adsabs/AstroCLIMB huggingface dataset:
Paper: The Unanticipated Phenomenology of the Blazar PKS 2131–021: A Unique Supermassive Black Hole Binary Candidate
Authors: S. O'Neill, S. Kiehlmann, A. C. S. Readhead, M. F. Aller, R. D. Blandford, I. Liodakis, M. L. Lister, P. Mróz, C. P. O'Dea, T. J. Pearson, V. Ravi, M. Vallisneri, K. A. Cleary, M. J. Graham, K. J. B. Grainge, M. W. Hodges, T. Hovatta, A. Lähteenmäki, J. W. Lamb, T. J. W. Lazio, W. Max-Moerbeck, V. Pavlidou, T. A. Prince, R. A. Reeves, M. Tornikoski, P. Vergara de la Parra, and J. A. Zensus
Figure caption: PKS 2131−021 multifrequency light curves and cross-correlations. (a) Light curves at 22 GHz (purple crosses) and 37 GHz (purple circles) from MRO. (b) Cross-correlation of the MRO 37 GHz and OVRO 15 GHz light curves. (c) WISE infrared light curve in the W1 (2.8–3.8 μm) band. (d) Cross-correlation of the WISE W1 (using flux density) and OVRO 15 GHz light curves. (e) WISE infrared light curve in the W2 (4.1–5.2 μm band). (f) Cross-correlation of the WISE W2 (using flux density) and OVRO 15 GHz light curves. In both panels (c) and (e) the error bars are smaller than the symbols. The pink, orange, and green dashed curves indicate the 1σ, 2σ, and 3σ significance levels of the cross-correlation, respectively, using our simulated light curves, which assume a simple power-law form with a slope of 2, typical for blazars in these bands.
Paper: The Unanticipated Phenomenology of the Blazar PKS 2131–021: A Unique Supermassive Black Hole Binary Candidate
Authors: S. O'Neill, S. Kiehlmann, A. C. S. Readhead, M. F. Aller, R. D. Blandford, I. Liodakis, M. L. Lister, P. Mróz, C. P. O'Dea, T. J. Pearson, V. Ravi, M. Vallisneri, K. A. Cleary, M. J. Graham, K. J. B. Grainge, M. W. Hodges, T. Hovatta, A. Lähteenmäki, J. W. Lamb, T. J. W. Lazio, W. Max-Moerbeck, V. Pavlidou, T. A. Prince, R. A. Reeves, M. Tornikoski, P. Vergara de la Parra, and J. A. Zensus
Figure caption: Archival optical light curve of PKS 2131−021.
Paper: The Unanticipated Phenomenology of the Blazar PKS 2131–021: A Unique Supermassive Black Hole Binary Candidate
Authors: S. O'Neill, S. Kiehlmann, A. C. S. Readhead, M. F. Aller, R. D. Blandford, I. Liodakis, M. L. Lister, P. Mróz, C. P. O'Dea, T. J. Pearson, V. Ravi, M. Vallisneri, K. A. Cleary, M. J. Graham, K. J. B. Grainge, M. W. Hodges, T. Hovatta, A. Lähteenmäki, J. W. Lamb, T. J. W. Lazio, W. Max-Moerbeck, V. Pavlidou, T. A. Prince, R. A. Reeves, M. Tornikoski, P. Vergara de la Parra, and J. A. Zensus
Figure caption: Plots of the WWZ statistic computed from the PKS 2131−021 45.1 yr light curve. Top panel: WWZ statistic plot, in which the color scale at the right and the contour levels on the plot represent the value of the WWZ statistic (see Appendix B). In this panel all the features apart from the feature in epoch 3 are almost invisible because they are more than an order of magnitude weaker than the epoch 3 feature. Bottom panel: time-normalized WWZ plot of the 45.1 yr light curve of PKS 2131−021. Here we normalized each of the 164 100-day time bins by dividing the power across all the periods in each 100-day time bin by the maximum power in the bin. Thus, every time bin has a maximum power of unity. This enables us to see clearly how the periods change over the whole 45.1 yr span of the observations.
