Publications (125)
Response to Comment on "Dark Matter Annihilation Can Produce a Detectable Antihelium Flux through Decays"
Martin Wolfgang Winkler, Tim Linden
In a recent paper we showed that the decay of intermediate baryons can dramatically enhance the antihelium flux from dark matter annihilation. Our antihelium predictions…
Challenges in Explaining the Galactic Center Gamma-Ray Excess with Millisecond Pulsars
Ilias Cholis, Dan Hooper, Tim Linden
Millisecond pulsars have been discussed as a possible source of the gamma-ray excess observed from the region surrounding the Galactic Center. With this in mind, we use the observe…
Constraining the Charge-Sign and Rigidity-Dependence of Solar Modulation
Ilias Cholis, Dan Hooper, Tim Linden
Our ability to identify the sources of cosmic rays and understand how these particles propagate through the interstellar medium is hindered by the combined effects of the solar win…
TeV Gamma Rays From Galactic Center Pulsars
Dan Hooper, Ilias Cholis, Tim Linden
Measurements of the nearby pulsars Geminga and B0656+14 by the HAWC and Milagro telescopes have revealed the presence of bright TeV-emitting halos surrounding these objects. If you…
Gamma-ray Lines in the Fermi Data: is it a Bubble?
Stefano Profumo, Tim Linden
Recently, tentative evidence for an excess of gamma rays at energies around 130 GeV has been reported from analyses of data from the Fermi Large Area Telescope (LAT). The excess is…
Positron Annihilation in the Galaxy
Carolyn A. Kierans, John F. Beacom, Steve Boggs +27
The 511 keV line from positron annihilation in the Galaxy was the first -ray line detected to originate from outside our solar system. Going into the fifth decade since the dis…
Cosmic-Ray Propagation Models Elucidate the Prospects for Antinuclei Detection
Pedro De La Torre Luque, Martin Wolfgang Winkler, Tim Linden
Tentative observations of cosmic-ray antihelium by the AMS-02 collaboration have re-energized the quest to use antinuclei to search for physics beyond the standard model. However,…
Dark Matter Scattering Constraints from Observations of Stars Surrounding Sgr A*
Isabelle John, Rebecca K. Leane, Tim Linden
High resolution infrared data has revealed several young stars in close proximity to Sgr A*. These stars may encounter extremely high dark matter densities. We examine scenarios wh…
Self-Generated Cosmic-Ray Confinement in TeV Halos: Implications for TeV Gamma-Ray Emission and the Positron Excess
Carmelo Evoli, Tim Linden, Giovanni Morlino
Recent observations have detected extended TeV gamma-ray emission surrounding young and middle-aged pulsars. The morphology of these "TeV halos" requires cosmic-ray diffusion to be…
Putting Things Back Where They Belong: Tracing Cosmic-Ray Injection with H2
Eric Carlson, Tim Linden, Stefano Profumo
At present, all physical models of diffuse Galactic gamma-ray emission assume that the distribution of cosmic-ray sources traces the observed populations of either OB stars, pulsar…
The Characterization of the Gamma-Ray Signal from the Central Milky Way: A Compelling Case for Annihilating Dark Matter
Tansu Daylan, Douglas P. Finkbeiner, Dan Hooper +4
Past studies have identified a spatially extended excess of 1-3 GeV gamma rays from the region surrounding the Galactic Center, consistent with the emission expected from ann…
HAWC Observations Strongly Favor Pulsar Interpretations of the Cosmic-Ray Positron Excess
Dan Hooper, Ilias Cholis, Tim Linden +1
Recent measurements of the Geminga and B0656+14 pulsars by the gamma-ray telescope HAWC (along with earlier measurements by Milagro) indicate that these objects generate significan…
On the gamma-ray emission from the core of the Sagittarius dwarf galaxy
Addy J. Evans, Louis E. Strigari, Oskar Svenborn +5
We use data from the Large Area Telescope onboard the Fermi gamma-ray space telescope (Fermi-LAT) to analyze the faint gamma-ray source located at the center of the Sagittarius (Sg…
Snowmass2021 Cosmic Frontier White Paper: Puzzling Excesses in Dark Matter Searches and How to Resolve Them
