Dark matter constraints with stacked gamma rays scales with the number of galaxies

Hashimoto, Daiki; Nishizawa, Atsushi J.; Takada, Masahiro; Macías, Óscar

doi:10.48550/arxiv.2109.08832

Cited by 4 publications

(9 citation statements)

References 49 publications

(61 reference statements)

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“…In this work, we place the constraint on the DM annihilation cross-section by cross-correlating the DES-LSBG (23,790 objects in the sky coverage of ∼ 5, 000 deg 2 ) without individual distance information to the UGRB photon field obtained by the Fermi -LAT observation in the energy range of 500 MeV to 500 GeV, accumulated over 12 years. As performed in our previous work [21], the distance of individual galaxy is randomly drawn from the estimated dN/dz distribution, which is measured by the cross-correlation of LSBGs with galaxies whose distances are spectroscopically identified. For the dN/dz measurement, we have estimated the angular cross-correlation of all red or blue LSBG samples with different redshift samples of the 6dFGS spec-z sample which is divided into five redshift bins with equal width in the range of 0 < z < 0.15.…”

Section: Discussionmentioning

confidence: 99%

“…In this section, we revisit methodology for the crosssection constraint with a large number of objects without individual redshift. The method follows our previ-ous work [21] but we introduce the cross covariance between different redshift bins in the dN/dz measurement for more realistic sampling of the redshift distribution.…”

Section: Methodsmentioning

confidence: 99%

“…For the flux likelihood of our LSBG, we adopt the Bayesian method as described in section III B and define the likelihood of the annihilation γ-ray flux model for each LSBG as L(α ij | σv , J i ), where J i and α ij are the J-factor of i-th LSBG and the UGRB amplitude parameter at the object position in the j-th energy bin in Section III B, respectively. Given the density of LSBG sample in the sky, we assume that the flux amplitudes of all LSBGs are statistically independent of each other [21]. Then, the composite likelihood is given by log L(α| σv , J) = ij L(α ij | σv , J i ).…”

Section: B γ-Ray Flux Modeling For Dm Annihilationmentioning

confidence: 99%

“…We have explored the annihilation γ-ray signal in the UGRB sky performing the joint likelihood analysis with known-redshift LSBGs, which is included in a tiny fraction of a LSBG catalog produced from the Hyper Suprime-Cam (HSC) data [20]. In our another previous work [21], we have presented the method for the signal probe using all LSBGs (∼ 800 objects) of the HSC-LSBG catalog. In the method, we randomly assign object redshifts from the redshift distribution of the overall sample dN/dz, which is obtained by the so-called clustering redshift method, in which we measure angular cross-correlations of LSBGs and a spectroscopic redshift (spec-z) sample as a reference sample in different redshift bins, and convert the correlations to the dN/dz amplitudes.…”

Section: Introductionmentioning

confidence: 99%

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Constraining Dark matter annihilation with Dark Energy Survey Y3 LSBG sample

Hashimoto¹,

Nishizawa²,

Takada³

2022

Preprint

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To reveal natures of the dark matter (DM) particles, a γ-ray signal produced in annihilation processes of DM into the standard model particles has been one of the major probes. The crosscorrelation between highly DM dominated structures, such as local dwarf galaxies, and observed photons in the direction of the structures, has been explored and provided stringent constraints on the annihilation rate. In our previous work, we have shown that it is sufficient to know the distance distribution of the galaxy sample and individual distance measurement is not required for constraining the annihilation rate. In this work, we apply the method to low-surface brightness galaxies (LSBGs) with unknown individual redshifts provided from the Dark Energy Survey (DES) Year 3 data. With all DES-LSBGs of ∼24,000 objects, we find that the upper limits of the cross section σv for b b channel with 95% C.L. is ∼ 3 × 10 −25 cm 3 /s at DM mass of 100 GeV. To be more conservative, we remove ∼ 7000 LSBGs within 1 • from resolved γ-ray point sources and then the constraint becomes ∼30 % weaker than the one with all samples in all DM mass ranges.