Paper: The Unanticipated Phenomenology of the Blazar PKS 2131–021: A Unique Supermassive Black Hole Binary Candidate
Authors: S. O'Neill, S. Kiehlmann, A. C. S. Readhead, M. F. Aller, R. D. Blandford, I. Liodakis, M. L. Lister, P. Mróz, C. P. O'Dea, T. J. Pearson, V. Ravi, M. Vallisneri, K. A. Cleary, M. J. Graham, K. J. B. Grainge, M. W. Hodges, T. Hovatta, A. Lähteenmäki, J. W. Lamb, T. J. W. Lazio, W. Max-Moerbeck, V. Pavlidou, T. A. Prince, R. A. Reeves, M. Tornikoski, P. Vergara de la Parra, and J. A. Zensus
Figure caption: GLS analyses of the light curve of PKS 2131−021. In the upper three panels we show the GLS analyses for the three distinct epochs of activity. As is common practice, in the top panel the contours purport to show the significance levels of the features. The apparent significance of the peak in epoch 1 (top panel) is 2.3σ, whereas the true significance is 1.06σ (see Table 3). We do not plot contours in the middle and bottom panels because such contours are misleading and further exacerbate the problem of the misidentification of random features as significant peaks (see Section 3.4.1). The bottom panel shows the GLS power plot for the full 45.1 yr duration of the observations, i.e., for epochs 1, 2, and 3 combined. (see text).
Paper: The Unanticipated Phenomenology of the Blazar PKS 2131–021: A Unique Supermassive Black Hole Binary Candidate
Authors: S. O'Neill, S. Kiehlmann, A. C. S. Readhead, M. F. Aller, R. D. Blandford, I. Liodakis, M. L. Lister, P. Mróz, C. P. O'Dea, T. J. Pearson, V. Ravi, M. Vallisneri, K. A. Cleary, M. J. Graham, K. J. B. Grainge, M. W. Hodges, T. Hovatta, A. Lähteenmäki, J. W. Lamb, T. J. W. Lazio, W. Max-Moerbeck, V. Pavlidou, T. A. Prince, R. A. Reeves, M. Tornikoski, P. Vergara de la Parra, and J. A. Zensus
Figure caption: Period variations in the 14.5–15.5 GHz light curve of PKS 2131−021. (a) The Haystack data are shown by the green squares, the UMRAO data by the brown triangles, and the OVRO data by the blue circles. The solid green line shows the least-squares sine-wave fit to the Haystack data, and the dotted blue line shows the least-squares sine-wave fit to the OVRO data extrapolated backward to provide a phase comparison with the Haystack data. In epoch 2 we show a 6th-degree polynomial fit to the light curve, and it is seen to be sinusoidal in character. This oscillation has about twice the period of that in epoch 1, but it bears no obvious phase relationship with the oscillation of epoch 1, and it also bears no obvious phase relation with the epoch 3 periodicity. In epoch 3 we have fitted the combined Haystack and OVRO data (black sine wave). This fit, adjusted for the different amplitudes of the Haystack and OVRO periodic signals, has been subtracted from the OVRO data to provide the residual light curve in absence of the periodic signal (black data points). The black curve in panels (b) and (c) shows a 6° polynomial fit to the residual OVRO data. The gray curve is the sine-wave fit to the OVRO data after correcting for the slowly varying component in the residual signal of epoch 3 (black point), which brings the phase into alignment with that of epoch 1, as expected. (b) The blue points and blue curve show the raw OVRO data and sine-wave fit, and the gray points show the corrected OVRO light curve after applying the slowly varying component given by the black 6° polynomial fit to the residuals. The gray sine wave is the least-squares fit to the adjusted (gray) OVRO data. (c) Fractional flux density deviation from the mean value with the OVRO sine wave subtracted. This shows the fractional flux density variations that would be required to bring the Haystack and OVRO data into phase coherence.
Paper: The Unanticipated Phenomenology of the Blazar PKS 2131–021: A Unique Supermassive Black Hole Binary Candidate
Authors: S. O'Neill, S. Kiehlmann, A. C. S. Readhead, M. F. Aller, R. D. Blandford, I. Liodakis, M. L. Lister, P. Mróz, C. P. O'Dea, T. J. Pearson, V. Ravi, M. Vallisneri, K. A. Cleary, M. J. Graham, K. J. B. Grainge, M. W. Hodges, T. Hovatta, A. Lähteenmäki, J. W. Lamb, T. J. W. Lazio, W. Max-Moerbeck, V. Pavlidou, T. A. Prince, R. A. Reeves, M. Tornikoski, P. Vergara de la Parra, and J. A. Zensus
Figure caption: Simple model that produces sinusoidal flux density variations in an SMBHB blazar. In the proposed SMBHB, the larger mass, M1, and smaller mass, M2, orbit the center of mass with period in the rest frame of the binary, P. We assume that the jet originates in M1, although this is not necessary for the model. The angle between the jet axis and the line of sight is θ. We suppose that the relativistic jet is launched along the black hole spin axis with constant velocity cβ relative to the black hole. The orbital velocity can significantly change the relativistic jet Doppler factor if γ ≫ 1 in the jet, as is the case in PKS 2131−021.
