap Complexity
Authors: David R. Rice, Jason H. Steffen, Allona Vazan
Figure caption: Black: empirical cumulative distribution function of gap complexity for our 238 systems. Purple circles: the average ΔP/P  i  in the systems (left axis) against their gap complexities. Low-C systems have planets close together in period, while the dispersion in period spacing is much larger in high-C systems. Red diamonds: the Gini index of planet period ratio (right axis) vs. gap complexity for our systems. These two measures of period spacing uniformity are highly correlated. For both the purple and red points a linear regression fit is shown with the slope and correlation coefficient (r) reported.
Paper: The Distribution of Planet Radius in Kepler Multiplanet Systems Depends on Gap Complexity
Authors: David R. Rice, Jason H. Steffen, Allona Vazan
Figure caption: Top: gap complexity vs. planet radius for our 783 planets with a running average of gap complexity in 80 planets (red line). Light-blue lines are 50 realizations of the running average gap complexity if the gap complexities are randomly assigned to systems. Blue shows the average and ±1σ of 500 realizations. Bottom: the absolute difference between the average gap complexity in the observations (red line) and the average gap complexity in the random shuffled experiment (blue line) as a multiple of the standard deviation of the randomized planets. While only between 1σ and 2σ do the peaks align with peaks and dips in the radius distribution (black dashed), planets in these peaks/dips tend to be anomalous in average gap complexity.
Paper: The Distribution of Planet Radius in Kepler Multiplanet Systems Depends on Gap Complexity
Authors: David R. Rice, Jason H. Steffen, Allona Vazan
Figure caption: We perform K-S tests between the radius of planets separated by the system’s gap complexities (C). One radius sample has a maximum C given by the x-axis, and the other has a minimum set by the y-axis. The significance when using all planets from 0 to 6 R ⊕ is shown with purple crosses, while the significance for planets between 1 and 3 R ⊕ is shown with red circles. Size and darkness of the marker represent the significance value without considering radius uncertainties.
Paper: The Distribution of Planet Radius in Kepler Multiplanet Systems Depends on Gap Complexity
Authors: David R. Rice, Jason H. Steffen, Allona Vazan
Figure caption: Planet radius with radius uncertainties vs. orbital period for planets in systems of more than three planets. We use the data from J. J. Lissauer et al. (2024) and limit the study to FGK stars. The radius gap is visible near 2 R ⊕, with a slope that depends on orbital period. Planets with periods over 1000 days are excluded from the gap complexity (C) analysis. Additionally, planets with a radius over 6 R ⊕ or radius uncertainties over 50% are used in the C calculation but excluded from the radius distribution analysis.
Paper: The Distribution of Planet Radius in Kepler Multiplanet Systems Depends on Gap Complexity
Authors: David R. Rice, Jason H. Steffen, Allona Vazan
Figure caption: The median frequency of planet radius from 500 Gaussian KDEs where each planet’s radius is drawn from a normal distribution centered at the planet’s reported radius and standard deviation set the average of the plus and minus uncertainties. This is then repeated for each set of planets limited by minimum gap complexity given by the color. The 1σ uncertainty is given at three points for the entire set of planets and planets with C > 0.4. While the uncertainty increases from the smaller sample size, there is a systematic increase in super-Earth and a decrease in sub-Neptune frequency.
Paper: The Distribution of Planet Radius in Kepler Multiplanet Systems Depends on Gap Complexity
Authors: David R. Rice, Jason H. Steffen, Allona Vazan
Figure caption: Architectures of planetary systems where each horizontal line is a system with the star’s KOI number and the system’s C noted. Every fifth planetary system when the 238 systems are ordered by C (48 systems) are shown. Points are placed for each planet at its orbital period with a size proportional to the planet radius. Planets are colored by size category. Unfilled planets are over 6 R ⊕ or have radius uncertainties over 50%. Unfilled planets are used to calculate the gap complexity, but the radius is not used in later analyses. The inner solar system is also shown.
Paper: The Distribution of Planet Radius in Kepler Multiplanet Systems Depends on Gap Complexity
Authors: David R. Rice, Jason H. Steffen, Allona Vazan
Figure caption: The radius distribution at low and high gap complexity with divisions based on the K-S tests from Figure 6. For each sample, 100 Gaussian KDEs of radius draw from reported observational uncertainties, with bandwidth equal to the average radius error. The thick line shows the average of the 100 realizations. Left: radius of planets split by their system’s C for the minimum p-value of a K-S test across all radii. Right: radius of planets split by their system’s C for the minimum p-value of a K-S test in the 1–3 R ⊕ region.