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Section: Discussionmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: B γ-Ray Flux Modeling For Dm Annihilationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Constraining Dark matter annihilation with Dark Energy Survey Y3 LSBG sample

Hashimoto¹,

Nishizawa²,

Takada³

2022

Preprint

Self Cite

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“…Previous studies have placed constraints on σv through cross-correlation between Fermi -LAT data and galaxy [e.g. 39,40] or lensing [41] catalogues, or by studying nearby dwarf galaxies [42][43][44] or groups [45]. Moreover, such emission should increase the kinetic energy of baryons, so by considering the impact on the Cosmic Microwave Background (CMB) [46] or galaxy formation [47], one can rule out a velocity-independent crosssection for thermal relic DM particles less massive that ∼ 30 GeV.…”

Section: Introductionmentioning

confidence: 99%

Constraints on dark matter annihilation and decay from the large-scale structure of the nearby universe

Bartlett¹,

Kostić²,

Desmond³

et al. 2022

Preprint

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Decaying or annihilating dark matter particles could be detected through gamma-ray emission from the species they decay or annihilate into. This is usually done by modelling the flux from specific dark matter-rich objects such as the Milky Way halo, Local Group dwarfs and nearby groups. However, these objects are expected to have significant emission from baryonic processes as well, and the analyses discard gamma-ray data over most of the sky. Here we construct full-sky templates for gamma-ray flux from the large-scale structure within ∼200 Mpc by means of a suite of constrained N -body simulations (CSiBORG) produced using the Bayesian Origin Reconstruction from Galaxies algorithm. Marginalising over uncertainties in this reconstruction, small-scale structure and parameters describing astrophysical contributions to the observed gamma ray sky, we compare to observations from the Fermi Large Area Telescope to constrain dark matter annihilation crosssections and decay rates through a Markov Chain Monte Carlo analysis. We rule out the thermal relic cross-section for s-wave annihilation for all mχ < ∼ 7 GeV/c 2 at 95% confidence if the annihilation produces Z bosons, gluons or quarks less massive than the bottom quark. We infer a contribution to the gamma ray sky with the same spatial distribution as dark matter decay at 3.3σ. Although this could be due to dark matter decay via these channels with a decay rate Γ ≈ 3 × 10 −28 s −1 , we find that a power-law spectrum of index p = −2.75 +0.71 −0.46 , likely of baryonic origin, is preferred by the data.

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Constraints on dark matter annihilation and decay from the large-scale structure of the nearby Universe

et al. 2022

View full text Add to dashboard Cite

Decaying or annihilating dark matter particles could be detected through gamma-ray emission from the species they decay or annihilate into. This is usually done by modeling the flux from specific dark matterrich objects such as the Milky Way halo, Local Group dwarfs, and nearby groups. However, these objects are expected to have significant emission from baryonic processes as well, and the analyses discard gamma-ray data over most of the sky. Here we construct full-sky templates for gamma-ray flux from the large-scale structure within ∼200 Mpc by means of a suite of constrained N-body simulations (CSIBORG) produced using the Bayesian Origin Reconstruction from Galaxies algorithm. Marginalizing over uncertainties in this reconstruction, small-scale structure, and parameters describing astrophysical contributions to the observed gamma-ray sky, we compare to observations from the Fermi Large Area Telescope to constrain dark matter annihilation cross sections and decay rates through a Markov chain Monte Carlo analysis. We rule out the thermal relic cross section for s-wave annihilation for all m χ ≲ 7 GeV=c 2 at 95% confidence if the annihilation produces gluons or quarks less massive than the bottom quark. We infer a contribution to the gamma-ray sky with the same spatial distribution as dark matter decay at 3.3σ. Although this could be due to dark matter decay via these channels with a decay rate Γ ≈ 6 × 10 −28 s −1 , we find that a power-law spectrum of index p ¼ −2.75 þ0.71 −0.46 , likely of baryonic origin, is preferred by the data.

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Dark matter constraints with stacked gamma rays scales with the number of galaxies

Cited by 4 publications

References 49 publications

Constraining Dark matter annihilation with Dark Energy Survey Y3 LSBG sample

Constraining Dark matter annihilation with Dark Energy Survey Y3 LSBG sample

Constraints on dark matter annihilation and decay from the large-scale structure of the nearby universe

Constraints on dark matter annihilation and decay from the large-scale structure of the nearby Universe

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