Pith. sign in

REVIEW 3 major objections 4 minor 86 references

Exploring the Mass Segregation Effect of X-ray Sources in Globular Clusters. II. The Case of Terzan 5

T0 review · 3 major / 4 minor · reviewed 2026-08-14 · deepseek-v4-flash

Challenge this review Re-run · record.json Download PDF Read on arXiv ↗ Review JSON

Pith's one-line read The radial distribution of X-ray sources in the globular cluster Terzan 5 shows mass segregation, with bright sources heavier and more centrally concentrated than faint ones.

desk verdict Solid catalog and a likely real mass-segregation signal, but the model-dependent masses and an error-bar-free dynamical-age comparison keep this short of a clean accept. read the letter →

arxiv 1908.06392 v1 pith:WVL6MIHQ submitted 2019-08-18 astro-ph.HE astro-ph.GA

Zhongqun Cheng , Zhiyuan Li , Taotao Fang , Xiangdong Li , Xiaojie Xu This is my paper · ORCID
classification astro-ph.HEastro-ph.GA
keywords globularclustersX-raybinariesmasssegregationTerzan5dynamicalevolutionChandraobservationsgeneralizedKingmodelmillisecondpulsars
verification ladder T0 review T1 audit T2 compute T3 formal

The pith

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The reading

This paper claims that the X-ray source population of the globular cluster Terzan 5 is mass segregated: bright sources, presumably heavier binaries, are concentrated toward the cluster core while fainter sources trail farther out. Using 734 ks of archival X-ray observations, the authors detect 489 point sources and find dips in the surface-density profiles, with the bright sample's dip centered at a larger radius and wider than the faint sample's dip. Fitting the radial distributions with a generalized King model yields average masses of 1.48 ± 0.11 solar masses for bright sources and 1.27 ± 0.13 solar masses for faint ones. If correct, this makes Terzan 5 the second globular cluster, after 47 Tuc, to show such an effect and suggests that mass segregation of X-ray binaries is a general feature of dense star clusters.

What carries the argument

The load-bearing tool is the generalized King model, a projected surface-density profile $S(R)=S_0\left[1+(R/R_c)^2\right]^{(1-3q)/2}$, where $q$ is the ratio of the mean mass of the X-ray sources to that of reference main-sequence turnoff stars. Fitting cumulative radial distributions within $R<31$ arcsec, where the sources are assumed dynamically relaxed and in thermal equilibrium with normal stars, yields $q$ for the bright and faint groups. The companion diagnostic is the distribution dip: the radius and width where the observed X-ray surface density falls below the King-model stellar profile, which traces how far the heavy population has segregated. The $A^+$ parameter, the area between the cumulative distributions of X-ray sources and reference stars, is then used to compare dynamical ages between clusters.

What would settle it

One concrete check is to measure radial velocities or proper motions of the X-ray sources: if the bright sources' velocity dispersion is lower than that of faint sources, the thermal-equilibrium assumption is supported, whereas equality or an inverted trend would break it. Alternatively, a deeper, higher-resolution observation that resolves the apparent deficit of sources near 40 arcsec into faint undetected sources would remove the dip and with it the mass-segregation signal.

Watch

Extended reading notes

Core claim

Using 18 merged archival X-ray observations with a total effective exposure of 734 ks, the authors build a catalog of 489 point sources within 4.3 arcmin of Terzan 5. They report a bimodal radial distribution: the surface density peaks in the core, dips near R ∼ 40 arcsec (with the bright sample dipping near 70 arcsec over a width of about 130 arcsec and the faint sample near 35 arcsec over about 30 arcsec), and recovers outward. They interpret this as delayed sedimentation: heavier X-ray binaries sink toward the center faster than lighter ones. Fitting with the generalized King model gives mass ratios q = 1.61 ± 0.12 for bright and q = 1.38 ± 0.14 for faint sources relative to turnoff stars, corresponding to 1.48 ± 0.11 and 1.27 ± 0.13 solar masses. The paper further argues that Terzan 5's dynamical age, measured by the A+ parameter, is younger than 47 Tuc despite a shorter two-body relaxation timescale, implicating tidal stripping as an accelerator of the cluster's dynamical evolution.

