adsabs/AstroCLIMB huggingface dataset:
Paper: A XRISM View of Relativistic Reflection in Cygnus X-1
Authors: Paul A. Draghis, Jon M. Miller, Erin Kara, Elisa Costantini, Oluwashina Adegoke, Javier A. García
Figure caption: The top panel shows the XRISM Resolve spectrum from the first half of the observation (black) compared with simultaneous NuSTAR FPMA (red) and FPMB (blue) spectra. The bottom panels show the ratio of data/model for the XRISM and NuSTAR spectra when all parameters in the spectral model are linked (panel (b)), and when the parameters of the reflection component are allowed to vary independently (panel (c)). All parameters produce agreement within 1σ between the spectra from the two instruments.
Paper: Evolution of the ZTF SLRN-2020 Star-Planet Merger
Authors: Ricardo Yarza, Morgan MacLeod, Benjamin Idini, Ruth Murray-Clay, Enrico Ramirez-Ruiz
Figure caption: Bolometric properties of ZTF SLRN-2020 as a function of time. Open points show the observations (K. De et al. 2023). Solid opaque lines show a model of a contracting envelope of mass 1.1 × 10−6M⊙ around the merger remnant; semitransparent lines show models with masses three times as small or as large. The horizontal dashed line is the constant effective temperature (5850 K) assumed in the envelope model. A dotted line shows the approximate required mass-loss rate if the light curve were powered by the recombination of hydrogen in an outflow.
Paper: Evolution of the ZTF SLRN-2020 Star-Planet Merger
Authors: Ricardo Yarza, Morgan MacLeod, Benjamin Idini, Ruth Murray-Clay, Enrico Ramirez-Ruiz
Figure caption: Important quantities during the merger between a Sun-like star and a Neptune (15M⊕, 3.5R⊕; left panel) or a giant planet (10MJ, 1RJ; right panel), as a function of the timescale of orbital decay as a result of drag. Vertical dashed lines show the two epochs at which pre-merger constraints exist, as well as the orbital period at the surface of the star. The plots show the Mach number of the planet ﹩{ \mathcal M }\equiv {v}_{\mathrm{orb}}/{c}_{s}﹩, ερ ≡ number of density scale heights across the planet, the depth z ≡ R⋆–r (with a circle indicating the location where the depth equals twice the radius of the planet), the stellar density ρ, and the density scale height Hρ. The motion of the planet is always supersonic, leading to shocks. During the surface interaction, the flow is strongly stratified at the scale of the planet (ερ > 1).
Paper: Evolution of the ZTF SLRN-2020 Star-Planet Merger
Authors: Ricardo Yarza, Morgan MacLeod, Benjamin Idini, Ruth Murray-Clay, Enrico Ramirez-Ruiz
Figure caption: Comparison between the time needed for ejecta at speed vej to reach the observed photosphere (Rphot/vej) and the duration of the transient t90 (defined as the time since peak at which 90% of the total radiated energy has been radiated). Scatter points show the observed properties of several stellar mergers. For most of them, these two timescales are within a factor of a few from each other. ZTF SLRN-2020 lies somewhere in the shaded region, depending on the definition of the duration of the transient (only the plateau ≈25 days or the full light curve ≈100 days) and on the assumed speed of the ejecta (ranging from the speed of the expanding inner dust shell ≈35 km s−1 to the escape velocity from a Sun-like star ≈618 km s−1). The duration of ZTF SLRN-2020 is much longer than the time it would take ejecta to reach the observed photosphere, so it is likely not powered by hydrogen recombination from a single episode of mass ejection.
Paper: Evolution of the ZTF SLRN-2020 Star-Planet Merger
Authors: Ricardo Yarza, Morgan MacLeod, Benjamin Idini, Ruth Murray-Clay, Enrico Ramirez-Ruiz
Figure caption: Mass shocked by the planet as a function of the drag decay time, for different planet masses. Circles show the point at which the planet is fully immersed. A dashed vertical line shows the orbital period of the planet when the orbital separation equals the stellar radius. Black error bars show constraints for the ejecta mass at two pre-merger epochs. These constraints suggest a planet with Mp ≳ 5MJ.
