GRB 251215A: Swift observation summary

Mission:	Swift/BAT
GRB RA:	122.653°
GRB Dec:	-36.739°
GRB Err:	5.0 arcmin
T0:	2025-12-15 04:21:21 UT
Galactic:	253.96° -1.79°
Galactic N_H:	7.25× 10²¹ cm^-2
Galactic E(B-V):	1.154595

Sun distance:	109.04°
Sun angle:	9.33 [hr](West of Sun)
Moon distance:	76.27°
Visibility of this field.

Data analysed so far:

ObsID: 00021894001 with 5.2 ks exposure.

Source 5 has been manually confirmed as the GRB afterglow; data for this object are now available through the main GRB results area for this GRB.

About ToO analysis.

Probable afterglow details

A source was found which matches the afterglow criteria.

#	RA (J2000)	Dec (J2000)	Err₉₀¹	Detection Flag²	Dist from Swift/BAT pos	Exposure	Notes	Vizier
5 [details]	08h 10m 28.54s122.61893°	-36° 44′ 33.6″-36.74266°	5.7′′	Good	1.7′	9.9 ks	The source is fading with 3.6-σ significance.
Mean XRT rate: 5.0 (±1.2) ×10^-3 ct s^-1 Peak XRT rate: 5.0 (±1.2) ×10^-3 ct s^-1 RASS PSPC 3-σ upper limit: 0.07 ct s^-1 (XRT equiv count-rate) Mean XRT flux: 1.9 (±0.5) ×10^-13 erg cm^-1s^-1 Peak XRT flux: 1.9 (±0.5) ×10^-13 erg cm^-1s^-1 Products: Spectrum \| Enhanced position \| Expected serendipitous sources: ~0.00×10⁺⁰ [What is this?] Note: this is extragalactic sources only, whereas the GRB trigger is at b=-1.79°

¹ Radius, 90% confidence.
² Indicates how likely the source is to be real. See the 2SXPS documentation.
^* 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 9 sources have been found in the XRT data. 4 sources match catalogued sources.