Load-bearing premise

The result rests on the assumption that the X-ray sources inside 31 arcsec are dynamically relaxed and in thermal equilibrium with the normal stars; if they are not, the fitted masses are not valid, though the qualitative concentration difference might survive.

Editorial extensions

If this is right

  • If the finding generalizes, the radial distribution of X-ray sources can serve as a mass-segregation clock for globular clusters, complementing blue straggler studies.
  • The luminosity dependence of the dip locations implies that sedimentation is a continuous process: heavier X-ray sources reach the core first, leaving a measurable gap between bright and faint populations.
  • Terzan 5's dynamically young state despite its short relaxation timescale points to tidal stripping as a significant driver of evolution for clusters on tight Galactic orbits.
  • The agreement between the mass ratio of bright X-ray sources and millisecond pulsars supports a shared dynamical formation channel for these objects.
  • With two clusters now showing the effect, the universality claim for X-ray source mass segregation can be tested by applying the same analysis to other globular clusters with deep X-ray surveys.

Reading between the lines

Editorial extensions of the paper, not claims the author makes directly.

  • A direct extension would be to measure proper motions or radial velocities of the X-ray sources: if the bright sources' velocity dispersion is not lower than the faint sources', the thermal-equilibrium assumption behind the generalized King model fails, although a qualitatively different radial distribution might survive.
  • The generalized King model assumes equipartition, which is unlikely to hold perfectly in a cluster the authors themselves argue is dynamically young; the quoted masses may therefore be biased even if the qualitative segregation signal is real.
  • The faint-source bump near 150 arcsec could indicate contamination from background galaxies or foreground stars; deeper multi-wavelength follow-up would test whether the faint-source mass estimate is affected.
  • If X-ray source mass segregation is universal, the dip radius should scale with cluster relaxation state, a prediction that can be checked by comparing several clusters with existing archival data.
Share X Bluesky LinkedIn Reddit HN

Signed reviews

No signed human review yet.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, and a circularity audit.

Referee Report

3 major / 4 minor

Summary. This paper presents an updated Chandra catalog of 489 point sources in the globular cluster Terzan 5, built from 18 ACIS observations with a combined effective exposure of 734 ks and covering R ≤ 4.3 arcmin; more than 75% of the sources are new detections. The authors construct radial surface-density profiles for bright and faint X-ray sources, identify significant dips at intermediate radii, and fit the cumulative radial distributions with a 'generalized King model' to infer average masses of 1.48 ± 0.11 M_sun (bright) and 1.27 ± 0.13 M_sun (faint). They compare the results with 47 Tuc to argue for a universal mass-segregation effect for X-ray sources in globular clusters, and use A+_rh values to conclude that Terzan 5 is dynamically younger than 47 Tuc despite its much shorter two-body relaxation time, attributing the difference to tidal stripping.

Significance. If the quantitative mass estimates hold, this would provide the second clear case of mass segregation of X-ray sources in a globular cluster and would extend the phenomenon to a very dense, dynamically active system. The paper has genuine strengths: a carefully constructed source catalog with explicit sensitivity maps, blending corrections, Monte Carlo tests for the significance of the radial dips, and an independent MSP cross-check of the mass-ratio interpretation. The qualitative bright-versus-faint concentration difference and the catalog itself are likely robust; the model-dependent masses and the dynamical-age comparison are the parts that need further support. The paper is therefore a useful contribution to the field, but the central quantitative conclusions currently rest on assumptions that are stated rather than demonstrated.

