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REVIEW 4 major objections 4 minor 2 cited by

Relaxation of Energy Constraints for Positrons Generating the Galactic Annihilation Signal

T0 review · 4 major / 4 minor · reviewed 2026-08-07 · deepseek-v4-flash

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Pith's one-line read The Milky Way's 511 keV positrons may be born with up to ~50 MeV of energy, not just a few MeV.

desk verdict Solid forward-modeling reanalysis that probably relaxes the 511 keV positron injection bound to tens of MeV, but the quoted 62 MeV number depends on an AIC-selected CGRO scaling and the abstract/text disagree about 50 MeV. read the letter →

arxiv 2506.00847 v1 pith:CWPQGIX7 submitted 2025-06-01 astro-ph.HE astro-ph.GAhep-ph

Souradeep Das , Mark R. Krumholz , Roland M. Crocker , Thomas Siegert , Laura Eisenberger This is my paper
classification astro-ph.HEastro-ph.GAhep-ph PACS 95.85.Pw95.35.+d98.35.Jk
keywords 511keVlinepositronannihilationGalacticcentergamma-raycontinuumINTEGRAL/SPICOMPTEL/EGRETinjectionenergydarkmatter
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

The 511 keV positron-annihilation line from the inner Milky Way has defied explanation for 50 years, partly because earlier analyses claimed that the positrons must be injected with kinetic energies below a few MeV, ruling out pulsars and most dark-matter models. This paper argues that those limits were an artifact of simplified modeling: by forward-modeling the full gamma-ray spectrum, marginalizing over the unknown relative sky shapes of the line and the continuum, and using updated energy-loss calculations, the data are consistent with injection energies up to about 50 MeV. The 95% upper limit from the fiducial 9-degree region is 62 MeV, and even the most conservative interstellar-medium assumption gives 37 MeV. If correct, this reopens relativistic astrophysical sources and a slice of dark-matter parameter space as explanations for the bulge positrons.

What carries the argument

The load-bearing object is the forward spectral model that ties the positron injection energy to the observed line-to-continuum ratio. The model computes the gamma-ray spectrum from four channels: internal bremsstrahlung during pair creation, the 1809 keV line from $^{26}$Al decay, cooling radiation (bremsstrahlung, inverse Compton, in-flight annihilation) obtained from the criptic cosmic-ray propagation code, and thermalized positronium annihilation producing the 511 keV line and the ortho-positronium continuum. Because the constraint on $E_{\rm inj}$ comes almost entirely from the ratio of the 511 keV line to the continuum above it, the analysis must stitch together SPI/INTEGRAL data (30 keV to 8 MeV) with COMPTEL/EGRET data (10 to 300 MeV), whose sky coverage does not match the SPI regions; three scaling strategies (flat, ptsrc, like511) are used to assign the high-energy fluxes to each ROI, and the model with the highest Bayes factor is selected for each ROI.

What would settle it

A determination of the diffuse Galactic gamma-ray spectrum in the 1 to 100 MeV band with matched angular coverage for line and continuum would settle the issue: if a joint morphological deconvolution yields the flat or like511 scaling for the fiducial 9-degree region rather than ptsrc, or finds a continuum level higher than the model's best fit, the $E_{\rm inj}$ bound would tighten toward the old few-MeV limits; a measurement confirming the ptsrc scaling would support the roughly 50 MeV conclusion.

Watch

Extended reading notes

Core claim

The paper's central claim is that the gamma-ray data do not require the positrons that produce the Galactic 511 keV line to be born non-relativistic. Earlier bounds of roughly 3 to 7 MeV came from comparing the line flux to the continuum just above it while assuming the line is emitted solely from the bulge and treating the cooling radiation with approximate loss formulas. Here, with a multi-component injection model (relativistic pairs plus $\beta^+$-decay of $^{26}$Al and other nuclides), a numerical treatment of bremsstrahlung, Coulomb, ionization, inverse-Compton, and in-flight annihilation, and a Bayesian fit that tries four regions of interest and three ad hoc prescriptions for the relative normalization of INTEGRAL and CGRO data, the 95% upper bound on the injection energy is $E_{\rm inj}<62$ MeV for the fiducial 9-degree region, and the most conservative ISM choice gives $E_{\rm inj}<37$ MeV. The fit also prefers about 65% of positrons from the relativistic component, but the paper notes this lower bound is not robust, since the same continuum could come from electrons. The result is presented as a relaxation, not a detection of high-energy injection.

Load-bearing premise

The constraint on injection energy depends on the assumed relative normalization and sky distribution of the high-energy continuum measured by CGRO compared with the low-energy line measured by INTEGRAL, and that relative normalization is set by one of three ad hoc scaling choices, with the best-fitting choice selected by Bayes factor rather than averaged over.

Editorial extensions

If this is right

  • Pulsars, microquasars, and other sources of relativistic $e^\pm$ pairs are no longer excluded by the few-MeV limit and can be considered as contributors to the bulge annihilation signal.
  • Thermal-relic dark matter particles with masses up to roughly 120 MeV (and as low as about 2 MeV for a cusped halo) are consistent with the 511 keV line, though the required annihilation rate is at most 1 to 10 percent of the signal.
  • The lower limits on the injection energy and the relativistic fraction are not robust, so a model in which the 511 keV line comes entirely from $\beta^+$-decay plus a separate source of roughly 50 MeV electrons remains viable.
  • Because the CGRO high-energy bands are treated as upper limits in the fit, the true constraints are even weaker if those measurements are biased high.

Reading between the lines

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

  • A joint fit that marginalizes over a continuous morphological mapping between the line and continuum, rather than choosing among three discrete scalings, would turn the $E_{\rm inj}$ bound into a genuine posterior probability rather than a conditional one.
  • The positron-electron degeneracy in producing the continuum means that high-energy injection can always be rescued by an electron source; a future MeV mission with better angular resolution could break this degeneracy by comparing the 511 keV line morphology with the continuum morphology.
  • The same forward-model machinery could be applied to other positron-producing channels, such as primordial black hole evaporation, whose current constraints use the same line-to-continuum logic that this paper weakens.
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Editorial analysis

A structured set of objections, weighed in public.

