adsabs/AstroCLIMB huggingface dataset:
Paper: Lost Sisters Found: TESS and Gaia Reveal a Dissolving Pleiades Complex
Authors: Andrew W. Boyle, Luke G. Bouma, Andrew W. Mann
Figure caption: The Greater Pleiades Complex connects multiple known associations. Left panel: an XY projection of the stars in our final membership list with a probability ﹩P\left(M| {P}_{{\rm{rot}}}\right)\gt 0.5﹩. This includes stars without radial-velocity measurements that were not present in Figure 2. Right panel: the results of cross-matching our membership list with the groups from M. Kounkel & K. Covey (2019) and E. L. Hunt & S. Reffert (2023), keeping only matches with more than 50 stars. Stars from AB Dor are taken from the Montreal Open Clusters and Associations (MOCA) database (J. Gagné et al., in preparation; J. Gagné 2024). Multiple known groups in the region of the Pleiades appear to be connected by a bridge of coeval, comoving stars.
Paper: Lost Sisters Found: TESS and Gaia Reveal a Dissolving Pleiades Complex
Authors: Andrew W. Boyle, Luke G. Bouma, Andrew W. Mann
Figure caption: TESS’s near all-sky coverage enables studies of large stellar complexes. Left panel:TESS coverage from 2018 July to 2026 August (Sectors 1–107), color coded by the number of months over which each star has been observed by TESS. Right panel: Galactocentric X- and Y-positions of Orion (t < 12 Myr), Sco-Cen (t ∼ 17 Myr), and Vela (t ∼ 19 Myr), with the Sun at the origin. Even at young ages, these hierarchically structured groups span hundreds of parsecs in X and Y. Gray points are all stars in our T < 16, d < 500 pc target list. The membership list for Orion is taken from M. Kounkel et al. (2018; excluding stars in that work marked as field stars or not assigned to an Orion subgroup), Sco-Cen is from R. Kerr et al. (2023), and Vela is from (T. Cantat-Gaudin et al. 2019; including only stars with a >99% probability from that work of being part of a Vela subgroup). Positive Y is in the direction of Galactic rotation, and positive X is in the direction of the Galactic center. This will be the orientation of our plots for the rest of this work.
Paper: Lost Sisters Found: TESS and Gaia Reveal a Dissolving Pleiades Complex
Authors: Andrew W. Boyle, Luke G. Bouma, Andrew W. Mann
Figure caption: The AB Doradus moving group compared with the Pleiades. The structure of the plots is the same as in Figure 4. Similar to other regions, kinematics, metallicity, and the CMD show evidence that AB Dor is related to the Pleiades core. AB Dor’s back integration is not as definitive as for UPK 303, HSC 1964, and UPK 545.
Paper: Lost Sisters Found: TESS and Gaia Reveal a Dissolving Pleiades Complex
Authors: Andrew W. Boyle, Luke G. Bouma, Andrew W. Mann
Figure caption: The diffuse GPC-2 region compared with the Pleiades. The structure of the plot is the same as in Figure 4. Similar to the GPC-1 region, this region displays a large population of stars coeval with the Pleiades, albeit with a large amount of scatter in the CMD and rotation diagrams. The back integration is similarly ambiguous. As with GPC-1, we suspect this region contains a combination of stars associated with the Pleiades, field stars, and other young populations.
Paper: Lost Sisters Found: TESS and Gaia Reveal a Dissolving Pleiades Complex
Authors: Andrew W. Boyle, Luke G. Bouma, Andrew W. Mann
Figure caption: The diffuse GPC-1 region compared with the Pleiades. The structure of the plot is the same as in Figure 4. GPC-1 appears to have a large population of stars that are coeval with the Pleiades, though there is more scatter than in the CMD and rotation sequences than for UPK 303, HSC 1964, and UPK 545, and the back integration suggests that this region and the Pleiades were not closer in the past. This suggests a population that could be associated with the Pleiades, but that could also be mixed with the field or other young populations.