Paper: The Unanticipated Phenomenology of the Blazar PKS 2131–021: A Unique Supermassive Black Hole Binary Candidate
Authors: S. O'Neill, S. Kiehlmann, A. C. S. Readhead, M. F. Aller, R. D. Blandford, I. Liodakis, M. L. Lister, P. Mróz, C. P. O'Dea, T. J. Pearson, V. Ravi, M. Vallisneri, K. A. Cleary, M. J. Graham, K. J. B. Grainge, M. W. Hodges, T. Hovatta, A. Lähteenmäki, J. W. Lamb, T. J. W. Lazio, W. Max-Moerbeck, V. Pavlidou, T. A. Prince, R. A. Reeves, M. Tornikoski, P. Vergara de la Parra, and J. A. Zensus
Figure caption: Mass limits from GW observations. Both the period and the location of PKS 2131−021 are in the windows of maximum sensitivity for the NANOGrav pulsar timing array (Aggarwal et al. 2019). Here we show the observed GW strain and time to coalescence for primary−SMBH rest masses ranging from 107 to 1010 M⊙ and for binary mass ratios of q = 1.0 and q = 0.1.
Paper: The Unanticipated Phenomenology of the Blazar PKS 2131–021: A Unique Supermassive Black Hole Binary Candidate
Authors: S. O'Neill, S. Kiehlmann, A. C. S. Readhead, M. F. Aller, R. D. Blandford, I. Liodakis, M. L. Lister, P. Mróz, C. P. O'Dea, T. J. Pearson, V. Ravi, M. Vallisneri, K. A. Cleary, M. J. Graham, K. J. B. Grainge, M. W. Hodges, T. Hovatta, A. Lähteenmäki, J. W. Lamb, T. J. W. Lazio, W. Max-Moerbeck, V. Pavlidou, T. A. Prince, R. A. Reeves, M. Tornikoski, P. Vergara de la Parra, and J. A. Zensus
Figure caption: Calculation of the global p-value using epoch 1 as an example. The quantization of the periods is due to the quantization in frequency, Δf = 1/(ζT), with ζ = 10, which we impose in running the GLS. So the sampled periods are separated by 1/(10Δf). Step 1: Orange vertical and horizontal lines mark the period and power, respectively, of the strongest peak identified in the GLS of the epoch 1 data. The curves plotted here are merely a visualization tool; they do not represent levels of significance unless there are a priori reasons for selecting particular periods. Hence, in the next step (Step 2), the detection of the strongest peak in the GLS of the data at the period Ppeak is a 2.3σ event only in the case that there is an a priori reason for selecting this particular period. The significance is obtained by summing the simulations with p-values less than that observed at this particular period. The red line connects the 2.3σ significance level at each period. The purple curves indicate the 1σ, 2σ, and 3σ significance levels at each specific period, as also shown in the top panel of Figure 9, which are misleading unless there is an a priori reason for selecting a specific period. Step 3: For each simulation the strongest peak is identified in the GLS. The peak periods and powers are shown as gray circles. Step 4: To estimate the global p-value, simulations at all periods are counted in which the power of the strongest peak lies above the 2.3σ significance level (red line).
Paper: Magnetic Flux Transport Identification of Active Reconnection: MMS Observations in Earth’s Magnetosphere
Authors: Yi Qi, Tak Chu Li, Christopher T. Russell, Robert E. Ergun, Ying-Dong Jia, and Mark Hubbert
Figure caption: MMS observations of an example event on 2015 October 25. Vectors are transformed in LMN coordinates (L = [0.31, −0.91, 0.28], M = [0.31, 0.37, 0.87], N = [−0.90, −0.19, 0.40] in GSE). Four-spacecraft-averaged (a) magnetic field and (b) electric field. (c) Radius of curvature Rc normalized to the electron (red) and ion (blue) gyroradius. (d), (e) Electron bulk flow velocity (with ion velocity subtracted) and ion bulk flow velocity. (f) MFT velocity Uψ. (with ion velocity subtracted). (g) ∇ · Uψ normalized to the local electron cyclotron frequency fce (h) Sketch of the MMS trajectory and expected MFT flows, adapted from Eriksson et al. (2018).
