J/ApJ/894/88 γ-ray emission of star-forming galaxies (Ajello+, 2020)
The γ-ray emission of star-forming galaxies.
Ajello M., Di Mauro M., Paliya V.S., Garrappa S.
<Astrophys. J., 894, 88-88 (2020)>
=2020ApJ...894...88A 2020ApJ...894...88A (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, IR; Gamma rays
Keywords: Starburst galaxies; Gamma-rays; Neutrino astronomy
Abstract:
A majority of the γ-ray emission from star-forming galaxies is
generated by the interaction of high-energy cosmic rays with the
interstellar gas and radiation fields. Star-forming galaxies are
expected to contribute to both the extragalactic γ-ray
background and the IceCube astrophysical neutrino flux. Using roughly
10yr of γ-ray data taken by the Fermi Large Area Telescope, in
this study we constrain the γ-ray properties of star-forming
galaxies. We report the detection of 11 bona fide γ-ray-emitting
galaxies and 2 candidates. Moreover, we show that the cumulative
γ-ray emission of below-threshold galaxies is also significantly
detected at ∼5σ confidence. The γ-ray luminosity of
resolved and unresolved galaxies is found to correlate with the total
(8-1000µm) infrared luminosity as previously determined. Above
1GeV, the spectral energy distribution of resolved and unresolved
galaxies is found to be compatible with a power law with a photon
index of ∼2.2-2.3. Finally, we find that star-forming galaxies account
for roughly 5% and 3% of the extragalactic γ-ray background and
the IceCube neutrino flux, respectively.
Description:
We analyze almost 10yr of Fermi-LAT Pass 8 data, from 2008 August 4 to
2018 March 4, selecting γ-ray events in star-forming galaxies
(SFGs).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 61 13 List of star-forming galaxies (SFGs)
detected in our analysis
fig2.dat 71 165 SEDs of bona fide SFGs
fig3.dat 71 30 SEDs for candidate SFGs
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See also:
VII/274 : The Roma BZCAT - 5th edition (Massaro+, 2015)
J/ApJS/112/315 : Spectroscopic parameters of Seyfert nuclei (Ho+ 1997)
J/ApJS/143/377 : UV-to-FIR magnitudes for 83 starburst galaxies (Wu+, 2002)
J/AJ/126/1607 : IRAS Revised Bright Galaxy Sample (Sanders+, 2003)
J/A+A/465/71 : 21cm observations of 452 galaxies (Theureau+, 2007)
J/ApJS/184/230 : Spitzer high-res. MIR spectral atlas (Bernard-Salas+, 2009)
J/A+A/534/A31 : Spectroscopic study of 283 AGNs in Coma (Gavazzi+, 2011)
J/A+A/532/A104 : Hubble flow around Fornax cluster of gal. (Nasonova+, 2011)
J/ApJS/199/31 : Fermi LAT second source catalog (2FGL) (Nolan+, 2012)
J/AJ/146/86 : Cosmicflows-2 catalog (Tully+, 2013)
J/ApJS/218/23 : Fermi LAT third source catalog (3FGL) (Acero+, 2015)
J/A+A/586/A71 : LMC 0.2-100GeV images (Ackermann+, 2016)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- Name Name of the galaxy
10 A1 --- f_Name Flag on Name (1)
12- 17 F6.2 deg RAdeg [10.69/233.74]? Right ascension (J2000)
19- 24 F6.2 deg DEdeg [-72.83/78.36]? Declination (J2000)
26- 31 F6.3 Mpc Dist [0.05/79.9]? Distance from Earth
33 A1 --- r_Dist Distance reference (2)
35- 39 F5.2 [Lsun] logLIR [7.86/12.21]? log of IR luminosity (3)
41- 44 I4 --- TS [32/4797]? Test statistic (4)
46- 50 F5.2 10-14W/m2 S [0.13/10.7]? γ-ray energy flux
in units of 10-11erg/cm2/s
52- 55 F4.2 10-14W/m2 e_S [0.04/0.3]? S uncertainty
57- 61 F5.2 [10-7W] logLgam [37.14/42.42]? log of γ-ray luminosity
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Note (1): Flag as follows:
b = bona fide γ-ray emitting sample;
c = candidates: SFGs that are offset with respect to the IR-γ-ray
luminosity correlation.
Note (2): Reference as follows:
a = Ackermann et al. 2012ApJ...755..164A 2012ApJ...755..164A for the Local Group galaxies
m = Mouhcine et al. (2005ApJ...633..810M 2005ApJ...633..810M)
h = Bland-Hawthorn (1997Ap&SS.248....9B 1997Ap&SS.248....9B)
d = Adamo et al. (2012MNRAS.426.1185A 2012MNRAS.426.1185A)
v = Vacca et al. (2015ApJ...804...66V 2015ApJ...804...66V)
r = the redshift for Arp 229 and Arp 220
s = Mould & Sakai (2008ApJ...686L..75M 2008ApJ...686L..75M)
u = Tully et al. (2013, J/AJ/146/86)
t = Theureau et al. (2007, J/A+A/465/71)
Note (3): IR luminosities are taken from Wu et al. (2002, J/ApJS/143/377),
Sanders et al. (2003, J/AJ/126/1607), and Gao & Solomon (2004ApJ...606..271G 2004ApJ...606..271G).
Note (4): The test statistic, TS, is defined as TS=2(logL1-logL0), where
logL1 and logL0 are the log-likelihood values for the case of background plus
source and only background, respectively (Mattox et al. 1996ApJ...461..396M 1996ApJ...461..396M).
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Byte-by-byte Description of file: fig[23].dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- Name Galaxy identifier (1)
10- 19 F10.3 GeV E [131.6/447353] Energy of bin center
21- 30 F10.3 GeV b_E Lower boundary of E
32- 41 F10.3 GeV B_E Upper boundary of E
43- 51 E9.3 MeV/cm2/s Flux [9.6e-8/1.4e-5]?=0 Best fit value of the SED
53- 61 E9.3 MeV/cm2/s e_Flux ?=0 The 1σ uncertainty in Flux
63- 71 E9.3 MeV/cm2/s Limit ?=0 Upper limit on Flux
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Note (1): The galaxies have been ordered by increasing IR luminosity.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 17-Sep-2021