$Fermi$-LAT Observations of $\gamma$-Ray Emission Towards the Outer Halo of M31 - INSPIRE

DataBETA

$Fermi$ -LAT Observations of $\gamma$ -Ray Emission Towards the Outer Halo of M31

Chris Karwin
(
- UC, Irvine
)
,
Simona Murgia
(
- UC, Irvine
)
,
Sheldon Campbell
(
- UC, Irvine
)
,
Igor Moskalenko
(
- Stanford U., HEPL and
- KIPAC, Menlo Park
)

Mar 25, 2019

8 pages

Published in:

PoS ICRC2019 (2021) 570

Contribution to:

- ICRC 2019
, 570

e-Print:

1903.10533 [astro-ph.HE]

DOI:

10.22323/1.358.0570

View in:

ADS Abstract Service

reference search21 citations

Citations per year

Abstract: (SISSA)

The Andromeda galaxy is the closest spiral galaxy to us and has been the subject of numerous studies. It harbors a massive dark matter halo which may span up to ~600 kpc across and comprises ~90% of the galaxy's total mass. This halo size translates into a large diameter of 42 degrees on the sky for an M31-Milky Way (MW) distance of 785 kpc, but its presumably low surface brightness makes it challenging to detect with gamma-ray telescopes. Using 7.6 years of Fermi Large Area Telescope (Fermi-LAT) observations, we make a detailed study of the gamma-ray emission between 1-100 GeV towards M31's outer halo, with a total field radius of 60 degrees centered at M31, and perform an in-depth analysis of the systematic uncertainties related to the observations. We use the cosmic ray propagation code GALPROP to construct specialized interstellar emission models to characterize the foreground gamma-ray emission from the MW, including a self-consistent determination of the isotropic component. We find evidence for an extended excess that appears to be distinct from the conventional MW foreground, having a total radial extension upwards of ~120-200 kpc from the center of M31. We discuss plausible interpretations of the excess emission but emphasize that uncertainties in the MW foreground, and in particular, modeling of the H I-related components, have not been fully explored and may impact the results.

Note:

49 pages, 48 figures, and 23 tables, accepted for publication in The Astrophysical Journal •
Submitted to Astrophys.J.

gamma ray: emission
gamma ray: detector
emission: model
dark matter: halo
galaxy
dark matter: annihilation
GLAST
cosmic radiation
propagation
brightness

References(259)

Figures(0)

Astrophysical and Dark Matter Interpretations of Extended Gamma-Ray Emission from the Galactic Center

- Phys.Rev.D 90 (2014) 2, 023526
•
e-Print:
- 1402.4090
•
DOI:
- 10.1103/PhysRevD.90.023526

Discovery of a New Galactic Center Excess Consistent with Upscattered Starlight

Kevork N. Abazajian
(
- UC, Irvine
)
,
Nicolas Canac
(
- UC, Irvine
)
,
Shunsaku Horiuchi
(
- UC, Irvine and
- Virginia Tech.
)
,
Manoj Kaplinghat
(
- UC, Irvine
)
,
Anna Kwa
(
- UC, Irvine
)

- JCAP 07 (2015) 013
•
e-Print:
- 1410.6168
•
DOI:
- 10.1088/1475-7516/2015/07/013

Detection of a Gamma-Ray Source in the Galactic Center Consistent with Extended Emission from Dark Matter Annihilation and Concentrated Astrophysical Emission

Kevork N. Abazajian
(
- UC, Irvine
)
,
Manoj Kaplinghat
(
- UC, Irvine
)

- Phys.Rev.D 86 (2012) 083511,
- Phys.Rev.D 87 (2013) 129902 (erratum)
•
e-Print:
- 1207.6047
•
DOI:
- 10.1103/PhysRevD.86.083511

DOI:
- 10.1103/PhysRevD

87.129902

Fermi LAT Observation of Diffuse Gamma-Rays Produced Through Interactions between Local Interstellar Matter and High Energy Cosmic Rays

Fermi-LAT

Collaboration

•

A.A. Abdo
(
- Naval Research Lab, Wash., D.C. and
- Federal City Coll.
)

et al.

- Astrophys.J. 703 (2009) 1249-1256
•
e-Print:
- 0908.1171
•
DOI:
- 10.1088/0004-637X/703/2/1249

The On-orbit calibrations for the Fermi Large Area Telescope

Fermi-LAT

Collaboration

•

Aous A. Abdo
(
- Naval Research Lab, Wash., D.C.
)

et al.

- Astropart.Phys. 32 (2009) 193-219
•
e-Print:
- 0904.2226
•
DOI:
- 10.1016/j.astropartphys.2009.08.002

Fermi Large Area Telescope observations of Local Group galaxies: Detection of M31 and search for M33

Fermi-LAT

Collaboration

- Astron.Astrophys. 523 (2010) L2
•
e-Print:
- 1012.1952
•
DOI:
- 10.1051/0004-6361/201015759

Sensitivity of HAWC to high-mass dark matter annihilations

HAWC

Collaboration

•

A.U. Abeysekara
(
- Michigan State U.
)

et al.

- Phys.Rev.D 90 (2014) 12, 122002
•
e-Print:
- 1405.1730
•
DOI:
- 10.1103/PhysRevD.90.122002

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

Fermi-LAT

Collaboration

•

F. Acero
(
- DAPNIA, Saclay
)

et al.