Paper: Magnetic Flux Transport Identification of Active Reconnection: MMS Observations in Earth’s Magnetosphere
Authors: Yi Qi, Tak Chu Li, Christopher T. Russell, Robert E. Ergun, Ying-Dong Jia, and Mark Hubbert
Figure caption: MFT velocity on each spacecraft. (a) The L and (b) N components of Uψ measured by the four spacecraft.
Paper: Magnetic Flux Transport Identification of Active Reconnection: MMS Observations in Earth’s Magnetosphere
Authors: Yi Qi, Tak Chu Li, Christopher T. Russell, Robert E. Ergun, Ying-Dong Jia, and Mark Hubbert
Figure caption: MFT signatures in 37 events. The peak values of (a) Uψ in the L and N directions normalized to VA and (b) ∇ · Uψ normalized to fce. The red arrows indicate L/N jets and ∇ · Uψ out of the plotted range. The dashed lines represent (a) ±0.5 VA and (b) ±0.05 fce.
Paper: Biases in Estimates of Black Hole Kicks from the Spin Distribution of Binary Black Holes
Authors: Simon Stevenson
Figure caption: Normalized probability distributions for the secondary spin magnitude χ2. The blue area shows a typical result from the analysis of Callister et al. (2021) when assuming large black hole natal kicks (μχ = 0.2, σχ = 0.4), while in orange we show our model accounting for inefficient tidal synchronization in wide binaries using the fits from Bavera et al. (2021). Binary evolution naturally predicts a bimodal secondary spin magnitude distribution, which is not well captured by a Gaussian.
Paper: Biases in Estimates of Black Hole Kicks from the Spin Distribution of Binary Black Holes
Authors: Simon Stevenson
Figure caption: Normalized probability distributions for the effective spin parameter χeff. In the top panel, the blue distribution shows the result from our modified version of the Callister et al. (2021) model described in Section 2 when assuming no black hole kicks (σ = 0 km s−1). Wide binaries result in a peak at χeff = 0, while in tighter binaries the secondary can be tidally spun up, resulting in χeff > 0. The dotted black line shows the result when assuming large black hole kicks (σ = 1000 km s−1) and that the spin magnitude of the second-born black hole (χ2) is given by the Gaussian distribution assumed by Callister et al. (2021) and shown in Figure 1. This symmetric distribution of χeff is a typical result found by Callister et al. (2021); see their Figure 3. The bottom panel shows two example distributions from the population synthesis models from Bavera et al. (2021), the stable mass-transfer channel (SMT; yellow) and the common-envelope channel (CE; red), demonstrating how the results of this model may change with different assumptions about the masses and orbital periods of BH + He star binaries. We also show the fit to the gravitational-wave observations from Galaudage et al. (2021) in dark blue. The y-axis is arbitrarily cut off in both plots for clarity.
Paper: Biases in Estimates of Black Hole Kicks from the Spin Distribution of Binary Black Holes
Authors: Simon Stevenson
Figure caption: Normalized probability distribution for ﹩\cos {\theta }_{2}﹩, the cosine of the angle between the spin of the secondary black hole and the binary orbital angular momentum, for several choices of σ. Also shown in the solid black curve is the fit to the gravitational-wave observations from Galaudage et al. (2021).
Paper: Universality of the Turbulent Magnetic Field in Hypermassive Neutron Stars Produced by Binary Mergers
Authors: Ricard Aguilera-Miret, Daniele Viganò, and Carlos Palenzuela
Figure caption: Magnetic field evolution. Values of the magnetic intensity ﹩| \vec{B}| ﹩ in the orbital plane for (from top to bottom) Dip, BHigh, Misal, and Mult simulations at (from left to right) t = {2, 5, 10, 20} ms after the merger. Outer and inner black lines mark the contours ρ = 1013 and 1014 g cm−3, respectively. The lengths are given in geometrical units (corresponding to 1.47 km).
