pith. sign in

arxiv: 1907.07737 · v1 · pith:RYOW2BUNnew · submitted 2019-07-17 · 🌌 astro-ph.IM · astro-ph.HE

The Southern Wide-Field Gamma-Ray Observatory (SWGO): A Next-Generation Ground-Based Survey Instrument for VHE Gamma-Ray Astronomy

Pith reviewed 2026-05-24 19:50 UTC · model grok-4.3

classification 🌌 astro-ph.IM astro-ph.HE
keywords gamma-ray astronomywide-field observatorysouthern hemisphereextensive air showersmulti-messenger astronomyVHE gamma raysparticle detector array
0
0 comments X

The pith

SWGO will survey the southern sky in very-high-energy gamma rays with a particle-detector array built from proven technology at an estimated 54 million USD.

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

The paper presents plans for the Southern Wide-field Gamma-ray Observatory, an instrument that will observe very-high-energy gamma rays across a wide field in the Southern Hemisphere. It claims this observatory can be assembled from existing detector technology already used for air-shower measurements and will fill a gap left by northern instruments. The design uses a dense inner array surrounded by a thinner outer array, with projected construction costs of 54 million USD and operations beginning in 2026. A US contribution of 20 million USD is expected to give American researchers a leading role. The instrument is positioned to support studies of Galactic accelerators, transient events, and tests of physics beyond the Standard Model through multi-messenger observations.

Core claim

A next-generation wide-field gamma-ray observatory in the Southern Hemisphere can be constructed using current, already-proven technology for detecting extensive air showers, delivering wide coverage of the southern sky at a construction cost of 54 million USD and five-year operations cost of 7.5 million USD, with full operations starting in 2026.

What carries the argument

The detector array of a compact inner array of particle detection units surrounded by a sparser outer array, which records extensive air showers to achieve wide-field sensitivity.

If this is right

  • Wide-field coverage of a large portion of the southern sky becomes available for very-high-energy gamma-ray observations.
  • Current and future northern instruments gain a southern complement for coordinated multi-messenger studies.
  • Science programs on Galactic particle accelerators, the dynamic universe, and physics beyond the Standard Model receive dedicated southern-sky data.
  • A US investment of 20 million USD positions American groups to lead aspects of the project.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • Joint observations with neutrino and gravitational-wave detectors could increase the fraction of transients that receive prompt very-high-energy follow-up.
  • The modular array design may allow staged deployment that reduces initial risk while still delivering early science results.
  • If site selection succeeds in a high-altitude location with clear skies, the effective energy threshold could drop below current southern instruments.

Load-bearing premise

The detector can be built with already-proven technology at the stated cost without major unforeseen technical or funding problems.

What would settle it

An independent cost and performance review that shows the array cannot reach the required sensitivity or that total construction exceeds 54 million USD by more than 20 percent.

Figures

Figures reproduced from arXiv: 1907.07737 by A. Albert, A. Carrami\~nana, A. Chiavassa, A. De Angelis, A. Haungs, A. Insolia, A. Jardin-Blicq, A. M. Brown, A. Pichel, A. Reisenegger, A. Rovero, A. Sandoval, A. Smith, A. Viana, A. Zepeda, B. Dingus, B. Hona, B. Tom\'e, B. Zhou, C. Alvarez, C. Brisbois, C. Dib, C. Duffy, D. Dorner, E. Moreno, E. Prandini, E. Ruiz-Velasco, F. Barao, F. Brun, F. Peron, F. Sch\"ussler, G. Cotter, G. Di Sciascio, G. La Mura, H. Fleischhack, H. Mart\'inez-Huerta, H. Schoorlemmer, H. Zhou, I. Torres, J. A. Garc\'ia-Gonz\'alez, J. A. Goodman, J. Bazo, J. Bellido, J. C. D\'iaz V\'elez, J. F. Beacom, J. Lapington, J. Martinez-Castro, J. P. Harding, J. P. Lenain, J. Rodriguez, K. C. Y. Ng, K. Kawata, K. Malone, K. Satalecka, K. S. Caballero Mora, K. Tollefson, L. Mendes, M. Buscemi, M. De Maria, M. Doro, M. DuVernois, M. Fernandez Alonso, M. M. Gonz\'alez, M. Mostaf\'a, M. Pimenta, M. Roth, M. Santander, M. Schneider, M. U. Nisa, N. Fraija, P. Abreu, P. Assis, P. Camarri, P. Cristofari, P. Desiati, P. Fonte, P. Huentemeyer, P. Surajbali, R. Alfaro, R. Arceo, R. Concei\c{c}\~ao, R. C. Shellard, R. Engel, R. L\'opez-Coto, R. Wischnewski, S. BenZvi, S. Casanova, S. Dasso, S. Funk, S. Kunwar, S. Rain\`o, S. Spencer, T. Bretz, T. Greenshaw, T. Sako, T. Weisgarber, V. Joshi, W. Springer.

