2024ApJ...971..180Y

Query : 2024ApJ...971..180Y

2024ApJ...971..180Y - Astrophys. J., 971, 180 (2024/August-3)

A Multiwavelength Machine-learning Approach to Classifying X-Ray Sources in the Fields of Unidentified 4FGL-DR4 Sources.

YANG H., HARE J. and KARGALTSEV O.

Abstract (from CDS):

A large fraction of Fermi-Large Area Telescope (LAT) sources in the fourth Fermi-LAT 14 yr catalog (4FGL) still remain unidentified (unIDed). We continued to improve our machine-learning pipeline and used it to classify 1206 X-ray sources with signal-to-noise ratios >3 located within the extent of 73 unIDed 4FGL sources with Chandra X-ray Observatory observations included in the Chandra Source Catalog 2.0. Recent improvements to our pipeline include astrometric corrections, probabilistic cross-matching to lower-frequency counterparts, and a more realistic oversampling method. X-ray sources are classified into eight broad predetermined astrophysical classes defined in the updated training data set, which we also release. We present details of the machine-learning classification, describe the pipeline improvements, and perform an additional spectral and variability analysis for brighter sources. The classifications give 103 plausible X-ray counterparts to 42 GeV sources. We identify 2 GeV sources as isolated neutron star candidates, 16 as active galactic nucleus candidates, seven as sources associated with star-forming regions, and eight as ambiguous cases. For the remaining 40 unIDed 4FGL sources, we could not identify any plausible counterpart in X-rays, or they are too close to the Galactic Center. Finally, we outline the observational strategies and further improvements in the pipeline that can lead to more accurate classifications.

Abstract Copyright: © 2024. The Author(s). Published by the American Astronomical Society.

Journal keyword(s): X-ray sources - Classification - Active galactic nuclei - Compact objects - Catalogs - Neutron stars - Astronomical object identification - Astrostatistics tools - X-ray surveys - Gamma-ray sources - X-ray binary stars - Random Forests

Status at CDS : Large table(s) will be appraised for possible ingestion in VizieR.

