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Miller AL, Zhao Y. Probing the Pulsar Explanation of the Galactic-Center GeV Excess Using Continuous Gravitational-Wave Searches. PHYSICAL REVIEW LETTERS 2023; 131:081401. [PMID: 37683174 DOI: 10.1103/physrevlett.131.081401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 04/03/2023] [Accepted: 07/12/2023] [Indexed: 09/10/2023]
Abstract
Over 10 years ago, Fermi observed an excess of GeV gamma rays from the Galactic Center whose origin is still under debate. One explanation for this excess involves annihilating dark matter, another requires an unresolved population of millisecond pulsars concentrated at the Galactic Center. In this work, we use the results from LIGO and Virgo's most recent all-sky search for quasimonochromatic, persistent gravitational-wave signals from isolated neutron stars, which is estimated to be about 20%-50% of the population, to determine whether unresolved millisecond pulsars could actually explain this excess. First, we choose a luminosity function that determines the number of millisecond pulsars required to explain the observed excess. Then, we consider two models for deformations on millisecond pulsars to determine their ellipticity distributions, which are directly related to their gravitational-wave radiation. Lastly, based on null results from the O3 frequency-Hough all-sky search for continuous gravitational waves, we find that a large set of the parameter space in the pulsar luminosity function can be excluded. We also evaluate how these exclusion regions may change with respect to various model choices. Our results are the first of their kind and represent a bridge between gamma-ray astrophysics, gravitational-wave astronomy, and dark-matter physics.
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Affiliation(s)
- Andrew L Miller
- Université catholique de Louvain, B-1348 Louvain-la-Neuve, Belgium
- Nikhef-National Institute for Subatomic Physics, Science Park 105, 1098 XG Amsterdam, The Netherlands
- Institute for Gravitational and Subatomic Physics (GRASP), Utrecht University, Princetonplein 1, 3584 CC Utrecht, The Netherlands
| | - Yue Zhao
- Department of Physics and Astronomy, University of Utah, Salt Lake City, Utah 84112, USA
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Zhu CR, Cui MY, Xia ZQ, Yu ZH, Huang X, Yuan Q, Fan YZ. Explaining the GeV Antiproton Excess, GeV γ-Ray Excess, and W-Boson Mass Anomaly in an Inert Two Higgs Doublet Model. PHYSICAL REVIEW LETTERS 2022; 129:231101. [PMID: 36563204 DOI: 10.1103/physrevlett.129.231101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Revised: 09/20/2022] [Accepted: 10/31/2022] [Indexed: 06/17/2023]
Abstract
For the newly discovered W-boson mass anomaly, one of the simplest dark matter (DM) models that can account for the anomaly without violating other astrophysical and experimental constraints is the inert two Higgs doublet model, in which the DM mass (m_{S}) is found to be within ∼54-74 GeV. In this model, the annihilation of DM via SS→bb[over ¯] and SS→WW^{*} would produce antiprotons and gamma rays, and may account for the excesses identified previously in both particles. Motivated by this, we reanalyze the AMS-02 antiproton and Fermi-LAT Galactic center γ-ray data. For the antiproton analysis, the novel treatment is the inclusion of the charge-sign-dependent three-dimensional solar modulation model as constrained by the time-dependent proton data. We find that the excess of antiprotons is more distinct than previous results based on the force-field solar modulation model. The interpretation of this excess as the annihilation of SS→WW^{*} (SS→bb[over ¯]) requires a DM mass of ∼40-80 (40-60) GeV and a velocity-averaged cross section of O(10^{-26}) cm^{3} s^{-1}. As for the γ-ray data analysis, besides adopting the widely used spatial template fitting, we employ an orthogonal approach with a data-driven spectral template analysis. The fitting to the GeV γ-ray excess yields DM model parameters overlapped with those to fit the antiproton excess via the WW^{*} channel. The consistency of the DM particle properties required to account for the W-boson mass anomaly, the GeV antiproton excess, and the GeV γ-ray excess suggests a common origin of them.