- Astrophys.J.Suppl. 223 (2016) 2, 26
•
e-Print:
- 1602.07246
•
DOI:
- 10.3847/0067-0049/223/2/26

Limits on Dark Matter Annihilation Signals from the Fermi LAT 4-year Measurement of the Isotropic Gamma-Ray Background

Fermi-LAT

Collaboration

•

M. Ackermann
(
- DESY, Zeuthen
)

et al.

- JCAP 09 (2015) 008
•
e-Print:
- 1501.05464
•
DOI:
- 10.1088/1475-7516/2015/09/008

The Fermi Large Area Telescope On Orbit: Event Classification, Instrument Response Functions, and Calibration

Fermi-LAT

Collaboration

•

M. Ackermann
(
- DESY, Zeuthen
)

et al.

- Astrophys.J.Suppl. 203 (2012) 4
•
e-Print:
- 1206.1896
•
DOI:
- 10.1088/0067-0049/203/1/4

Fermi-LAT Observations of the Diffuse Gamma-Ray Emission: Implications for Cosmic Rays and the Interstellar Medium

Fermi-LAT

Collaboration

•

M. Ackermann
(
- DESY
)

et al.

- Astrophys.J. 750 (2012) 3
•
e-Print:
- 1202.4039
•
DOI:
- 10.1088/0004-637X/750/1/3

Fermi LAT study of cosmic-rays and the interstellar medium in nearby molecular clouds

Fermi-LAT

Collaboration

•

M. Ackermann
(
- DESY
)

et al.

- Astrophys.J. 755 (2012) 22,
- Astrophys.J. 778 (2013) 82 (erratum)
•
e-Print:
- 1207.6275
•
DOI:
- 10.1088/0004-637X/755/1/22

b, Physical Review

M. Ackermann
,
A. Albert
,
B. Anderson

Searching for Dark Matter Annihilation from Milky Way Dwarf Spheroidal Galaxies with Six Years of Fermi Large Area Telescope Data

Fermi-LAT

Collaboration

•

M. Ackermann
(
- DESY
)

et al.

- Phys.Rev.Lett. 115 (2015) 23, 231301
•
e-Print:
- 1503.02641
•
DOI:
- 10.1103/PhysRevLett.115.231301

Observations of M31 and M33 with the Fermi Large Area Telescope: A Galactic Center Excess in Andromeda?

Fermi-LAT

Collaboration

•

M. Ackermann
(
- DESY, Zeuthen
)

et al.

- Astrophys.J. 836 (2017) 2, 208
•
e-Print:
- 1702.08602
•
DOI:
- 10.3847/1538-4357/aa5c3d

The Fermi Galactic Center GeV Excess and Implications for Dark Matter

Fermi-LAT

Collaboration

•

M. Ackermann
(
- DESY, Zeuthen
)

et al.

- Astrophys.J. 840 (2017) 1, 43
•
e-Print:
- 1704.03910
•
DOI:
- 10.3847/1538-4357/aa6cab

Planck intermediate results. XXV. The Andromeda Galaxy as seen by Planck

Planck

Collaboration

•

P.A.R. Ade

et al.

- Astron.Astrophys. 582 (2015) A28
•
e-Print:
- 1407.5452
•
DOI:
- 10.1051/0004-6361/201424643

Point Sources from Dissipative Dark Matter

- JCAP 12 (2017) 019
•
e-Print:
- 1706.04195
•
DOI:
- 10.1088/1475-7516/2017/12/019

Precision Measurement of the ( $e^+ + e^−$ ) Flux in Primary Cosmic Rays from 0.5 GeV to 1 TeV with the Alpha Magnetic Spectrometer on the International Space Station

AMS

Collaboration

•

M. Aguilar
(
- Madrid, CIEMAT
)

et al.

- Phys.Rev.Lett. 113 (2014) 221102
•
DOI:
- 10.1103/PhysRevLett.113.221102

Precision Measurement of the Proton Flux in Primary Cosmic Rays from Rigidity 1 GV to 1.8 TV with the Alpha Magnetic Spectrometer on the International Space Station

AMS

Collaboration

•

M. Aguilar
(
- Madrid, CIEMAT
)

et al.

- Phys.Rev.Lett. 114 (2015) 171103
•
DOI:
- 10.1103/PhysRevLett.114.171103

Precision Measurement of the Helium Flux in Primary Cosmic Rays of Rigidities 1.9 GV to 3 TV with the Alpha Magnetic Spectrometer on the International Space Station

AMS

Collaboration

•

M. Aguilar
(
- Madrid, CIEMAT
)

et al.

- Phys.Rev.Lett. 115 (2015) 21, 211101
•
DOI:
- 10.1103/PhysRevLett.115.211101

Submitted to

M. Ajello
,
L. Baldini
,
J. Ballet
,
G. Barbiellini

Characterizing the population of pulsars in the inner Galaxy with the Fermi Large Area Telescope

Fermi-LAT

Collaboration

•

M. Ajello
(
- Clemson U.
)

et al.

e-Print:
- 1705.00009

1-25 of 259
1
2
3
4
5
•••
11
25 / page