Figure 1
Figure 1. Figure 1: Left: Differential point-source sensitivity as a function of energy for the proposed SWGO detector compared to other existing or proposed instruments. Right: Sky coverage of SWGO in Galactic coordinates overlaid on HAWC significance map containing over 50 sources. Unveiling Galactic particle accelerators – Sensitivity to astrophysical particle accelerators in the local Galactic neighborhood is one of the g… view at source ↗
Figure 2
Figure 2. Figure 2: Left: Illustration of detection unit design. Right: Muon and gamma-ray passing through a detection unit. Red lines indicate a fraction of the Cherekov photon tracks, while the green, blue, and yellow lines indicate the tracks of muons, gamma rays and electrons respectively. objectives require a significantly improved sensitivity in the sub-TeV energy domain. For a detection unit this means lowering the ene… view at source ↗
Figure 3
Figure 3. Figure 3: Left: Average number density at 5 km above sea level for air showers initiated by 1 TeV protons (adapted from [91]). Right: Detection threshold probability for secondary gamma rays of the SWGO unit design. The top compartment is compared to a HAWC detector unit. A 8” PMT R5912 Hamamatsu PMT has been assumed in this simulation. The vertical dashed line in both panels indicates 10MeV. This will aid the high-… view at source ↗
Figure 4
Figure 4. Figure 4: Left: Array configuration with instrumented areas and ground coverage indicated (and HAWC equivalent for comparison). Right: SWGO response for two simulated gamma-ray events. The color coding indicates the time gradient. The 200 GeV example illustrates the large particle spread even at low energy. 7 [PITH_FULL_IMAGE:figures/full_fig_p008_4.png] view at source ↗
read the original abstract

We describe plans for the development of the Southern Wide-field Gamma-ray Observatory (SWGO), a next-generation instrument with sensitivity to the very-high-energy (VHE) band to be constructed in the Southern Hemisphere. SWGO will provide wide-field coverage of a large portion of the southern sky, effectively complementing current and future instruments in the global multi-messenger effort to understand extreme astrophysical phenomena throughout the universe. A detailed description of science topics addressed by SWGO is available in the science case white paper [1]. The development of SWGO will draw on extensive experience within the community in designing, constructing, and successfully operating wide-field instruments using observations of extensive air showers. The detector will consist of a compact inner array of particle detection units surrounded by a sparser outer array. A key advantage of the design of SWGO is that it can be constructed using current, already proven technology. We estimate a construction cost of 54M USD and a cost of 7.5M USD for 5 years of operation, with an anticipated US contribution of 20M USD ensuring that the US will be a driving force for the SWGO effort. The recently formed SWGO collaboration will conduct site selection and detector optimization studies prior to construction, with full operations foreseen to begin in 2026. Throughout this document, references to science white papers submitted to the Astro2020 Decadal Survey with particular relevance to the key science goals of SWGO, which include unveiling Galactic particle accelerators [2-10], exploring the dynamic universe [11-21], and probing physics beyond the Standard Model [22-25], are highlighted in red boldface.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

1 major / 1 minor

Summary. The manuscript is a white paper describing plans for the Southern Wide-field Gamma-ray Observatory (SWGO), a proposed next-generation wide-field VHE gamma-ray detector array in the Southern Hemisphere. It outlines a design using proven extensive air shower technology with a compact inner array surrounded by a sparser outer array, defers the detailed science case to a companion white paper, provides community-based cost estimates (54M USD construction, 7.5M USD for 5 years operation, 20M USD anticipated US contribution), and projects full operations beginning in 2026 following site selection and optimization studies.

Significance. If realized, SWGO would fill a critical gap by providing wide-field southern-sky coverage to complement northern instruments such as HAWC and future facilities like CTA, supporting multi-messenger astrophysics. The explicit reliance on already-proven technology and community experience with similar arrays is a clear strength that lowers technical risk. The cost and timeline projections, however, are presented without supporting breakdowns or validation data.

major comments (1)
  1. [Abstract] Abstract: The construction cost of 54M USD, 5-year operation cost of 7.5M USD, and US contribution of 20M USD are stated as community estimates without detailed breakdowns, error bars, contingency allowances, or comparisons to analogous projects (e.g., HAWC construction costs). These figures are load-bearing for the feasibility claim and the projected 2026 start date.
minor comments (1)
  1. [Abstract] The manuscript appropriately references the science case to a separate white paper [1] and highlights relevant Astro2020 submissions in red boldface, but the latter formatting may not be preserved in all viewing formats.

Simulated Author's Rebuttal

1 responses · 0 unresolved

We thank the referee for the positive assessment of SWGO's scientific potential and technical approach, and for the constructive feedback on the cost and timeline estimates. We address the single major comment below.

read point-by-point responses
  1. Referee: [Abstract] Abstract: The construction cost of 54M USD, 5-year operation cost of 7.5M USD, and US contribution of 20M USD are stated as community estimates without detailed breakdowns, error bars, contingency allowances, or comparisons to analogous projects (e.g., HAWC construction costs). These figures are load-bearing for the feasibility claim and the projected 2026 start date.