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Affiliation(s)
- Cheng-Rui Zhu
- Key Laboratory of Dark Matter and Space Astronomy, Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210023, China
- Shandong Institute of Advanced Technology, Jinan 250100, China
| | - Ming-Yang Cui
- Key Laboratory of Dark Matter and Space Astronomy, Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210023, China
| | - Zi-Qing Xia
- Key Laboratory of Dark Matter and Space Astronomy, Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210023, China
| | - Zhao-Huan Yu
- School of Physics, Sun Yat-Sen University, Guangzhou 510275, China
| | - Xiaoyuan Huang
- Key Laboratory of Dark Matter and Space Astronomy, Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210023, China
- School of Astronomy and Space Science, University of Science and Technology of China, Hefei 230026, Anhui, China
| | - Qiang Yuan
- Key Laboratory of Dark Matter and Space Astronomy, Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210023, China
- School of Astronomy and Space Science, University of Science and Technology of China, Hefei 230026, Anhui, China
| | - Yi-Zhong Fan
- Key Laboratory of Dark Matter and Space Astronomy, Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210023, China
- School of Astronomy and Space Science, University of Science and Technology of China, Hefei 230026, Anhui, China
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Abstract
This is a brief review of aspects of galactic astrophysics and astronomy which have a possible bearing on particle dark matter. It is still quite normal for particle physicists to try to solve “well known anomalies“ that are apparently seen in observations of galaxies (missing satellites, cusp vs. core, etc.) whereas a lot of these anomalies have actually been resolved many years ago. We will try to briefly review the field and discuss many of the areas in question.
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Smyth N, Huckabee G, Profumo S. Optimal observing strategies for velocity-suppressed dark matter annihilation. Int J Clin Exp Med 2021. [DOI: 10.1103/physrevd.104.123003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Calore F, Donato F, Manconi S. Dissecting the Inner Galaxy with γ-Ray Pixel Count Statistics. PHYSICAL REVIEW LETTERS 2021; 127:161102. [PMID: 34723610 DOI: 10.1103/physrevlett.127.161102] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 05/11/2021] [Accepted: 09/03/2021] [Indexed: 06/13/2023]
Abstract
We combine adaptive template fitting and pixel count statistics in order to assess the nature of the Galactic Center excess in Fermi-LAT data. We reconstruct the flux distribution of point sources well below the Fermi-LAT detection threshold, and measure their radial and longitudinal profiles in the inner Galaxy. We find that all point sources and the bulge-correlated diffuse emission each contributes O(10%) of the total inner Galaxy emission, and disclose a potential subthreshold point-source contribution to the Galactic Center excess.
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Affiliation(s)
- F Calore
- Université Grenoble Alpes, USMB, CNRS, LAPTh, F-74940 Annecy, France
| | - F Donato
- Dipartimento di Fisica, Università di Torino, via P. Giuria, 1, I-10125 Torino, Italy
- Istituto Nazionale di Fisica Nucleare, Sezione di Torino, via P. Giuria, 1, I-10125 Torino, Italy
| | - S Manconi
- Institute for Theoretical Particle Physics and Cosmology, RWTH Aachen University, Sommerfeldstraße 16, 52056 Aachen, Germany
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Di Mauro M, Winkler MW. Multimessenger constraints on the dark matter interpretation of the
Fermi
-LAT Galactic Center excess. Int J Clin Exp Med 2021. [DOI: 10.1103/physrevd.103.123005] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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List F, Rodd NL, Lewis GF, Bhat I. Galactic Center Excess in a New Light: Disentangling the γ-Ray Sky with Bayesian Graph Convolutional Neural Networks. PHYSICAL REVIEW LETTERS 2020; 125:241102. [PMID: 33412055 DOI: 10.1103/physrevlett.125.241102] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 09/24/2020] [Accepted: 10/26/2020] [Indexed: 06/12/2023]
Abstract
A fundamental question regarding the Galactic Center excess (GCE) is whether the underlying structure is pointlike or smooth, often framed in terms of a millisecond pulsar or annihilating dark matter (DM) origin for the emission. We show that Bayesian neural networks (NNs) have the potential to resolve this debate. In simulated data, the method is able to predict the flux fractions from inner Galaxy emission components to on average ∼0.5%. When applied to the Fermi photon-count map, the NN identifies a smooth GCE in the data, suggestive of the presence of DM, with the estimates for the background templates being consistent with existing results.