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

Referee Report

4 major / 4 minor

Summary. The paper revisits constraints on the injection energy of positrons that produce the Galactic 511 keV annihilation line. The authors construct a forward model of the line and continuum emission, including a relativistic pair component injected at energy Einj, beta-decay components from 26Al and other nuclides, and a positronium-annihilation channel. Cooling radiation (bremsstrahlung, in-flight annihilation, inverse Compton) is computed with the criptic code, and backgrounds from unresolved point sources and cosmic-ray inverse Compton emission are modeled. The model is fit with an 11-parameter MCMC to INTEGRAL/SPI data in four ROIs combined with CGRO/COMPTEL-EGRET data, using three ad hoc strategies to assign the CGRO fluxes to the SPI ROIs and selecting the strategy with the highest AIC weight. The central result is that the 95% upper limit on Einj is 62 MeV for the fiducial 9-degree ROI, and 37 MeV if the positrons cool in neutral rather than ionized gas, a substantial relaxation from earlier few-MeV limits. The paper argues this reopens compact sources and some dark-matter models as positron sources, while noting that thermal-relic dark matter can contribute only a small fraction of the signal.

Significance. If the central claim holds, this is an important and timely result: it overturns a long-standing few-MeV bound that excluded many proposed positron sources. The analysis is a genuine methodological advance in several respects: it uses a full forward model rather than analytic ratios; it includes a multi-component injection model; it uses modern cooling calculations from criptic; and it explicitly confronts the mismatch between INTEGRAL and CGRO sky regions. The paper also demonstrates robustness of the qualitative relaxation across ISM compositions and ROIs. However, the specific headline numbers rest on a model-selection step whose uncertainty is not propagated into the quoted bounds, and the abstract overstates the conservative case. The core conclusion that injection energies of tens of MeV are allowed appears likely to survive, but the exact upper limit needs to be re-derived with per-scaling or marginalized results.

major comments (4)
  1. [Results and Supplemental Material (Table S1, Table S2)] The main text states that for the 9-degree ROI 'the results are similar regardless of the scaling', but no per-scaling posterior for Einj is shown anywhere. Table S1 reports only AIC weights; Table S2 gives posteriors only for the single best-scaling model for each ROI and ISM variant. Since the three scaling strategies assign CGRO fluxes to the 9-degree ROI that differ by up to a factor of roughly 1.6, and since the Einj bound is driven by the line-to-continuum ratio across the mismatched sky regions, the quoted 62 MeV bound is a single-model result from the AIC winner (ptsrc, weight 0.51) and may tighten substantially under the flat or like511 scalings. Please report the 95% upper limit on Einj for each scaling and each ISM model, or marginalize over the scaling models and quote the model-averaged bound. Without this, the 'similar regardless of scaling' claim and the headline number are not supported.
  2. [Abstract and Results (neutral-gas case)] The abstract claims that 'even under conservative assumptions the data are consistent with initial energies up to ~50 MeV', but the Results state that the most conservative ISM choice (atomic/neutral gas) yields Einj < 37 MeV at 95% confidence, while the fiducial 9-degree ROI gives <62 MeV. The value ~50 MeV does not appear as any reported bound, and the conservative case gives a lower, not higher, limit than the fiducial case. This is internally inconsistent. Please revise the abstract and any summary statements to quote the actual range of bounds (e.g., 37-62 MeV depending on ISM and ROI), or clearly identify which assumption yields the 50 MeV figure.
  3. [End Matter: Fitting Method, Eqs. (A1)-(A2)] The paper claims in the Introduction to 'properly marginalize over uncertainties in both the data analysis and the astrophysical background', but the scaling uncertainty is handled by selecting the model with the highest AIC weight, not by marginalization. Equations (A1)-(A2) define weights proportional to exp(-AIC/2), which are Akaike weights, not Bayes factors: they do not integrate over the prior and are not posterior model probabilities. This is a methodological mismatch with the stated goal. At minimum, the text should call these 'Akaike weights' rather than 'Bayes factors', and the final Einj bound should be accompanied by an assessment of sensitivity to the scaling choice. Ideally the authors should compute marginal likelihoods and either report per-scaling bounds or the model-averaged posterior.
  4. [Results (lower-limit discussion, frel degeneracy)] The statement that 'we cannot exclude a model with no relativistic positrons at all (i.e., the 511 keV line is entirely from beta+ decay) but with an additional source of ~50 MeV electrons' exposes a degeneracy that is not captured by the fitted model. The quoted upper bound on Einj assumes that the relativistic source produces both the positrons and the continuum above 511 keV; if that continuum could instead be produced by a separate electron population, then Einj for the positrons could be much higher or unconstrained. This is a load-bearing caveat for the dark-matter interpretation in Figure 3. Please either include a separate electron-only component in the model (with its own normalization) or explicitly state that the Einj constraint applies only under the assumption that the same pair source generates the continuum. The current wording in the Results is ambiguous because the model as defined has no separate electron component.
minor comments (4)
  1. [End Matter: Fitting Method, Eq. (A2)] Calling exp(-AIC/2) a 'Bayes factor' is technically inaccurate; these are Akaike weights. Please update the terminology throughout the Supplemental Material and the main text.
  2. [Lepton injection model, Eq. (1)] The normalization of the electron injection spectrum needs clarification: the text says 'the corresponding expression for electron injection is identical, but with f_beta = f_26Al = 0', but it is not stated whether the electron injection rate equals frel times the total positron injection rate or has its own normalization. Please state the assumed e+/e- pair multiplicity explicitly.
  3. [Figure 3] The caption says the allowed parameter space regions are shown in magenta and green, but the figure appears to show contours and shaded regions without a clear legend mapping the colors to the 1-sigma and 2-sigma levels. Please make the allowed-region shading unambiguous.
  4. [Gamma-ray data] Please report the actual CGRO upper-limit values used in the fit and the model-predicted CGRO fluxes at the best fit and at the 95% Einj bound, so that the effect of treating these measurements as upper limits (rather than detections) can be assessed by the reader.