Paper: Lost Sisters Found: TESS and Gaia Reveal a Dissolving Pleiades Complex
Authors: Andrew W. Boyle, Luke G. Bouma, Andrew W. Mann
Figure caption: UPK 545 and surrounding stars compared with the Pleiades. The structure of the plot is the same as in Figure 4. UPK 545 is farther from the Sun than the other groups, leading to a dearth of M dwarfs in the CMD and Prot–Teff diagram, as well as a larger spread in velocities (larger velocity uncertainties); see Section 5.1.3 for more details. All available information again points toward a common origin with the Pleiades.
Paper: Lost Sisters Found: TESS and Gaia Reveal a Dissolving Pleiades Complex
Authors: Andrew W. Boyle, Luke G. Bouma, Andrew W. Mann
Figure caption: HSC 1964 and surrounding stars compared with the Pleiades. The structure of the plot is the same as in Figure 4. Like UPK 303, kinematics, age diagnostics, metallicity, and back integrations all provide independent lines of evidence that HSC 1964 and the core of the Pleiades share a common origin.
Paper: UHECRs Propagation and Their Multimessengers: Upper Limits and the Impact of the Extragalactic Magnetic Field
Authors: Rodrigo Sasse, Rubens Costa, Adriel G.B. Mocellin, Carlos H. Coimbra-Araujo, R. C. Dos Anjos
Figure caption: The plots illustrate the integral gamma-ray flux ﹩\,{I}_{\gamma }^{{\rm{UHECR}}}﹩ as a function of the source distance, calculated using the UL on the flux observed by the PAO at 95% CL within the EGMF simulation framework. Panel (a) presents ﹩{I}_{\gamma }^{{\rm{UHECR}}}﹩ for fixed parameters, with Ecut and spectral index α = 2.3, and an energy threshold of Eth = 0.1 GeV. For comparative purposes, the solid blue line represents ﹩{I}_{\gamma }^{{\rm{UHECR}}}﹩ obtained using the 1D simulation framework. Panel (b) explores the dependence of ﹩{I}_{\gamma }^{{\rm{UHECR}}}(\gt {E}_{{\rm{th}}})﹩ on the energy threshold, keeping fixed parameters of Ecut = Z × 1021 eV and α = 2.3. Panels (c) and (d) analyze the effect of varying the spectral index α on ﹩{I}_{\gamma }^{{\rm{UHECR}}}(\gt {E}_{{\rm{th}}})﹩. Both subfigures use fixed parameters of Ecut = Z × 1021 eV and an energy threshold of Eth = 330 GeV. Panel (c) corresponds to the proton composition, while panel (d) represents the iron composition. The shaded regions in all plots indicate the uncertainty associated with the integral values, estimated at 95% CL using a chi-squared distribution.
Paper: UHECRs Propagation and Their Multimessengers: Upper Limits and the Impact of the Extragalactic Magnetic Field
Authors: Rodrigo Sasse, Rubens Costa, Adriel G.B. Mocellin, Carlos H. Coimbra-Araujo, R. C. Dos Anjos
Figure caption: ULs on the integral flux of gamma rays (﹩{I}_{\gamma }^{{\rm{UHECR}}}﹩) and neutrinos (﹩{I}_{\nu }^{{\rm{UHECR}}}﹩) as a function of the source distance, obtained using the UL of the flux from the PAO at 95% confidence level (CL). The calculations assume a fixed spectral index of α = 2.0, a cutoff energy of Ecut = Z × 1021 eV, a mixed composition at the source, and energy thresholds of ﹩{E}_{{\rm{th}}}^{\gamma }=1\,{\rm{TeV}}﹩ for gamma rays and ﹩{E}_{{\rm{th}}}^{\nu }=0.1\,{\rm{PeV}}﹩ for neutrinos. Different marker styles indicate the composition used in each simulation: circles represent protons, while thin diamonds correspond to an iron composition injected at the source. The blue vertical axis represents the integral of the simulated gamma-ray flux as a function of distance (horizontal axis, in megaparsecs), while the green vertical axis represents the integral of the simulated neutrino flux, also as a function of distance. The colored arrows indicate the ULs of the gamma-ray fluxes obtained by the observatories. The solid lines correspond to the simulated photon flux integrals, whereas the dashed lines depict the neutrino flux integrals.