major comments (3)
  1. [Section 5.1, Eq. (6)] The inferred average masses assume that X-ray sources within R ≤ 31 arcsec are dynamically relaxed and in thermal equilibrium with reference normal stars, but this is not demonstrated. The text justifies the fitting radius only as 'slightly smaller than the distribution dip'; no local two-body relaxation time at R = 31 arcsec is computed from Eq. (5) using the adopted King-model density and velocity-dispersion profiles. This is load-bearing because q = M_X/M_* in Eq. (6) is interpreted as a physical mass ratio; if relaxation/equipartition has not actually been established, q is merely a fitted concentration parameter and the quoted masses (1.48 ± 0.11 and 1.27 ± 0.13 M_sun) do not follow. The internal tension with Section 5.2, where A+_rh = 0.14 is used to conclude that Terzan 5 is dynamically younger than 47 Tuc, makes the relaxation assumption even less self-evident. Please compute trelax at R = 31 arcsec from Eq. (5), or demonstrate equipartition empirically, and add a systematic error on the masses that reflects this assumption.
  2. [Section 5.1, reference mass] The conversion from fitted q to physical mass uses a single main-sequence turnoff mass of 0.92 M_sun for the 12 Gyr sub-solar component, but Terzan 5 hosts at least two stellar populations (a 12 Gyr sub-solar population and a 4.5 Gyr super-solar population). If the reference population in the King model is a mixture of these components, the effective turnoff mass could differ, and the quoted absolute masses scale linearly with the adopted M_TO. Please either justify that the sub-solar component dominates the reference stars inside R ≤ 31 arcsec or quote a systematic uncertainty on M_X from this choice.
  3. [Section 5.2, Eq. (7) and Figure 7] The conclusion that Terzan 5 is dynamically younger than 47 Tuc rests on the comparison A+_rh = 0.14 versus 0.19, but no uncertainties are quoted for these A+ values. Since the sample sizes, blending corrections, and background subtraction are all uncertain, a bootstrap or Monte Carlo estimate should be feasible; without error bars, the claim that the two values are significantly different is not established. Please provide confidence intervals for A+_rh in both clusters.
minor comments (4)
  1. [Table 1 caption] The cluster name is misspelled as 'Teran 5' in the table note; this should be corrected to 'Terzan 5'.
  2. [Section 5.1] There is a duplicated article in the sentence 'that the the locations and widths of the distribution dips...'; this should be fixed.
  3. [Section 4] The text gives median dip locations and widths (e.g., Rdip ~ 40'', ΔRdip ~ 70'') while Table 3 lists annulus ranges (e.g., 39-46 arcsec); please clarify how 'width' is defined and how the two quantities are related.
  4. [References] The entries for Hénon (1961, 1965) contain LaTeX accent artifacts ('H´ enon'); these should be typeset correctly in the published version.

Circularity Check

0 steps flagged · score 0.0 of 10

No significant circularity: the mass estimates are explicitly fitted via an external model, and the Terzan 5 data are new.

full rationale

The derivation chain is self-contained and contains no step that reduces to its own inputs. The central quantitative claim—average masses of 1.48 and 1.27 solar masses for the bright and faint X-ray sources—is explicitly obtained by maximum-likelihood fitting of the cumulative radial distributions with Eq. (6), a generalized King model whose form (Grindlay et al. 1984, 2002; Heinke et al. 2005) and parameters (Rc = 9 arcsec from Lanzoni et al. 2010; M_TO = 0.92 solar masses from Lanzoni et al. 2010 and Ferraro et al. 2016) are external to this paper. The fitted parameter q is labeled an 'estimated' mass ratio, not a predicted one. The dip significance in Table 3 is computed against background-plus-King-model expectations and tested with 1000 Poisson simulations, so the existence of the dips is an empirical, model-independent result. The choice of fitting region R <= 31 arcsec is justified by the faint-group dip position, but the fit itself uses the inner cumulative distribution rather than the dip annulus, so the mass estimate is not derived from the dip by construction. The comparison with 47 Tuc uses Cheng et al. (2019) as an external data set; although the same group performed that analysis, the Terzan 5 observations, source catalog, and dip measurements are new, and the comparison is not used to force the mass values. The A+ dynamical-age comparison relies on Alessandrini et al. (2016) and Ferraro et al. (2018), not on the authors' own theorems. The MSP mass-ratio cross-check (q = 1.57 +/- 0.15) is cited from Prager et al. (2017), an independent group. The main vulnerability—the unverified assumption that sources inside 31 arcsec are dynamically relaxed—is a correctness risk, not circularity, because the paper does not define relaxation in terms of the target masses. Overall, no predicted quantity is equivalent by construction to an input, and no load-bearing argument reduces to a self-citation.