    Authors: We agree that the cost figures would benefit from additional context to support the feasibility discussion. These values are community-derived estimates informed by direct experience with HAWC and other air-shower arrays; however, as this is a high-level white paper rather than a technical design report, detailed breakdowns, contingencies, and error bars were not included. We will revise the abstract and add a short paragraph (or footnote) that (i) references HAWC construction costs for comparison, (ii) notes the absence of contingency allowances at this stage, and (iii) states that full cost-validation studies will appear in subsequent technical documents. The 2026 operations date remains a planning target contingent on site selection and funding timelines, which we will clarify. revision: yes

Circularity Check

0 steps flagged

No significant circularity; proposal with no derivations or equations

full rationale

This is an instrument proposal white paper describing plans for SWGO construction, site selection, science complementarity, and cost estimates (54M USD construction, 7.5M USD operations). No equations, parameters, predictions, or derivation chains appear anywhere in the document. Claims rest on engineering experience with proven technology and references to separate science white papers, none of which reduce to self-definition or fitted inputs by construction. The document is self-contained as a forward-looking proposal without any load-bearing mathematical steps that could exhibit circularity.

Axiom & Free-Parameter Ledger

3 free parameters · 2 axioms · 0 invented entities

The proposal rests on cost estimates treated as free parameters and domain assumptions about technology readiness and collaboration success; no new physical entities are introduced.

free parameters (3)
  • construction cost = 54M USD
    Stated as 54M USD based on experience with similar instruments.
  • 5-year operation cost = 7.5M USD
    Stated as 7.5M USD projected operational expense.
  • US contribution = 20M USD
    Anticipated share of 20M USD to lead the project.
axioms (2)
  • domain assumption Wide-field instruments using observations of extensive air showers are effective for VHE gamma-ray detection.
    Invoked when describing the detector design and its advantages.
  • domain assumption Current proven technology is sufficient to construct SWGO at the estimated cost.
    Explicitly stated as a key advantage of the design.

pith-pipeline@v0.9.0 · 6384 in / 1539 out tokens · 37281 ms · 2026-05-24T19:50:36.435809+00:00 · methodology

discussion (0)

Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.

Forward citations

Cited by 1 Pith paper

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

  1. Enhancing event reconstruction for $\gamma$-ray particle detector arrays using transformers

    astro-ph.IM 2026-04 unverdicted novelty 6.0

    Transformer models applied to simulated water-Cherenkov array data improve gamma-hadron separation and reconstruction of direction, core position, and energy compared to established techniques.

Reference graph

Works this paper leans on

92 extracted references · 92 canonical work pages · cited by 1 Pith paper · 58 internal anchors

  1. [1]

    Science Case for a Wide Field-of-View Very-High-Energy Gamma-Ray Observatory in the Southern Hemisphere

    A. Albert, et al.,Science Case for a Wide Field-of-V iew V ery-High-Energy Gamma-Ray Observatory in the Southern Hemisphere, arXiv e-prints, arXiv:1902.08429 (2019),1902.08429

  2. [2]

    H. Fleischhack, et al.,Pulsars in a Bubble? F ollowing Electron Diffusion in the Galaxy with T eV Gamma Rays, in Astro2020: Decadal Survey on Astronomy and Astrophysics, Bulletin of the AAS, Bd. 51, 311 (2019),1903.07647

  3. [3]

    Prospects for the detection of synchrotron halos around middle-age pulsars

    M. Di Mauro, S. Manconi, & F. Donato,Prospects for the detection of synchrotron halos around middle-age pulsars, in Astro2020: Decadal Survey on Astronomy and Astrophysics, Bulletin of the AAS, Bd. 51, 183 (2019),1903.05699

  4. [4]

    J. Gelfand, et al., MeV Emission from Pulsar Wind Nebulae: Understanding Extreme P article Acceleration in Highly Relativistic Outflows, in Astro2020: Decadal Survey on Astronomy and Astrophysics, Bulletin of the AAS, Bd. 51, 513 (2019)

  5. [5]

    Cristofari, et al.,Where are the pevatrons?, in Astro2020: Decadal Survey on Astronomy and Astrophysics, Bulletin of the AAS, Bd

    P . Cristofari, et al.,Where are the pevatrons?, in Astro2020: Decadal Survey on Astronomy and Astrophysics, Bulletin of the AAS, Bd. 51, 115 (2019)

  6. [6]

    J. Holder, et al., Understanding the Origin and Impact of Relativistic Cosmic P articles with V ery-High-Energy Gamma-rays, in Astro2020: Decadal Survey on Astronomy and Astrophysics, Bulletin of the AAS, Bd. 51, 267 (2019)

  7. [7]

    Fryer, et al.,Core-Collapse Supernovae and Multi-Messenger Astronomy, in Astro2020: Decadal Survey on Astronomy and Astrophysics, Bulletin of the AAS, Bd