Paper: Time Evolution Images of the Hypergiant RW Cephei during the Rebrightening Phase Following the Great Dimming
Authors: Narsireddy Anugu, Douglas R. Gies, Rachael M. Roettenbacher, John D. Monnier, Miguel Montargés, Antoine Mérand, Fabien Baron, Gail H. Schaefer, Katherine A. Shepard, Stefan Kraus, Matthew D. Anderson, Isabelle Codron, Tyler Gardner, Mayra Gutierrez, Rainer Köhler, Karolina Kubiak, Cyprien Lanthermann, Olli Majoinen, Nicholas J. Scott, Wolfgang Vollmann
Figure caption: Panel (a): the visual brightness variations of RW Cep, spanning from 2020 January to 2024 May. The vertical lines indicate the specific epochs during which we conducted our CHARA interferometric observations (detailed information on the full light curve can be found in Section 2). The Great Dimming began at the start of 2020 and reached its faintest level at the end of 2022. Subsequently, it started rebrightening at the beginning of 2023 and returned to its normal brightness by 2024. Interestingly, it began dimming again in 2024 March. Panel (b): all the dimming events are centered at the faintest magnitude to compare the fall and rise times of major dimming events since 1900. The dimming event that occurred in 1962 has the longest fall time, while the one in 1908.5 has the shortest fall time. The remaining events have an average fall time of around 3 yr.
Paper: Time Evolution Images of the Hypergiant RW Cephei during the Rebrightening Phase Following the Great Dimming
Authors: Narsireddy Anugu, Douglas R. Gies, Rachael M. Roettenbacher, John D. Monnier, Miguel Montargés, Antoine Mérand, Fabien Baron, Gail H. Schaefer, Katherine A. Shepard, Stefan Kraus, Matthew D. Anderson, Isabelle Codron, Tyler Gardner, Mayra Gutierrez, Rainer Köhler, Karolina Kubiak, Cyprien Lanthermann, Olli Majoinen, Nicholas J. Scott, Wolfgang Vollmann
Figure caption: The OITOOLS reconstructed images of RW Cep for epochs 2023 July, August, September, and October while the star is rebrightened. The top panels correspond to the H-band MIRC-X, while the bottom panels correspond to the K-band MYSTIC. Pixel scale is 0.05 mas. The linear intensity scale is employed for plotting all images. The stellar surface appears asymmetric, deviating from a circular shape. The K-band images show three bright spots arranged in a V shape on the star surface comparable to the PMOIRED images (Figure 5) that we interpret as giant convection cells. The H-band images, with (×1.4) higher resolution, reveal more structures than the K-band images. The darker regions on the star surface correspond to cool, infalling material located between these giant convection cells. Additionally, small variations are observed in the images from epoch to epoch; these changes could be attributed to the time-varying dispersal of dust away from the star.
Paper: Time Evolution Images of the Hypergiant RW Cephei during the Rebrightening Phase Following the Great Dimming
Authors: Narsireddy Anugu, Douglas R. Gies, Rachael M. Roettenbacher, John D. Monnier, Miguel Montargés, Antoine Mérand, Fabien Baron, Gail H. Schaefer, Katherine A. Shepard, Stefan Kraus, Matthew D. Anderson, Isabelle Codron, Tyler Gardner, Mayra Gutierrez, Rainer Köhler, Karolina Kubiak, Cyprien Lanthermann, Olli Majoinen, Nicholas J. Scott, Wolfgang Vollmann
Figure caption: The visual brightness of RW Cep as recorded from 1900 to 2024. Gray data points represent data from DASCH, while black points represent data from AAVSO. To ensure consistency, we adjusted the DASCH data by applying a −2.32 mag offset to match the AAVSO data. The dimming event recorded in 2022 December is the faintest observed, compared to all previous dimming events. Another prominent outburst event is evident in 1951, although the data appear noisy.
Paper: Time Evolution Images of the Hypergiant RW Cephei during the Rebrightening Phase Following the Great Dimming
Authors: Narsireddy Anugu, Douglas R. Gies, Rachael M. Roettenbacher, John D. Monnier, Miguel Montargés, Antoine Mérand, Fabien Baron, Gail H. Schaefer, Katherine A. Shepard, Stefan Kraus, Matthew D. Anderson, Isabelle Codron, Tyler Gardner, Mayra Gutierrez, Rainer Köhler, Karolina Kubiak, Cyprien Lanthermann, Olli Majoinen, Nicholas J. Scott, Wolfgang Vollmann
Figure caption: The PMOIRED best-fit model fitting of K-band data sets for the epochs from 2022 December to 2023 October. The images are centered at λ ∼ 2.2 μm. The image colors are plotted on a linear intensity scale. The colored plus signs and “Y” symbols indicate the center of the star and the circumstellar envelope, while the black plus signs denote the locations of the bright spots.