Rebecca K. Leane, Seodong Shin, Liang Yang +36
Intriguing signals with excesses over expected backgrounds have been observed in many astrophysical and terrestrial settings, which could potentially have a dark matter origin. Ast…
Exploring the Nature of the Galactic Center Gamma-Ray Source with the Cherenkov Telescope Array
Tim Linden, Stefano Profumo
Observations from multiple gamma-ray telescopes have uncovered a high energy gamma-ray source spatially coincident with the Galactic center. Recently, a compelling model for the br…
Where are the Cascades from Blazar Jets? An Emerging Tension in the -ray sky
Carlos Blanco, Oindrila Ghosh, Sunniva Jacobsen +1
Blazars are among the most powerful accelerators and are expected to produce a bright TeV -ray flux. However, TeV -rays are attenuated by interactions with intergalactic ra…
Dark Matter Annihilation Can Produce a Detectable Antihelium Flux through Decays
Martin Wolfgang Winkler, Tim Linden
Recent observations by the Alpha Magnetic Spectrometer (AMS-02) have tentatively detected a handful of cosmic-ray antihelium events. Such events have long been considered as smokin…
Searching for Dark Matter with Neutron Star Mergers and Quiet Kilonovae
Joseph Bramante, Tim Linden, Yu-Dai Tsai
We identify new astrophysical signatures of dark matter that implodes neutron stars (NSs), which could decisively test whether NS-imploding dark matter is responsible for missing p…
Millisecond Pulsars in Globular Clusters and Implications for the Galactic Center Gamma-Ray Excess
Aurelio Amerio, Dan Hooper, Tim Linden
We study the gamma-ray emission from millisecond pulsars within the Milky Way's globular cluster system in order to measure the luminosity function of this source population. We fi…
Strong Constraints on Dark Matter Annihilation in Ursa Major III/UNIONS 1
Milena CrnogorÄeviÄ, Tim Linden
Very recent work has identified a new satellite galaxy, Ursa Major III/UNIONS I, which is the faintest such system ever observed. Dynamical considerations indicate that if the syst…
Radio Galaxies Dominate the High-Energy Diffuse Gamma-Ray Background
Dan Hooper, Tim Linden, Alejandro Lopez
It has been suggested that unresolved radio galaxies and radio quasars (sometimes referred to as misaligned active galactic nuclei) could be responsible for a significant fraction…
The Impact of Muon and Pion Cooling on the Neutrino Spectrum of NGC 1068
Carlos Blanco, Dan Hooper, Tim Linden +1
The IceCube Neutrino Observatory has detected a flux of neutrinos from the active galaxy, NGC 1068. The soft spectral index of these neutrinos has previous…
Unexpected Dip in the Solar Gamma-Ray Spectrum
Qing-Wen Tang, Kenny C. Y. Ng, Tim Linden +3
The solar disk is a bright source of multi-GeV gamma rays, due to the interactions of hadronic cosmic rays with the solar atmosphere. However, the underlying production mechanism i…
Strong Constraints on Dark Photon and Scalar Dark Matter Decay from INTEGRAL and AMS-02 data
Thong T. Q. Nguyen, Isabelle John, Tim Linden +1
We investigate the decay of bosonic dark matter with masses between 1 MeV and 2 TeV into Standard Model final states. We specifically focus on dark photons that kinetically mix wit…
Cluster Mergers and the Origin of the ARCADE-2 Excess
Ke Fang, Tim Linden
Radio observations at multiple frequencies have detected a significant isotropic emission component between 22~MHz and 10~GHz, commonly termed the ARCADE-2 Excess. The origin of th…
Comment on "Characterizing the population of pulsars in the Galactic bulge with the Large Area Telescope" [arXiv:1705.00009v1]
Richard Bartels, Dan Hooper, Tim Linden +4
The -LAT Collaboration recently presented a new catalog of gamma-ray sources located within the region around the Galactic Center~(Aj…
Dark matter silences Cepheids in the Galactic Center
Djuna Croon, Tim Linden, Jeremy Sakstein
Upcoming near-infrared facilities (e.g. JWST/NIRCam, ELT/MICADO) will dramatically increase the detectability of galactic center Cepheids despite extreme extinction at optical wave…
Dark Matter and Synchrotron Emission from Galactic Center Radio Filaments