    C. Fryer, et al.,Core-Collapse Supernovae and Multi-Messenger Astronomy, in Astro2020: Decadal Survey on Astronomy and Astrophysics, Bulletin of the AAS, Bd. 51, 122 (2019)

  8. [8]

    Schroeder, et al., High-Energy Galactic Cosmic Rays, in Astro2020: Decadal Survey on Astronomy and Astrophysics, Bulletin of the AAS, Bd

    F. Schroeder, et al., High-Energy Galactic Cosmic Rays, in Astro2020: Decadal Survey on Astronomy and Astrophysics, Bulletin of the AAS, Bd. 51, 131 (2019)

  9. [9]

    Fraija, et al.,Cosmic rays in the T eV to P eV primary energy range, Astro2020: Decadal Survey on Astronomy and Astrophysics,2020, 459 (2019)

    N. Fraija, et al.,Cosmic rays in the T eV to P eV primary energy range, Astro2020: Decadal Survey on Astronomy and Astrophysics,2020, 459 (2019)

  10. [10]

    The Sun at GeV--TeV Energies: A New Laboratory for Astroparticle Physics

    M. Nisa, et al., The Sun at GeV-T eV Energies: A New Laboratory for Astroparticle Physics, in Astro2020: Decadal Survey on Astronomy and Astrophysics, Bulletin of the AAS, Bd. 51, 194 (2019),1903.06349

  11. [11]

    Fraija, et al., Surveying T eV gamma-ray emission from active galactic nuclei, Astro2020: Decadal Survey on Astronomy and Astrophysics,2020, 444 (2019)

    N. Fraija, et al., Surveying T eV gamma-ray emission from active galactic nuclei, Astro2020: Decadal Survey on Astronomy and Astrophysics,2020, 444 (2019)

  12. [12]

    H. Ji, et al., Major Scientific Challenges and Opportunities in Understanding Magnetic Recon- nection and Related Explosive Phenomena throughout the Universe, in Astro2020: Decadal Survey on Astronomy and Astrophysics, Bulletin of the AAS, Bd. 51, 5 (2019)

  13. [13]

    Multi-Physics of AGN Jets in the Multi-Messenger Era

    B. Rani, et al., Multi-Physics of AGN Jets in the Multi-Messenger Era, in Astro2020: Decadal Survey on Astronomy and Astrophysics, Bulletin of the AAS, Bd. 51, 92 (2019),1903.04504

  14. [14]

    Williams,Probing Extreme Environments with V ery-High-Energy Gamma Rays, in Astro2020: Decadal Survey on Astronomy and Astrophysics, Bulletin of the AAS, Bd

    D. Williams,Probing Extreme Environments with V ery-High-Energy Gamma Rays, in Astro2020: Decadal Survey on Astronomy and Astrophysics, Bulletin of the AAS, Bd. 51, 265 (2019) 13

  15. [15]

    Vieregg, et al., Astrophysics Uniquely Enabled by Observations of High-Energy Cosmic Neutrinos, in Astro2020: Decadal Survey on Astronomy and Astrophysics, Bulletin of the AAS, Bd

    A. Vieregg, et al., Astrophysics Uniquely Enabled by Observations of High-Energy Cosmic Neutrinos, in Astro2020: Decadal Survey on Astronomy and Astrophysics, Bulletin of the AAS, Bd. 51, 185 (2019)

  16. [16]

    V andenbroucke & M

    J. V andenbroucke & M. Santander,Multi-messenger and transient astrophysics with very-high- energy gamma rays, in Astro2020: Decadal Survey on Astronomy and Astrophysics, Bulletin of the AAS, Bd. 51, 553 (2019)

  17. [17]

    Santander, et al.,A Unique Messenger to Probe Active Galactic Nuclei: High-Energy Neutrinos, in Astro2020: Decadal Survey on Astronomy and Astrophysics, Bulletin of the AAS, Bd

    M. Santander, et al.,A Unique Messenger to Probe Active Galactic Nuclei: High-Energy Neutrinos, in Astro2020: Decadal Survey on Astronomy and Astrophysics, Bulletin of the AAS, Bd. 51, 228 (2019)

  18. [18]

    Schussler & K

    F. Schussler & K. Satalecka,All-Sky time domain astrophysics with V ery High Energy Gamma rays, in Astro2020: Decadal Survey on Astronomy and Astrophysics, Bulletin of the AAS, Bd. 51, 357 (2019)

  19. [19]

    Gamma Rays and Gravitational Waves

    E. Burns, et al., Gamma Rays and Gravitational W aves, in Astro2020: Decadal Survey on Astronomy and Astrophysics, Bulletin of the AAS, Bd. 51, 260 (2019),1903.04472

  20. [20]

    Opportunities for Multimessenger Astronomy in the 2020s

    E. Burns, et al.,Opportunities for Multimessenger Astronomy in the 2020s, in Astro2020: Decadal Survey on Astronomy and Astrophysics, Bulletin of the AAS, Bd. 51, 250 (2019),1903.04461

