J/other/PhRvD/103.H3016 Antimatter sources E flux sensitivity (Dupourque+, 2021)
Constraints on the antistar fraction in the Solar system neighborhood from the
10-years Fermi Large Area Telescope gamma-ray source catalog.
Dupourque S, Tibaldo L, von Ballmoos P.
<Physical Review D, 103, h3016 (2021)>
=2021PhRvD.103h3016D 2021PhRvD.103h3016D (SIMBAD/NED BibCode)
ADC_Keywords: Stars, nearby ; Gamma rays
Keywords: stars: abundances - gamma rays: stars
Abstract:
It is generally taken for granted that our Universe is free of
antimatter objects and domains. This certitude has recently been
challenged by the possible detection of anti-helium nuclei by AMS-02.
Should the observation be confirmed, the existence of nearby antistars
would make a plausible hypothesis to explain the origin of the
antinuclei. In this paper we use the 10-years F Large Area Telescope
(LAT) gamma-ray source catalog to set constraints on the abundance of
antistars around the Sun. We identify in the catalog 14 antistar
candidates not associated with any objects belonging to established
gamma-ray source classes and with a spectrum compatible with
baryon-antibaryon annihilation. We use them along with an estimate of
the LAT sensitivity to antistars to set upper limits on the local
antistar fraction fbar* with respect to normal stars. We provide
parametric limits as a function of the closest antistar mass,
velocity, and surrounding matter density. We also employ a novel
Monte∼Carlo method to set limits for a few hypotheses about the
antistar population. For a population with properties equivalent to
those of regular stars concentrated in the Galactic disk we obtain
fbar*<2.5x10-6 at 95% confidence level, which is 20 times more
constraining than limits previously available. For a primordial
population of antistars distributed in the Galactic halo we obtain new
local upper limits which decrease as a function of antistar mass M
from fbar*<0.2 at 95% confidence level for M=1M☉ to
fbar*<1.6x10-4 at 95% confidence level for M=10M☉. By
combining these limits with existing microlensing constraints for
lighter objects in the Magellanic clouds, we infer that a primordial
population of halo antistars must have a density lower than O
(10-5pc-3) to O (10-2pc-3) depending on their masses. Our
limits can constrain models for the origin and propagation of
antinuclei in cosmic rays.
Description:
Minimum energy flux threshold for the detection of a matter-antimatter
annihilation source by Fermi-LAT for the 4FGL-DR2 catalog for the
whole sky. See the associated article for the construction method and
discussions.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 217 1 Information on fits image
fits/* . 1 fits image
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See also:
J/ApJS/247/33 : The Fermi LAT fourth source catalog (4FGL) (Abdollahi+, 2020)
Byte-by-byte Description of file: list.dat
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Bytes Format Units Label Explanations
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1- 9 F9.5 deg GLON Galactic longitude of center (J2000)
10- 18 F9.5 deg GLAT Galactic latitude of center (J2000)
20- 23 I4 --- Nx Number of pixels along X-axis
25- 28 I4 --- Ny Number of pixels along Y-axis
30- 53 A24 "datime" Obs.date Observation date
55- 59 I5 Kibyte size Size of FITS file
61- 70 A10 --- FileName Name of FITS file, in subdirectory fits
72-217 A146 --- Title Title of the FITS file
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Acknowledgements:
Simon Dupourque, sdupourque(at)irap.omp.eu
(End) Patricia Vannier [CDS] 17-Mar-2021