Tim Linden, Dan Hooper, Farhad Yusef-Zadeh
The inner degrees of the Galactic center contain a large population of filamentary structures observed at radio frequencies. These so-called non-thermal radio filaments (NRFs) trac…
TeV Halos are Everywhere: Prospects for New Discoveries
Takahiro Sudoh, Tim Linden, John F. Beacom
Milagro and HAWC have detected extended TeV gamma-ray emission around nearby pulsar wind nebulae (PWNe). Building on these discoveries, Linden et al. [1] identified a new source cl…
Dark Branches of Immortal Stars at the Galactic Center
Isabelle John, Rebecca K. Leane, Tim Linden
We show that stars in the inner parsec of the Milky Way can be significantly affected by dark matter annihilation, producing population-level effects that are visible in a Hertzspr…
Looking for the γ-Ray Cascades of the KM3-230213A Neutrino Source
Milena CrnogorÄeviÄ, Carlos Blanco, Tim Linden
The extreme energy of the KM3-230213A event could transform our understanding of the most energetic sources in the Universe. However, it also reveals an inconsistency between the K…
Cosmic-Ray Positrons Strongly Constrain Leptophilic Dark Matter
Isabelle John, Tim Linden
Cosmic-ray positrons have long been considered a powerful probe of dark matter annihilation. In particular, myriad studies of the unexpected rise in the positron fraction have deba…
Dark Kinetic Heating of Neutron Stars and An Infrared Window On WIMPs, SIMPs, and Pure Higgsinos
Masha Baryakhtar, Joseph Bramante, Shirley Weishi Li +2
We identify a largely model-independent signature of dark matter interactions with nucleons and electrons. Dark matter in the local galactic halo, gravitationally accelerated to ov…
On The Origin Of The Gamma Rays From The Galactic Center
Dan Hooper, Tim Linden
The region surrounding the center of the Milky Way is both astrophysically rich and complex, and is predicted to contain very high densities of dark matter. Utilizing three years o…
The Sun Can Strongly Constrain Spin-Dependent Dark Matter Nucleon Scattering Below the Evaporation Limit
Thong T. Q. Nguyen, Tim Linden
The Sun is a promising target for dark matter (DM) searches due to its ability to accumulate DM particles via scattering and catalyze their self-annihilation. However, at low DM ma…
Detecting Dark Matter with Imploding Pulsars in the Galactic Center
Joseph Bramante, Tim Linden
The paucity of old millisecond pulsars observed at the galactic center of the Milky Way could be the result of dark matter accumulating in and destroying neutron stars. In regions…
First Observations of Solar Disk Gamma Rays over a Full Solar Cycle
Tim Linden, John F. Beacom, Annika H. G. Peter +3
The solar disk is among the brightest gamma-ray sources in the sky. It is also among the most mysterious. No existing model fully explains the luminosity, spectrum, time variabilit…
The High-Energy Tail of the Galactic Center Gamma-Ray Excess
Tim Linden, Nicholas L. Rodd, Benjamin R. Safdi +1
Observations by the Fermi-LAT have uncovered a bright, spherically symmetric excess surrounding the center of the Milky Way galaxy. The spectrum of the gamma-ray excess peaks sharp…
Tying Dark Matter to Baryons with Self-interactions
Manoj Kaplinghat, Ryan E. Keeley, Tim Linden +1
Self-interacting dark matter (SIDM) models have been proposed to solve the small-scale issues with the collisionless cold dark matter (CDM) paradigm. We derive equilibrium solution…
The Isotropic Radio Background and Annihilating Dark Matter
Dan Hooper, Alexander V. Belikov, Tesla E. Jeltema +3
Observations by ARCADE-2 and other telescopes sensitive to low frequency radiation have revealed the presence of an isotropic radio background with a hard spectral index. The inten…
The Sensitivity of Future Gamma-Ray Telescopes to Primordial Black Holes
Celeste Keith, Dan Hooper, Tim Linden +1
The strongest existing constraints on primordial black holes with masses in the range of have been derived from measurements of the loc…
Is The Gamma-Ray Source 3FGL J2212.5+0703 A Dark Matter Subhalo?
