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Home > Einstein Probe follow up > EP#01709179036

EP_FIELD00048

EP

48

/EP

EP#01709179036: Swift observation summary

Data analysed so far:

• ObsID: 00019885001 with 0.9 ks exposure.

About tiled field analysis.

So far 1 fields have been scheduled for observations. Data are available and processed for 1 of these.

• 19885 — 862 s of cleaned data taken between 2025-06-19 16:34:33 and 2025-06-19 16:53:20

Details of afterglow candidates

4 sources were found which matches the afterglow criteria.

#	RA (J2000)	Dec (J2000)	Err901	Detection Flag2	Rank3	Dist from Einstein Probe/WXT pos	Exposure	Notes	Vizier
1 [details]	17h 42m 40.01s265.66669°	-27° 44′ 51.1″-27.74753°	2.6′′ *	Good	2 (O)	0.9′	862 s	Matches SIMBAD source: V* V2606 Oph, 2″ away. Matches known X-ray source: LSXPS J174240.0-274452 (from LSXPS), 1.4″ away.
Mean XRT rate: 13.0 (±0.4) ct s-1 Peak XRT rate: 19 (±3) ct s-1 -5.09 σ above the catalogued flux from LSXPS. RASS PSPC 3-σ upper limit: 0.0×100 ct s-1 (PSPC count-rate) Mean XRT rate converted to PSPC: 5.57 (±0.18) ct s-1 Peak XRT rate converted to PSPC: 8.0 (±1.5) ct s-1 Mean XRT flux: 8.22 (±0.26) ×10-10 erg cm-1s-1 Peak XRT flux: 1.18 (±0.22) ×10-9 erg cm-1s-1 Products: Light curve | Spectrum | Enhanced position
6 [details]	17h 42m 39.53s265.66470°	-27° 43′ 47.6″-27.72990°	8.0′′	Poor	2 (O)	0.2′	862 s	Matches SIMBAD source: 2MASS J17424005-2743424, 8.6″ away. Matches known X-ray source: LSXPS J174239.2-274359 (from LSXPS), 12.2″ away.
Mean XRT rate: 10.6 (±0.4) ct s-1 Peak XRT rate: 15.2 (±2.8) ct s-1 -5.43 σ above the catalogued flux from LSXPS. RASS PSPC 3-σ upper limit: 0.0×100 ct s-1 (PSPC count-rate) Mean XRT rate converted to PSPC: 3.75 (±0.14) ct s-1 Peak XRT rate converted to PSPC: 5.4 (±1.0) ct s-1 Mean XRT flux: 7.74 (±0.29) ×10-10 erg cm-1s-1 Peak XRT flux: 1.11 (±0.20) ×10-9 erg cm-1s-1 Products: Light curve | Spectrum
10 [details]	17h 42m 45.26s265.68857°	-27° 44′ 50.7″-27.74741°	9.7′′	Poor	2 (O)	1.7′	862 s	Matches SIMBAD source: 2MASS J17424569-2744415, 11.1″ away. Matches known X-ray source: 1RXH J174244.4-274504 (from ROSAT/ROSHRI), 17.948257920663″ away.
Mean XRT rate: 7.9 (±0.3) ct s-1 Peak XRT rate: 10.9 (±2.0) ct s-1 -5.02 σ above the catalogued flux from ROSAT/ROSHRI. RASS PSPC 3-σ upper limit: 0.0×100 ct s-1 (PSPC count-rate) Mean XRT rate converted to PSPC: 3.62 (±0.14) ct s-1 Peak XRT rate converted to PSPC: 5.0 (±0.9) ct s-1 Mean XRT flux: 5.32 (±0.21) ×10-10 erg cm-1s-1 Peak XRT flux: 7.3 (±1.4) ×10-10 erg cm-1s-1 Products: Light curve | Spectrum
11 [details]	17h 42m 31.60s265.63165°	-27° 44′ 46.3″-27.74621°	9.9′′	Poor	2 (O)	1.8′	862 s	Matches SIMBAD source: Gaia DR3 4060681301136237824, 11.3″ away. Matches known X-ray source: LSXPS J174232.2-274439 (from LSXPS), 11″ away.
Mean XRT rate: 0.114 (±0.016) ct s-1 Peak XRT rate: 0.12 (±0.03) ct s-1 -3.65 σ above the catalogued flux from LSXPS. RASS PSPC 3-σ upper limit: 0.0×100 ct s-1 (PSPC count-rate) Mean XRT rate converted to PSPC: 0.070 (±0.010) ct s-1 Peak XRT rate converted to PSPC: 0.075 (±0.020) ct s-1 Mean XRT flux: 6.9 (±1.0) ×10-12 erg cm-1s-1 Peak XRT flux: 7.3 (±2.0) ×10-12 erg cm-1s-1 Products: Light curve | Spectrum

¹ Radius, 90% confidence.
² Indicates how likely the source is to be real. See the LSXPS documentation.
³ T=Transient Source, O=Outbursting known source, U=Uncatalogued X-ray source, K=Known X-ray source.
^* The position was enhanced using astrometry derived from the Swift UVOT.
^† The position was astrometrically corrected using the XRT sources and the 2MASS catalogue.