Paper: UHECRs Propagation and Their Multimessengers: Upper Limits and the Impact of the Extragalactic Magnetic Field
Authors: Rodrigo Sasse, Rubens Costa, Adriel G.B. Mocellin, Carlos H. Coimbra-Araujo, R. C. Dos Anjos
Figure caption: Upper limits (ULs) on the neutrino flux, ﹩{I}_{\nu }^{{\rm{UHECR}}}(\gt {E}_{{\rm{th}}})﹩, as a function of the source distance, calculated using the UL on the flux observed by the Pierre Auger Observatory at the 95% confidence level (CL) for a given energy threshold Eth. (a) Dependence on the cutoff energy Ecut, with fixed parameters α = 2.3 and Eth = 0.1 PeV. (b) Dependence on the spectral index α, for fixed parameters Ecut = Z × 1021 eV and Eth = 0.1 PeV. (c) Dependence on the energy threshold Eth, for fixed parameters Ecut = Z × 1021 eV and α = 2.3.
Paper: UHECRs Propagation and Their Multimessengers: Upper Limits and the Impact of the Extragalactic Magnetic Field
Authors: Rodrigo Sasse, Rubens Costa, Adriel G.B. Mocellin, Carlos H. Coimbra-Araujo, R. C. Dos Anjos
Figure caption: Full-sky map in Hammer projection showing the average angular deflection of protons due to the regular and turbulent galactic magnetic field, modeled using the JF12 framework. The map is presented in galactic coordinates, with the Galactic center located at (ℓ, b) = (0°, 0°). Star markers indicate the positions of candidate source galaxies, each labeled with its name. The surrounding colored regions represent the 95% confidence level contours for the backtracked particle arrival directions. The percentage next to each source indicates the fraction of simulated particles that arrive within the corresponding confidence region.
Paper: UHECRs Propagation and Their Multimessengers: Upper Limits and the Impact of the Extragalactic Magnetic Field
Authors: Rodrigo Sasse, Rubens Costa, Adriel G.B. Mocellin, Carlos H. Coimbra-Araujo, R. C. Dos Anjos
Figure caption: Fraction of injected protons ξEGMF, as a function of distance D, with a cutoff energy of Ecut = Z × 1021 eV that successfully reach the observer, shown as a function of source distance for different values of the spectral index α.
Paper: UHECRs Propagation and Their Multimessengers: Upper Limits and the Impact of the Extragalactic Magnetic Field
Authors: Rodrigo Sasse, Rubens Costa, Adriel G.B. Mocellin, Carlos H. Coimbra-Araujo, R. C. Dos Anjos
Figure caption: UL on the integral neutrino flux (﹩{I}_{\nu }^{{\rm{UL}}}﹩) as a function of the spectral index at the distance of NGC 1068. The maximum energy of the injected particles is set to Ecut = Z × 1021 eV, while the energy threshold used in the integral calculation is Eth = 200 GeV, as defined by MAGIC (V. A. Acciari et al. 2019).
Paper: UHECRs Propagation and Their Multimessengers: Upper Limits and the Impact of the Extragalactic Magnetic Field
Authors: Rodrigo Sasse, Rubens Costa, Adriel G.B. Mocellin, Carlos H. Coimbra-Araujo, R. C. Dos Anjos
Figure caption: An illustration of rigidity-dependent cosmic-ray deflection in the JF12 galactic magnetic field. Trajectories are backtracked from an observer at the solar position (x = −8.5 kpc) to a spherical boundary at 20 kpc. The black dot at the sphere’s center marks the galactic center. Blue curves show the strongly deflected paths of ten 1 EeV protons (Z = 1), while red curves show the nearly rectilinear paths of ten 100 EeV protons. The figure shows how the GMF shapes charged-particle propagation within the Galaxy.
