405 citations · 863 across the 34 of their papers we have counts for
26 papers · 1 filter
Legacy analysis of Milky Way dwarf spheroidal satellite galaxies: an update
A. Circiello, M. Di Mauro, M. Ajello +3
Studies of Fermi-Large Area Telescope (LAT) data coincident with dwarf spheroidal satellite galaxies (dSphs) of the Milky Way (MW) have put the most stringent constraints on models…
Detectability of Polarized Gamma-ray Emission from Blazar Flares with COSI
Garrett A. Latiolais, Jorge Otero-Santos, Michela Negro +18
We investigate the detectability of polarized gamma-ray emission from blazar flares with the Compton Spectrometer and Imager (COSI). Using 17 years of Fermi Large Area Telescope ob…
Characterizing the Gamma-ray Emission from Low-Luminosity AGN
Chris Karwin, Nikita Khatiya, Margot Boughelilba +3
A majority of the active galactic nuclei (AGN) in the local Universe are classified as low-luminosity AGN (LLAGN), having bolometric luminosities $\lesssim 10^{42} \ \mathrm{erg \…
The gamma-ray emission from Radio Galaxies and their contribution to the Isotropic Gamma-Ray Background
A. Circiello, A. McDaniel, M. Di Mauro +6
We evaluate the contribution to the Isotropic Gamma-Ray Background (IGRB) coming from Radio Galaxies (RGs), the subclass of radio-loud Active Galactic Nuclei (AGN) with the highest…
Fermi detection of gamma-ray Emission from the Hot Coronae of Radio-quiet Active Galactic Nuclei
Jun-Rong Liu, Jian-Min Wang, Fermi-LAT Collaboration
Relativistic jets around supermassive black holes (SMBHs) are well-known powerful -ray emitters. In absence of the jets in radio-quiet active galactic nuclei (AGNs), how the SMB…
Imaging and Spectral Fitting of Bright Gamma-ray Sources with the COSI Balloon Payload
Jarred M. Roberts, Steven Boggs, Thomas Siegert +17
The Compton Spectrometer and Imager balloon payload (COSI-Balloon) is a wide-field-of-view Compton -ray telescope that operates in the 0.2 - 5 MeV bandpass. COSI-Balloon had a s…
Atmospheric Response for MeV Gamma Rays Observed with Balloon-Borne Detectors
Chris Karwin, Carolyn Kierans, Albert Shih +9
The atmospheric response for MeV gamma rays (~ 0.1 - 10 MeV) can be characterized in terms of two observed components. The first component is due to photons that reach the detector…
Evaluating the Potential to Constrain Dark Matter Annihilation with Fermi-LAT Observations of Ultra-Faint Compact Stellar Systems
A. Circiello, A. McDaniel, A. Drlica-Wagner +4
Recent results from numerical simulations and models of galaxy formation suggest that recently discovered ultra-faint compact stellar systems (UFCSs) in the halo of the Milky Way (…
Sub-GeV Gamma Rays from Nearby Seyfert Galaxies and Implications for Coronal Neutrino Emission
Kohta Murase, Christopher M. Karwin, Shigeo S. Kimura +2
Recent observations of high-energy neutrinos by IceCube and gamma rays by the Fermi Large Area Telescope (LAT) and the MAGIC telescope have suggested that neutrinos are produced in…
Legacy Analysis of Dark Matter Annihilation from the Milky Way Dwarf Spheroidal Galaxies with 14 Years of Fermi-LAT Data
Alex McDaniel, Marco Ajello, Christopher M. Karwin +3
The Milky Way (MW) dwarf spheroidal satellite galaxies (dSphs) are particularly intriguing targets to search for gamma rays from Weakly Interacting Massive Particle (WIMP) dark mat…
Characterizing the -ray Emission from FR0 Radio Galaxies
Nikita S. Khatiya, Margot Boughelilba, Christopher M. Karwin +5
FR0 galaxies constitute the most abundant jet population in the local Universe. With their compact jet structure, they are broadband photon emitters and have been proposed as multi…
Probing the Galactic Diffuse Continuum Emission with COSI
Christopher Karwin, Thomas Siegert, Jacqueline Beechert +9
In 2016 the Compton Spectrometer and Imager (COSI) had a successful 46-day flight onboard NASA's Super Pressure Balloon platform. In this work we report measurements of the Galacti…