  21. [21]

    High-Energy Astrophysics in the 2020s and Beyond

    C. Reynolds, et al.,High-Energy Astrophysics in the 2020s and Beyond, in Astro2020: Decadal Survey on Astronomy and Astrophysics, Bulletin of the AAS, Bd. 51, 385 (2019),1903.07760

  22. [22]

    Viana,Searching for T eV Dark Matter in the Milky W ay Galactic Center, in Astro2020: Decadal Survey on Astronomy and Astrophysics, Bulletin of the AAS, Bd

    A. Viana,Searching for T eV Dark Matter in the Milky W ay Galactic Center, in Astro2020: Decadal Survey on Astronomy and Astrophysics, Bulletin of the AAS, Bd. 51, 308 (2019)

  23. [23]

    Albert, et al.,Searching for Sources of T eV P article Dark Matter in the Southern Hemisphere, in Astro2020: Decadal Survey on Astronomy and Astrophysics, Bulletin of the AAS, Bd

    A. Albert, et al.,Searching for Sources of T eV P article Dark Matter in the Southern Hemisphere, in Astro2020: Decadal Survey on Astronomy and Astrophysics, Bulletin of the AAS, Bd. 51, 202 (2019)

  24. [24]

    Mukherjee & A

    R. Mukherjee & A. N. Otte,Exploring Frontiers in Physics with V ery-High-Energy Gamma Rays, in Astro2020: Decadal Survey on Astronomy and Astrophysics, Bulletin of the AAS, Bd. 51, 203 (2019)

  25. [25]

    J. P . Harding, et al.,Exploring Beyond-the-Standard-Model Physics with T eV Gamma-rays, in Astro2020: Decadal Survey on Astronomy and Astrophysics, Bulletin of the AAS, Bd. 51, 272 (2019)

  26. [26]

    A. U. Abeysekara, et al. (HAWC Collaboration),Search for Gamma-Rays from the Unusually Bright GRB 130427A with the HA WC Gamma-Ray Observatory, Astrophys. J.,800, 78 (2015), 1410.1536, URL http://dx.doi.org/10.1088/0004-637X/800/2/78

  27. [27]

    A. U. Abeysekara, et al. (HAWC Collaboration),Daily Monitoring of T eV Gamma-Ray Emission from Mrk 421, Mrk 501, and the Crab Nebula with HA WC , Astrophys. J., 841, 100 (2017), 1703.06968, URL http://dx.doi.org/10.3847/1538-4357/aa729e

  28. [28]

    Icecube Collaboration, et al. (including HAWC Collaboration),Multiwavelength follow-up of a rare IceCube neutrino multiplet, Astronomy & Astrophysics,607, A115 (2017),1702.06131, URL http://dx.doi.org/10.1051/0004-6361/201730620 14

  29. [29]

    A. U. Abeysekara, et al. (HAWC Collaboration),Search for V ery High-energy Gamma Rays from the Northern F ermi Bubble Region with HA WC, Astrophys. J.,842, 85 (2017), 1703.01344, URL http://dx.doi.org/10.3847/1538-4357/aa751a

  30. [30]

    A. U. Abeysekara, et al. (including HAWC Collaboration),Observation of the Crab Nebula with the HA WC Gamma-Ray Observatory, Astrophys. J.,843, 39 (2017), 1701.01778, URL http://dx.doi.org/10.3847/1538-4357/aa7555

  31. [31]

    A. U. Abeysekara, et al. (HAWC Collaboration), The 2HWC HA WC Observa- tory Gamma-Ray Catalog , Astrophys. J., 843, 40 (2017), 1702.02992, URL http://dx.doi.org/10.3847/1538-4357/aa7556

  32. [32]

    Search for very-high-energy emission from Gamma-ray Bursts using the first 18 months of data from the HAWC Gamma-ray Observatory

    R. Alfaro, et al. (HAWC Collaboration), Search for V ery-high-energy Emission from Gamma-Ray Bursts Using the First 18 Months of Data from the HA WC Gamma-Ray Observatory , Astrophys. J., 843, 88 (2017), 1705.01551, URL http://dx.doi.org/10.3847/1538-4357/aa756f

  33. [33]

    A. U. Abeysekara, et al. (HAWC Collaboration), The HA WC Real-time Flare Monitor for Rapid Detection of Transient Events, Astrophys. J., 843, 116 (2017), 1704.07411, URL http://dx.doi.org/10.3847/1538-4357/aa789f

  34. [34]

    B. P . Abbott, et al. (including HAWC Collaboration), Multi-messenger Observations of a Binary Neutron Star Merger , Astrophys. J. Lett., 848, L12 (2017), 1710.05833, URL http://dx.doi.org/10.3847/2041-8213/aa91c9

  35. [35]