Bridget Bertoni, Dan Hooper, Tim Linden
In a previous paper, we pointed out that the gamma-ray source 3FGL J2212.5+0703 shows evidence of being spatially extended. If a gamma-ray source without detectable emission at oth…
Improved Cosmic-Ray Injection Models and the Galactic Center Gamma-Ray Excess
Eric Carlson, Tim Linden, Stefano Profumo
Fermi-LAT observations of the Galactic Center (GC) have revealed a spherically- symmetric excess of GeV gamma rays extending to at least 10 deg from the dynamical center of the Gal…
Looking Under a Better Lamppost: MeV-scale Dark Matter Candidates
Regina Caputo, Tim Linden, John Tomsick +6
The era of precision cosmology has revealed that about 85% of the matter in the universe is dark matter. Two well-motivated candidates are weakly interacting massive particles (WIM…
Searching for Dark Matter Annihilation in the Smith High-Velocity Cloud
Alex Drlica-Wagner, German A. Gomez-Vargas, John W. Hewitt +2
Recent observations suggest that some high-velocity clouds may be confined by massive dark matter halos. In particular, the proximity and proposed dark matter content of the Smith…
Limits on dark matter annihilation in prompt cusps from the isotropic gamma-ray background
M. Sten Delos, Michael Korsmeier, Axel Widmark +3
Recent studies indicate that thermally produced dark matter will form highly concentrated, low-mass cusps in the early universe that often survive until the present. While these cu…
White Dwarfs in Dwarf Spheroidal Galaxies: A New Class of Compact-Dark-Matter Detectors
Juri Smirnov, Ariel Goobar, Tim Linden +1
Recent surveys have discovered a population of faint supernovae, known as Ca-rich gap transients, inferred to originate from explosive ignitions of white dwarfs. In addition to the…
Are Lines From Unassociated Gamma-Ray Sources Evidence For Dark Matter Annihilation?
Dan Hooper, Tim Linden
Very recently, it was pointed out that there exists a population of gamma-ray sources without associations at other wavelengths which exhibit spectral features consistent with mono…
Self-Generated Cosmic-Ray Turbulence Can Explain the Morphology of TeV Halos
Payel Mukhopadhyay, Tim Linden
Observations have shown that spatially extended "TeV halos" are a common (and potentially generic) feature surrounding young and middle-aged pulsars. However, their morphology is n…
The Galactic Center GeV Excess from a Series of Leptonic Cosmic-Ray Outbursts
Ilias Cholis, Carmelo Evoli, Francesca Calore +3
It has been proposed that a recent outburst of cosmic-ray electrons could account for the excess of GeV-scale gamma rays observed from the region surrounding the Galactic Center. A…
Circular Polarization of Pulsar Wind Nebulae and the Cosmic-Ray Positron Excess
Tim Linden
Recent observations by the PAMELA and AMS-02 telescopes have uncovered an anomalous rise in the positron fraction at energies above 10~GeV. One possible explanation for this excess…
Examining The Fermi-LAT Third Source Catalog In Search Of Dark Matter Subhalos
Bridget Bertoni, Dan Hooper, Tim Linden
Dark matter annihilations taking place in nearby subhalos could appear as gamma-ray sources without detectable counterparts at other wavelengths. In this study, we consider the col…
Probing the Pulsar Origin of the Anomalous Positron Fraction with AMS-02 and Atmospheric Cherenkov Telescopes
Tim Linden, Stefano Profumo
Recent observations by PAMELA, Fermi-LAT, and AMS-02 have conclusively indicated a rise in the cosmic-ray positron fraction above 10 GeV, a feature which is impossible to mimic und…
Improving the Sensitivity of Gamma-Ray Telescopes to Dark Matter Annihilation in Dwarf Spheroidal Galaxies
Eric Carlson, Dan Hooper, Tim Linden
The Fermi-LAT collaboration has studied the gamma-ray emission from a stacked population of dwarf spheroidal galaxies and used this information to set constraints on the dark matte…
Possible Evidence for the Stochastic Acceleration of Secondary Antiprotons by Supernova Remnants
Ilias Cholis, Dan Hooper, Tim Linden
The antiproton-to-proton ratio in the cosmic-ray spectrum is a sensitive probe of new physics. Using recent measurements of the cosmic-ray antiproton and proton fluxes in the energ…
Are X-Ray Detected Active Galactic Nuclei in Dwarf Galaxies Gamma-Ray Bright?