Circularity Check

0 steps flagged · score 0.0 of 10

No circularity: the central Einj bound is an MCMC fit to external line and continuum data, and the self-citations (criptic cooling code, SPI morphology and fluxes) are independent published inputs not fitted to the 511 keV result.

full rationale

The paper's central claim is a posterior upper bound on the fitted parameter Einj, obtained by forward-modeling the SPI line/continuum and CGRO upper-limit data. Reporting a bound on a fitted parameter is an inference, not a prediction, so there is no fitted-input-called-prediction step. The dark-matter discussion (Figure 3) sets m_chi = Einj and compares the fitted pair-production rate to the external thermal-relic expectation of Slatyer (2016); this is an application of the fitted constraint, not a derivation of the constraint from the DM assumption. Self-citations are present but provide independent support: the criptic cooling tables [60] and the approach of [79] are published code with stated microphysical assumptions (BEQ ionization, Gould Coulomb, Blumenthal-Gould bremsstrahlung) and are not calibrated to the 511 keV data; the morphological decomposition [10] and SPI fluxes [62] are separate observational analyses of INTEGRAL data. The only notable issue is statistical, not circular: the paper selects among the flat/ptsrc/like511 scalings by AIC and reports posteriors only for the best scaling, while asserting without tabulated per-scaling bounds that results are 'similar regardless of the scaling.' That is a model-selection and reporting concern about robustness of the exact 62 MeV number, not a reduction of the derived bound to its own inputs. No equation in the paper is equivalent by construction to the quantity it claims to constrain.

Assumptions & free parameters 12 free parameters · 6 assumptions · 0 invented entities

The central constraint rests on 12 fitted parameters and several domain assumptions about cooling, backgrounds, and relative data normalization. The key free parameters are Einj and frel; the key axioms are the monoenergetic injection, CGRO-as-upper-limits, and the criptic cooling calculation.

free parameters (12)
  • Einj (relativistic pair injection energy) = 33 MeV posterior median, 95% upper bound 62 MeV (9 deg ROI, benchmark ISM)
    The energy scale whose upper bound is the paper's central result; constrained directly by the fitted gamma-ray spectrum, not by independent physics.
  • frel (fraction of positrons injected relativistically) = 0.65 posterior median (9 deg ROI)
    Determines how much of the 511 keV flux comes from the relativistic source versus radioactivity; fit to data.
  • fbeta (fraction from beta+ decay except 26Al) = 0.30 posterior median
    Fitted with flat Dirichlet prior together with frel and f26Al.
  • f26Al (fraction from 26Al decay) = 0.054 posterior median (derived as 1-frel-fbeta)
    Not independent but constrained by the 1809 keV line data.
  • fPs (positronium fraction) = 0.97 posterior median, prior U(0.9,1.0)
    Sets the ortho-positronium continuum; tightly prior-limited because measured elsewhere.
  • ndot_inj/4piD^2 (positron injection rate normalization) = 10^-2.81 cm^-2 s^-1 for 9 deg ROI
    Overall normalization fitted to the 511 keV flux.
  • NCMB/4piD^2 (IC background normalization) = 10^-6.90 cm^-2 s^-1 median
    Normalization of inverse Compton emission from high-energy electrons; fitted.
  • xFIR (FIR energy density ratio) = 10^1.15 median
    Ratio of FIR radiation energy density to local value; fitted.
  • xNIR (NIR energy density ratio) = 10^-0.06 median
    Ratio of NIR radiation energy density to local value; fitted.
  • p (CR electron spectral slope) = -2.51 median, prior U(-3,-2)
    Slope of the injected electron spectrum at energies above 1 GeV; fitted.
  • NUPS/4piD^2 (unresolved point source normalization) = 10^-2.4 cm^-2 s^-1 median
    Normalization of the power-law background below 511 keV; fitted.
  • alphaUPS (UPS power-law slope) = posterior range about -8 to -4
    Fitted with a Jeffreys prior over the slope angle.
assumptions (6)
  • domain assumption All leptons injected in a given ROI cool completely within that region before annihilating.
    Invoked in the Forward model section (Eq. 3) citing [67]; if positrons escape before cooling, the continuum morphology differs.
  • domain assumption The relativistic source injects positrons as a monoenergetic delta function at Einj (Eq. 1).
    The shape of the injection spectrum is assumed; a broad spectrum would change the line-to-continuum ratio.
  • domain assumption COMPTEL and EGRET fluxes can be treated as upper limits without applying instrument response functions.
    Stated in the Fitting method: 'we treat the CGRO measurements only as upper limits'; no response is applied, which weakens the constraint.
  • domain assumption Unresolved point source and IC backgrounds have the specified functional forms and priors (UPS power law with cutoff at 511 keV; IC electron slope p in [-3,-2]).
    Background model defined in End Matter; if a different component (e.g., pi0 decay tail) contributes above a few MeV, the Einj bound changes.
  • domain assumption The criptic cooling radiation tables (using ionized ISM with fIC=fsync=1e-6 as fiducial) are accurate for the Galactic ISM.
    Cooling emission strength is the main physics driving the constraint; computed with prior code by overlapping authors, varied over five ISM models in the supplement.
  • domain assumption Dark matter halo profiles (NFW/Einasto from refs [75,76]) and thermal-relic cross-section from [59] apply to the Milky Way inner region.
    Used only for the DM interpretation in Figure 3, not for the main central constraint.