Paper: Universality of the Turbulent Magnetic Field in Hypermassive Neutron Stars Produced by Binary Mergers
Authors: Ricard Aguilera-Miret, Daniele Viganò, and Carlos Palenzuela
Figure caption: Energy evolution. Top: rotational (dashed lines) and thermal (solid lines) energies, integrated over the whole dominion, for different simulations as a function of time. Bottom: magnetic energy for the same simulations.
Paper: Universality of the Turbulent Magnetic Field in Hypermassive Neutron Stars Produced by Binary Mergers
Authors: Ricard Aguilera-Miret, Daniele Viganò, and Carlos Palenzuela
Figure caption: Average intensity of the magnetic field components. Average intensity evolution of the poloidal (solid lines) and toroidal (dashed lines) components of the magnetic field for all cases in the bulk of the remnant where ρ ≥ 1013 g cm−3.
Paper: Universality of the Turbulent Magnetic Field in Hypermassive Neutron Stars Produced by Binary Mergers
Authors: Ricard Aguilera-Miret, Daniele Viganò, and Carlos Palenzuela
Figure caption: Energy spectra. Top: kinetic (solid) and magnetic (dotted) energy spectra for different configurations as a function of the wavenumber at (from left to right) t = {5, 10, 20, 30} ms after the merger. The solid thin black line corresponds to the Kolmogorov slope, while the dotted one belongs to the Kazantsev slope. The dots are the wavenumbers which contain, in average, most the energy of each spectra.
Paper: Universality of the Turbulent Magnetic Field in Hypermassive Neutron Stars Produced by Binary Mergers
Authors: Ricard Aguilera-Miret, Daniele Viganò, and Carlos Palenzuela
Figure caption: Magnetic energy spectra. Poloidal (solid) and toroidal (dotted) components of the magnetic spectra for different configurations as a function of the wavenumber at (from left to right) t = {5, 10, 20, 30} ms after the merger.
Paper: Peculiar Radio–X-Ray Relationship in Active Stars
Authors: H. K. Vedantham, J. R. Callingham, T. W. Shimwell, A. O. Benz, M. Hajduk, T. P. Ray, C. Tasse, and A. Drabent
Figure caption: Top panel: The peculiar adherence of our highly polarized sample at 144 MHz (total flux), shown in black triangles, to the Güdel–Benz relationship shown by the solid red line, ﹩{L}_{{\rm{X}}}=9.48\times {10}^{18}{L}_{\nu ,\mathrm{rad}}^{0.73}﹩ (Williams et al. 2014). The other points are literature values at 5 GHz that were initially used to establish the Güdel–Benz relationship (Benz & Güdel 1994). The X-ray flux is in the 0.1–2.4 keV band. Bottom panel: Dispersion of the data from the Güdel–Benz relationship showing that our sample has the same level of scatter as the 5 GHz data from the literature.
Paper: Peculiar Radio–X-Ray Relationship in Active Stars
Authors: H. K. Vedantham, J. R. Callingham, T. W. Shimwell, A. O. Benz, M. Hajduk, T. P. Ray, C. Tasse, and A. Drabent
Figure caption: Results of the Monte Carlo simulation of radio and X-ray detections under the null hypothesis (i.e., radio and X-ray luminosities are uncorrelated). The top panel shows the sample (black crosses) and the subset that will cross the radio-detection threshold of our survey (red circles), in one realization. The bottom panel shows the distribution of the Kendall tau correlation coefficient between the radio and X-ray luminosity of the radio-detected population from 105 realizations (blue step curve) in comparison to the measured coefficient from our sample (magenta line).
Paper: Thermal Instability–Induced Fundamental Magnetic Field Strands in the Solar Corona
Authors: Patrick Antolin, Juan Martínez-Sykora, and Seray Şahin
Figure caption: Density map (left) in the numerical domain, Joule heating per unit volume (middle), and footpoint heating asymmetry (right) along a thermally unstable loop. The red lines indicate selected magnetic field lines intersecting the region where coronal rain forms. The middle panel shows the Joule heating per unit volume profiles along the red field lines for all the time steps (in gray) and the average (in black). The TR location at each footpoint is indicated by dashed vertical lines. The right panel shows the ratio of the Joule heating per unit volume between the right and left footpoints (as seen in the left panel), averaged over 10% of the loop length from the TR upward.
