A differentiable forward model and likelihood enable probabilistic inference over many spatial morphologies for the Galactic Center gamma-ray Excess using variational methods on GPUs.
Ackermannet al.(Fermi-LAT), Astrophys
5 Pith papers cite this work. Polarity classification is still indexing.
5
Pith papers citing it
abstract
The Fermi bubbles are two large structures in the gamma-ray sky extending to $55^\circ$ above and below the Galactic center. We analyze 50 months of Fermi Large Area Telescope data between 100 MeV and 500 GeV above $10^\circ$ in Galactic latitude to derive the spectrum and morphology of the Fermi bubbles. We thoroughly explore the systematic uncertainties that arise when modeling the Galactic diffuse emission through two separate approaches. The gamma-ray spectrum is well described by either a log parabola or a power law with an exponential cutoff. We exclude a simple power law with more than 7$\sigma$ significance. The power law with an exponential cutoff has an index of $1.9 \pm 0.2$ and a cutoff energy of $110\pm 50$ GeV. We find that the gamma-ray luminosity of the bubbles is $4.4^{+2.4}_{-0.9} \times 10^{37}$ erg s$^{-1}$. We confirm a significant enhancement of gamma-ray emission in the south-eastern part of the bubbles, but we do not find significant evidence for a jet. No significant variation of the spectrum across the bubbles is detected. The width of the boundary of the bubbles is estimated to be $3.4^{+3.7}_{-2.6}$ deg. Both inverse Compton (IC) models and hadronic models including IC emission from secondary leptons fit the gamma-ray data well. In the IC scenario, the synchrotron emission from the same population of electrons can also explain the WMAP and Planck microwave haze with a magnetic field between 5 and 20 $\mu$G.
citation-role summary
background 1
citation-polarity summary
roles
background 1polarities
background 1representative citing papers
SPICE-RACS DR2 delivers the largest single Faraday rotation measure catalog from a radio survey, with 250,000-340,000 RMs across most of the sky at median uncertainty of 2 rad m^{-2}.
Reports ~20% projected polarization in synchrotron and thermal dust emission from Fermi bubbles, with fields parallel to edges, and attributes larger lobes to an older supermassive black hole outburst.
SWGO is proposed as a wide-field VHE gamma-ray survey instrument with a compact inner detector array and sparser outer array, estimated at 54M USD construction cost and full operations by 2026.
citing papers explorer
-
High-dimensional inference for the $\gamma$-ray sky with differentiable programming
A differentiable forward model and likelihood enable probabilistic inference over many spatial morphologies for the Galactic Center gamma-ray Excess using variational methods on GPUs.
-
The Rapid ASKAP Continuum Survey VII: Spectra and Polarisation In Cutouts of Extragalactic Sources (SPICE-RACS) Second Data Release -- Unveiling the Magnetised Sky
SPICE-RACS DR2 delivers the largest single Faraday rotation measure catalog from a radio survey, with 250,000-340,000 RMs across most of the sky at median uncertainty of 2 rad m^{-2}.
-
Detection of polarized Fermi-bubble synchrotron and dust emission
Reports ~20% projected polarization in synchrotron and thermal dust emission from Fermi bubbles, with fields parallel to edges, and attributes larger lobes to an older supermassive black hole outburst.
-
The Southern Wide-Field Gamma-Ray Observatory (SWGO): A Next-Generation Ground-Based Survey Instrument for VHE Gamma-Ray Astronomy
SWGO is proposed as a wide-field VHE gamma-ray survey instrument with a compact inner detector array and sparser outer array, estimated at 54M USD construction cost and full operations by 2026.
- A Precise Measurement of the Fermi-LAT Galactic Center Excess Morphology and Spectrum