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Cite this review

Pith. "Pith review of Relaxation of Energy Constraints for Positrons Generating the Galactic Annihilation Signal." pith.science (2026). https://pith.science/paper/CWPQGIX7

@misc{pith2026250600847,
  author       = {Pith},
  title        = {Pith review of: Relaxation of Energy Constraints for Positrons Generating the Galactic Annihilation Signal},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/CWPQGIX7}},
  note         = {Machine review of arXiv:2506.00847}
}
abstract

Even 50 years after the discovery of a positron annihilation line from the inner Galaxy, no class of astrophysical sources has emerged as a definitive explanation for both the emission morphology and flux. Positrons produced by dark matter annihilation or decay have been proposed, but the mass of any such candidate is constrained by continuum $\gamma$-ray emission at energies $>511$ keV. Earlier analyses have claimed that this emission requires that the positrons have kinetic energies less than a few MeV at injection, disfavoring both much of the dark matter parameter space and many potential compact astrophysical source classes such as pulsars. However, these constraints were not based on a full forward model of the $\gamma$-ray line and continuum data, and did not marginalize over uncertainties about the relative angular distributions of the line and continuum. Here we describe an improved analysis that overcomes these limitations, and show that constraints on the injection energy are much weaker than previously claimed; even under conservative assumptions the data are consistent with initial energies up to $\sim 50$ MeV.

Figures

Figures reproduced from arXiv: 2506.00847 by the authors.

Figure 1
Figure 1. FIG. 1: Posterior distribution for the pair injection [PITH_FULL_IMAGE:figures/full_fig_p003_1.png] view at source ↗
Figure 3
Figure 3. FIG. 3: Thermal relic dark matter annihilation rate [PITH_FULL_IMAGE:figures/full_fig_p004_3.png] view at source ↗

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Forward citations

Cited by 2 Pith papers

Reviewed papers in the Pith corpus that reference this work. Sorted by Pith novelty score. Full citation record

  1. Cosmological $\gamma$-$\gamma$ Pair-Production Background

    astro-ph.CO 2026-07 conditional novelty 6.0 of 10

    Cosmic background photons colliding with each other produce enough electron-positron pairs that their Inverse Compton emission could supply 10-20% of the 1 MeV-1 GeV cosmic gamma-ray background.

  2. Stellar flares cannot explain the Galactic 511 keV emission

    astro-ph.GA 2026-07 conditional novelty 6.0 of 10

    Stellar flares fall short by orders of magnitude and cannot match the morphology of the Galactic 511 keV positron-annihilation signal.

Reference graph

Works this paper leans on

84 extracted references · 42 canonical work pages · cited by 2 Pith papers

  1. [1]

    Johnson, W

    I. Johnson, W. N., J. Harnden, F. R., and R. C. Haymes, The Spectrum of Low-Energy Gamma Radiation from the Galactic-Center Region., ApJ 172, L1 (1972)

    1972

  2. [2]

    Leventhal, C

    M. Leventhal, C. J. MacCallum, and P. D. Stang, Detec- tion of 511 keV positron annihilation radiation from the galactic center direction., ApJ 225, L11 (1978)

    1978

  3. [3]

    W. R. Purcell, L. X. Cheng, D. D. Dixon, R. L. Kinzer, J. D. Kurfess, M. Leventhal, M. A. Saunders, J. G. Skibo, D. M. Smith, and J. Tueller, OSSE Mapping of Galactic 511 keV Positron Annihilation Line Emission, ApJ 491, 725 (1997)

    1997

  4. [4]

    R. L. Kinzer, P. A. Milne, J. D. Kurfess, M. S. Strickman, W. N. Johnson, and W. R. Purcell, Positron Annihilation Radiation from the Inner Galaxy, ApJ 559, 282 (2001)

    2001

  5. [5]

    Astrophysical constraints from gamma-ray spectroscopy

    R. Diehl, N. Prantzos, and P. von Ballmoos, As- trophysical constraints from gamma-ray spectroscopy, Nucl. Phys. A 777, 70 (2006), arXiv:astro-ph/0502324 [astro-ph]

    work page Pith review arXiv 2006

  6. [6]

    Prantzos, C

    N. Prantzos, C. Boehm, A. M. Bykov, R. Diehl, K. Ferri` ere, N. Guessoum, P. Jean, J. Knoedlseder, A. Marcowith, I. V. Moskalenko, A. Strong, and G. Wei- denspointner, The 511 keV emission from positron anni- hilation in the Galaxy, Reviews of Modern Physics 83, 1001 (2011), arXiv:1009.4620 [astro-ph.HE]

    arXiv 2011

  7. [7]

    Positron Annihilation in the Galaxy

    C. Kierans, J. F. Beacom, S. Boggs, M. Buckley, R. Ca- puto, R. Crocker, M. De Becker, R. Diehl, C. L. Fryer, S. Griffin, D. Hartmann, E. Hays, P. Jean, M. G. H. Krause, T. Linden, A. Marcowith, P. Martin, A. Moi- seev, U. Oberlack, E. Orlando, F. Panther, N. Prant- zos, R. Rothschild, I. Seitenzahl, C. Shrader, T. Siegert, A. Strong, J. Tomsick, W. T. Ve...

    work page Pith review arXiv 2019

  8. [8]

    Siegert, The Positron Puzzle, Ap&SS 368, 27 (2023), arXiv:2303.15582 [astro-ph.HE]

    T. Siegert, The Positron Puzzle, Ap&SS 368, 27 (2023), arXiv:2303.15582 [astro-ph.HE]

    arXiv 2023

Show all 84 references
  1. [9]

    F. A. Aharonian and A. M. Atoyan, On the Origin of the Galactic Annihilation Radiation, Soviet Astronomy Letters 7, 395 (1981)

    1981

  2. [10]

    Siegert, R

    T. Siegert, R. Diehl, G. Khachatryan, M. G. H. Krause, F. Guglielmetti, J. Greiner, A. W. Strong, and X. Zhang, Gamma-ray spectroscopy of positron annihilation in the Milky Way, A&A 586, A84 (2016), arXiv:1512.00325 [astro-ph.HE]

    2016 arXiv

  3. [11]

    Chan and R

    K.-W. Chan and R. E. Lingenfelter, Positrons from Su- pernovae, ApJ 405, 614 (1993)

    1993

  4. [12]

    Kn¨ odlseder, V

    J. Kn¨ odlseder, V. Lonjou, P. Jean, M. Allain, P. Man- drou, J. P. Roques, G. K. Skinner, G. Vedrenne, P. von Ballmoos, G. Weidenspointner, P. Caraveo, B. Cordier, V. Sch¨ onfelder, and B. J. Teegarden, Early SPI/INTEGRAL constraints on the morphology of the 511 keV line emis...

