Swift-XRT Survey of Fermi Unassociated Sources

These results are part of the Swift program to follow-up Fermi unassociated sources in an attempt to find X-ray counterparts to the unidentified gamma-ray sources. As new observations are performed, these pages will be updated in nearly real time. Please use these results as a guide and proceed with caution when using them in a publication since they are the result of an automated analysis.

When using these data and results in publications, please reference M.C. Stroh & A.D. Falcone 2013, ApJS, 207, 28; arXiv: 1305.4949 for a description of many of the analysis techniques used to reduce these data (note: a more detailed paper describing the complete data set and analysis is forthcoming). Please contact Abe Falcone and Michael Stroh at unassociated@swift.psu.edu if you have any questions about the program or the analysis, or to simply to let us know that you've made use of these data.
Caution: For completeness, sources are listed if the "detection" exceeds 3 sigma. The significances and images are shown so you can make more stringent significance cuts, if desired.

4FGL J1557.2+3822

Field

Detected Excesses
Swift-XRT image of the field for 4FGL J1557.2+3822 Swift-XRT detections in the field for 4FGL J1557.2+3822

Detected Excesses (SNR(Sosta) > 3.0)

# R.A. (J2000) Dec. (J2000) Pos. Error (") Rate (cts/s) Counts SNR (Detect) SNR (Sosta)
1 15 57 11.96 +38 20 29.25 4.34 (9.0 ± 1.3) x 10-3 77 7.604 7.124
2 15 56 34.36 +38 22 10.15 5.35 (3.2 ± 0.8) x 10-3 28 4.486 4.253
3 15 56 57.01 +38 28 24.77 4.97 (3.8 ± 0.9) x 10-3 29 4.511 4.243
4 15 57 06.51 +38 31 03.45 5.82 (2.0 ± 0.6) x 10-3 17 3.214 3.140
5 15 57 29.85 +38 15 04.54 5.76 (1.8 ± 0.6) x 10-3 16 3.079 3.016

Rejected Excesses (Due to Overlaps or SNR(Sosta) < 3.0)

# R.A. (J2000) Dec. (J2000) Pos. Error (") Rate (cts/s) Counts SNR (Detect) SNR (Sosta)
1 15 57 38.59 +38 22 02.07 6.52 (1.6 ± 0.6) x 10-3 15 2.815 2.944
2 15 57 14.97 +38 23 51.75 5.82 (1.8 ± 0.7) x 10-3 20 3.027 2.709
3 15 57 28.95 +38 32 18.42 6.78 (1.3 ± 0.5) x 10-3 9 2.408 2.490
4 15 57 12.24 +38 20 30.46 4.33 (1.7 ± 0.7) x 10-3 73 2.790 2.398
5 15 57 34.26 +38 20 34.04 6.04 (1.1 ± 0.5) x 10-3 15 2.599 2.231
6 15 57 13.39 +38 36 56.73 6.52 (1.6 ± 0.7) x 10-3 8 2.346 2.230
7 15 57 11.85 +38 20 28.98 4.34 (1.3 ± 0.7) x 10-3 81 2.562 1.794

X-Ray and Gamma Ray Catalogs

More Catalogs
Swift-XRT image with known X-ray and gamma ray sources for 4FGL J1557.2+3822 Swift-XRT image with known radio, optical and UV sources for 4FGL J1557.2+3822

Known X-Ray and Gamma Ray Sources

# Source Name R.A. (J2000) Dec. (J2000) Offset (') Observatory/Database Table
1 2RXS J155719.0+382141 15 57 19.08 +38 21 41.40 1.26 ROSAT
2RXS J155719.0+382141 15 57 19.08 +38 21 41.40 1.26 ROSAT
2 X155707.93+382637.5 15 57 07.92 +38 26 37.32 4.17 CHANDRA
2CXO J155708.0+382638 15 57 08.11 +38 26 38.40 4.17 CHANDRA
3 X155657.26+382827.2 15 56 57.26 +38 28 27.12 6.74 CHANDRA
CXOGSG J155657.1+382827 15 56 57.12 +38 28 27.48 6.76 CHANDRA
2CXO J155657.0+382827 15 56 57.02 +38 28 27.12 6.77 CHANDRA
4 1RXS J155640.5+382233 15 56 40.51 +38 22 33.60 6.85 ROSAT
2RXS J155640.3+382241 15 56 40.34 +38 22 41.16 6.88 ROSAT
2RXS J155640.3+382241 15 56 40.34 +38 22 41.16 6.88 ROSAT
5 2CXO J155634.1+382208 15 56 34.18 +38 22 08.04 8.11 CHANDRA
6 X155706.07+383105.6 15 57 06.07 +38 31 05.52 8.57 CHANDRA
CXOGSG J155706.0+383105 15 57 06.07 +38 31 05.88 8.57 CHANDRA
2CXO J155706.1+383106 15 57 06.17 +38 31 06.24 8.57 CHANDRA
7 CXOGSG J155644.3+383230 15 56 44.35 +38 32 30.48 11.52 CHANDRA
X155644.34+383230.6 15 56 44.35 +38 32 30.48 11.52 CHANDRA
8 2CXO J155617.8+383019 15 56 17.88 +38 30 19.80 13.60 CHANDRA