    A. U. Abeysekara, et al. (HAWC Collaboration),Extended gamma-ray sources around pulsars constrain the origin of the positron flux at Earth, Science,358, 911 (2017),1711.06223, URL http://dx.doi.org/10.1126/science.aan4880

  36. [36]

    Dark Matter Limits From Dwarf Spheroidal Galaxies with The HAWC Gamma-Ray Observatory

    A. Albert, et al. (HAWC Collaboration),Dark Matter Limits from Dwarf Spheroidal Galaxies with the HA WC Gamma-Ray Observatory, Astrophys. J.,853, 154 (2018),1706.01277, URL http://dx.doi.org/10.3847/1538-4357/aaa6d8

  37. [37]

    A. U. Abeysekara, et al. (HAWC Collaboration), A search for dark matter in the Galactic halo with HA WC, J. Cosmol. Astropart. Phys., 2018, 049 (2018), 1710.10288, URL http://dx.doi.org/10.1088/1475-7516/2018/02/049

  38. [38]

    Search for Dark Matter Gamma-ray Emission from the Andromeda Galaxy with the High-Altitude Water Cherenkov Observatory

    A. Albert, et al. (HAWC Collaboration), Search for dark matter gamma-ray emis- sion from the Andromeda Galaxy with the High-Altitude W ater Cherenkov Ob- servatory, J. Cosmol. Astropart. Phys., 2018, 043 (2018), 1804.00628, URL http://dx.doi.org/10.1088/1475-7516/2018/06/043

  39. [39]

    IceCube Collaboration, et al. (including HAWC Collaboration),Multimessenger observations of a flaring blazar coincident with high-energy neutrino IceCube-170922A, Science,361, eaat1378 (2018),1807.08816, URL http://dx.doi.org/10.1126/science.aat1378

  40. [40]

    Constraints on Spin-Dependent Dark Matter Scattering with Long-Lived Mediators from TeV Observations of the Sun with HAWC

    A. Albert, et al. (HAWC Collaboration),Constraints on spin-dependent dark matter scattering with long-lived mediators from T eV observations of the Sun with HA WC, Phys. Rev. D,98, 123012 (2018),1808.05624, URL http://dx.doi.org/10.1103/PhysRevD.98.123012 15

  41. [41]

    A. U. Abeysekara, et al. (HAWC Collaboration), V ery-high-energy particle accelera- tion powered by the jets of the microquasar SS 433 , Nature, 562, 82 (2018), URL http://dx.doi.org/10.1038/s41586-018-0565-5

  42. [42]

    Abeysekara et al

    HAWC Collaboration, et al.,Measurement of the Crab Nebula at the Highest Energies with HA WC, arXiv e-prints (accepted for pub. in Astrophys. J.), arXiv:1905.12518 (2019),1905.12518

  43. [43]

    Bai, et al.,The Large High Altitude Air Shower Observatory (LHAASO) Science White P aper, arXiv e-prints, arXiv:1905.02773 (2019),1905.02773

    X. Bai, et al.,The Large High Altitude Air Shower Observatory (LHAASO) Science White P aper, arXiv e-prints, arXiv:1905.02773 (2019),1905.02773

  44. [44]

    Mirzoyan,First time detection of a GRB at sub-T eV energies; MAGIC detects the GRB 190114C, The Astronomer’s Telegram,12390(2019)

    R. Mirzoyan,First time detection of a GRB at sub-T eV energies; MAGIC detects the GRB 190114C, The Astronomer’s Telegram,12390(2019)

  45. [45]

    Cherenkov Telescope Array Consortium, et al.,Science with the Cherenkov T elescope Array, World Scientific Publishing Co. Pte. Ltd. (2019), URLhttp://dx.doi.org/10.1142/10986

  46. [46]

    Using HAWC to Discover Invisible Pulsars

    T. Linden, et al.,Using HA WC to discover invisible pulsars, Phys. Rev. D, 96, 103016 (2017), 1703.09704, URL http://dx.doi.org/10.1103/PhysRevD.96.103016

  47. [47]

    Observation of an anomalous positron abundance in the cosmic radiation

    O. Adriani, et al.,An anomalous positron abundance in cosmic rays with energies 1.5-100GeV, Na- ture,458, 607 (2009),0810.4995, URLhttp://dx.doi.org/10.1038/nature07942

  48. [48]

    HESS Collaboration, et al.,Acceleration of petaelectronvolt protons in the Galactic Centre, Nature, 531, 476 (2016),1603.07730, URL http://dx.doi.org/10.1038/nature17147

  49. [49]

    The Spectrum and Morphology of the Fermi Bubbles

    M. Ackermann, et al.,The Spectrum and Morphology of the F ermi Bubbles, Astrophys. J.,793, 64 (2014),1407.7905, URL http://dx.doi.org/10.1088/0004-637X/793/1/64

  50. [50]

    Constraints on very high energy gamma-ray emission from the Fermi Bubbles with future ground-based experiments

