J/ApJ/933/204 4FGL sources with sp. breaks between 50MeV-1GeV (Abdollahi+, 2022)
Search for new cosmic-ray acceleration sites within the 4FGL catalog Galactic
plane sources.
Abdollahi S., Acero F., Ackermann M., Baldini L., Ballet J.,
Barbiellini G., Bastieri D., Bellazzini R., Berenji B., Berretta A.,
Bissaldi E., Blandford R.D., Bonino R., Bruel P., Buson S., Cameron R.A.,
Caputo R., Caraveo P.A., Castro D., Chiaro G., Cibrario N., Ciprini S.,
Coronado-Blazquez J., Crnogorcevic M., Cutini S., D'Ammando F.,
De Gaetano S., Di Lalla N., Dirirsa F., Di Venere L., Dominguez A.,
Fegan S.J., Fiori A., Fleischhack H., Franckowiak A., Fukazawa Y.,
Fusco P., Gammaldi V., Gargano F., Gasparrini D., Giacchino F.,
Giglietto N., Giordano F., Giroletti M., Glanzman T., Green D.,
Grenier I.A., Grondin M.-H., Guiriec S., Gustafsson M., Harding A.K.,
Hays E., Hewitt J.W., Horan D., Hou X., Johannesson G., Kayanoki T.,
Kerr M., Kuss M., Larsson S., Latronico L., Lemoine-Goumard M., Li J.,
Longo F., Loparco F., Lubrano P., Maldera S., Malyshev D., Manfreda A.,
Marti-Devesa G., Mazziotta M.N., Mereu I., Michelson P.F., Mirabal N.,
Mitthumsiri W., Mizuno T., Monzani M.E., Morselli A., Moskalenko I.V.,
Nuss E., Omodei N., Orienti M., Orlando E., Ormes J.F., Paneque D.,
Pei Z., Persic M., Pesce-Rollins M., Pillera R., Poon H., Porter T.A.,
Principe G., Raino S., Rando R., Rani B., Razzano M., Razzaque S.,
Reimer A., Reimer O., Reposeur T., Sanchez-Conde M., Saz Parkinson P.M.,
Scotton L., Serini D., Sgro C., Siskind E.J., Spandre G., Spinelli P.,
Sueoka K., Suson D.J., Tajima H., Tak D., Thayer J.B., Torres D.F.,
Troja E., Valverde J., Wadiasingh Z., Wood K., Zaharijas G.
<Astrophys. J., 933, 204 (2022)>
=2022ApJ...933..204A 2022ApJ...933..204A
ADC_Keywords: Gamma rays; Supernova remnants; Galactic plane
Keywords: Gamma-ray sources ; Supernova remnants
Abstract:
Cosmic rays are mostly composed of protons accelerated to relativistic
speeds. When those protons encounter interstellar material, they
produce neutral pions, which in turn decay into gamma-rays. This
offers a compelling way to identify the acceleration sites of protons.
A characteristic hadronic spectrum, with a low-energy break around
200MeV, was detected in the gamma-ray spectra of four supernova
remnants (SNRs), IC 443, W44, W49B, and W51C, with the Fermi Large
Area Telescope. This detection provided direct evidence that
cosmic-ray protons are (re-)accelerated in SNRs. Here, we present a
comprehensive search for low-energy spectral breaks among 311 4FGL
catalog sources located within 5° from the Galactic plane. Using
8yr of data from the Fermi Large Area Telescope between 50MeV and
1GeV, we find and present the spectral characteristics of 56 sources
with a spectral break confirmed by a thorough study of systematic
uncertainty. Our population of sources includes 13 SNRs for which the
proton-proton interaction is enhanced by the dense target material;
the high-mass gamma-ray binary LS I+61 303; the colliding wind binary
η Carinae; and the Cygnus star-forming region. This analysis
better constrains the origin of the gamma-ray emission and enlarges
our view to potential new cosmic-ray acceleration sites.
Description:
In this paper, we use 8 years of Pass 8 Fermi/LAT data to analyze
311 Galactic sources detected in the 4FGL catalog and search for
significant spectral breaks between 50MeV and 1GeV. We used exactly
the same data set as that used to derive the 4FGL catalog of sources,
namely, 8yr (2008 August 4-2016 August 2) of Pass 8 SOURCE class
photons (see Abdollahi+ 2020, J/ApJS/247/33). This means that
similarly to the 4FGL data set, our data were filtered removing time
periods when the rocking angle was greater than 90° and intervals
around solar flares and bright gamma-ray bursts (GRBs) were excised.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tableb1.dat 76 311 List of selected Galactic plane candidates
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See also:
IX/67 : Incremental Fermi LAT 4th source cat. (4FGL-DR3) (Fermi-LAT col., 2022)
J/A+AS/118/329 : MOST supernova remnant catalogue (MSC) (Whiteoak+ 1996)
J/ApJS/224/8 : The first Fermi LAT SNR catalog (1SC) (Acero+, 2016)
J/ApJ/843/40 : The 2HWC HAWC Observatory gamma-ray cat. (Abeysekara+, 2017)
J/ApJS/237/32 : Fermi cat. of High-lat. Extended Sources (Ackermann+, 2018)
J/A+A/612/A5 : W49B with H.E.S.S. and Fermi-LAT (HESS+, 2018)
J/A+A/612/A1 : H.E.S.S. Galactic Plane Survey (HESS+, 2018)
J/ApJS/247/33 : The Fermi LAT fourth source catalog (4FGL) (Abdollahi+, 2020)
http://fermi.gsfc.nasa.gov/ssc/ : Fermi homepage
Byte-by-byte Description of file: tableb1.dat
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Bytes Format Units Label Explanations
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1- 1 A1 --- f_4FGL [*] *: spectral breaks that are robust to
all tests
3- 6 A4 --- --- [4FGL]
8- 20 A13 --- 4FGL 4FGL name (JHHMM.m+DDMMa) (1)
22- 27 F6.2 deg GLON Galactic longitude
29- 33 F5.2 deg GLAT [-5/5] Galactic latitude
35- 39 F5.2 --- SigCurv [0/29] 4FGL curvature significance
41- 46 F6.2 --- sqrtTS [3/107.3] 4FGL significance, TS0.5
between 300MeV and 1GeV
48- 50 A3 --- Class Source class reported in the 4FGL catalog (2)
52- 58 F7.1 --- TS [0.3/39496] Test statistic, power-law
60- 64 F5.1 --- TS-LP [0/194]? Test statistic improvement
with log-parabola
66- 70 F5.1 --- TS-SBPL [9/176]? Test statistic improvement
with smooth broken power law
72- 76 F5.1 --- TS-SBPL2 [4.8/168]? Test statistic improvement with
smooth broken power law with sub-exponential
cutoff
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Note (1): 18 4FGL identifiers without letter 'c' at the end have been corrected
by CDS
Note (2): Source class reported in the 4FGL catalog (See Table 5) as follows:
spp = Supernova remnant/pulsar wind nebula, association (37 occurrences)
unk = Unknown (31 occurrences)
SNR = Supernova remnant, firm identification (15 occurrences)
snr = Supernova remnant, association (8 occurrences)
HMB = High-mass binary, firm identification (4 occurrences)
PWN = Pulsar wind nebula, firm identification (3 occurrences)
pwn = Pulsar wind nebula, association (1 occurrence)
BIN = Binary, firm identification (1 occurrence)
SFR = Star-forming region, firm identification (1 occurrence)
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History:
From electronic version of the journal
(End) Prepared by [AAS], Katia van der Woerd [CDS] 08-Oct-2024