Assumptions & free parameters 3 free parameters · 6 assumptions · 0 invented entities

The central mass estimates depend on a set of modeling assumptions: the generalized King model with thermal equilibrium, the King model parameters and turnoff mass for the reference population from Lanzoni et al. (2010), the logN-logS CXB relation from Kim et al. (2007), and uniform Galactic foreground. No new entities are introduced.

free parameters (3)
  • q_bright (mass ratio of bright X-ray sources to reference stars) = 1.61 +/- 0.12
    Fitted with a maximum-likelihood method to the cumulative radial distribution of the bright sample within R < 31 arcsec (Section 5.1).
  • q_faint (mass ratio of faint X-ray sources to reference stars) = 1.38 +/- 0.14
    Fitted the same way for the faint sample (Section 5.1).
  • Galactic background normalization (NG) = not quoted
    Normalized so the model CXB+Galactic component matches the observed surface density of X-ray sources beyond R = 175 arcsec (Section 4).
assumptions (6)
  • domain assumption X-ray sources within R < 31 arcsec are dynamically relaxed and in thermal equilibrium with the reference stars
    Required for the generalized King model (Eq. 6) to yield a valid mass ratio q; invoked in Section 5.1 when restricting the fit region.
  • domain assumption The reference normal stars follow a King model with Rc = 9 arcsec and c = 1.49, with turnoff mass M_TO = 0.92 Msun
    Adopted from Lanzoni et al. (2010) and Ferraro et al. (2016); used to compute the expected stellar profile and to convert q to physical masses.
  • domain assumption The CXB source counts follow the Kim et al. (2007) logN-logS relations with the assumed photon index and column density
    Used in Eqs. (3)-(4) to subtract cosmic X-ray background from the radial profiles.
  • domain assumption Galactic foreground and bulge X-ray sources are uniformly distributed with no significant cluster contribution beyond R = 175 arcsec
    Used to normalize the Galactic component; based on the claim from Lanzoni et al. (2010) that stellar density is dominated by Galactic stars beyond this radius.
  • domain assumption The A+ parameter measured within the half-light radius is a reliable binning-independent indicator of dynamical age
    Adopted from Alessandrini et al. (2016), Lanzoni et al. (2016), and Ferraro et al. (2018); used in Section 5.2 to compare dynamical ages.
  • standard math The two-body relaxation timescale formula (Eq. 5) with Coulomb logarithm lnLambda = ln(0.11N) is valid for these clusters
    Standard formula from Heggie & Hut (2003); used to estimate relaxation timescales for Terzan 5 and 47 Tuc.

how reviews work

0 comments
Cite this review

Pith. "Pith review of Exploring the Mass Segregation Effect of X-ray Sources in Globular Clusters. II. The Case of Terzan 5." pith.science (2026). https://pith.science/paper/WVL6MIHQ

@misc{pith2026190806392,
  author       = {Pith},
  title        = {Pith review of: Exploring the Mass Segregation Effect of X-ray Sources in Globular Clusters. II. The Case of Terzan 5},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/WVL6MIHQ}},
  note         = {Machine review of arXiv:1908.06392}
}
abstract

Using archival {\it Chandra} observations with a total effective exposure of 734 ks, we derive an updated catalog of point sources in the massive globular cluster Terzan 5. Our catalog covers an area of $58.1\, \rm arcmin^{2}$ ($R\leq 4.3 \, \rm arcmin$) with 489 X-ray sources, and more than $75\%$ of these sources are first detected in this cluster. We find significant dips in the radial distribution profiles of X-ray sources in Terzan 5, with the projected distance and width of the distribution dips for bright ($L_{X} \gtrsim 9.5\times 10^{30} {\rm\ erg\ \,s^{-1}}$) X-ray sources are larger than that of the faint ($L_{X} \lesssim 9.5\times 10^{30} {\rm\ erg\ \,s^{-1}}$) sources. By fitting the radial distribution of the X-ray sources with a"generalized King model", we estimated an average mass of $1.48\pm0.11\,M_{\odot}$ and $1.27\pm0.13\,M_{\odot}$ for the bright and faint X-ray sources, respectively. These results are in agreement with that observed in 47 Tuc, which may suggest a universal mass segregation effect for X-ray sources in GCs. Compared with 47 Tuc, we show that the two-body relaxation timescale of Terzan 5 is much smaller, but its dynamical age is significantly younger than 47 Tuc. These features suggest that the evolution of Terzan 5 is not purely driven by two-body relaxation, and tidal stripping effect also plays an important role in accelerating the dynamical evolution of this cluster.