    L. Y ang & S. Razzaque,Constraints on very high energy gamma-ray emission from the F ermi bubbles with future ground-based experiments, Phys. Rev. D,99, 083007 (2019),1811.10970, URL http://dx.doi.org/10.1103/PhysRevD.99.083007

  51. [51]

    Development of the Model of Galactic Interstellar Emission for Standard Point-Source Analysis of Fermi Large Area Telescope Data

    F. Acero, et al., Development of the Model of Galactic Interstellar Emission for Standard P oint-source Analysis of F ermi Large Area T elescope Data, Astrophys. J. Suppl.,223, 26 (2016), 1602.07246, URL http://dx.doi.org/10.3847/0067-0049/223/2/26

  52. [52]

    A. U. Abeysekara, et al. (including HAWC Collaboration),All-sky Measurement of the Anisotropy of Cosmic Rays at 10 T eV and Mapping of the Local Interstellar Magnetic Field, Astrophys. J.,871, 96 (2019),1812.05682, URL http://dx.doi.org/10.3847/1538-4357/aaf5cc

  53. [53]

    Seckel, T

    D. Seckel, T. Stanev, & T. K. Gaisser,Signatures of Cosmic-Ray Interactions on the Solar Surface, Astrophys. J.,382, 652 (1991), URLhttp://dx.doi.org/10.1086/170753

  54. [54]

    A. A. Abdo, et al., F ermi Large Area T elescope Observations of T wo Gamma-Ray Emission Components from the Quiescent Sun , Astrophys. J., 734, 116 (2011), 1104.2093, URL http://dx.doi.org/10.1088/0004-637X/734/2/116

  55. [55]

    K. C. Y . Ng, et al., First observation of time variation in the solar-disk gamma- ray flux with F ermi , Phys. Rev. D, 94, 023004 (2016), 1508.06276, URL http://dx.doi.org/10.1103/PhysRevD.94.023004 16

  56. [56]

    TeV Solar Gamma Rays From Cosmic-Ray Interactions

    B. Zhou, et al.,T eV solar gamma rays from cosmic-ray interactions, Phys. Rev. D,96, 023015 (2017),1612.02420, URL http://dx.doi.org/10.1103/PhysRevD.96.023015

  57. [57]

    Evidence for a New Component of High-Energy Solar Gamma-Ray Production

    T. Linden, et al., Evidence for a New Component of High-Energy Solar Gamma- Ray Production , Phys. Rev. Lett.., 121, 131103 (2018), 1803.05436, URL http://dx.doi.org/10.1103/PhysRevLett.121.131103

  58. [58]

    Unexpected Dip in the Solar Gamma-Ray Spectrum

    Q.-W. Tang, et al.,Unexpected dip in the solar gamma-ray spectrum, Phys. Rev. D,98, 063019 (2018),1804.06846, URL http://dx.doi.org/10.1103/PhysRevD.98.063019

  59. [59]

    High Energy Neutrino Production by Cosmic Ray Interactions in the Sun

    G. Ingelman & M. Thunman, High energy neutrino production by cosmic ray in- teractions in the Sun , Phys. Rev. D, 54, 4385 (1996), hep-ph/9604288, URL http://dx.doi.org/10.1103/PhysRevD.54.4385

  60. [60]

    K. C. Y . Ng, et al., Solar atmospheric neutrinos: A new neutrino floor for dark matter searches , Phys. Rev. D, 96, 103006 (2017), 1703.10280, URL http: //dx.doi.org/10.1103/PhysRevD.96.103006

  61. [61]

    C. A. Arg¨uelles, et al.,Solar atmospheric neutrinos and the sensitivity floor for solar dark matter annihilation searches, J. Cosmol. Astropart. Phys., 2017, 024 (2017), 1703.07798, URL http://dx.doi.org/10.1088/1475-7516/2017/07/024

  62. [62]

    Neutrinos from cosmic ray interactions in the Sun

    J. Edsj¨o, et al.,Neutrinos from cosmic ray interactions in the Sun, J. Cosmol. Astropart. Phys.,2017, 033 (2017), 1704.02892, URL http://dx.doi.org/10.1088/1475-7516/2017/ 06/033

  63. [63]

    S. In, M. Jeong, & IceCube Collaboration, Solar atmospheric neutrino search with IceCube, International Cosmic Ray Conference,301, 965 (2017)

  64. [64]

    Probe of the Solar Magnetic Field Using the "Cosmic-Ray Shadow" of the Sun

    M. Amenomori, et al., Probe of the Solar Magnetic Field Using the “Cosmic-Ray Shadow” of the Sun , Phys. Rev. Lett.., 111, 011101 (2013), 1306.3009, URL http://dx.doi.org/10.1103/PhysRevLett.111.011101

  65. [65]

    Evaluation of the Interplanetary Magnetic Field Strength Using the Cosmic-Ray Shadow of the Sun