Paper: Time Evolution Images of the Hypergiant RW Cephei during the Rebrightening Phase Following the Great Dimming
Authors: Narsireddy Anugu, Douglas R. Gies, Rachael M. Roettenbacher, John D. Monnier, Miguel Montargés, Antoine Mérand, Fabien Baron, Gail H. Schaefer, Katherine A. Shepard, Stefan Kraus, Matthew D. Anderson, Isabelle Codron, Tyler Gardner, Mayra Gutierrez, Rainer Köhler, Karolina Kubiak, Cyprien Lanthermann, Olli Majoinen, Nicholas J. Scott, Wolfgang Vollmann
Figure caption: Four images of RW Cep that were obtained from the CHARA Array observations conducted on 2022 December 23 (top panels) and 2023 August 4 (bottom panels) in the H- and K-band wavelengths. The left panels are from the MIRC-X H band, while the right panels are from the MYSTIC K band. The orientation of the images is north pointing upward and the east toward the left. These images were produced using the image reconstruction techniques described in Section 5. The images are plotted with linear intensity scale.
Paper: Time Evolution Images of the Hypergiant RW Cephei during the Rebrightening Phase Following the Great Dimming
Authors: Narsireddy Anugu, Douglas R. Gies, Rachael M. Roettenbacher, John D. Monnier, Miguel Montargés, Antoine Mérand, Fabien Baron, Gail H. Schaefer, Katherine A. Shepard, Stefan Kraus, Matthew D. Anderson, Isabelle Codron, Tyler Gardner, Mayra Gutierrez, Rainer Köhler, Karolina Kubiak, Cyprien Lanthermann, Olli Majoinen, Nicholas J. Scott, Wolfgang Vollmann
Figure caption: The Lomb–Scargle periodogram was computed from the AAVSO data. The inset image details the region near the pulsation peak. The pulsation peak occurs at 403 ± 20 days, and the long secondary period is 2495 ± 30 days, equivalent to 6.8 yr.
Paper: Time Evolution Images of the Hypergiant RW Cephei during the Rebrightening Phase Following the Great Dimming
Authors: Narsireddy Anugu, Douglas R. Gies, Rachael M. Roettenbacher, John D. Monnier, Miguel Montargés, Antoine Mérand, Fabien Baron, Gail H. Schaefer, Katherine A. Shepard, Stefan Kraus, Matthew D. Anderson, Isabelle Codron, Tyler Gardner, Mayra Gutierrez, Rainer Köhler, Karolina Kubiak, Cyprien Lanthermann, Olli Majoinen, Nicholas J. Scott, Wolfgang Vollmann
Figure caption: OITOOLS reconstructed images of RW Cep in the CO bands (λ = 2.31−2.39 μm). Each image corresponds to a distinct epoch, which is indicated at the top of each panel. The intensities in these images are depicted on a linear intensity scale. In these reconstructions, the central bright region extending 2.6 mas corresponds to the stellar photosphere, while the outer region encapsulates the circumstellar envelope characterized by CO bands.
Paper: Time Evolution Images of the Hypergiant RW Cephei during the Rebrightening Phase Following the Great Dimming
Authors: Narsireddy Anugu, Douglas R. Gies, Rachael M. Roettenbacher, John D. Monnier, Miguel Montargés, Antoine Mérand, Fabien Baron, Gail H. Schaefer, Katherine A. Shepard, Stefan Kraus, Matthew D. Anderson, Isabelle Codron, Tyler Gardner, Mayra Gutierrez, Rainer Köhler, Karolina Kubiak, Cyprien Lanthermann, Olli Majoinen, Nicholas J. Scott, Wolfgang Vollmann
Figure caption: The near-infrared spectrum of RW Cep made with the Apache Point Observatory TripleSpec spectrograph. The black line shows the spectrum obtained close to minimum brightness during the Great Dimming (observed on 2023 January 9 and 12), and the dark gray line shows the spectrum after the star had almost returned to normal brightness (observed on 2023 September 26). The difference (bright minus faint state) is shown in light gray at the bottom, and this demonstrates that the Great Dimming had a larger amplitude at lower wavelengths (as expected for dust extinction).