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Affiliation(s)
- Florian List
- Sydney Institute for Astronomy, School of Physics, A28, The University of Sydney, New South Wales 2006, Australia
| | - Nicholas L Rodd
- Berkeley Center for Theoretical Physics, University of California, Berkeley, California 94720, USA
- Theoretical Physics Group, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Geraint F Lewis
- Sydney Institute for Astronomy, School of Physics, A28, The University of Sydney, New South Wales 2006, Australia
| | - Ishaan Bhat
- UMC Utrecht, Image Sciences Institute, 3508 GA Utrecht, The Netherlands
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Leane RK, Slatyer TR. Spurious Point Source Signals in the Galactic Center Excess. PHYSICAL REVIEW LETTERS 2020; 125:121105. [PMID: 33016744 DOI: 10.1103/physrevlett.125.121105] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Accepted: 08/24/2020] [Indexed: 06/11/2023]
Abstract
We reexamine evidence that the Galactic Center Excess (GCE) originates primarily from point sources (PSs). We show that in our region of interest, non-Poissonian template fitting evidence for GCE PSs is an artifact of unmodeled north-south asymmetry of the GCE. This asymmetry is strongly favored by the fit (although it is unclear if this is physical), and when it is allowed, the preference for PSs becomes insignificant. We reproduce this behavior in simulations, including detailed properties of the spurious PS population. We conclude that the non-Poissonian template fitting evidence for GCE PSs is highly susceptible to certain systematic errors and should not at present be taken to robustly disfavor a dominantly smooth GCE.
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Affiliation(s)
- Rebecca K Leane
- Center for Theoretical Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Tracy R Slatyer
- Center for Theoretical Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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Leane RK, Slatyer TR. The enigmatic Galactic Center excess: Spurious point sources and signal mismodeling. Int J Clin Exp Med 2020. [DOI: 10.1103/physrevd.102.063019] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Zhong YM, McDermott SD, Cholis I, Fox PJ. Testing the Sensitivity of the Galactic Center Excess to the Point Source Mask. PHYSICAL REVIEW LETTERS 2020; 124:231103. [PMID: 32603155 DOI: 10.1103/physrevlett.124.231103] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 03/02/2020] [Accepted: 05/22/2020] [Indexed: 06/11/2023]
Abstract
The Fermi Large Area Telescope (Fermi-LAT) Collaboration has an updated point source catalog, referred to as 4FGL. We perform the first template fit using a mask based on this new catalog and find that the excess in gamma rays detected at the Galactic Center in Fermi-LAT data persists. On the other hand, we find that a search for point sources is highly sensitive to the use of the 4FGL catalog: no sizable excess of bright pixels is apparent in the inner Galaxy when we mask out 4FGL point sources. Combining these observations restricts the ability of point sources to contribute to the Galactic Center excess. After identifying which bright sources have no known counterpart, we place strong constraints on any point source luminosity function capable of explaining the smooth emission identified in the template fit.
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Affiliation(s)
- Yi-Ming Zhong
- Kavli Institute for Cosmological Physics, University of Chicago, Chicago, Illinois 60637, USA
| | | | - Ilias Cholis
- Department of Physics, Oakland University, Rochester, Michigan 48326, USA
| | - Patrick J Fox
- Fermi National Accelerator Laboratory, Batavia, Illinois 60510, USA
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