Known Radio, Optical and UV Sources

# Source Name R.A. (J2000) Dec. (J2000) Offset (') Database Table
FIRST J155712.2+382033 15 57 12.29 +38 20 33.00 2.26 FIRST
QORG J155712.2+382033 15 57 12.19 +38 20 33.00 2.27 QORGCAT
1 NVSS J155712+382027 15 57 12.50 +38 20 27.96 2.34 NVSS
2 NVSS J155727+382050 15 57 27.41 +38 20 49.92 3.01 NVSS
QORG J155727.2+382044 15 57 27.19 +38 20 44.16 3.05 QORGCAT
FIRST J155727.1+382043 15 57 27.19 +38 20 43.08 3.05 FIRST
3 NVSS J155734+382030 15 57 34.49 +38 20 30.12 4.35 NVSS
FIRST J155734.6+382030 15 57 34.61 +38 20 30.12 4.37 FIRST
TGSSADR J155734.6+382029 15 57 34.70 +38 20 30.12 4.38 GMRTAS150M
WN 1555.7+3829 15 57 34.99 +38 20 30.12 4.43 WENSS
4 FIRST J155720.5+382717 15 57 20.50 +38 27 18.00 4.68 FIRST
5 FIRST J155738.8+382031 15 57 38.90 +38 20 31.92 5.09 FIRST
6 NVSS J155741+382207 15 57 41.50 +38 22 06.96 5.14 NVSS
FIRST J155742.0+382209 15 57 42.10 +38 22 09.12 5.25 FIRST
FIRST J155644.9+382247 15 56 45.00 +38 22 46.92 5.97 FIRST
7 NVSS J155644+382248 15 56 44.90 +38 22 48.00 5.98 NVSS
WN 1554.9+3831 15 56 44.81 +38 22 54.84 6.02 WENSS
8 BD+38 2714 15 56 37.10 +38 22 04.08 7.55 ACRS
PPM 78926 15 56 37.10 +38 22 03.36 7.55 PPM
9 FIRST J155728.5+382958 15 57 28.61 +38 29 57.84 7.68 FIRST
SDSS J15565+3822 15 56 34.61 +38 22 05.88 8.03 VERONCAT
10 NVSS J155702+383029 15 57 02.81 +38 30 29.16 8.14 NVSS
WN 1555.2+3839 15 57 02.90 +38 30 29.88 8.14 WENSS
FIRST J155703.0+383031 15 57 03.00 +38 30 30.96 8.16 FIRST
TGSSADR J155703.1+383032 15 57 03.10 +38 30 32.04 8.18 GMRTAS150M
11 WDS J15568+3816 15 56 48.00 +38 16 00.12 8.62 WDS
12 SDSS J15565+3825 15 56 30.10 +38 25 05.88 9.20 VERONCAT
13 PGC 2123814 15 56 28.70 +38 19 12.00 9.82 PGC2003
14 FIRST J155626.2+381829 15 56 26.21 +38 18 29.88 10.54 FIRST
QORG J155739.4+383417 15 57 39.41 +38 34 17.04 12.47 QORGCAT
15 NVSS J155740+383417 15 57 40.20 +38 34 17.04 12.53 NVSS
16 NVSS J155627+383101 15 56 27.10 +38 31 00.84 12.58 NVSS
FIRST J155808.6+382956 15 58 08.59 +38 29 57.12 12.67 FIRST
QORG J155808.8+382956 15 58 08.81 +38 29 56.04 12.69 QORGCAT
17 NVSS J155808+383003 15 58 08.59 +38 30 02.88 12.73 NVSS
FIRST J155808.8+383005 15 58 08.81 +38 30 05.04 12.78 FIRST
18 SDSS J15565+3832 15 56 31.20 +38 32 16.08 12.89 VERONCAT
QORG J155622.8+381313 15 56 22.80 +38 13 13.08 14.04 QORGCAT
19 FIRST J155622.7+381313 15 56 22.70 +38 13 14.16 14.04 FIRST
QORG J155813.0+383141 15 58 13.01 +38 31 41.16 14.39 QORGCAT
FIRST J155813.0+383142 15 58 13.01 +38 31 41.88 14.41 FIRST
20 NVSS J155813+383141 15 58 13.10 +38 31 41.88 14.41 NVSS

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