Paper: Characterization of the Host Binary of the Directly Imaged Exoplanet HD 143811 AB b
Authors: Anne E. Peck, William Roberson, Eric L. Nielsen, Robert J. De Rosa, Nathalie Jones, Jason Wang, Bruce A. Macintosh, Briley L. Lewis, Gaspard Duchêne, Stanimir Metchev, Asif Abbas, Jerry W. Xuan, Aniket Sanghi, Jennifer Patience, Travis S. Barman, Joanna Bulger, Jeffrey K. Chilcote, Thomas M. Esposito, Michael P. Fitzgerald, Katherine B. Follette, Hannah Gallamore, Stephen Goodsell, James R. Graham, Alexandra Z. Greenbaum, Pascale Hibon, Patrick Ingraham, Paul Kalas, Quinn M. Konopacky, Franck Marchis, Jérôme Maire, Christian Marois, Brenda Matthews, Dimitri Mawet, Maxwell A. Millar-Blanchaer, Rebecca Oppenheimer, David W. Palmer, Marshall D. Perrin, Lisa Poyneer, Laurent Pueyo, Abhijith Rajan, Julien Rameau, Fredrik T. Rantakyrö, Bin Ren, Jean-Baptiste Ruffio, Dmitry Savransky, Adam C. Schneider, Anand Sivaramakrishnan, Adam J. R. W. Smith, Inseok Song, Remi Soummer, Sandrine Thomas, Kimberly Ward-Duong, Schuyler G. Wolff
Figure caption: FEROS spectra of HD 143811 AB taken on 2018 April 22 (black points with error bars), showing two sets of well-resolved lines. Red tracks are drawn from the posterior (lowest χ2 solution in dark red) of a two-star model that best fits the data. The blue and yellow lines are drawn from single-star models for A and B, respectively. Given the high resolution and signal-to-noise ratio of these data, we are able to recover the RVs and vsin(i) of both components.
Paper: Characterization of the Host Binary of the Directly Imaged Exoplanet HD 143811 AB b
Authors: Anne E. Peck, William Roberson, Eric L. Nielsen, Robert J. De Rosa, Nathalie Jones, Jason Wang, Bruce A. Macintosh, Briley L. Lewis, Gaspard Duchêne, Stanimir Metchev, Asif Abbas, Jerry W. Xuan, Aniket Sanghi, Jennifer Patience, Travis S. Barman, Joanna Bulger, Jeffrey K. Chilcote, Thomas M. Esposito, Michael P. Fitzgerald, Katherine B. Follette, Hannah Gallamore, Stephen Goodsell, James R. Graham, Alexandra Z. Greenbaum, Pascale Hibon, Patrick Ingraham, Paul Kalas, Quinn M. Konopacky, Franck Marchis, Jérôme Maire, Christian Marois, Brenda Matthews, Dimitri Mawet, Maxwell A. Millar-Blanchaer, Rebecca Oppenheimer, David W. Palmer, Marshall D. Perrin, Lisa Poyneer, Laurent Pueyo, Abhijith Rajan, Julien Rameau, Fredrik T. Rantakyrö, Bin Ren, Jean-Baptiste Ruffio, Dmitry Savransky, Adam C. Schneider, Anand Sivaramakrishnan, Adam J. R. W. Smith, Inseok Song, Remi Soummer, Sandrine Thomas, Kimberly Ward-Duong, Schuyler G. Wolff
Figure caption: RV measurements of both HD 143811 A and HD 143811 B with orbits drawn from the posteriors, with the darkest blue and red lines representing the lowest χ2 orbit. The Observed − Calculated (O − C) panels show the residuals with respect to the lowest χ2 orbit (black line at 0), as well as the offset of other draws from the posterior with respect to the best-fitting orbit. The ∼18-day orbit is an excellent fit to the data, and the combination of multiple observations over 2 weeks and a multiyear baseline strongly constrains the orbital parameters.
Paper: Characterization of the Host Binary of the Directly Imaged Exoplanet HD 143811 AB b
Authors: Anne E. Peck, William Roberson, Eric L. Nielsen, Robert J. De Rosa, Nathalie Jones, Jason Wang, Bruce A. Macintosh, Briley L. Lewis, Gaspard Duchêne, Stanimir Metchev, Asif Abbas, Jerry W. Xuan, Aniket Sanghi, Jennifer Patience, Travis S. Barman, Joanna Bulger, Jeffrey K. Chilcote, Thomas M. Esposito, Michael P. Fitzgerald, Katherine B. Follette, Hannah Gallamore, Stephen Goodsell, James R. Graham, Alexandra Z. Greenbaum, Pascale Hibon, Patrick Ingraham, Paul Kalas, Quinn M. Konopacky, Franck Marchis, Jérôme Maire, Christian Marois, Brenda Matthews, Dimitri Mawet, Maxwell A. Millar-Blanchaer, Rebecca Oppenheimer, David W. Palmer, Marshall D. Perrin, Lisa Poyneer, Laurent Pueyo, Abhijith Rajan, Julien Rameau, Fredrik T. Rantakyrö, Bin Ren, Jean-Baptiste Ruffio, Dmitry Savransky, Adam C. Schneider, Anand Sivaramakrishnan, Adam J. R. W. Smith, Inseok Song, Remi Soummer, Sandrine Thomas, Kimberly Ward-Duong, Schuyler G. Wolff
Figure caption: Posterior on the SB2 RV orbit of HD 143811 AB. The orbit is very well constrained by the FEROS data, with orbital period known to 6 s precision. Direct measurement of both semiamplitudes allows a measurement of mass ratio at the sub-1% level: 0.886  ±  0.003.