Paper: Time Evolution Images of the Hypergiant RW Cephei during the Rebrightening Phase Following the Great Dimming
Authors: Narsireddy Anugu, Douglas R. Gies, Rachael M. Roettenbacher, John D. Monnier, Miguel Montargés, Antoine Mérand, Fabien Baron, Gail H. Schaefer, Katherine A. Shepard, Stefan Kraus, Matthew D. Anderson, Isabelle Codron, Tyler Gardner, Mayra Gutierrez, Rainer Köhler, Karolina Kubiak, Cyprien Lanthermann, Olli Majoinen, Nicholas J. Scott, Wolfgang Vollmann
Figure caption: The best-fit model fitting of the K band at λ = 2.35 μm using the PMOIRED software is presented for the epochs during dimming on 2022 December 23 (left panel) and rebrightening on 2023 July 21 (right panel). The image colors are plotted on a linear intensity scale. The symbols on the images represent the same elements as in Figure 5.
Paper: Time Evolution Images of the Hypergiant RW Cephei during the Rebrightening Phase Following the Great Dimming
Authors: Narsireddy Anugu, Douglas R. Gies, Rachael M. Roettenbacher, John D. Monnier, Miguel Montargés, Antoine Mérand, Fabien Baron, Gail H. Schaefer, Katherine A. Shepard, Stefan Kraus, Matthew D. Anderson, Isabelle Codron, Tyler Gardner, Mayra Gutierrez, Rainer Köhler, Karolina Kubiak, Cyprien Lanthermann, Olli Majoinen, Nicholas J. Scott, Wolfgang Vollmann
Figure caption: The ROTIR reconstructed images of RW Cep for epochs 2023 July, August, September, and October. The top panels correspond to the H-band MIRC-X, while the bottom panels correspond to the K-band MYSTIC. The ROTIR method enforces a spherical shape to the star. The bright and dark spots on the star surface are interpreted similarly to those in Figure 7. In the 2024 July and August epochs, the K-band images show three bright spots arranged in a V shape on the star surface, while later epochs (September and October) reveal more bright spots, likely due to the time-varying dispersal of dust away from the star. The H-band images, with higher resolution, uncover more structures than the K-band images. The darker regions on the star surface correspond to cool, infalling material situated between these giant convection cells.
Paper: Time Evolution Images of the Hypergiant RW Cephei during the Rebrightening Phase Following the Great Dimming
Authors: Narsireddy Anugu, Douglas R. Gies, Rachael M. Roettenbacher, John D. Monnier, Miguel Montargés, Antoine Mérand, Fabien Baron, Gail H. Schaefer, Katherine A. Shepard, Stefan Kraus, Matthew D. Anderson, Isabelle Codron, Tyler Gardner, Mayra Gutierrez, Rainer Köhler, Karolina Kubiak, Cyprien Lanthermann, Olli Majoinen, Nicholas J. Scott, Wolfgang Vollmann
Figure caption: A comparison of the RW Cep 2020–2022 dimming event with the Great Dimming of Betelgeuse (recorded in 2019–2020), ρ Cas (a major dimming event recorded in 1946–47), and VY CMa (a major dimming event recorded in 1988–1993). To compare the fall and rise times of the dimming events, the minimum point of each dimming event is set as the zero-point reference on the X-axis. We subtracted the mean value of each data set to obtain a relative magnitude along the Y-axis. This plot is made with AAVSO data.
Paper: Time Evolution Images of the Hypergiant RW Cephei during the Rebrightening Phase Following the Great Dimming
Authors: Narsireddy Anugu, Douglas R. Gies, Rachael M. Roettenbacher, John D. Monnier, Miguel Montargés, Antoine Mérand, Fabien Baron, Gail H. Schaefer, Katherine A. Shepard, Stefan Kraus, Matthew D. Anderson, Isabelle Codron, Tyler Gardner, Mayra Gutierrez, Rainer Köhler, Karolina Kubiak, Cyprien Lanthermann, Olli Majoinen, Nicholas J. Scott, Wolfgang Vollmann
Figure caption: The SURFING reconstructed images of RW Cep for epochs 2023 July, August, September, and October. The top panels correspond to the H-band MIRC-X, while the bottom panels correspond to the K-band MYSTIC. These images are interpreted in the same way as those in Figure 15. However, the SURFING method shows that the bright and dark spots appear larger, even though the pixel scales are similar to those in ROTIR.