Paper: UHECRs Propagation and Their Multimessengers: Upper Limits and the Impact of the Extragalactic Magnetic Field
Authors: Rodrigo Sasse, Rubens Costa, Adriel G.B. Mocellin, Carlos H. Coimbra-Araujo, R. C. Dos Anjos
Figure caption: ULs on the cosmic-ray luminosity for mixed compositions, as inferred from gamma-ray observations, for different sources as a function of the spectral index (α). The ULs are calculated for the specific energy threshold (Eth) defined for each source and assuming a fixed cutoff energy of Ecut = Z × 1021 eV. The numbered models correspond to the mixed compositions described in Table 1.
Paper: XL-Calibur Polarimetry of Cyg X-1 Further Constrains the Origin of Its Hard-state X-Ray Emission
Authors: Hisamitsu Awaki, Matthew G. Baring, Richard Bose, Jacob Casey, Sohee Chun, Adrika Dasgupta, Pavel Galchenko, Ephraim Gau, Kazuho Goya, Tomohiro Hakamata, Takayuki Hayashi, Scott Heatwole, Kun Hu, Daiki Ishi, Manabu Ishida, Fabian Kislat, Mózsi Kiss, Kassi Klepper, Henric Krawczynski, Haruki Kuramoto, Lindsey Lisalda, Yoshitomo Maeda, Hironori Matsumoto, Shravan Vengalil Menon, Aiko Miyamoto, Asca Miyamoto, Kaito Murakami, Takashi Okajima, Mark Pearce, Brian Rauch, Nicole Rodriguez Cavero, Kentaro Shirahama, Sean Spooner, Hiromitsu Takahashi, Keisuke Tamura, Yuusuke Uchida, Kasun Wimalasena, Masato Yokota, Marina Yoshimoto
Figure caption: Ratio (blue data points) of the Cyg X-1 to the Crab background-subtracted signal count detection rates as a function of energy, with both axes in logarithmic scale. The counts are between 20 and 50 keV, as measured in only the polarimeter CZT detectors, and are binned in intervals of 5 keV. The Cyg X-1 energy spectrum is harder than the Crab spectrum by ΔΓ  ≈  0.60 ± 0.03. The red line gives the best linear fit to this ratio spectrum. The uncertainty on the ΔΓ is given by standard error propagation, taking into account the uncertainty arising both from the division of the two spectra as well as from the determination of the linear fit slope.
Paper: XL-Calibur Polarimetry of Cyg X-1 Further Constrains the Origin of Its Hard-state X-Ray Emission
Authors: Hisamitsu Awaki, Matthew G. Baring, Richard Bose, Jacob Casey, Sohee Chun, Adrika Dasgupta, Pavel Galchenko, Ephraim Gau, Kazuho Goya, Tomohiro Hakamata, Takayuki Hayashi, Scott Heatwole, Kun Hu, Daiki Ishi, Manabu Ishida, Fabian Kislat, Mózsi Kiss, Kassi Klepper, Henric Krawczynski, Haruki Kuramoto, Lindsey Lisalda, Yoshitomo Maeda, Hironori Matsumoto, Shravan Vengalil Menon, Aiko Miyamoto, Asca Miyamoto, Kaito Murakami, Takashi Okajima, Mark Pearce, Brian Rauch, Nicole Rodriguez Cavero, Kentaro Shirahama, Sean Spooner, Hiromitsu Takahashi, Keisuke Tamura, Yuusuke Uchida, Kasun Wimalasena, Masato Yokota, Marina Yoshimoto
Figure caption: On-source (red circles) and off-source/background (black squares) events, of energies between ∼19 and 64 keV and arriving in the polarimeter detectors, passing the analysis cuts described in Section 2.2. Time bins of duration no longer than 300 s are used. The daily gaps between Cyg X-1 observations were used for observing the Crab (H. Awaki et al. 2025). Smaller variations within each day (for example, the drop in the third observation) are generally correlated with changes in the elevation of the source.