Paper: Evolution of the ZTF SLRN-2020 Star-Planet Merger
Authors: Ricardo Yarza, Morgan MacLeod, Benjamin Idini, Ruth Murray-Clay, Enrico Ramirez-Ruiz
Figure caption: Schematic representation of the evolution of ZTF SLRN-2020 as discussed in this work.
Paper: The First out-of-Ecliptic Observations of the Polar Magnetic Field of the Sun
Authors: D. Calchetti, S. K. Solanki, J. Hirzberger, G. Valori, L. P. Chitta, J. Blanco Rodríguez, A. Giunta, T. Grundy, K. Albert, T. Appourchaux, F. J. Bailén, L. R. Bellot Rubio, A. Feller, A. Gandorfer, L. Gizon, A. Korpi-Lagg, X. Li, A. Moreno Vacas, T. Oba, D. Orozco Suárez, J. Schou, U. Schühle, J. Sinjan, H. Strecker, J. C. del Toro Iniesta, A. Ulyanov, R. Volkmer, J. Woch
Figure caption: Magnetic fluxes for the north (upper panel) and south pole (bottom panel) campaigns. The green and pink lines show the absolute positive and negative fluxes, respectively, and the dark gray line shows the net flux as a function of the heliographic latitude. The latitudinal bins have a size of 2°. The thick lines show the flux averaged over the different observations; the shaded areas show the 1σ variance between the individual snapshots. The blue line shows the average percentage of area coverage through the campaign at different latitudes. In both panels, the respective pole is located on the left side.
Paper: The First out-of-Ecliptic Observations of the Polar Magnetic Field of the Sun
Authors: D. Calchetti, S. K. Solanki, J. Hirzberger, G. Valori, L. P. Chitta, J. Blanco Rodríguez, A. Giunta, T. Grundy, K. Albert, T. Appourchaux, F. J. Bailén, L. R. Bellot Rubio, A. Feller, A. Gandorfer, L. Gizon, A. Korpi-Lagg, X. Li, A. Moreno Vacas, T. Oba, D. Orozco Suárez, J. Schou, U. Schühle, J. Sinjan, H. Strecker, J. C. del Toro Iniesta, A. Ulyanov, R. Volkmer, J. Woch
Figure caption: Magnetic flux densities for the north (upper panel) and south pole (bottom panel). The colors are represented as in Figure 3.
Paper: The First out-of-Ecliptic Observations of the Polar Magnetic Field of the Sun
Authors: D. Calchetti, S. K. Solanki, J. Hirzberger, G. Valori, L. P. Chitta, J. Blanco Rodríguez, A. Giunta, T. Grundy, K. Albert, T. Appourchaux, F. J. Bailén, L. R. Bellot Rubio, A. Feller, A. Gandorfer, L. Gizon, A. Korpi-Lagg, X. Li, A. Moreno Vacas, T. Oba, D. Orozco Suárez, J. Schou, U. Schühle, J. Sinjan, H. Strecker, J. C. del Toro Iniesta, A. Ulyanov, R. Volkmer, J. Woch
Figure caption: Number density of the magnetic elements as a function of the magnetic fluxes of these elements measured during the south (left panel) and north (right panel) pole campaigns. Only values with absolute heliographic latitude above 70° are considered.