Milena CrnogorÄeviÄ, Tim Linden, Annika H. G. Peter
The -ray emission from active galactic nuclei (AGN), including both beamed blazars and misaligned-AGN, dominates the extragalactic -ray point-source population count and fl…
First Analysis of Jupiter in Gamma Rays and a New Search for Dark Matter
Rebecca K. Leane, Tim Linden
We present the first dedicated -ray analysis of Jupiter, using 12 years of data from the Fermi Telescope. We find no robust evidence of -ray emission, and set upper limits…
A Robust Method for Treating Astrophysical Mismodeling in Dark Matter Annihilation Searches of Dwarf Spheroidal Galaxies
Tim Linden
Fermi-LAT observations have strongly constrained dark matter annihilation through the joint-likelihood analysis of dwarf spheroidal galaxies (dSphs). These constraints are expected…
Antiproton Bounds on Dark Matter Annihilation from a Combined Analysis Using the DRAGON2 Code
Pedro De la Torre Luque, Martin Wolfgang Winkler, Tim Linden
Early studies of the AMS-02 antiproton ratio identified a possible excess over the expected astrophysical background that could be fit by the annihilation of a weakly interacting m…
A Robust Excess in the Cosmic-Ray Antiproton Spectrum: Implications for Annihilating Dark Matter
Ilias Cholis, Tim Linden, Dan Hooper
An excess of 10-20 GeV cosmic-ray antiprotons has been identified in the spectrum reported by the AMS-02 Collaboration. The systematic uncertainties associated with this sign…
Celestial-Body Focused Dark Matter Annihilation Throughout the Galaxy
Rebecca K. Leane, Tim Linden, Payel Mukhopadhyay +1
Indirect detection experiments typically measure the flux of annihilating dark matter (DM) particles propagating freely through galactic halos. We consider a new scenario where cel…
Low Mass X-Ray Binaries in the Inner Galaxy: Implications for Millisecond Pulsars and the GeV Excess
Daryl Haggard, Craig Heinke, Dan Hooper +1
If millisecond pulsars (MSPs) are responsible for the excess gamma-ray emission observed from the region surrounding the Galactic Center, the same region should also contain a larg…
Pulsar TeV Halos Explain the TeV Excess Observed by Milagro
Tim Linden, Benjamin J. Buckman
Milagro observations have found bright, diffuse TeV emission concentrated along the galactic plane of the Milky Way. The intensity and spectrum of this emission is difficult to exp…
Super-Kamiokande Strongly Constrains Leptophilic Dark Matter Capture in the Sun
Thong T. Q. Nguyen, Tim Linden, Pierluca Carenza +1
The Sun can efficiently capture leptophilic dark matter that scatters with free electrons. If this dark matter subsequently annihilates into leptonic states, it can produce a detec…
Pulsars Cannot Account for the Inner Galaxy's GeV Excess
Dan Hooper, Ilias Cholis, Tim Linden +2
Using data from the Fermi Gamma-Ray Space Telescope, a spatially extended component of gamma rays has been identified from the direction of the Galactic Center, peaking at energies…
Active Galactic Nuclei and the Origin of IceCube's Diffuse Neutrino Flux
Dan Hooper, Tim Linden, Abby Vieregg
The excess of neutrino candidate events detected by IceCube from the direction of TXS 0506+056 has generated a great deal of interest in blazars as sources of high-energy neutrinos…
Extraterrestrial Axion Search with the Breakthrough Listen Galactic Center Survey
Joshua W. Foster, Samuel J. Witte, Matthew Lawson +4
Axion dark matter (DM) may efficiently convert to photons in the magnetospheres of neutron stars (NSs), producing nearly monochromatic radio emission. This process is resonantly tr…
What Does The PAMELA Antiproton Spectrum Tell Us About Dark Matter?