Paper: XL-Calibur Polarimetry of Cyg X-1 Further Constrains the Origin of Its Hard-state X-Ray Emission
Authors: Hisamitsu Awaki, Matthew G. Baring, Richard Bose, Jacob Casey, Sohee Chun, Adrika Dasgupta, Pavel Galchenko, Ephraim Gau, Kazuho Goya, Tomohiro Hakamata, Takayuki Hayashi, Scott Heatwole, Kun Hu, Daiki Ishi, Manabu Ishida, Fabian Kislat, Mózsi Kiss, Kassi Klepper, Henric Krawczynski, Haruki Kuramoto, Lindsey Lisalda, Yoshitomo Maeda, Hironori Matsumoto, Shravan Vengalil Menon, Aiko Miyamoto, Asca Miyamoto, Kaito Murakami, Takashi Okajima, Mark Pearce, Brian Rauch, Nicole Rodriguez Cavero, Kentaro Shirahama, Sean Spooner, Hiromitsu Takahashi, Keisuke Tamura, Yuusuke Uchida, Kasun Wimalasena, Masato Yokota, Marina Yoshimoto
Figure caption: The ∼19–64 keV (red dot), ∼19–35 keV (green square), and ∼35–64 keV (blue triangle) background-subtracted, normalized Stokes results, with error bars giving the 1σ confidence level. The circles delineate the MDP99 values (also given in Table 1) of each of these energy ranges (inner circle ∼19–64 keV, middle circle ∼19–35 keV, and outer circle ∼35–64 keV; all energy ranges as recorded in the CZT detectors).
Paper: XL-Calibur Polarimetry of Cyg X-1 Further Constrains the Origin of Its Hard-state X-Ray Emission
Authors: Hisamitsu Awaki, Matthew G. Baring, Richard Bose, Jacob Casey, Sohee Chun, Adrika Dasgupta, Pavel Galchenko, Ephraim Gau, Kazuho Goya, Tomohiro Hakamata, Takayuki Hayashi, Scott Heatwole, Kun Hu, Daiki Ishi, Manabu Ishida, Fabian Kislat, Mózsi Kiss, Kassi Klepper, Henric Krawczynski, Haruki Kuramoto, Lindsey Lisalda, Yoshitomo Maeda, Hironori Matsumoto, Shravan Vengalil Menon, Aiko Miyamoto, Asca Miyamoto, Kaito Murakami, Takashi Okajima, Mark Pearce, Brian Rauch, Nicole Rodriguez Cavero, Kentaro Shirahama, Sean Spooner, Hiromitsu Takahashi, Keisuke Tamura, Yuusuke Uchida, Kasun Wimalasena, Masato Yokota, Marina Yoshimoto
Figure caption: Azimuthal scattering angle distribution (black data points) of the ∼19–64 keV background-subtracted Cyg X-1 signal arriving in the polarimeter detectors. The overall best-fit (purple solid line) is shown, as well as the 180° component (red dotted line) and 360° component (blue dashed line) contributions to the overall signal.
Paper: XL-Calibur Polarimetry of Cyg X-1 Further Constrains the Origin of Its Hard-state X-Ray Emission
Authors: Hisamitsu Awaki, Matthew G. Baring, Richard Bose, Jacob Casey, Sohee Chun, Adrika Dasgupta, Pavel Galchenko, Ephraim Gau, Kazuho Goya, Tomohiro Hakamata, Takayuki Hayashi, Scott Heatwole, Kun Hu, Daiki Ishi, Manabu Ishida, Fabian Kislat, Mózsi Kiss, Kassi Klepper, Henric Krawczynski, Haruki Kuramoto, Lindsey Lisalda, Yoshitomo Maeda, Hironori Matsumoto, Shravan Vengalil Menon, Aiko Miyamoto, Asca Miyamoto, Kaito Murakami, Takashi Okajima, Mark Pearce, Brian Rauch, Nicole Rodriguez Cavero, Kentaro Shirahama, Sean Spooner, Hiromitsu Takahashi, Keisuke Tamura, Yuusuke Uchida, Kasun Wimalasena, Masato Yokota, Marina Yoshimoto
Figure caption: Results from the Bayesian analysis of the XL-Calibur data. Contour lines denote the 1σ, 2σ, and 3σ credibility regions. The color/darkness scale denotes the lowest-percentile credibility level into which each region could fall.