Figures

Figures reproduced from arXiv: 1908.06392 by the authors.

Figure 1
Figure 1. — The full-band (0.5-7 keV) Chandra merged image of Terzan 5. The images are smoothed with a Gaussian kernel with a radius of 3 pixels. Only X-ray sources located within the green circle (R = 4.3 ′ ) have been detected and analyzed in this work. X-ray sources shown in blue are new detections of this work, while those in red and green were already identified by (Heinke et al. 2006). We reidentified those sources in r… view at source ↗
Figure 2
Figure 2. — Chandra merged image of the central 2′ × 2 ′ region of Terzan 5. The image was rebinned to 0′′ .25 pixel−1 . The color-coded symbols denote the different types of sources, as in Figure-1. 5 [PITH_FULL_IMAGE:figures/full_fig_p005_2.png] view at source ↗
Figure 3
Figure 3. — Full band (a) and hard band (b) photon flux as a function of p [PITH_FULL_IMAGE:figures/full_fig_p008_3.png] view at source ↗
Figures from the paper (4 more)
Figure 4
Figure 4. Figure 4: — Radial surface density distribution of X-ray sources in Terz [PITH_FULL_IMAGE:figures/full_fig_p009_4.png]
Figure 5
Figure 5. Figure 5: — Radial surface density distribution of X-ray sources in Terz [PITH_FULL_IMAGE:figures/full_fig_p010_5.png]
Figure 6
Figure 6. Figure 6: — (a): Cumulative radial distribution of each group of heavy ob [PITH_FULL_IMAGE:figures/full_fig_p013_6.png]
Figure 7
Figure 7. Figure 7: — Cumulative radial distribution of X-ray [PITH_FULL_IMAGE:figures/full_fig_p015_7.png]

Discussion (0). Continue with ORCID to comment.

Reference graph

Works this paper leans on

86 extracted references · 79 canonical work pages

  1. [1]

    R., Miocchi, P., & Vesperini, E.\ 2016, , 833, 252

    Alessandrini, E., Lanzoni, B., Ferraro, F. R., Miocchi, P., & Vesperini, E.\ 2016, , 833, 252

    2016

  2. [2]

    Askar, A., Szkudlarek, M., Gondek-Rosi \'n ska, D., Giersz, M., & Bulik, T.\ 2017, , 464, L36

    2017

  3. [3]

    O., Sivakoff, G.R., & Gladstone, J.C

    Bahramian, A., Heinke, C. O., Sivakoff, G.R., & Gladstone, J.C. 2013, , 766, 136

    2013

  4. [4]

    O., Sivakoff, G

    Bahramian, A., Heinke, C. O., Sivakoff, G. R., et al.\ 2014, , 780, 127

    2014

  5. [5]

    Bastian, N., & Lardo, C.\ 2015, , 453, 357

    2015

  6. [6]

    Bastian, N., & Lardo, C.\ 2018, , 56, 83

    2018

  7. [7]

    Baumgardt, H., & Hilker, M.\ 2018, , 478, 1520

    work page 2018

  8. [8]

    Baumgardt, H., Hilker, M., Sollima, A., & Bellini, A.\ 2019, , 482, 5138

    work page 2019

Show all 86 references
  1. [9]

    E., et al.\ 2019, , 483, 315

    Belloni, D., Giersz, M., Rivera Sandoval, L. E., et al.\ 2019, , 483, 315

    2019

  2. [10]

