J/ApJ/854/99 The Einstein@Home gamma-ray pulsar survey. II. (Wu+, 2018)
The Einstein@Home gamma-ray pulsar survey.
II. Source selection, spectral analysis, and multiwavelength follow-up.
Wu J., Clark C.J., Pletsch H.J., Guillemot L., Johnson T.J., Torne P.,
Champion D.J., Deneva J., Ray P.S., Salvetti D., Kramer M., Aulbert C.,
Beer C., Bhattacharyya B., Bock O., Camilo F., Cognard I., Cuellar A.,
Eggenstein H.B., Fehrmann H., Ferrara E.C., Kerr M., Machenschalk B.,
Ransom S.M., Sanpa-Arsa S., Wood K.
<Astrophys. J., 854, 99 (2018)>
=2018ApJ...854...99W 2018ApJ...854...99W
ADC_Keywords: Pulsars; Gamma rays; Surveys
Keywords: gamma rays: stars ; pulsars: individual (PSR J0002+6216,
PSR J0631+0646, PSR J1624-4041, PSR J2017+3625)
Abstract:
We report on the analysis of 13 gamma-ray pulsars discovered in the
Einstein@Home blind search survey using Fermi Large Area Telescope
(LAT) Pass 8 data. The 13 new gamma-ray pulsars were discovered by
searching 118 unassociated LAT sources from the third LAT source
catalog (3FGL), selected using the Gaussian Mixture Model
machine-learning algorithm on the basis of their gamma-ray emission
properties being suggestive of pulsar magnetospheric emission. The new
gamma-ray pulsars have pulse profiles and spectral properties similar
to those of previously detected young gamma-ray pulsars. Follow-up
radio observations have revealed faint radio pulsations from two of
the newly discovered pulsars and enabled us to derive upper limits on
the radio emission from the others, demonstrating that they are likely
radio-quiet gamma-ray pulsars. We also present results from modeling
the gamma-ray pulse profiles and radio profiles, if available, using
different geometric emission models of pulsars. The high discovery
rate of this survey, despite the increasing difficulty of blind pulsar
searches in gamma rays, suggests that new systematic surveys such as
presented in this article should be continued when new LAT source
catalogs become available.
Description:
Using information from a preliminary version of the 3FGL catalog of
Fermi LAT sources (Acero+ 2015, J/ApJS/218/23), we have selected 118
targets with pulsar-like emission properties. We initially considered
LAT data recorded between 2008 August 4 and 2014 April 6 for our
survey and included photons recorded until 2015 July 7 after a few
tens of sources had been searched. We produced Pass 8 LAT data sets
for each of the sources, and these data sets were then searched for
pulsations with a multistage blind search algorithm, utilizing the
volunteer computing system Einstein@Home (http://einsteinathome.org/).
This survey led to the discovery of 17 pulsars, of which 13 are
presented in this article.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 92 118 Ranked source list
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See also:
B/psr : ATNF Pulsar Catalogue (Manchester+, 2005)
J/MNRAS/424/2832 : Pulsars in γ-ray sources (Lee+, 2012)
J/MNRAS/424/L64 : AGN/pulsar distinction for 2FGL sources (Mirabal+, 2012)
J/ApJS/208/17 : 2nd Fermi LAT cat. of gamma-ray pulsars (2PC) (Abdo+, 2013)
J/ApJ/763/80 : GBT 350MHz survey. I. 13 new pulsars (Boyles+, 2013)
J/ApJS/218/23 : Fermi LAT third source catalog (3FGL) (Acero+, 2015)
J/ApJ/810/85 : Obs. of first Fermi-LAT sources at Parkes (Camilo+, 2015)
J/ApJS/224/8 : The first Fermi LAT SNR catalog (1SC) (Acero+, 2016)
J/ApJ/820/8 : 3FGL sources statistical classifications (Saz Parkinson+, 2016)
http://einsteinathome.org/ : Einstein@Home home page
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1 A1 --- n_3FGL [r] r: sources searched with relocalized
positions, as mentioned in Sec. 3.2
3- 15 A13 --- 3FGL 3FGL catalog identifier (1)
17- 19 A3 --- f_3FGL Flag on 3FGL (2)
21- 22 I2 h RAh Hour of searched Right Ascension (J2000)
24- 25 I2 min RAm Minute of searched Right Ascension (J2000)
27- 31 F5.2 s RAs Second of searched Right Ascension (J2000)
33 A1 --- DE- Sign of the searched Declination (J2000)
34- 35 I2 deg DEd Degree of searched Declination (J2000)
37- 38 I2 arcmin DEm Arcminute of searched Declination (J2000)
40- 44 F5.2 arcsec DEs Arcsecond of searched Declination (J2000)
46- 50 F5.2 arcmin Rad [1/13.7] Searched radius
52- 56 F5.2 --- Var [23.3/90.7] Variability index (3)
58- 62 F5.1 --- TScurve [0.5/275.2] Curvature Test Statistic (3)
64- 68 F5.1 --- TScut [0/378.7] Spectral cutoff Test Statistic (4)
70- 73 F4.1 GeV Ecut [0/45.8]? Cutoff energy (4)
75- 77 F3.1 --- Gamma [0/3.1] Photon index (4)
79- 82 I4 --- TS [80/4790] Test Statistic value (4)
84- 88 F5.2 [-] logRS [3.4/19] log pulsar likelihood value
from our Gaussian Mixture Model (GMM) analysis
90- 92 A3 --- Class Class flags (5)
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Note (1): List of the 118 3FGL sources with logRS>0 searched for gamma-ray
pulsars using Einstein@Home, ranked by their probability to be
pulsars according to the GMM analysis presented in Section 2.2.
Note (2): Flag as follows:
d = searched in a previous Einstein@Home and Atlas survey for
gamma-ray pulsars.
* = suspiciously low or high cutoff energies were measured.
b = A pulsar discovered in this survey. The discovery and analysis of
PSRs J1906+0722 and J1208-6238 are presented in
Clark+ (2015ApJ...809L...2C 2015ApJ...809L...2C) and Clark+ (2016ApJ...832L..15C 2016ApJ...832L..15C),
while PSRs J1035-6720 and PSR J1744-7619 discovered in
3FGL J1035.7-6720 and 3FGL J1744.1-7619 will be presented in a
future publication.
Note (3): From a preliminary version of the 3FGL catalog.
Note (4): From our binned maximum likelihood analysis with Pointlike. Cutoff
energies are listed for sources with TScut > 9.
Note (5): Association flags from the 3FGL catalog: "pwn" and "snr" labels
indicate possible associations with pulsar wind nebulae (PWN) and
supernova remnants (SNR) respectively, sources with class "spp" are
special cases with potential PWN or SNR associations.
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History:
From electronic version of the journal
References:
Clark et al. Paper I. 2017ApJ...834..106C 2017ApJ...834..106C
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 09-Nov-2018