    2003 arXiv

  5. [13]

    Kn¨ odlseder, P

    J. Kn¨ odlseder, P. Jean, V. Lonjou, G. Weidenspointner, N. Guessoum, W. Gillard, G. Skinner, P. von Ballmoos, G. Vedrenne, J. P. Roques, S. Schanne, B. Teegarden, V. Sch¨ onfelder, and C. Winkler, The all-sky distribution of 511 keV electron-positron annihilation emission, A&...

    2005 arXiv

  6. [14]

    Weidenspointner, C

    G. Weidenspointner, C. R. Shrader, J. Kn¨ odlseder, P. Jean, V. Lonjou, N. Guessoum, R. Diehl, W. Gillard, M. J. Harris, G. K. Skinner, P. von Ballmoos, G. Ve- drenne, J. P. Roques, S. Schanne, P. Sizun, B. J. Tee- garden, V. Sch¨ onfelder, and C. Winkler, The sky distri- buti...

    2006 arXiv

  7. [15]

    Prantzos, On the intensity and spatial morphology of the 511 keV emission in the Milky Way, A&A 449, 869 (2006), arXiv:astro-ph/0511190 [astro-ph]

    N. Prantzos, On the intensity and spatial morphology of the 511 keV emission in the Milky Way, A&A 449, 869 (2006), arXiv:astro-ph/0511190 [astro-ph]

    2006 arXiv

  8. [16]

    Bouchet, J

    L. Bouchet, J. P. Roques, and E. Jourdain, On the Morphology of the Electron-Positron Annihilation Emis- sion as Seen by Spi/integral, ApJ 720, 1772 (2010), arXiv:1007.4753 [astro-ph.HE]

    2010 arXiv

  9. [17]

    R. M. Crocker, A. J. Ruiter, I. R. Seitenzahl, F. H. Pan- ther, S. Sim, H. Baumgardt, A. M¨ oller, D. M. Nataf, L. Ferrario, J. J. Eldridge, M. White, B. E. Tucker, and F. Aharonian, Diffuse Galactic antimatter from faint thermonuclear supernovae in old stellar populations, Na...

    2017 arXiv

  10. [18]

    T. B. Mera Evans, P. Hoeflich, and R. Diehl, Galactic Positrons from Thermonuclear Supernovae, ApJ930, 107 (2022), arXiv:2202.05417 [astro-ph.HE]

    2022

  11. [19]

    P. Jean, W. Gillard, A. Marcowith, and K. Ferri` ere, Positron transport in the interstellar medium, A&A 508, 1099 (2009), arXiv:0909.4022 [astro-ph.HE]

    2009 arXiv

  12. [20]

    J. C. Higdon, R. E. Lingenfelter, and R. E. Rothschild, The Galactic Positron Annihilation Radiation and the Propagation of Positrons in the Interstellar Medium, ApJ 698, 350 (2009), arXiv:0711.3008 [astro-ph]

    2009 arXiv

  13. [21]

    R. E. Lingenfelter, J. C. Higdon, and R. E. Rothschild, Is There a Dark Matter Signal in the Galactic Positron Annihilation Radiation?, Phys. Rev. Lett. 103, 031301 (2009), arXiv:0904.1025 [astro-ph.HE]

    2009 arXiv

  14. [22]

    F. H. Panther, Positron Transport and Annihila- tion in the Galactic Bulge, Galaxies 6, 39 (2018), arXiv:1801.09365 [astro-ph.HE]

    2018 arXiv

  15. [23]

    Siegert, R

    T. Siegert, R. M. Crocker, O. Macias, F. H. Panther, F. Calore, D. Song, and S. Horiuchi, Measuring the smearing of the Galactic 511-keV signal: positron prop- agation or supernova kicks?, MNRAS 509, L11 (2022), arXiv:2109.03691 [astro-ph.HE]

    2022 arXiv

  16. [24]

    De la Torre Luque, S

    P. De la Torre Luque, S. Balaji, and J. Koech- ler, Importance of Cosmic-Ray Propagation on Sub- GeV Dark Matter Constraints, ApJ 968, 46 (2024), arXiv:2311.04979 [hep-ph]

    2024 arXiv

  17. [25]

    W. Wang, C. S. J. Pun, and K. S. Cheng, Could electron- positron annihilation lines in the Galactic center result from pulsar winds?, A&A 446, 943 (2006), arXiv:astro- 6 ph/0509760 [astro-ph]

    2006

  18. [26]

    Heinz and R

    S. Heinz and R. Sunyaev, Cosmic rays from microquasars: A narrow component to the CR spectrum?, A&A 390, 751 (2002), arXiv:astro-ph/0204183 [astro-ph]

    2002 arXiv

  19. [27]

    Guessoum, P

    N. Guessoum, P. Jean, and N. Prantzos, Microquasars as sources of positron annihilation radiation, A&A 457, 753 (2006), arXiv:astro-ph/0607296 [astro-ph]

    2006 arXiv

  20. [28]

    Siegert, R

    T. Siegert, R. Diehl, J. Greiner, M. G. H. Krause, A. M. Beloborodov, M. C. Bel, F. Guglielmetti, J. Rodriguez, A. W. Strong, and X. Zhang, Positron annihilation sig- natures associated with the outburst of the microquasar V404 Cygni, Nature 531, 341 (2016), arXiv:1603.01169 [...