Paper: The First out-of-Ecliptic Observations of the Polar Magnetic Field of the Sun
Authors: D. Calchetti, S. K. Solanki, J. Hirzberger, G. Valori, L. P. Chitta, J. Blanco Rodríguez, A. Giunta, T. Grundy, K. Albert, T. Appourchaux, F. J. Bailén, L. R. Bellot Rubio, A. Feller, A. Gandorfer, L. Gizon, A. Korpi-Lagg, X. Li, A. Moreno Vacas, T. Oba, D. Orozco Suárez, J. Schou, U. Schühle, J. Sinjan, H. Strecker, J. C. del Toro Iniesta, A. Ulyanov, R. Volkmer, J. Woch
Figure caption: Distribution of the logarithm of the magnetic flux (y-axis) of each selected magnetic element at the south and north poles as function of μ (x-axis). The color bar shows the number of counts in each bin on a logarithmic scale. The white line represents the average of the flux for each μ bin.
Paper: The First out-of-Ecliptic Observations of the Polar Magnetic Field of the Sun
Authors: D. Calchetti, S. K. Solanki, J. Hirzberger, G. Valori, L. P. Chitta, J. Blanco Rodríguez, A. Giunta, T. Grundy, K. Albert, T. Appourchaux, F. J. Bailén, L. R. Bellot Rubio, A. Feller, A. Gandorfer, L. Gizon, A. Korpi-Lagg, X. Li, A. Moreno Vacas, T. Oba, D. Orozco Suárez, J. Schou, U. Schühle, J. Sinjan, H. Strecker, J. C. del Toro Iniesta, A. Ulyanov, R. Volkmer, J. Woch
Figure caption: Histogram showing the absolute value of the radial magnetic field measured during the polar campaigns.
Paper: The Detection-versus-retrieval Challenge: Titan as an Exoplanet
Authors: Prajwal Niraula, Julien de Wit, Robert J. Hargreaves, Iouli E. Gordon, Clara Sousa-Silva
Figure caption: A family portrait of hydrocarbons in Titan’s transmission spectrum obtained with Cassini/VIMS. Best-fit model (thick blue line), corresponding to the maximum-likelihood solution, is shown for Titan’s spectrum obtained during visit T10 (see Table 1) from T. D. Robinson et al. (2014), together with the individual contributions of the absorbing molecules (see legend) that comprise the molecular combination case 25 (see Table 3). The residuals, expressed in units of scaled observational uncertainty (see Equation A2), are shown in the bottom-right panel along with their distribution. An Anderson–Darling test indicates a deviation from Gaussianity at the 5% significance level.
Paper: Probing the Evolution of Solar Wind Temperature Anisotropies in the Inner Heliosphere
Authors: Vamsee Krishna Jagarlamudi, P. Mostafavi, J. C. Palacios, S. Bourouaine, N. E. Raouafi, Rungployphan Kieokaew, Tereza Ďurovcová, Andrey Fedorov, Philippe Louarn
Figure caption: Mean alpha (orange) and proton (blue) temperature anisotropy as a function of normalized differential speed between alpha-particles and protons at different radial distances. The error bars correspond to standard deviation.
Paper: Probing the Evolution of Solar Wind Temperature Anisotropies in the Inner Heliosphere
Authors: Vamsee Krishna Jagarlamudi, P. Mostafavi, J. C. Palacios, S. Bourouaine, N. E. Raouafi, Rungployphan Kieokaew, Tereza Ďurovcová, Andrey Fedorov, Philippe Louarn
Figure caption: Mean alpha (orange) and proton (blue) temperature anisotropy as a function of radial distance (R). In the top panel we show the variations in the fast solar wind, and in the bottom panel we show the anisotropy variations in the slow solar wind. The error bars correspond to standard deviation.
Paper: Probing the Evolution of Solar Wind Temperature Anisotropies in the Inner Heliosphere
Authors: Vamsee Krishna Jagarlamudi, P. Mostafavi, J. C. Palacios, S. Bourouaine, N. E. Raouafi, Rungployphan Kieokaew, Tereza Ďurovcová, Andrey Fedorov, Philippe Louarn
Figure caption: 2D histogram of alpha-particle temperature anisotropy as a function of solar wind speed for different radial-distance bins. The color bar represents the normalized probability density.
Paper: Probing the Evolution of Solar Wind Temperature Anisotropies in the Inner Heliosphere
Authors: Vamsee Krishna Jagarlamudi, P. Mostafavi, J. C. Palacios, S. Bourouaine, N. E. Raouafi, Rungployphan Kieokaew, Tereza Ďurovcová, Andrey Fedorov, Philippe Louarn
Figure caption: Mean alpha (orange) and proton (blue) temperature anisotropy as a function of solar wind speed at different radial distances. The error bars correspond to standard deviation.
