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 J1644.8+1850

Field

Detected Excesses
Swift-XRT image of the field for 4FGL J1644.8+1850 Swift-XRT detections in the field for 4FGL J1644.8+1850

Detected Excesses (SNR(Sosta) > 3.0)

# R.A. (J2000) Dec. (J2000) Pos. Error (") Rate (cts/s) Counts SNR (Detect) SNR (Sosta)
1 16 44 57.42 +18 51 50.04 5.05 (9 ± 2) x 10-3 43 5.695 5.958
2 16 45 09.64 +18 54 30.02 6.21 (3.3 ± 1.0) x 10-3 16 3.391 3.353
3 16 44 33.37 +18 42 56.07 5.59 (3.2 ± 1.0) x 10-3 20 3.473 3.189

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 16 44 07.19 +18 45 56.84 5.82 (2.2 ± 0.9) x 10-3 11 2.548 2.466
2 16 44 36.90 +18 53 10.81 6.41 (2.3 ± 0.9) x 10-3 14 2.483 2.462
3 16 45 20.44 +18 52 12.72 6.78 (1.9 ± 0.8) x 10-3 14 2.499 2.446
4 16 44 43.59 +18 45 18.56 7.09 (2.0 ± 0.8) x 10-3 9 2.375 2.421

X-Ray and Gamma Ray Catalogs

More Catalogs
Swift-XRT image with known X-ray and gamma ray sources for 4FGL J1644.8+1850 Swift-XRT image with known radio, optical and UV sources for 4FGL J1644.8+1850

Known X-Ray and Gamma Ray Sources

# Source Name R.A. (J2000) Dec. (J2000) Offset (') Observatory/Database Table
1 2RXS J164455.1+185209 16 44 55.10 +18 52 09.12 2.37 ROSAT
2RXS J164455.1+185209 16 44 55.10 +18 52 09.12 2.37 ROSAT
1RXS J164456.2+185204 16 44 56.21 +18 52 04.44 2.47 ROSAT

Known Radio, Optical and UV Sources

# Source Name R.A. (J2000) Dec. (J2000) Offset (') Database Table
1 NVSS J164435+185133 16 44 35.30 +18 51 33.12 3.53 NVSS
FIRST J164435.2+185135 16 44 35.21 +18 51 34.92 3.56 FIRST
QORG J164434.9+185135 16 44 34.90 +18 51 34.92 3.63 QORGCAT
1642+1857 16 44 25.39 +18 52 23.16 6.02 NORTH6CM
2 FIRST J164437.2+185535 16 44 37.30 +18 55 36.12 6.04 FIRST
GB6 J1644+1852 16 44 25.30 +18 52 27.84 6.06 GB6
3 NVSS J164425+185243 16 44 25.70 +18 52 44.04 6.07 NVSS
QORG J164425.6+185240 16 44 25.61 +18 52 40.08 6.07 QORGCAT
FIRST J164425.6+185243 16 44 25.70 +18 52 44.04 6.08 FIRST
TGSSADR J164425.6+185243 16 44 25.61 +18 52 44.04 6.09 GMRTAS150M
4 FIRST J164452.2+185631 16 44 52.30 +18 56 31.92 6.32 FIRST
QORG J164452.3+185633 16 44 52.30 +18 56 33.00 6.34 QORGCAT
FIRST J164422.3+184932 16 44 22.30 +18 49 32.16 6.39 FIRST
FIRST J164501.0+184427 16 45 01.10 +18 44 26.88 6.45 FIRST
5 NVSS J164422+184929 16 44 22.01 +18 49 28.92 6.47 NVSS
6 NVSS J164500+184425 16 45 01.01 +18 44 25.08 6.47 NVSS
7 FIRST J164507.2+184414 16 45 07.20 +18 44 13.92 7.38 FIRST
QORG J164507.2+184411 16 45 07.20 +18 44 11.04 7.42 QORGCAT
FIRST J164433.6+184323 16 44 33.70 +18 43 23.16 7.78 FIRST
FIRST J164434.0+184316 16 44 34.01 +18 43 15.96 7.84 FIRST
FIRST J164433.5+184257 16 44 33.60 +18 42 56.88 8.18 FIRST
8 NVSS J164433+184256 16 44 33.60 +18 42 56.16 8.19 NVSS
9 1642+1848 16 44 31.10 +18 42 47.16 8.60 NORTH6CM
10 GB6 J1644+1842 16 44 33.60 +18 42 25.92 8.64 GB6
FIRST J164433.1+184229 16 44 33.10 +18 42 29.16 8.64 FIRST
11 FIRST J164507.1+184239 16 45 07.20 +18 42 38.88 8.71 FIRST
12 FIRST J164416.4+184603 16 44 16.39 +18 46 03.00 8.81 FIRST
QORG J164416.4+184603 16 44 16.39 +18 46 03.00 8.82 QORGCAT
FIRST J164421.4+184419 16 44 21.41 +18 44 18.96 8.84 FIRST
PGC 3090246 16 44 21.41 +18 44 18.96 8.85 PGC2003
QORG J164421.4+184418 16 44 21.41 +18 44 17.88 8.86 QORGCAT
13 NVSS J164421+184413 16 44 21.10 +18 44 13.92 8.96 NVSS
14 FIRST J164521.6+185504 16 45 21.60 +18 55 04.08 9.07 FIRST
15 MITG J1645+1845 16 45 23.69 +18 45 47.16 9.32 MITGB6CM
16 MITG J1645+1844 16 45 21.41 +18 44 34.08 9.52 MITGB6CM
FIRST J164522.9+184504 16 45 22.90 +18 45 05.04 9.52 FIRST
FIRST J164523.2+184505 16 45 23.21 +18 45 05.04 9.58 FIRST
TXS 1643+188 16 45 23.81 +18 45 02.88 9.70 TEXAS
17 NVSS J164523+184503 16 45 23.81 +18 45 03.96 9.71 NVSS
1643+1850 16 45 23.90 +18 45 02.16 9.74 NORTH6CM
GLEAM J164524+184507 16 45 24.10 +18 45 06.84 9.74 GLEAMEGCAT
TGSSADR J164524.0+184504 16 45 24.00 +18 45 05.04 9.74 GMRTAS150M
FIRST J164524.0+184504 16 45 24.10 +18 45 05.04 9.75 FIRST
FIRST J164524.9+184503 16 45 24.91 +18 45 03.96 9.93 FIRST
18 GB6 J1645+1845 16 45 27.19 +18 45 10.08 10.34 GB6
19 NVSS J164508+185956 16 45 08.69 +18 59 56.04 10.73 NVSS
FIRST J164526.4+185657 16 45 26.40 +18 56 57.12 11.07 FIRST
20 NVSS J164526+185659 16 45 26.40 +18 56 60.00 11.09 NVSS
21 NVSS J164531+184513 16 45 31.39 +18 45 14.04 11.20 NVSS
FIRST J164531.4+184511 16 45 31.51 +18 45 11.16 11.23 FIRST
FIRST J164405.9+185556 16 44 06.00 +18 55 57.00 11.70 FIRST
22 NVSS J164405+185554 16 44 05.81 +18 55 54.12 11.71 NVSS
FIRST J164453.4+190214 16 44 53.50 +19 02 13.92 12.03 FIRST
23 NVSS J164400+184437 16 44 00.70 +18 44 38.04 12.77 NVSS

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