Paper: XL-Calibur Polarimetry of Cyg X-1 Further Constrains the Origin of Its Hard-state X-Ray Emission
Authors: Hisamitsu Awaki, Matthew G. Baring, Richard Bose, Jacob Casey, Sohee Chun, Adrika Dasgupta, Pavel Galchenko, Ephraim Gau, Kazuho Goya, Tomohiro Hakamata, Takayuki Hayashi, Scott Heatwole, Kun Hu, Daiki Ishi, Manabu Ishida, Fabian Kislat, Mózsi Kiss, Kassi Klepper, Henric Krawczynski, Haruki Kuramoto, Lindsey Lisalda, Yoshitomo Maeda, Hironori Matsumoto, Shravan Vengalil Menon, Aiko Miyamoto, Asca Miyamoto, Kaito Murakami, Takashi Okajima, Mark Pearce, Brian Rauch, Nicole Rodriguez Cavero, Kentaro Shirahama, Sean Spooner, Hiromitsu Takahashi, Keisuke Tamura, Yuusuke Uchida, Kasun Wimalasena, Masato Yokota, Marina Yoshimoto
Figure caption: Compilation of Cyg X-1 polarization results from the X-ray band to the γ-ray band. The shaded regions show the 2–8 keV energy range of IXPE (left), the ∼19–64 keV energy range of XL-Calibur (middle), and the 200 keV–5 MeV energy range of the upcoming Compton Spectrometer and Imager (COSI; right; J. Tomsick et al. 2024). The multiwavelength data are taken from K. S. Long et al. (1980), H. Krawczynski et al. (2022), M. Chauvin et al. (2018), T. Chattopadhyay et al. (2024), P. Laurent et al. (2011), E. Jourdain et al. (2012), and J. Rodriguez et al. (2015). The upper limits for XL-Calibur (at the 99% level) and PoGO+ (at the 90% level) are also given. All of these measurements observe Cyg X-1 in some hard (or intermediate-hard) state (T. Chattopadhyay et al. 2024), except for OSO-8. The solid blue line delineates the PD prediction of the 55° inclination kerrC-light model (see the main text; see also H. Krawczynski & B. Beheshtipour 2022). The dotted orange line delineates the PD prediction of the 90° model from M. Moscibrodzka (2024). Both of these models predict a slight increase of the PD and a roughly constant PA, parallel to the jet, across the IXPE and XL-Calibur energy ranges.
Paper: XL-Calibur Polarimetry of Cyg X-1 Further Constrains the Origin of Its Hard-state X-Ray Emission
Authors: Hisamitsu Awaki, Matthew G. Baring, Richard Bose, Jacob Casey, Sohee Chun, Adrika Dasgupta, Pavel Galchenko, Ephraim Gau, Kazuho Goya, Tomohiro Hakamata, Takayuki Hayashi, Scott Heatwole, Kun Hu, Daiki Ishi, Manabu Ishida, Fabian Kislat, Mózsi Kiss, Kassi Klepper, Henric Krawczynski, Haruki Kuramoto, Lindsey Lisalda, Yoshitomo Maeda, Hironori Matsumoto, Shravan Vengalil Menon, Aiko Miyamoto, Asca Miyamoto, Kaito Murakami, Takashi Okajima, Mark Pearce, Brian Rauch, Nicole Rodriguez Cavero, Kentaro Shirahama, Sean Spooner, Hiromitsu Takahashi, Keisuke Tamura, Yuusuke Uchida, Kasun Wimalasena, Masato Yokota, Marina Yoshimoto
Figure caption: Top: simulated Cyg X-1 energy spectrum from the kerrC-light code, assuming a geometrically thin, optically thick accretion disk with a sandwich corona of opening angle 10°, of optical depth τ  =  0.41, and of inclination angle 55°. While the dashed orange line shows the flux of the photons that reach the observer without any scattering off the disk, the dotted green line shows the flux of the photons scattering off the disk one or several times. A dotted–dashed red line is also presented to indicate the power-law index calculated in Figure 2. Bottom: polarization degree spectra of the kerrC-light model from the above panel, varying only the inclination in each instance (with the model from the highest inclination having the highest PDs). The IXPE (from 2022) and XL-Calibur data are overlaid, as in Figures 7 and 8. PD as a function of energy, for the direct and reflected components, is also plotted for the 55° case as dashed and dotted gray lines. The abrupt changes in the flux of the direct component at higher energies reflect the low statistics due to the low proportion of flux it comprises at those energies.