Paper: The Hubble Tension Resolved by the DESI Baryon Acoustic Oscillations Measurements
Authors: X. D. Jia, J. P. Hu, D. H. Gao, S. X. Yi, F. Y. Wang
Figure caption: The descending trend of the Hubble constant H0 derived from the dark energy equation of state w(z) in Figure 2. (a) The green points indicate the maximum a posteriori estimates of H0(z) with 1σ error bars from the DESI DR2 BAO measurements and Pantheon plus SNe Ia sample. The redshift of the green points corresponds to the midpoint of each redshift bin. The blue solid line and blue band show the H0 value and 1σ confidence level measured from the local distance ladder (A. G. Riess et al. 2022). The orange solid line and orange band represent the H0 value and 1σ confidence level derived from the CMB data (Planck Collaboration et al. 2020). The H0 value agrees with that measured from the local distance ladder at 1σ confidence level at low redshift, and it gradually drops to the value measured from the Planck CMB at high redshift. The Hubble tension is effectively resolved by DESI DR2 BAO measurements. (b) Same as panel (a), but for the DESI DR2 BAO measurements and DESY5 SNe Ia sample. The H0 values in panels (a) and (b) are consistent within 1σ confidence level.
Paper: The Hubble Tension Resolved by the DESI Baryon Acoustic Oscillations Measurements
Authors: X. D. Jia, J. P. Hu, D. H. Gao, S. X. Yi, F. Y. Wang
Figure caption: The descending trend of the Hubble constant H0 derived from the dark energy equation of state w(z) in Figure 2. The points and their 1σ error bars in this figure follow the same convention as in Figure 5. The yellow points indicate the value of H0 with 1σ error obtained from gravitational lensing observations (M. Millon et al. 2020; K. C. Wong et al. 2020; P. L. Kelly et al. 2023; M. Pascale et al. 2025).
Paper: Speed-dependent Threshold for Electron Injection into Diffusive Shock Acceleration
Authors: Siddhartha Gupta, Damiano Caprioli, Anatoly Spitkovsky
Figure caption: Fractional momentum change Δp/p in one upstream–downstream–upstream cycle, as a function of speed/momentum (top/bottom axis) for the ﹩{{ \mathcal M }}_{{\rm{A}}}=20﹩ shock. The cyan and white curves show the mean of the distribution obtained from our simulations and Equation (1), respectively. The error bars display the positional uncertainties in the cyan curve due to the finite bin sizes of the 2D histogram. The measured 〈Δp/p〉 matches the DSA prediction when electron speed exceeds the shock speed, shown by the arrow.
Paper: Speed-dependent Threshold for Electron Injection into Diffusive Shock Acceleration
Authors: Siddhartha Gupta, Damiano Caprioli, Anatoly Spitkovsky
Figure caption: Typical electron trajectories in a shock with ﹩{{ \mathcal M }}_{{\rm{A}}}=20﹩, ﹩{{ \mathcal M }}_{{\rm{s}}}=40﹩, and mR = 100. The background colors display the evolution of the transverse field ﹩{B}_{\perp }=\sqrt{{B}_{{\rm{y}}}^{2}+{B}_{{\rm{z}}}^{2}}﹩; the horizontal axis denotes the mean distance from the shock, with instantaneous shock locations denoted by the dashed white curves. Trajectories are color-coded with momentum p (in the upstream frame), also shown on the bottom axis of panel (b); the local pitch angle α between momentum and magnetic field is shown by magenta curves (top axis).
Paper: Speed-dependent Threshold for Electron Injection into Diffusive Shock Acceleration
Authors: Siddhartha Gupta, Damiano Caprioli, Anatoly Spitkovsky
Figure caption: The electron diffusion coefficient, De(p), normalized to the Bohm diffusion coefficient of the initial magnetic field (Equation (2)). The red and blue curves stand for ﹩{{ \mathcal M }}_{{\rm{A}}}=20﹩ and ﹩{{ \mathcal M }}_{{\rm{A}}}=5﹩ shock, respectively, where vpt/c = 0.1, ﹩{{ \mathcal M }}_{{\rm{s}}}=40﹩. Panel (a) shows the time-averaged spatial profile of De using p = mivpt, with the shaded areas indicating temporal variations over ﹩100\,\unicode{x02013}\,275\,{\omega }_{{\rm{ci}}}^{-1}﹩. Panel (b) shows the time-averaged De as a function of p, with De,1,2 corresponding to a region around ﹩x={x}_{{\rm{sh}}}\pm 2.5\,{{ \mathcal M }}_{{\rm{A}}}{d}_{{\rm{i}}}﹩, using the same color scheme as in panel (a).