    M. Amenomori, et al., Evaluation of the Interplanetary Magnetic Field Strength Using the Cosmic-Ray Shadow of the Sun, Phys. Rev. Lett.., 120, 031101 (2018), 1801.06942, URL http://dx.doi.org/10.1103/PhysRevLett.120.031101

  66. [66]

    J. Becker Tjus, et al.,Cosmic-Ray Propagation Around the Sun - Investigating the Influence of the Solar Magnetic Field on the Cosmic-Ray Sun Shadow, arXiv e-prints, arXiv:1903.12638 (2019), 1903.12638

  67. [67]

    An Exceptional VHE Gamma-Ray Flare of PKS 2155-304

    F. Aharonian, et al., An Exceptional V ery High Energy Gamma-Ray Flare of PKS 2155-304, Astrophys. J. Lett.,664, L71 (2007),0706.0797, URL http://dx.doi.org/10.1086/ 520635

  68. [68]

    Study of 23 day periodicity of Blazar Mkn501 in 1997

    S. Osone, Study of 23 day periodicity of Blazar Mkn501 in 1997 , Astroparticle Physics, 26, 209 (2006), astro-ph/0506328, URL http://dx.doi.org/10.1016/j. astropartphys.2006.06.004 17

  69. [69]

    Long-term optical polarization variability and multiwavelength analysis of Blazar Mrk 421

    N. Fraija, et al., Long-term Optical P olarization V ariability and Multiwavelength Anal- ysis of Blazar Mrk 421 , Astrophys. J. Suppl., 232, 7 (2017), 1707.05624, URL http://dx.doi.org/10.3847/1538-4365/aa82cc

  70. [70]

    F. M. Rieger & K. Mannheim, The P eriodical V ariability and the Central Black Hole System in Mkn 501, in L. O. Takalo & E. V altaoja (Hg.),High Energy Blazar Astronomy, Bd. 299 von Astronomical Society of the P acific Conference Series, 83 (2003)

  71. [71]

    G. Bonnoli, et al.,An emerging population of BL Lacs with extreme properties: towards a class of EBL and cosmic magnetic field probes?, MNRAS, 451, 611 (2015), 1501.01974, URL http://dx.doi.org/10.1093/mnras/stv953

  72. [72]

    C. D. Dermer, et al., Time Delay of Cascade Radiation for T eV Blazars and the Measurement of the Intergalactic Magnetic Field , Astrophys. J., 733, L21 (2011), 1011.6660, URL http://dx.doi.org/10.1088/2041-8205/733/2/L21

  73. [73]

    Blazars as Ultra-High-Energy Cosmic-Ray Sources: Implications for TeV Gamma-Ray Observations

    K. Murase, et al., Blazars as Ultra-high-energy Cosmic-ray Sources: Implications for T eV Gamma-Ray Observations , Astrophys. J., 749, 63 (2012), 1107.5576, URL http://dx.doi.org/10.1088/0004-637X/749/1/63

  74. [74]

    Search for Spatial Extension in High-Latitude Sources Detected by the Fermi Large Area Telescope

    M. Ackermann, et al., The Search for Spatial Extension in High-latitude Sources Detected by the F ermi Large Area T elescope, Astrophys. J. Suppl., 237, 32 (2018), 1804.08035, URL http://dx.doi.org/10.3847/1538-4365/aacdf7

  75. [75]

    R. J. Gould & G. Schr´eder, Opacity of the Universe to High-Energy Photons, Phys. Rev. Lett.., 16, 252 (1966), URLhttp://dx.doi.org/10.1103/PhysRevLett.16.252

  76. [76]

    Pierre Auger Collaboration, et al., Correlation of the Highest-Energy Cosmic Rays with Nearby Extragalactic Objects , Science, 318, 938 (2007), 0711.2256, URL http://dx.doi.org/10.1126/science.1151124

  77. [77]

    Neutrino, $\gamma$-ray and cosmic ray fluxes from the core of the closest radio galaxies

    N. Fraija & A. Marinelli, Neutrino, γ-Ray, and Cosmic-Ray Fluxes from the Core of the Closest Radio Galaxies , Astrophys. J., 830, 81 (2016), 1607.04633, URL http://dx.doi.org/10.3847/0004-637X/830/2/81

  78. [78]

    IceCube Collaboration, et al., Neutrino emission from the direction of the blazar TXS 0506+056 prior to the IceCube-170922A alert, Science,361, 147 (2018),1807.08794, URL http://dx.doi.org/10.1126/science.aat2890

  79. [79]

    FRBCAT: The Fast Radio Burst Catalogue

    E. Petroff, et al.,FRBCAT: The F ast Radio Burst Catalogue, P ASA,33, e045 (2016),1601.03547, URL http://dx.doi.org/10.1017/pasa.2016.35

  80. [80]

    M. W. E. Smith, et al., The Astrophysical Multimessenger Observatory Network (AMON), Astroparticle Physics,45, 56 (2013),1211.5602, URL http://dx.doi.org/10.1016/ j.astropartphys.2013.03.003

Showing first 80 references.