    2016 arXiv

  21. [29]

    Weidenspointner, G

    G. Weidenspointner, G. Skinner, P. Jean, J. Kn¨ odlseder, P. von Ballmoos, G. Bignami, R. Diehl, A. W. Strong, B. Cordier, S. Schanne, and C. Winkler, An asymmetric distribution of positrons in the Galactic disk revealed by γ-rays, Nature 451, 159 (2008)

    2008

  22. [30]

    Weidenspointner, G

    G. Weidenspointner, G. K. Skinner, P. Jean, J. Kn¨ odlseder, P. von Ballmoos, R. Diehl, A. Strong, B. Cordier, S. Schanne, and C. Winkler, Positron astronomy with SPI/INTEGRAL, New A Rev. 52, 454 (2008)

    2008

  23. [31]

    Bartels, F

    R. Bartels, F. Calore, E. Storm, and C. Weniger, Galac- tic binaries can explain the Fermi Galactic centre ex- cess and 511 keV emission, MNRAS 480, 3826 (2018), arXiv:1803.04370 [astro-ph.HE]

    2018 arXiv

  24. [32]

    G. M. Fuller, A. Kusenko, D. Radice, and V. Takhistov, Positrons and 511 keV Radiation as Tracers of Recent Bi- nary Neutron Star Mergers, Phys. Rev. Lett.122, 121101 (2019), arXiv:1811.00133 [astro-ph.HE]

    2019 arXiv

  25. [33]

    Boehm, D

    C. Boehm, D. Hooper, J. Silk, M. Casse, and J. Paul, MeV Dark Matter: Has It Been Detected?, Phys. Rev. Lett. 92, 101301 (2004), arXiv:astro- ph/0309686 [astro-ph]

    2004

  26. [34]

    Hooper and L.-T

    D. Hooper and L.-T. Wang, Possible evidence for ax- ino dark matter in the galactic bulge, Phys. Rev. D 70, 063506 (2004), arXiv:hep-ph/0402220 [astro-ph]

    2004 arXiv

  27. [35]

    Ascasibar, P

    Y. Ascasibar, P. Jean, C. Bœhm, and J. Kn¨ odlseder, Constraints on dark matter and the shape of the Milky Way dark halo from the 511-keV line, MNRAS368, 1695 (2006), arXiv:astro-ph/0507142 [astro-ph]

    2006 arXiv

  28. [36]

    Pospelov and A

    M. Pospelov and A. Ritz, The galactic 511 keV line from electroweak scale WIMPs, Physics Letters B 651, 208 (2007), arXiv:hep-ph/0703128 [hep-ph]

    2007 arXiv

  29. [37]

    Arkani-Hamed, D

    N. Arkani-Hamed, D. P. Finkbeiner, T. R. Slatyer, and N. Weiner, A theory of dark matter, Phys. Rev. D 79, 015014 (2009), arXiv:0810.0713 [hep-ph]

    2009 arXiv

  30. [38]

    A. C. Vincent, P. Martin, and J. M. Cline, Interacting dark matter contribution to the galactic 511 keV gamma ray emission: constraining the morphology with INTE- GRAL/SPI observations, J. Cosmology Astropart. Phys. 2012, 022 (2012), arXiv:1201.0997 [hep-ph]

    2012 arXiv

  31. [39]

    Y. Ema, F. Sala, and R. Sato, Dark matter models for the 511 keV galactic line predict keV electron recoils on Earth, European Physical Journal C 81, 129 (2021), arXiv:2007.09105 [hep-ph]

    2021 arXiv

  32. [40]

    De la Torre Luque, S

    P. De la Torre Luque, S. Balaji, and J. Silk, New 511 keV line data provides strongest sub-GeV dark mat- ter constraints, arXiv e-prints , arXiv:2312.04907 (2023), arXiv:2312.04907 [hep-ph]

    2023

  33. [41]

    D. P. Finkbeiner and N. Weiner, Exciting dark matter and the INTEGRAL/SPI 511keV signal, Phys. Rev. D 76, 083519 (2007), arXiv:astro-ph/0702587 [astro-ph]

    2007 arXiv

  34. [42]

    D. P. Finkbeiner, T. R. Slatyer, N. Weiner, and I. Yavin, PAMELA, DAMA, INTEGRAL and signatures of metastable excited WIMPs, J. Cosmology Astropart. Phys. 2009, 037 (2009), arXiv:0903.1037 [hep-ph]

    2009 arXiv

  35. [43]

    F. Chen, J. M. Cline, and A. R. Frey, New twist on excited dark matter: Implications for INTEGRAL, PAMELA/ATIC/PPB-BETS, DAMA, Phys. Rev. D 79, 063530 (2009), arXiv:0901.4327 [hep-ph]

    2009 arXiv

  36. [44]

    F. Chen, J. M. Cline, A. Fradette, A. R. Frey, and C. Ra- bideau, Exciting dark matter in the Galactic Center, Phys. Rev. D 81, 043523 (2010), arXiv:0911.2222 [hep- ph]

    2010 arXiv

  37. [45]

    J. M. Cline, A. R. Frey, and F. Chen, Metastable dark matter mechanisms for INTEGRAL 511 keV γ rays and DAMA/CoGeNT events, Phys. Rev. D 83, 083511 (2011), arXiv:1008.1784 [hep-ph]

    2011 arXiv

  38. [46]

    J. M. Cline and A. R. Frey, Abelian dark matter models for 511 keV γ rays and direct detection, Annalen der Physik 524, 579 (2012), arXiv:1204.1965 [hep-ph]

    2012 arXiv

  39. [47]

    C. V. Cappiello, M. Jafs, and A. C. Vincent, The mor- phology of exciting dark matter and the galactic 511 keV signal, J. Cosmology Astropart. Phys. 2023, 003 (2023), arXiv:2307.15114 [hep-ph]