Dan Hooper, Tim Linden, Philipp Mertsch
Measurements of the cosmic ray antiproton spectrum can be used to search for contributions from annihilating dark matter and to constrain the dark matter annihilation cross section…
Millisecond Pulsars Modify the Radio-SFR Correlation in Quiescent Galaxies
Takahiro Sudoh, Tim Linden, John F. Beacom
The observed correlation between the far-infrared and radio luminosities of galaxies illustrates the close connection between star formation and cosmic-ray production. Intriguingly…
The Anisotropy of the Extragalactic Radio Background from Dark Matter Annihilation
Ke Fang, Tim Linden
Observations of the extragalactic radio background have uncovered a significant isotropic emission across multiple frequencies spanning from 22 MHz to 10 GHz. The intensity of this…
IceCube and HAWC constraints on very-high-energy emission from the Fermi bubbles
Ke Fang, Meng Su, Tim Linden +1
The nature of the -ray emission from the \emph{Fermi} bubbles is unknown. Both hadronic and leptonic models have been formulated to explain the peculiar -ray signal observe…
On the Gamma-ray Efficiency of Superluminous Supernovae: Potential Detections and Population-Level Constraints
Milena CrnogorÄeviÄ, Tim Linden, Ariel Goobar +1
Superluminous supernovae (SLSNe) are among the most energetic stellar explosions, yet their central power source remains uncertain. Models invoking magnetar spin-down or circumstel…
On the R-Process Enrichment of Dwarf Spheroidal Galaxies
Joseph Bramante, Tim Linden
Recent observations of Reticulum II have uncovered an overabundance of r-process elements, compared to similar ultra-faint dwarf spheroidal galaxies (UFDs). Because the metallicity…
Galactic Gas Models Strongly Affect the Determination of the Diffusive Halo Height
Pedro De La Torre Luque, Tim Linden
The height of the Milky Way diffusion halo, above which cosmic-rays can freely escape the galaxy, is among the most critical, yet poorly known, parameters in cosmic-ray physics. Me…
Gamma Rays From The Galactic Center and the WMAP Haze
Dan Hooper, Tim Linden
Recently, an analysis of data from the Fermi Gamma Ray Space Telescope has revealed a flux of gamma rays concentrated around the inner ~0.5 degrees of the Milky Way, with a spectru…
Anti-Deuterons and Anti-Helium Nuclei from Annihilating Dark Matter
Ilias Cholis, Tim Linden, Dan Hooper
Recent studies of the cosmic-ray antiproton-to-proton ratio have identified an excess of 10-20 GeV antiprotons relative to the predictions of standard astrophysical models. I…
Breaking a dark degeneracy: The gamma-ray signature of early matter domination
M. Sten Delos, Tim Linden, Adrienne L. Erickcek
The Universe's early thermal history is poorly constrained, and it is possible that it underwent a period of early matter domination driven by a heavy particle or an oscillating sc…
Investigating the Gamma-Ray Emission from Explosive Dispersal Outflows with Fermi-LAT
Paarmita Pandey, Stephen C. Lenker, Laura A. Lopez +6
We present the first systematic study of explosive dispersal outflows (EDOs) as potential sources of high-energy emission in the Milky Way. EDOs are energetic outflows produced dur…
A Clustering Analysis of the Morphology of the 130 GeV Gamma-Ray Feature
Eric Carlson, Tim Linden, Stefano Profumo +1
Recent observations indicating the existence of a monochromatic gamma-ray line with energy ~130 GeV in the Fermi-LAT data have attracted great interest due to the possibility that…
Accurate Inverse-Compton Models Strongly Enhance Leptophilic Dark Matter Signals
Isabelle John, Tim Linden
The annihilation of TeV-scale leptophilic dark matter into electron-positron pairs (hereafter ) will produce a sharp cutoff in the local cosmic-ray spectrum at an…
A Predictive Analytic Model for the Solar Modulation of Cosmic Rays
Ilias Cholis, Dan Hooper, Tim Linden
An important factor limiting our ability to understand the production and propagation of cosmic rays pertains to the effects of heliospheric forces, commonly known as solar modulat…
First Observations of Solar Halo Gamma Rays Over a Full Solar Cycle
Tim Linden, Jung-Tsung Li, Bei Zhou +4
We analyze 15 years of Fermi-LAT data and produce a detailed model of the Sun's inverse-Compton scattering emission (solar halo), which is powered by interactions between ambient c…
Gamma-Ray Lines in 15 Years of Fermi-LAT Data: New Constraints on Higgs Portal Dark Matter
Pedro De La Torre Luque, Juri Smirnov, Tim Linden
Monoenergetic -ray spectral lines are among the cleanest signatures of dark matter annihilation. We analyze 15 years of Fermi-LAT data, find no spectral lines, and place strong…
The Morphology of Hadronic Emission Models for the Gamma-Ray Source at the Galactic Center
Tim Linden, Elizabeth Lovegrove, Stefano Profumo
Recently, detections of a high-energy gamma-ray source at the position of the Galactic center have been reported by multiple gamma-ray telescopes, spanning the energy range between…