    S., Townsley L

    Broos P. S., Townsley L. K., Feigelson E. D., Getman K. V., Bauer F. E., Garmire G. P., 2010, , 714, 1582

    2010

  3. [11]

    C.\ 2003, , 346, L11

    Bekki, K., & Freeman, K. C.\ 2003, , 346, L11

    2003

  4. [12]

    M., Freire, P

    Cadelano, M., Ransom, S. M., Freire, P. C. C., et al.\ 2018, , 855, 125

    2018

  5. [13]

    Camilo, F., & Rasio, F. A. 2005, in ASP Conf. Ser. 328, Binary Radio Pulsars (San Francisco, CA: ASP), 147

    2005

  6. [14]

    M., Umbreit, S., & Rasio, F

    Chatterjee, S., Fregeau, J. M., Umbreit, S., & Rasio, F. A.\ 2010, , 719, 915

    2010

  7. [15]

    Cheng, Z., Li, Z., Xu, X., & Li, X.\ 2018a, , 858, 33

  8. [16]

    Cheng, Z., Li, Z., Xu, X., et al.\ 2018b, , 869, 52

  9. [17]

    Cheng, Z., Li, Z., Li, X., Xu, X., & Fang, T.\ 2019, , 876, 59

    2019

  10. [18]

    Clark, G. W. 1975, , 199, L143

    1975

  11. [19]

    B.\ 1997, , 288, 117

    Davies, M. B.\ 1997, , 288, 117

    1997

  12. [20]

    D., Gilliland, R

    Edmonds, P. D., Gilliland, R. L., Heinke, C. O., & Grindlay, J. E. 2003a, , 596, 1177

  13. [21]

    D., Gilliland, R

    Edmonds, P. D., Gilliland, R. L., Heinke, C. O., & Grindlay, J. E. 2003b, , 596, 1197

  14. [22]

    R., Dalessandro, E., Mucciarelli, A., et al.\ 2009, , 462, 483

    Ferraro, F. R., Dalessandro, E., Mucciarelli, A., et al.\ 2009, , 462, 483

    2009

  15. [23]

    R., Lanzoni, B., Dalessandro, E., et al

    Ferraro, F. R., Lanzoni, B., Dalessandro, E., et al. 2012, , 492, 393

    2012

  16. [24]

    R., Massari, D., Dalessandro, E., et al.\ 2016, , 828, 75

    Ferraro, F. R., Massari, D., Dalessandro, E., et al.\ 2016, , 828, 75

    2016

  17. [25]

    R., Lanzoni, B., Raso, S., et al.\ 2018, , 860, 36

    Ferraro, F. R., Lanzoni, B., Raso, S., et al.\ 2018, , 860, 36

    2018

  18. [26]

    A., & Bridges, T.\ 2010, , 404, 1203

    Forbes, D. A., & Bridges, T.\ 2010, , 404, 1203

    2010

  19. [27]

    M., Cheung, P., Portegies Zwart, S

    Fregeau, J. M., Cheung, P., Portegies Zwart, S. F., & Rasio, F. A.\ 2004, , 352, 1

    2004

  20. [28]

    M., G \"u rkan, M

    Fregeau, J. M., G \"u rkan, M. A., Joshi, K. J., & Rasio, F. A.\ 2003, , 593, 772

    2003

  21. [29]

    Gao, B., Goodman, J., Cohn, H., & Murphy, B.\ 1991, , 370, 567

    1991

  22. [30]

    Gehrels, N.\ 1986, , 303, 336

    1986

  23. [31]

    C., & Zhao, H.\ 2011, , 413, 2509

    Gieles, M., Heggie, D. C., & Zhao, H.\ 2011, , 413, 2509

    2011

  24. [32]

    Y., Lee, H

    Gnedin, O. Y., Lee, H. M., & Ostriker, J. P.\ 1999, , 522, 935

    1999

  25. [33]

    E., Hertz, P., et al

    Grindlay, J. E., Hertz, P., et al. 1984, , 282, 13

    1984

  26. [34]