    2023 arXiv

  40. [48]

    Laha, Primordial Black Holes as a Dark Matter Can- didate Are Severely Constrained by the Galactic Cen- ter 511 keV γ -Ray Line, Phys

    R. Laha, Primordial Black Holes as a Dark Matter Can- didate Are Severely Constrained by the Galactic Cen- ter 511 keV γ -Ray Line, Phys. Rev. Lett. 123, 251101 (2019), arXiv:1906.09994 [astro-ph.HE]

    2019 arXiv

  41. [49]

    DeRocco and P

    W. DeRocco and P. W. Graham, Constraining Pri- mordial Black Hole Abundance with the Galactic 511 keV Line, Phys. Rev. Lett. 123, 251102 (2019), arXiv:1906.07740 [astro-ph.CO]

    2019 arXiv

  42. [50]

    Dasgupta, R

    B. Dasgupta, R. Laha, and A. Ray, Neutrino and Positron Constraints on Spinning Primordial Black Hole Dark Matter, Phys. Rev. Lett. 125, 101101 (2020), arXiv:1912.01014 [hep-ph]

    2020 arXiv

  43. [51]

    Keith and D

    C. Keith and D. Hooper, 511 keV excess and primor- dial black holes, Phys. Rev. D 104, 063033 (2021), arXiv:2103.08611 [astro-ph.CO]

    2021 arXiv

  44. [52]

    De la Torre Luque, J

    P. De la Torre Luque, J. Koechler, and S. Balaji, Refining Galactic primordial black hole evaporation constraints, arXiv e-prints , arXiv:2406.11949 (2024), arXiv:2406.11949 [astro-ph.HE]

    2024

  45. [53]

    Cai, Y.-C

    R.-G. Cai, Y.-C. Ding, X.-Y. Yang, and Y.-F. Zhou, Constraints on a mixed model of dark matter particles and primordial black holes from the galactic 511 keV line, J. Cosmology Astropart. Phys. 2021, 057 (2021), arXiv:2007.11804 [astro-ph.CO]

    2021 arXiv

  46. [54]

    De la Torre Luque, S

    P. De la Torre Luque, S. Balaji, M. Fairbairn, F. Sala, and J. Silk, 511 keV Galactic Photons from a Dark Matter Spike, arXiv e-prints , arXiv:2410.16379 (2024), arXiv:2410.16379 [astro-ph.HE]

    2024 arXiv

  47. [55]

    J. F. Beacom and H. Y¨ uksel, Stringent Constraint on Galactic Positron Production, Phys. Rev. Lett. 97, 071102 (2006), arXiv:astro-ph/0512411 [astro-ph]

    2006 arXiv

  48. [56]

    Sizun, M

    P. Sizun, M. Cass´ e, and S. Schanne, Continuum γ-ray emission from light dark matter positrons and electrons, Phys. Rev. D 74, 063514 (2006), arXiv:astro-ph/0607374 [astro-ph]

    2006 arXiv

  49. [57]

    Sizun, M

    P. Sizun, M. Cass´ e, S. Schanne, and B. Cordier, Con- straints on the Injection Energy of Positrons in the Galac- tic Centre Region, in The Obscured Universe. Proceed- ings of the VI INTEGRAL Workshop, ESA Special Pub- lication, Vol. 622 (2007) p. 61, arXiv:astro-ph/0702061 [...

    2007 arXiv

  50. [58]

    Pospelov, A

    M. Pospelov, A. Ritz, and M. Voloshin, Secluded WIMP dark matter, Physics Letters B 662, 53 (2008), arXiv:0711.4866 [hep-ph]

    2008 arXiv

  51. [59]

    T. R. Slatyer, Indirect dark matter signatures in the cos- mic dark ages. I. Generalizing the bound on s -wave dark matter annihilation from Planck results, Phys. Rev. D 93, 023527 (2016), arXiv:1506.03811 [hep-ph]

    2016 arXiv

  52. [60]

    M. R. Krumholz, R. M. Crocker, and M. L. Sampson, Cosmic ray interstellar propagation tool using Itˆ o Calcu- lus (CRIPTIC): software for simultaneous calculation of cosmic ray transport and observational signatures, MN- RAS 517, 1355 (2022), arXiv:2207.13838 [astro-ph.HE]

    2022 arXiv

  53. [61]

    Diehl, T

    R. Diehl, T. Siegert, J. Greiner, M. Krause, K. Kretschmer, M. Lang, M. Pleintinger, A. W. Strong, C. Weinberger, and X. Zhang, INTEGRAL/SPI γ-ray line spectroscopy. Response and background character- istics, A&A 611, A12 (2018), arXiv:1710.10139 [astro- ph.IM]

    2018 arXiv

  54. [62]

    Siegert, J

    T. Siegert, J. Berteaud, F. Calore, P. D. Serpico, and C. Weinberger, Diffuse Galactic emission spectrum between 0.5 and 8.0 MeV, A&A 660, A130 (2022), arXiv:2202.04574 [astro-ph.HE]

    2022 arXiv

  55. [63]

    Churazov, S

    E. Churazov, S. Sazonov, S. Tsygankov, R. Sunyaev, and D. Varshalovich, Positron annihilation spectrum from the Galactic Centre region observed by SPI/INTEGRAL re- visited: annihilation in a cooling ISM?, MNRAS 411, 1727 (2011), arXiv:1010.0864 [astro-ph.HE]

    2011 arXiv

  56. [64]

    A. W. Strong, H. Bloemen, R. Diehl, W. Hermsen, and V. Sch¨ onfelder, COMPTEL Skymapping: a New Approach Using Parallel Computing, Astrophysical Let- ters and Communications 39, 209 (1999), arXiv:astro- ph/9811211 [astro-ph]

    1999

  57. [65]