Galactic Center Excess in Gamma Rays from Annihilation of Self-Interacting Dark Matter
Manoj Kaplinghat, Tim Linden, Hai-Bo Yu
Observations by the Fermi-LAT telescope have uncovered a significant -ray excess toward the Milky Way Galactic Center. There has been no detection of a similar signal in the di…
All-sky Medium Energy Gamma-ray Observatory: Exploring the Extreme Multimessenger Universe
Julie McEnery, Juan Abel Barrio, Ivan Agudo +182
The All-sky Medium Energy Gamma-ray Observatory (AMEGO) is a probe class mission concept that will provide essential contributions to multimessenger astrophysics in the late 2020s…
Gamma-Rays from Star Forming Activity Appear to Outshine Misaligned Active Galactic Nuclei
Carlos Blanco, Tim Linden
The total extragalactic -ray flux provides a powerful probe into the origin and evolution of the highest energy processes in our universe. An important component of this emissi…
Cosmic Rays and Magnetic Fields in the Core and Halo of the Starburst M82: Implications for Galactic Wind Physics
Benjamin J. Buckman, Tim Linden, Todd A. Thompson
Cosmic rays (CRs) and magnetic fields may be dynamically important in driving large-scale galactic outflows from rapidly star-forming galaxies. We construct two-dimensional axisymm…
Millisecond Pulsars, TeV Halos, and Implications For The Galactic Center Gamma-Ray Excess
Dan Hooper, Tim Linden
Observations by HAWC indicate that many young pulsars (including Geminga and Monogem) are surrounded by spatially extended, multi-TeV emitting regions. It is not currently known, h…
Antihelium from Dark Matter
Eric Carlson, Adam Coogan, Tim Linden +3
Cosmic-ray anti-nuclei provide a promising discovery channel for the indirect detection of particle dark matter. Hadron showers produced by the pair-annihilation or decay of Galact…
X-Ray Constraints on Dark Photon Tridents
Tim Linden, Thong T. Q. Nguyen, Tim M. P. Tait
Dark photons that are sufficiently light and/or weakly-interacting represent a compelling vision of dark matter. Dark photon decay into three photons, which we call the dark photon…
Weighing the Local Interstellar Medium using Gamma Rays and Dust
Axel Widmark, Michael Korsmeier, Tim Linden
Cold gas forms a significant mass fraction of the Milky Way disk, but is its most uncertain baryonic component. The density and distribution of cold gas is of critical importance f…
On the Formation of Ultraluminous X-ray Sources with Neutron Star Accretors: the Case of M82 X-2
Tassos Fragos, Tim Linden, Vicky Kalogera +1
The recent discovery of a neutron star accretor in the ultra-luminous X-ray source M82 X-2 challenges our understanding of high-mass X-ray binary formation and evolution. By combin…
Is the Ultra-High Energy Cosmic-Ray Excess Observed by the Telescope Array Correlated with IceCube Neutrinos?
Ke Fang, Toshihiro Fujii, Tim Linden +1
The Telescope Array (TA) has observed a statistically significant excess in cosmic-rays with energies above 57 EeV in a region of approximately 1150 square degrees centered on coor…
Indirect Searches for Dark Photon-Photon Tridents in Celestial Objects
Tim Linden, Thong T. Q. Nguyen, Tim M. P. Tait
We model and constrain the unique indirect detection signature produced by dark matter particles that annihilate through a gauge symmetry into dark photons that subsequently…
Measuring the Local Diffusion Coefficient with H.E.S.S. Observations of Very High-Energy Electrons
Dan Hooper, Tim Linden
The HAWC Collaboration has recently reported the detection of bright and spatially extended multi-TeV gamma-ray emission from Geminga, Monogem, and a handful of other nearby, middl…
Constraining the Diffusion Coefficient and Cosmic-Ray Acceleration Efficiency using Gamma-ray Emission from the Star-Forming Region RCW 38
Paarmita Pandey, Laura A. Lopez, Anna L. Rosen +3
Stellar winds from massive stars may be significant sources of cosmic rays (CRs). To investigate this connection, we report a detailed study of gamma-ray emission near the young Mi…
A Critical Reevaluation of Radio Constraints on Annihilating Dark Matter
Ilias Cholis, Dan Hooper, Tim Linden
A number of groups have employed radio observations of the Galactic center to derive stringent constraints on the annihilation cross section of weakly interacting dark matter. In t…
Star-Forming Galaxies Significantly Contribute to the Isotropic Gamma-Ray Background
Tim Linden
The origin of the isotropic gamma-ray background (IGRB) --- the portion of the extragalactic gamma-ray sky that is not resolvable into individual point sources --- provides a power…
Dark Matter Microhalos in the Solar Neighborhood: Pulsar Timing Signatures of Early Matter Domination
M. Sten Delos, Tim Linden
Pulsar timing provides a sensitive probe of small-scale structure. Gravitational perturbations arising from an inhomogeneous environment could manifest as detectable perturbations…