Paper: XL-Calibur Polarimetry of Cyg X-1 Further Constrains the Origin of Its Hard-state X-Ray Emission
Authors: Hisamitsu Awaki, Matthew G. Baring, Richard Bose, Jacob Casey, Sohee Chun, Adrika Dasgupta, Pavel Galchenko, Ephraim Gau, Kazuho Goya, Tomohiro Hakamata, Takayuki Hayashi, Scott Heatwole, Kun Hu, Daiki Ishi, Manabu Ishida, Fabian Kislat, Mózsi Kiss, Kassi Klepper, Henric Krawczynski, Haruki Kuramoto, Lindsey Lisalda, Yoshitomo Maeda, Hironori Matsumoto, Shravan Vengalil Menon, Aiko Miyamoto, Asca Miyamoto, Kaito Murakami, Takashi Okajima, Mark Pearce, Brian Rauch, Nicole Rodriguez Cavero, Kentaro Shirahama, Sean Spooner, Hiromitsu Takahashi, Keisuke Tamura, Yuusuke Uchida, Kasun Wimalasena, Masato Yokota, Marina Yoshimoto
Figure caption: A zoom-in on the models and data in the X-ray band. The kerrC model is a Monte Carlo-based model: 68,040 combinations of system parameters were simulated, with 20,000,000 photons used for each configuration. The IXPE 2024 data come from IXPE observations 03010001, 03010101, and 03003101 of Cyg X-1, which were taken within a couple of months before the XL-Calibur observation, and are analyzed jointly with ixpeobssim (L. Baldini et al. 2022).
Paper: XL-Calibur Polarimetry of Cyg X-1 Further Constrains the Origin of Its Hard-state X-Ray Emission
Authors: Hisamitsu Awaki, Matthew G. Baring, Richard Bose, Jacob Casey, Sohee Chun, Adrika Dasgupta, Pavel Galchenko, Ephraim Gau, Kazuho Goya, Tomohiro Hakamata, Takayuki Hayashi, Scott Heatwole, Kun Hu, Daiki Ishi, Manabu Ishida, Fabian Kislat, Mózsi Kiss, Kassi Klepper, Henric Krawczynski, Haruki Kuramoto, Lindsey Lisalda, Yoshitomo Maeda, Hironori Matsumoto, Shravan Vengalil Menon, Aiko Miyamoto, Asca Miyamoto, Kaito Murakami, Takashi Okajima, Mark Pearce, Brian Rauch, Nicole Rodriguez Cavero, Kentaro Shirahama, Sean Spooner, Hiromitsu Takahashi, Keisuke Tamura, Yuusuke Uchida, Kasun Wimalasena, Masato Yokota, Marina Yoshimoto
Figure caption: The polar diagram of measured PD and PA values in the X-ray band overlaid atop the radio jet image from VLBA astrometry data (J. C. A. Miller-Jones et al. 2021); PD values are in percent in the radial direction. Results are given for the XL-Calibur (green) observation across the entire ∼19–64 keV energy range, as well as for the IXPE (magenta) results across its 2–8 keV band. The error bars of the polarization results are given at the 1σ level, as derived from the marginalized Bayesian analysis (for XL-Calibur) and as listed in Table S2 of H. Krawczynski et al. (2022) (for IXPE). The larger error bars of the XL-Calibur result indicate, as mentioned before, a measurement below the MDP99.