    J. F. Beacom, N. F. Bell, and G. Bertone, Gamma- Ray Constraint on Galactic Positron Production by MeV Dark Matter, Phys. Rev. Lett. 94, 171301 (2005), arXiv:astro-ph/0409403 [astro-ph]

    2005 arXiv

  58. [66]

    Boehm and P

    C. Boehm and P. Uwer, Revisiting Bremsstrahlung emission associated with Light Dark Matter annihila- tions, arXiv e-prints , hep-ph/0606058 (2006), arXiv:hep- ph/0606058 [hep-ph]

    2006 arXiv

  59. [67]

    Martin, A

    P. Martin, A. W. Strong, P. Jean, A. Alexis, and R. Diehl, Galactic annihilation emission from nucleosyn- thesis positrons, A&A 543, A3 (2012), arXiv:1205.1194 [astro-ph.HE]

    2012 arXiv

  60. [68]

    Guessoum, P

    N. Guessoum, P. Jean, and W. Gillard, The lives and deaths of positrons in the interstellar medium, A&A436, 171 (2005), arXiv:astro-ph/0504186 [astro-ph]

    2005 arXiv

  61. [69]

    Ore and J

    A. Ore and J. L. Powell, Three-photon annihilation of an electron-positron pair, Phys. Rev. 75, 1696 (1949)

    1949

  62. [70]

    Krivonos, M

    R. Krivonos, M. Revnivtsev, E. Churazov, S. Sazonov, S. Grebenev, and R. Sunyaev, Hard X-ray emission from the Galactic ridge, A&A 463, 957 (2007), arXiv:astro- ph/0605420 [astro-ph]

    2007

  63. [71]

    Lutovinov, V

    A. Lutovinov, V. Suleimanov, G. J. Manuel Luna, S. Sazonov, D. de Martino, L. Ducci, V. Doroshenko, and M. Falanga, INTEGRAL View on cataclysmic variables and symbiotic binaries, New A Rev. 91, 101547 (2020), arXiv:2008.10665 [astro-ph.HE]

    2020

  64. [72]

    Berteaud, F

    J. Berteaud, F. Calore, J. Iguaz, P. D. Serpico, and T. Siegert, Strong constraints on primordial black hole dark matter from 16 years of INTE- GRAL/SPI observations, Phys. Rev. D 106, 023030 (2022), arXiv:2202.07483 [astro-ph.HE]

    2022 arXiv

  65. [73]

    Calore, A

    F. Calore, A. Dekker, P. D. Serpico, and T. Siegert, Con- straints on light decaying dark matter candidates from 16 yr of INTEGRAL/SPI observations, MNRAS 520, 4167 (2023), arXiv:2209.06299 [hep-ph]

    2023

  66. [74]

    Siegert, Galactic Diffuse Emission Spectrum between 0.5 and 8.0 MeV and between 30 keV and 8 MeV for the search of PBH Dark Matter, 10.5281/zenodo.6505275 (2021)

    T. Siegert, Galactic Diffuse Emission Spectrum between 0.5 and 8.0 MeV and between 30 keV and 8 MeV for the search of PBH Dark Matter, 10.5281/zenodo.6505275 (2021)

    2021 doi

  67. [75]

    Lin and X

    H.-N. Lin and X. Li, The dark matter profiles in the Milky Way, MNRAS 487, 5679 (2019), arXiv:1906.08419 [astro-ph.GA]

    2019 arXiv

  68. [76]

    Y. Jiao, F. Hammer, H. Wang, J. Wang, P. Amram, L. Chemin, and Y. Yang, Detection of the Keplerian de- cline in the Milky Way rotation curve, A&A 678, A208 (2023), arXiv:2309.00048 [astro-ph.GA]

    2023

  69. [77]

    V. Zabalza, Naima: a Python package for infer- ence of particle distribution properties from nonther- mal spectra, in 34th International Cosmic Ray Confer- ence (ICRC2015), International Cosmic Ray Conference, Vol. 34 (2015) p. 922, arXiv:1509.03319 [astro-ph.HE]

    2015 arXiv

  70. [78]

    Khangulyan, F

    D. Khangulyan, F. A. Aharonian, and S. R. Kelner, Simple Analytical Approximations for Treatment of In- verse Compton Scattering of Relativistic Electrons in the Blackbody Radiation Field, ApJ 783, 100 (2014), arXiv:1310.7971 [astro-ph.HE]

    2014 arXiv

  71. [79]

    M. R. Krumholz, R. M. Crocker, and S. S. R. Offner, The cosmic ray ionization and γ-ray budgets of star-forming galaxies, MNRAS 520, 5126 (2023), arXiv:2211.03488 [astro-ph.GA]

    2023 arXiv

  72. [80]

    Y.-K. Kim, J. P. Santos, and F. Parente, Extension of the binary-encounter-dipole model to relativistic incident electrons, Phys. Rev. A 62, 052710 (2000)

    2000

  73. [81]

    R. J. Gould, Energy loss of fast electrons and positrons in a plasma, Physica 60, 145 (1972)

    1972

  74. [82]

    G. R. Blumenthal and R. J. Gould, Bremsstrahlung, Syn- chrotron Radiation, and Compton Scattering of High- Energy Electrons Traversing Dilute Gases, Reviews of Modern Physics 42, 237 (1970)

    1970

  75. [83]

    Foreman-Mackey, D

    D. Foreman-Mackey, D. W. Hogg, D. Lang, and J. Good- man, emcee: The MCMC Hammer, PASP 125, 306 (2013), arXiv:1202.3665 [astro-ph.IM]

    2013 arXiv

  76. [84]

    Kamionkowski, S

    M. Kamionkowski, S. M. Koushiappas, and M. Kuhlen, Galactic substructure and dark-matter annihilation in the Milky Way halo, Phys. Rev. D 81, 043532 (2010), arXiv:1001.3144 [astro-ph.GA]. 8 END MA TTER Background Emission Model Our model for the background to the lepton emis- ...

    2010 arXiv

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