Find an upper limit.

Sources found so far

So far 11 sources have been found in the XRT data. 11 sources match catalogued sources.

#	RA (J2000)	Dec (J2000)	Err901	Detection Flag2	Rank3	Dist from Einstein Probe/WXT pos	Exposure	Notes	Vizier
1 [details]	17h 42m 40.01s265.66669°	-27° 44′ 51.1″-27.74753°	2.6′′ *	Good	2 (O)	0.9′	862 s	Matches SIMBAD source: V* V2606 Oph, 2″ away. Matches known X-ray source: LSXPS J174240.0-274452 (from LSXPS), 1.4″ away.
Mean XRT rate: 13.0 (±0.4) ct s-1 Peak XRT rate: 19 (±3) ct s-1 -5.09 σ above the catalogued flux from LSXPS. RASS PSPC 3-σ upper limit: 0.0×100 ct s-1 (PSPC count-rate) Mean XRT rate converted to PSPC: 5.57 (±0.18) ct s-1 Peak XRT rate converted to PSPC: 8.0 (±1.5) ct s-1 Mean XRT flux: 8.22 (±0.26) ×10-10 erg cm-1s-1 Peak XRT flux: 1.18 (±0.22) ×10-9 erg cm-1s-1 Products: Light curve | Spectrum | Enhanced position
2 [details]	17h 42m 31.68s265.63198°	-27° 43′ 45.7″-27.72935°	6.2′′ *	Poor	4 (K)	1.6′	862 s	Matches SIMBAD source: 2MASS J17423155-2743482, 4.1″ away. Matches known X-ray source: LSXPS J174231.6-274347 (from LSXPS), 2.9″ away.
Mean XRT rate: 4.2 (+1.0, -0.9) ×10-2 ct s-1 Peak XRT rate: 5.4 (±1.4) ×10-2 ct s-1 -2.74 σ above the catalogued flux from LSXPS. RASS PSPC 3-σ upper limit: 0.0×100 ct s-1 (PSPC count-rate) Mean XRT rate converted to PSPC: 2.0 (+0.5, -0.4) ct s-1 Peak XRT rate converted to PSPC: 2.6 (±0.7) ×10-5 ct s-1 Mean XRT flux: 4.9 (±1.1) ×10-12 erg cm-1s-1 Peak XRT flux: 6.2 (±1.7) ×10-12 erg cm-1s-1 Products: Light curve | Spectrum | Enhanced position
3 [details]	17h 42m 53.04s265.72099°	-27° 43′ 31.4″-27.72538°	12.1′′	Poor	4 (K)	3.2′	862 s	Matches SIMBAD source: Gaia DR3 4060671336783815808, 8.9″ away. Matches known X-ray source: LSXPS J174253.6-274319 (from LSXPS), 15″ away.
Mean XRT rate: undetermined ct s-1 Peak XRT rate: undetermined ct s-1 -1.19 σ above the catalogued flux from LSXPS. RASS PSPC 3-σ upper limit: 0.0×100 ct s-1 (PSPC count-rate) Products: Light curve | Spectrum
4 [details]	17h 42m 18.58s265.57743°	-27° 41′ 01.2″-27.68366°	8.3′′	Poor	3 (U)	5.4′	862 s	Matches SIMBAD source: 2MASS J17421790-2740544, 11.4″ away.
Mean XRT rate: undetermined ct s-1 Peak XRT rate: undetermined ct s-1 RASS PSPC 3-σ upper limit: 0.03 ct s-1 (PSPC count-rate) Products: Light curve
5 [details]	17h 43m 03.64s265.76516°	-27° 47′ 16.0″-27.78778°	9.0′′	Poor	3 (U)	6.4′	862 s	Matches SIMBAD source: OGLE BLG-RRLYR-27118, 13.7″ away.
Mean XRT rate: undetermined ct s-1 Peak XRT rate: undetermined ct s-1 RASS PSPC 3-σ upper limit: 0.03 ct s-1 (PSPC count-rate) Products: Light curve
6 [details]	17h 42m 39.53s265.66470°	-27° 43′ 47.6″-27.72990°	8.0′′	Poor	2 (O)	0.2′	862 s	Matches SIMBAD source: 2MASS J17424005-2743424, 8.6″ away. Matches known X-ray source: LSXPS J174239.2-274359 (from LSXPS), 12.2″ away.
Mean XRT rate: 10.6 (±0.4) ct s-1 Peak XRT rate: 15.2 (±2.8) ct s-1 -5.43 σ above the catalogued flux from LSXPS. RASS PSPC 3-σ upper limit: 0.0×100 ct s-1 (PSPC count-rate) Mean XRT rate converted to PSPC: 3.75 (±0.14) ct s-1 Peak XRT rate converted to PSPC: 5.4 (±1.0) ct s-1 Mean XRT flux: 7.74 (±0.29) ×10-10 erg cm-1s-1 Peak XRT flux: 1.11 (±0.20) ×10-9 erg cm-1s-1 Products: Light curve | Spectrum