    E., Heinke, C

    Grindlay, J. E., Heinke, C. O., Edmonds, P. D., et al. 2001, Science, 292, 2290

    2001

  27. [35]

    E., Camilo, F., Heinke, C

    Grindlay, J. E., Camilo, F., Heinke, C. O., et al.\ 2002, , 581, 470

    2002

  28. [36]

    Harris, W. E. 1996(2010 edition), , 112, 1487

    1996

  29. [37]

    H \'e non, M.\ 1961, Annales d'Astrophysique, 24, 369

    1961

  30. [38]

    H \'e non, M.\ 1965, Annales d'Astrophysique, 28, 62

    1965

  31. [39]

    C., 1975, , 173, 729

    Heggie, D. C., 1975, , 173, 729

    1975

  32. [40]

    C., Hut P

    Heggie D. C., Hut P. 2003, The Gravitational Million-Body Problem: A Multidisciplinary Approach to Star Cluster Dynamics (Cambridge: Cambridge University Press)

    2003

  33. [41]

    O., Grindlay, J

    Heinke, C. O., Grindlay, J. E., Cohn, H. N., et al. 2005, , 625, 796

    2005

  34. [42]

    O., Wijnands, R., Cohn, H

    Heinke, C. O., Wijnands, R., Cohn, H. N., et al.\ 2006, , 651, 1098

    2006

  35. [43]

    G., 1975, , 80, 809

    Hills, J. G., 1975, , 80, 809

    1975

  36. [44]

    G.\ 1976, , 175, 1P

    Hills, J. G.\ 1976, , 175, 1P

    1976

  37. [45]

    Hut, P.\ 1983, , 272, L29

    1983

  38. [46]

    1992, , 104, 981

    Hut, P., McMillan, S., Goodman, J., et al. 1992, , 104, 981

    1992

  39. [47]

    W.\ 1992, , 389, 527

    Hut, P., McMillan, S., & Romani, R. W.\ 1992, , 389, 527

    1992

  40. [48]

    Hong, J., Vesperini, E., Belloni, D., & Giersz, M.\ 2017, , 464, 2511

    2017

  41. [49]

    Hut, P., 1993, , 403, 256

    1993

  42. [50]

    O., Rasio, F

    Ivanova, N., Heinke, C. O., Rasio, F. A., et al.\ 2006, , 372, 1043

    2006

  43. [51]

    O., Rasio, F

    Ivanova, N., Heinke, C. O., Rasio, F. A., Belczynski, K., & Fregeau, J. M.\ 2008, , 386, 553

    2008

  44. [52]

    M., & Verbunt, F.\ 1996, , 312, 80

    Ivanova, N., Chaichenets, S., Fregeau, J., et al.\ 2010, , 717, 948 Johnston, H. M., & Verbunt, F.\ 1996, , 312, 80

    2010

  45. [53]

    Jiang, L., & Li, X.-D.\ 2013, , 772, 6

    2013

  46. [54]

    Katz, J. I. 1975, , 253, 698

    1975

  47. [55]

    J., Kim, D.-W., et al

    Kim, M., Wilkes, B. J., Kim, D.-W., et al. 2007, , 659, 29

    2007

  48. [56]

    King, I., 1962, , 67, 471

    1962

  49. [57]

    R., Dalessandro, E., et al.\ 2010, , 717, 653

    Lanzoni, B., Ferraro, F. R., Dalessandro, E., et al.\ 2010, , 717, 653

    2010

  50. [58]

    Lanzoni, B., & Cosmic-Lab Team 2014, , 85, 536

    2014

  51. [59]

    R., Alessandrini, E., et al.\ 2016, , 833, L29

    Lanzoni, B., Ferraro, F. R., Alessandrini, E., et al.\ 2016, , 833, L29

    2016

  52. [60]

    N., Xue, Y

    Luo, B., Brandt, W. N., Xue, Y. Q., et al.\ 2017, , 228, 2

    2017

  53. [61]

    Mapelli, M., & Zampieri, L.\ 2014, , 794, 7

    2014

  54. [62]

    Massari, D., Mucciarelli, A., Dalessandro, E., et al.\ 2012, , 755, L32

    2012

  55. [63]