#	RA (J2000)	Dec (J2000)	Err₉₀¹	Detection Flag²	Dist from Swift/BAT pos	Exposure	Notes
1 [details]	08h 10m 42.68s122.67784°	-36° 45′ 32.3″-36.75897°	2.5′′	Good	1.7′	9.9 ks	Matches known X-ray source: LSXPS J081042.9-364534 (from LSXPS), 4.5″ away. Matches SIMBAD source: HD 68390, 1″ away.
Mean XRT rate: 2.26 (±0.18) ×10^-2 ct s^-1 Peak XRT rate: 3.0 (±0.7) ×10^-2 ct s^-1 RASS PSPC 3-σ upper limit: 0.0×10⁰ ct s^-1 (XRT equiv count-rate) Mean XRT flux: 4.3 (±0.3) ×10^-13 erg cm^-1s^-1 Peak XRT flux: 5.6 (±1.3) ×10^-13 erg cm^-1s^-1 Products: Light curve \| Spectrum \| Enhanced position \| Expected serendipitous sources: ~0.00×10⁺⁰ [What is this?] Note: this is extragalactic sources only, whereas the GRB trigger is at b=-1.79°
2 [details]	08h 10m 12.51s122.55213°	-36° 40′ 11.6″-36.66989°	3.5′′	Good	6.4′	9.9 ks
Mean XRT rate: 8.0 (±1.1) ×10^-3 ct s^-1 Peak XRT rate: 1.3 (±0.3) ×10^-2 ct s^-1 RASS PSPC 3-σ upper limit: 0.07 ct s^-1 (XRT equiv count-rate) Mean XRT flux: 3.8 (±0.5) ×10^-13 erg cm^-1s^-1 Peak XRT flux: 6.2 (±1.6) ×10^-13 erg cm^-1s^-1 Products: Light curve \| Spectrum \| Enhanced position \| Expected serendipitous sources: ~0.00×10⁺⁰ [What is this?] Note: this is extragalactic sources only, whereas the GRB trigger is at b=-1.79°
3 [details]	08h 09m 56.88s122.48701°	-36° 40′ 45.8″-36.67939°	4.7′′	Good	8.7′	9.9 ks	The source is fading with 3.3-σ significance.
Mean XRT rate: 6.6 (±1.5) ×10^-3 ct s^-1 Peak XRT rate: 6.6 (±1.5) ×10^-3 ct s^-1 RASS PSPC 3-σ upper limit: 0.02 ct s^-1 (XRT equiv count-rate) Mean XRT flux: 1.20 (±0.27) ×10^-13 erg cm^-1s^-1 Peak XRT flux: 1.20 (±0.27) ×10^-13 erg cm^-1s^-1 Products: Spectrum \| Enhanced position \| Expected serendipitous sources: ~0.00×10⁺⁰ [What is this?] Note: this is extragalactic sources only, whereas the GRB trigger is at b=-1.79°
4 [details]	08h 11m 14.11s122.80880°	-36° 52′ 42.6″-36.87849°	7.2′′	Good	11.2′	9.9 ks	Matches known X-ray source: LSXPS J081114.0-365246 (from LSXPS), 3.6″ away. Matches SIMBAD source: Gaia DR3 5541522493587877760, 1.6″ away.
Mean XRT rate: 3.6 (+1.0, -0.8) ×10^-3 ct s^-1 Peak XRT rate: 3.9 (+1.4, -1.2) ×10^-3 ct s^-1 RASS PSPC 3-σ upper limit: 0.0×10⁰ ct s^-1 (XRT equiv count-rate) Mean XRT flux: 5.0 (+1.3, -1.1) ×10^-14 erg cm^-1s^-1 Peak XRT flux: 5.3 (+2.0, -1.6) ×10^-14 erg cm^-1s^-1 Products: Spectrum \| Expected serendipitous sources: ~0.00×10⁺⁰ [What is this?] Note: this is extragalactic sources only, whereas the GRB trigger is at b=-1.79°
5 [details]	08h 10m 28.54s122.61893°	-36° 44′ 33.6″-36.74266°	5.7′′	Good	1.7′	9.9 ks	The source is fading with 3.6-σ significance.
Mean XRT rate: 5.0 (±1.2) ×10^-3 ct s^-1 Peak XRT rate: 5.0 (±1.2) ×10^-3 ct s^-1 RASS PSPC 3-σ upper limit: 0.07 ct s^-1 (XRT equiv count-rate) Mean XRT flux: 1.9 (±0.5) ×10^-13 erg cm^-1s^-1 Peak XRT flux: 1.9 (±0.5) ×10^-13 erg cm^-1s^-1 Products: Spectrum \| Enhanced position \| Expected serendipitous sources: ~0.00×10⁺⁰ [What is this?] Note: this is extragalactic sources only, whereas the GRB trigger is at b=-1.79°
6 [details]	08h 10m 46.90s122.69541°	-36° 37′ 11.5″-36.61985°	7.1′′	Good	7.4′	9.9 ks
Mean XRT rate: 3.1 (+0.9, -0.7) ×10^-3 ct s^-1 Peak XRT rate: 3.44 (+1.20, -0.99) ×10^-3 ct s^-1 RASS PSPC 3-σ upper limit: 0.10 ct s^-1 (XRT equiv count-rate) Mean XRT flux: 1.9 (+0.5, -0.4) ×10^-13 erg cm^-1s^-1 Peak XRT flux: 2.1 (+0.7, -0.6) ×10^-13 erg cm^-1s^-1 Products: Spectrum \| Enhanced position \| Expected serendipitous sources: ~0.00×10⁺⁰ [What is this?] Note: this is extragalactic sources only, whereas the GRB trigger is at b=-1.79°
7 [details]	08h 11m 21.54s122.83977°	-36° 48′ 04.9″-36.80137°	5.0′′	Good	9.7′	9.9 ks	This source may be affected by optical loading Matches known X-ray source: LSXPS J081121.6-364804 (from LSXPS), 1.5″ away. Matches SIMBAD source: HD 68510, 2.5″ away.
Mean XRT rate: 2.8 (+0.8, -0.7) ×10^-3 ct s^-1 Peak XRT rate: 3.5 (+1.3, -1.1) ×10^-3 ct s^-1 RASS PSPC 3-σ upper limit: 0.0×10⁰ ct s^-1 (XRT equiv count-rate) Mean XRT flux: 4.4 (+1.3, -1.1) ×10^-14 erg cm^-1s^-1 Peak XRT flux: 5.5 (+2.1, -1.7) ×10^-14 erg cm^-1s^-1 Products: Spectrum \| Expected serendipitous sources: ~0.00×10⁺⁰ [What is this?] Note: this is extragalactic sources only, whereas the GRB trigger is at b=-1.79°
8 [details]	08h 10m 39.88s122.66618°	-36° 38′ 53.8″-36.64828°	5.9′′	Good	5.5′	9.9 ks	Matches SIMBAD source: 2MASS J08104017-3638516, 4.1″ away.
Mean XRT rate: 1.8 (+0.9, -0.7) ×10^-3 ct s^-1 Peak XRT rate: 1.8 (+0.9, -0.7) ×10^-3 ct s^-1 RASS PSPC 3-σ upper limit: 0.03 ct s^-1 (XRT equiv count-rate) Products: Expected serendipitous sources: ~0.00×10⁺⁰ [What is this?] Note: this is extragalactic sources only, whereas the GRB trigger is at b=-1.79°
9 [details]	08h 11m 35.94s122.89975°	-36° 46′ 03.4″-36.76762°	9.9′′	Poor	12.0′	9.9 ks
Mean XRT rate: 1.73 (+1.00, -0.74) ×10^-3 ct s^-1 Peak XRT rate: 1.73 (+1.00, -0.74) ×10^-3 ct s^-1 RASS PSPC 3-σ upper limit: 3.73 ct s^-1 (XRT equiv count-rate) Mean XRT flux: 9 (+5, -4) ×10^-12 erg cm^-1s^-1 Peak XRT flux: 9 (+5, -4) ×10^-12 erg cm^-1s^-1 Products: Spectrum \| Expected serendipitous sources: ~0.00×10⁺⁰ [What is this?] Note: this is extragalactic sources only, whereas the GRB trigger is at b=-1.79°

¹ Radius, 90% confidence.
² Indicates how likely the source is to be real. See the 1SXPS documentation.
^* 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.