Simbad objects: 76

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Number of rows : 76
N Identifier Otype ICRS (J2000)
RA 		ICRS (J2000)
DEC 		Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2026 		#notes
1 1RXS J005807.5-460420 BL? 00 58 06.2216135789 -46 04 18.993546791           ~ 14 0
2 NAME Chandra Deep Field-South reg 03 32 28.0 -27 48 30           ~ 2282 1
3 4FGL J0335.6-0727 gam 03 35 39.7 -07 27 18           ~ 2 0
4 4FGL J0442.8+3609 gam 04 42 50.5 +36 09 50           ~ 6 0
5 1RXS J064103.9-801135 Psr 06 40 59.5272118533 -80 11 25.949943679           ~ 6 0
6 NGC 2403 AGN 07 36 51.3381434280 +65 36 09.650825640 9.31 8.84 8.38 8.19   ~ 1887 1
7 2MASS J07371703+6535579 HXB 07 37 17.0432126424 +65 35 57.826001220           SNIIP 317 1
8 4FGL J0737.4+6535 gam 07 37 30 +65 35.5           ~ 16 0
9 RCW 36 HII 08 59 00.9 -43 44 10     15.20     ~ 161 0
10 RCW 38 SFR 08 59 05.50 -47 30 39.4           ~ 327 2
11 3FGL J0859.3-4732 gam 08 59 13 -47 29.3           ~ 12 0
12 4FGL J0859.3-4342 gam 08 59 18 -43 42.7           ~ 8 0
13 NAME RCW 36 IR Cluster OpC 08 59 26 -43 45.1           ~ 6 0
14 NAME Car Arm PoG 10 00 -60.0           ~ 471 1
15 Cl Westerlund 2 OpC 10 23 58.1 -57 45 49           ~ 400 0
16 Z 65-31 EmG 10 25 53.0392674864 +12 42 39.069779544   15.3       ~ 51 0
17 NVSS J102557+124107 rG 10 25 57.986 +12 41 08.38           ~ 19 1
18 4FGL J1032.0+5725 gam 10 32 03.6 +57 25 19           ~ 6 0
19 NGC 3372 HII 10 45 02.23 -59 41 59.8           ~ 1071 2
20 * eta Car s*b 10 45 03.545808 -59 41 03.95124 6.37 7.03 6.48 6.123 4.41 LBV 2543 0
21 2FGL J1046.8-6005c gam 10 46 42.3 -60 10 24           ~ 18 0
22 Cl Bochum 11 OpC 10 47 06.3 -60 05 55           ~ 95 0
23 4FGL J1048.5-5923 gam 10 48 32.8 -59 23 32           ~ 7 0
24 4FGL J1106.4+0859 gam 11 06 29.1 +08 59 24           ~ 2 0
25 NGC 3603 OpC 11 14 57.9 -61 14 32           ~ 1136 1
26 1FGL J1115.2-6124c gam 11 15 06.2 -61 18 31           ~ 15 0
27 4FGL J1116.3+1818 gam 11 16 22.5 +18 18 17           ~ 2 0
28 NGC 4631 GiC 12 42 08.009 +32 32 29.44   9.78 9.19 9.10   ~ 1154 3
29 4FGL J1256.9+2736 gam 12 56 58.0 +27 36 27           ~ 13 0
30 NGC 4839 BiC 12 57 24.3563164776 +27 29 52.203087132 13.56 13.02 12.06     ~ 482 3
31 2FGL J1324.0-4330e gam 13 24 00.00 -43 30 00.0           ~ 11 0
32 NAME Centaurus A BLL 13 25 27.61521044 -43 01 08.8050291   8.18 6.84 6.66   ~ 4774 3
33 4FGL J1502.6+0207 gam 15 02 36.6 +02 07 43           ~ 5 0
34 4FGL J1510.9+0551 gam 15 10 57.6 +05 51 22           ~ 5 0
35 4FGL J1615.3-6034 gam 16 15 18.6 -60 34 06           ~ 2 0
36 ESO 137-7 rG 16 15 32.889 -60 39 55.25   13.90   12.23   ~ 33 0
37 PSR J1616-5017 Psr 16 16 29.8436526288 -50 17 14.292194784           ~ 9 0
38 4FGL J1616.6-5009 gam 16 16 37.8 -50 09 03           ~ 7 0
39 PSR J1617-5055 Psr 16 17 29.35 -50 55 12.8           ~ 128 1
40 1FGL J1619.7-5043c gam 16 19 22.8 -50 47 02           ~ 13 0
41 1FGL J1720.7-3707c gam 17 20 36.9 -37 06 31           ~ 12 0
42 TYC 7374-9-1 * 17 20 51.8050485552 -37 10 37.272768960   12.12 11.80     ~ 2 0
43 NGC 6357 OpC 17 24 44 -34 12.2           ~ 303 0
44 4FGL J1725.1-3408 gam 17 25 11.6 -34 08 10           ~ 4 0
45 4FGL J1732.8-3725 gam 17 32 51.9 -37 25 08           ~ 6 0
46 PSR B1730-37 Psr 17 33 26.754 -37 16 54.60           ~ 54 0
47 4FGL J1734.0-2933 gam 17 34 03 -29 33.1           ~ 11 0
48 4FGL J1737.1-2901 gam 17 37 06.2 -29 01 38           ~ 9 0
49 2FGL J1739.6-2726 gam 17 39 31.22 -27 27 45.3           ~ 20 0
50 4FGL J1742.5-2833 gam 17 42 32.0 -28 33 32           ~ 9 0
51 4FGL J1744.9-2905 gam 17 44 57.8 -29 05 23           ~ 2 0
52 NAME Galactic Center reg 17 45 39.60213 -29 00 22.0000           ~ 16269 0
53 4FGL J1745.6-3145 gam 17 45 40.3 -31 45 26           ~ 5 0
54 4FGL J1750.4-3023 gam 17 50 27.9 -30 23 57           ~ 7 0
55 4FGL J1757.6-2731 gam 17 57 36.3 -27 31 42           ~ 6 0
56 4FGL J1804.9-3001 gam 18 04 57.8 -30 01 32           ~ 7 0
57 3FGL J1819.5-2045c gam 18 19 30 -20 46.0           ~ 10 0
58 NGC 6618 OpC 18 20 47 -16 10.3           ~ 1700 0
59 M 22 GlC 18 36 23.94 -23 54 17.1           ~ 1459 0
60 PSR J1836-2354A Psr 18 36 25.4452 -23 54 52.390           ~ 21 0
61 PMN J1836-2406 Rad 18 36 32.716 -24 06 23.92           ~ 5 1
62 3FGL J1837.3-2403 Bla 18 36 50.7 -23 54 24           ~ 13 0
63 M 70 GlC 18 43 12.76 -32 17 31.6           ~ 421 0
64 4FGL J1843.7-3227 gam 18 43 43.5 -32 27 20           ~ 3 0
65 1FGL J1844.3-0309c gam 18 44 29 -03 07.0           ~ 12 0
66 SNR G029.37+00.1 SNR 18 44 34.3 -03 07 37           ~ 9 0
67 HESS J1844-030 gam 18 44 40.0 -03 06 00           ~ 17 0
68 PSR B1842-03.2 Psr 18 44 45.48 -03 10 37.1           ~ 12 0
69 1FGL J2004.7+3343 gam 20 04 23.0 +33 39 19           ~ 26 0
70 Min 3-60 LP? 20 04 23.6504906400 +33 39 04.363566300           K?e 66 1
71 3FGL J2038.4+4212 gam 20 38 30.0 +42 12 31           ~ 14 0
72 DR 21 SFR 20 39 01.6 +42 19 38           O4.5 1121 0
73 NGC 7000 Cl* 20 58 47 +44 19.8           ~ 427 0
74 4FGL J2236.9+1839 BLL 22 37 04.7848938113 +18 40 55.984423356           ~ 12 1
75 4FGL J2254.4+0108 gam 22 54 29.5 +01 08 14           ~ 2 0
76 NAME Lockman Hole Northwest reg ~ ~           ~ 14 0

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