    R., et al.\ 2014, , 795, 22

    Massari, D., Mucciarelli, A., Ferraro, F. R., et al.\ 2014, , 795, 22

    2014

  56. [64]

    McKenzie, M., & Bekki, K.\ 2018, , 479, 3126

    2018

  57. [65]

    E., Anderson, J., Meylan, G., et al

    McLaughlin, D. E., Anderson, J., Meylan, G., et al. 2006, , 166, 249

    2006

  58. [66]

    P., Piotto, G., Renzini, A., et al.\ 2017, , 464, 3636

    Milone, A. P., Piotto, G., Renzini, A., et al.\ 2017, , 464, 3636

    2017

  59. [67]

    Moretti, A., Pagani, C., Cusumano, G., et al.\ 2009, , 493, 501

    2009

  60. [68]

    M., & Rasio, F

    Morscher, M., Umbreit, S., Farr, W. M., & Rasio, F. A.\ 2013, , 763, L15

    2013

  61. [69]

    A., & Umbreit, S.\ 2015, , 800, 9

    Morscher, M., Pattabiraman, B., Rodriguez, C., Rasio, F. A., & Umbreit, S.\ 2015, , 800, 9

    2015

  62. [70]

    Papitto, A., D'A \`i , A., Motta, S., et al.\ 2011, , 526, L3

    2011

  63. [71]

    Pooley, D., Lewin, W. H. G., Homer L., et al. 2002, , 569, 405

    2002

  64. [72]

    2003, , 591, 131

    Pooley, D., et al. 2003, , 591, 131

    2003

  65. [73]

    2006, , 646, 143

    Pooley, D., & Hut, P. 2006, , 646, 143

    2006

  66. [74]

    J., Ransom, S

    Prager, B. J., Ransom, S. M., Freire, P. C. C., et al.\ 2017, , 845, 148

    2017

  67. [75]

    M., Hessels, J

    Ransom, S. M., Hessels, J. W. T., Stairs, I. H., et al.\ 2005, Science, 307, 892

    2005

  68. [76]

    Ransom, S. M. 2008, in AIP Conf. Ser. 983, 40 Years of Pulsars: Millisecond Pulsars, Magnetars and More (Melville, NY: AIP), 415

    2008

  69. [77]

    A., Pfahl, E

    Rasio, F. A., Pfahl, E. D., & Rappaport, S.\ 2000, , 532, L47

    2000

  70. [78]

    Reina-Campos, M., Kruijssen, J. M. D., Pfeffer, J., et al.\ 2018, , 481, 2851

    2018

  71. [79]

    R., 1953, , 58, 61

    Sandage, A. R., 1953, , 58, 61

    1953

  72. [80]

    Sigurdsson, S., & Hernquist, L.\ 1993, , 364, 423

    1993

  73. [81]

    Spitzer, L.\ 1987, Princeton, NJ, Princeton University Press, 1987, 191 p.,

    1987

  74. [82]

    E., & Markwardt, C

    Strohmayer, T. E., & Markwardt, C. B.\ 2010, The Astronomer's Telegram, 2929,

    2010

  75. [83]

    R., & Origlia, L.\ 2007, , 133, 1287

    Valenti, E., Ferraro, F. R., & Origlia, L.\ 2007, , 133, 1287

    2007

  76. [84]

    125, The Origin and Evolution of Neutron Stars, ed

    Verbunt, F., & Hut, P.\ 1987, IAU Symp. 125, The Origin and Evolution of Neutron Stars, ed. D. J. Helfand & J. H. Huang (Dordrecht: Reidel), 187

    1987

  77. [85]

    C., Wu, K., Trimble, V., et al.\ 2007, , 657, 1026

    Weisskopf, M. C., Wu, K., Trimble, V., et al.\ 2007, , 657, 1026

    2007

  78. [86]

    Q., Luo, B., Brandt, W

    Xue, Y. Q., Luo, B., Brandt, W. N., et al.\ 2011, , 195, 10

    2011

Pith tools

Reviewed August 14, 2026 · model on record in the stance chip above.