Paper: Constraints on Compact Dark Matter from Gravitational Wave Microlensing
Authors: S. Basak, A. Ganguly, K. Haris, S. Kapadia, A. K. Mehta, and P. Ajith
Figure caption: Cumulative distribution of ﹩\mathrm{ln}{{ \mathcal B }}_{{\rm\small{U}}}^{{\ell }}﹩ from LIGO–Virgo events from O1, O2, and O3a (number of events with ﹩{{ \mathcal B }}_{{\rm\small{U}}}^{{\ell }}﹩ less than the value shown in the horizontal axis). The largest value is ﹩\mathrm{ln}{{ \mathcal B }}_{{\rm\small{U}}}^{{\ell }}=1.15﹩, which is not large enough to provide strong evidence for lensing.
Paper: Constraints on Compact Dark Matter from Gravitational Wave Microlensing
Authors: S. Basak, A. Ganguly, K. Haris, S. Kapadia, A. K. Mehta, and P. Ajith
Figure caption: Posterior distributions of the Poisson mean of the total number of detections (Λ), that of the number of lensed events (Λℓ) and that of the fraction of lensed events (u) obtained from the O1, O2, and O3a observation runs of LIGO and Virgo. Here the observed number of events N = 54 and the observed number of lensed events is Nℓ = 0.
Paper: Constraints on Compact Dark Matter from Gravitational Wave Microlensing
Authors: S. Basak, A. Ganguly, K. Haris, S. Kapadia, A. K. Mehta, and P. Ajith
Figure caption: The fraction of simulated events with ﹩\mathrm{ln}{{ \mathcal B }}_{{\rm\small{U}}}^{{\ell }}﹩ greater than the threshold value 1.15 shown as a function of the fDM. The left, middle, and right plots correspond to different assumed redshift distribution of mergers. In each plot, different colors correspond to different lens masses (shown in legend). The solid, dashed, and dotted lines correspond to the lensing fraction estimated using the noise power spectral densities of LIGO–Virgo detectors from O3a, O3, and O1 observing runs, respectively. The error bars indicate the counting errors due to the finite number of samples of simulated binaries and the curves show quadratic polynomial fits.
Paper: Constraints on Compact Dark Matter from Gravitational Wave Microlensing
Authors: S. Basak, A. Ganguly, K. Haris, S. Kapadia, A. K. Mehta, and P. Ajith
Figure caption: Posteriors on fDM obtained by the nonobservation of microlensing signatures in the 54 BBH events detected in O1, O2, and O3a. Posteriors shown by solid (dotted) lines are obtained by assuming flat (Jeffreys) prior in Λ and Λℓ. The left, middle, and right plots correspond to different assumed redshift distribution models of binary black holes. In each subplot, different curves correspond to different assumed lens masses (shown in legends). The 90% credible upper limits are shown by dots.
Paper: Constraints on Compact Dark Matter from Gravitational Wave Microlensing
Authors: S. Basak, A. Ganguly, K. Haris, S. Kapadia, A. K. Mehta, and P. Ajith
Figure caption: 90% upper limits on fDM obtained from the O1, O2, and O3a events, assuming a monochromatic mass spectrum for MACHOs (lens mass shown in the horizontal axis). The left (right) panel corresponds to bounds computed assuming a flat (Jeffreys) prior on Λ and Λℓ. In each panel, three different exclusion regions correspond to three assumed models of the redshift distribution of BBHs. The dashed lines show some of the the existing constraints from the microlensing of supernovae (SN) and from the stability of wide binaries (WBs) and a star cluster in the galaxy Eridanus II (E) (Carr & Kuhnel 2020; Carr et al. 2021).
Paper: Constraints on Compact Dark Matter from Gravitational Wave Microlensing
Authors: S. Basak, A. Ganguly, K. Haris, S. Kapadia, A. K. Mehta, and P. Ajith
Figure caption: Upper bounds on fDM expected from future observing runs, shown as a function of the cumulative number of detected BBH events (for lens mass 103M⊙). The black (gray) curves show the bounds computed assuming flat (Jeffreys) prior on Λ and Λℓ. The number of detected events in O2 and O3a are shown as vertical lines. We also show the approximate number of detectable events in the second half of the third observing run (O3b) and the fourth observing run (O4). The expected bounds fall faster with increased sensitivity anticipated in upcoming observing runs. We have used the redshift distribution of binary mergers given by Belczynski et al. (2016a) to compute these expected bounds.