The Compton Spectrometer and Imager
John A. Tomsick, Steven E. Boggs, Andreas Zoglauer +72
The Compton Spectrometer and Imager (COSI) is a NASA Small Explorer (SMEX) satellite mission in development with a planned launch in 2027. COSI is a wide-field gamma-ray telescope…
The cosipy library: COSI's high-level analysis software
Israel Martinez-Castellanos, Savitri Gallego, Chien-You Huang +72
The Compton Spectrometer and Imager (COSI) is a selected Small Explorer (SMEX) mission launching in 2027. It consists of a large field-of-view Compton telescope that will probe wit…
Gamma-ray Emission from Galaxies Hosting Molecular Outflows
Alex McDaniel, Marco Ajello, Chris Karwin
Many star-forming galaxies and those hosting active galactic nuclei (AGN) show evidence of massive outflows of material in a variety of phases including ionized, neutral atomic, an…
Deep Learning Models of the Discrete Component of the Galactic Interstellar Gamma-Ray Emission
Alexander Shmakov, Mohammadamin Tavakoli, Pierre Baldi +3
A significant point-like component from the small scale (or discrete) structure in the H2 interstellar gas might be present in the Fermi-LAT data, but modeling this emission relies…
Improved Modeling of the Discrete Component of the Galactic Interstellar Gamma-ray Emission and Implications for the Fermi-LAT Galactic Center Excess
Christopher M. Karwin, Alex Broughton, Simona Murgia +3
The aim of this work is to improve models for the gamma-ray discrete or small-scale structure related to H2 interstellar gas. Reliably identifying this contribution is important to…
The Future of Gamma-Ray Experiments in the MeV-EeV Range
Kristi Engel, Jordan Goodman, Petra Huentemeyer +95
Gamma-rays, the most energetic photons, carry information from the far reaches of extragalactic space with minimal interaction or loss of information. They bring messages about par…
Modeling and Simulations of TXS 0506+056 Neutrino Events in the MeV Band
Tiffany R. Lewis, Christopher M. Karwin, Tonia M. Venters +5
Neutrino detections identified with multiwavelength blazar spectra represent the first $\g$-ray-neutrino multimessenger signals. The blazar, TXS 0506+056 is also unusual in its spe…
Improving the low-energy transient sensitivity of AMEGO-X using single-site events
I. Martinez-Castellanos, H. Fleischhack, C. Karwin +14
AMEGO-X, the All-sky Medium Energy Gamma-Ray Observatory eXplorer, is a proposed instrument designed to bridge the so-called "MeV gap" by surveying the sky with unprecedented sensi…
Dark Matter Interpretation of the Fermi-LAT Observations Toward the Outer Halo of M31
Chris Karwin, Simona Murgia, Igor Moskalenko +3
An excess -ray signal toward the outer halo of M31 has recently been reported. Although other explanations are plausible, the possibility that it arises from dark matter (DM) is…
On Dark Matter Explanations of the Gamma-Ray Excesses from the Galactic Center and M31
Anne-Katherine Burns, Max Fieg, Christopher M. Karwin +1
The presence of an excess gamma-ray signal toward the Galactic center (GC) has now been well established, and is known as the GC excess. Leading explanations for the signal include…
Search for gamma-ray emission from -wave dark matter annihilation in the Galactic Center
Christian Johnson, Regina Caputo, Chris Karwin +3
Indirect searches for dark matter through Standard Model products of its annihilation generally assume a cross-section which is dominated by a term independent of velocity (-wav…
Fermi-LAT Observations of Gamma-Ray Emission Towards the Outer Halo of M31
Chris Karwin, Simona Murgia, Sheldon Campbell +1
The Andromeda Galaxy is the closest spiral galaxy to us and has been the subject of numerous studies. It harbors a massive dark matter (DM) halo which may span up to ~600 kpc acros…