7 [details]	17h 42m 47.90s265.69959°	-27° 47′ 12.1″-27.78671°	6.6′′	Poor	3 (U)	3.8′	862 s	Matches SIMBAD source: 2MASS J17424739-2746543, 19.1″ away.
Mean XRT rate: undetermined ct s-1 Peak XRT rate: undetermined ct s-1 RASS PSPC 3-σ upper limit: 0.03 ct s-1 (PSPC count-rate) Mean XRT rate converted to PSPC: undetermined ct s-1 Peak XRT rate converted to PSPC: undetermined ct s-1 Mean XRT flux: undetermined erg cm-1s-1 Peak XRT flux: undetermined erg cm-1s-1 Products: Light curve | Spectrum
8 [details]	17h 42m 43.57s265.68153°	-27° 41′ 26.0″-27.69056°	7.5′′	Poor	3 (U)	2.7′	862 s	Matches SIMBAD source: [DG2020] 6836, 8.9″ away.
Mean XRT rate: undetermined ct s-1 Peak XRT rate: undetermined ct s-1 RASS PSPC 3-σ upper limit: 0.0×100 ct s-1 (PSPC count-rate) Mean XRT flux: undetermined erg cm-1s-1 Peak XRT flux: undetermined erg cm-1s-1 Products: Light curve | Spectrum
9 [details]	17h 42m 11.17s265.54654°	-27° 45′ 08.2″-27.75228°	15.4′′	Poor	4 (K)	6.2′	862 s	Matches SIMBAD source: 2MASS J17421174-2745195, 13.7″ away. Matches known X-ray source: LSXPS J174211.8-274505 (from LSXPS), 9.3″ away.
Mean XRT rate: undetermined ct s-1 Peak XRT rate: undetermined ct s-1 -1.60 σ above the catalogued flux from LSXPS. RASS PSPC 3-σ upper limit: 0.0×100 ct s-1 (PSPC count-rate) Products: Light curve
10 [details]	17h 42m 45.26s265.68857°	-27° 44′ 50.7″-27.74741°	9.7′′	Poor	2 (O)	1.7′	862 s	Matches SIMBAD source: 2MASS J17424569-2744415, 11.1″ away. Matches known X-ray source: 1RXH J174244.4-274504 (from ROSAT/ROSHRI), 17.948257920663″ away.
Mean XRT rate: 7.9 (±0.3) ct s-1 Peak XRT rate: 10.9 (±2.0) ct s-1 -5.02 σ above the catalogued flux from ROSAT/ROSHRI. RASS PSPC 3-σ upper limit: 0.0×100 ct s-1 (PSPC count-rate) Mean XRT rate converted to PSPC: 3.62 (±0.14) ct s-1 Peak XRT rate converted to PSPC: 5.0 (±0.9) ct s-1 Mean XRT flux: 5.32 (±0.21) ×10-10 erg cm-1s-1 Peak XRT flux: 7.3 (±1.4) ×10-10 erg cm-1s-1 Products: Light curve | Spectrum
11 [details]	17h 42m 31.60s265.63165°	-27° 44′ 46.3″-27.74621°	9.9′′	Poor	2 (O)	1.8′	862 s	Matches SIMBAD source: Gaia DR3 4060681301136237824, 11.3″ away. Matches known X-ray source: LSXPS J174232.2-274439 (from LSXPS), 11″ away.
Mean XRT rate: 0.114 (±0.016) ct s-1 Peak XRT rate: 0.12 (±0.03) ct s-1 -3.65 σ above the catalogued flux from LSXPS. RASS PSPC 3-σ upper limit: 0.0×100 ct s-1 (PSPC count-rate) Mean XRT rate converted to PSPC: 0.070 (±0.010) ct s-1 Peak XRT rate converted to PSPC: 0.075 (±0.020) ct s-1 Mean XRT flux: 6.9 (±1.0) ×10-12 erg cm-1s-1 Peak XRT flux: 7.3 (±2.0) ×10-12 erg cm-1s-1 Products: Light curve | Spectrum

¹ Radius, 90% confidence.
² Indicates how likely the source is to be real. See the LSXPS documentation.
³ T=Transient Source, O=Outbursting known source, U=Uncatalogued X-ray source, K=Known X-ray source.
^* The position was enhanced using astrometry derived from the Swift UVOT.
^† The position was astrometrically corrected using the XRT sources and the 2MASS catalogue.

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Exposure map

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FITS exposure map.