Paper: Speed-dependent Threshold for Electron Injection into Diffusive Shock Acceleration
Authors: Siddhartha Gupta, Damiano Caprioli, Anatoly Spitkovsky
Figure caption: Comparison of electron spectra between PIC simulations (solid curves, measured at ﹩275\,{\omega }_{{\rm{ci}}}^{-1}﹩ in the shock downstream) and synthetic model (cyan-filled symbols).
Paper: Speed-dependent Threshold for Electron Injection into Diffusive Shock Acceleration
Authors: Siddhartha Gupta, Damiano Caprioli, Anatoly Spitkovsky
Figure caption: As in Figure 1, but for a shock with ﹩{{ \mathcal M }}_{{\rm{A}}}=5﹩.
Paper: Speed-dependent Threshold for Electron Injection into Diffusive Shock Acceleration
Authors: Siddhartha Gupta, Damiano Caprioli, Anatoly Spitkovsky
Figure caption: Schematic presentation of different stages of electron outrunning the shock observed from the upstream frame.
Paper: Beyond Hierarchical Mergers: Accretion-driven Origins of Massive, Highly Spinning Black Holes in Dense Star Clusters
Authors: Fulya Kıroğlu, Kyle Kremer, Frederic A. Rasio
Figure caption: Secondary versus primary component masses for all BBH mergers in our simulations with facc = 1. Blue circles show binaries with both components non-spinning, while black circles indicate binaries with at least one spinning BH. Filled black circles indicate BHs that have grown and spun up through accretion (χ > 0), while open black circles represent second-generation (2G) BHs with a typical spin of χ ≈ 0.7. Red points with error bars show the GWTC-4 events with at least one component within or above the pair-instability mass gap (The LIGO Scientific Collaboration et al. 2025b), with several lying in the top-right region where both BHs are in or above the gap M1,2 > 40.5 M⊙. Gray dashed lines indicate constant mass ratios q = 0.2–1. Accretion-driven growth populates the red shaded region, where both BHs lie within or above the mass gap and have nearly equal mass ratios, whereas hierarchical mergers preferentially produce systems with lower mass ratios (q ≈ 0.5).
Paper: Beyond Hierarchical Mergers: Accretion-driven Origins of Massive, Highly Spinning Black Holes in Dense Star Clusters
Authors: Fulya Kıroğlu, Kyle Kremer, Frederic A. Rasio
Figure caption: Total mass of BBH mergers as a function of merger time without accretion (facc = 0, blue) and with accretion (facc = 1, orange) in globular clusters with an escape speed of about 50 km s−1. Solid and open circles indicate in-cluster and ejected mergers, respectively. Triangles and circles denote models with initial virial radii of rv = 1.0 pc and rv = 0.5 pc, respectively. The shaded orange band marks the mass range of GW231123 (The LIGO Scientific Collaboration et al. 2025a), with the dashed line indicating its median total mass. The dotted gray lines indicate the redshift z = 1, assuming present-day cluster ages of 10 and 12 Gyr.
Paper: Beyond Hierarchical Mergers: Accretion-driven Origins of Massive, Highly Spinning Black Holes in Dense Star Clusters
Authors: Fulya Kıroğlu, Kyle Kremer, Frederic A. Rasio
Figure caption: χeff distributions for BBHs merging within a Hubble time are shown as a function of the primary BH mass for different accretion efficiencies, facc. For each binary, χeff is computed by averaging over N = 103 realizations of randomly oriented spin vectors. Shaded regions indicate the 90th and 99th percentiles within each mass bin. The top panel shows the χeff distribution when accretion is disabled, where broadening arises solely from hierarchical mergers. With accretion enabled, χeff broadens with increasing mass up to ∼100 M⊙ and then narrows at higher masses due to spin-down from multiple randomly oriented accretion episodes, with the overall trend depending on facc.
Paper: Beyond Hierarchical Mergers: Accretion-driven Origins of Massive, Highly Spinning Black Holes in Dense Star Clusters
Authors: Fulya Kıroğlu, Kyle Kremer, Frederic A. Rasio
Figure caption: Example collision histories illustrating the assembly of a massive BH through a sequence of mergers, shown for three representative cases of spin evolution. The mass of each object is labeled before and after each collision, with the collision time indicated in brackets. For BHs, spin values are given in parentheses alongside their masses.