EXO 1722-363
Also known as: IGR J17252-3616, Ginga 1722-36, SWIFT J1725.2-3617, 2XMM J172511.3-361658 SIMBAD
Monitoring data: Swift/BAT MAXI
Coordinates
| RA | 17h 25m 11.392 s | Dec | -36° 15' 57.53" |
| RA | 261.297467 | Dec | -36.282647 |
| l | 351.4972 | b | -0.3539 |
Binary system
Distance: 8.0+2.5-2.0 kpc [1]
Orbit
| Parameter | Value | Unit | Reference |
|---|---|---|---|
| Porb | 9.742 | days | [2] |
| T90 | 2453761.62±0.1 | HJD | [2] |
| a sin i | 102±8 | lt-sec | [2] |
| e | <0.15 | [2] |
Optical Companion
2MASS J17251139-3616575
Stellar type: B0-B1Ia [1]
Available data from pointing instruments
- RXTE: 42 observations
- XMM-Newtown: 10 observations with source in FOV (3-19 ks each)
- INTEGRAL: Frequently covered (Galactic Centre area)
- Further data from EXOSAT, Ginga, ...
Description
First detected by EXOSAT as weak X-ray source in 1984 in Galactic Plane observations ([3]). Ginga observations found ~414 s pulsations ([4]), a very strong absorption (NH ~ 1024) and several flares with peak intensity of ~3 mCrab in the 1–38 keV band ([5]).
The source was later detected by INTEGRAL together with other hard X-ray sources in mosaics built from core programme observations ATel 229 (9 Feb 2004). [6] found eclipses and an orbital period of 9.741±0.004 days. Subtracting for Galactic ridge contribution, they found flux variations in the 0.5–5 mCrab range. The source was proposed to be a wind-accreting neutron star. [7] improved the accuracy of orbital parameters from pulse timing.
INTEGRAL and XMM-Newton observations allowed a more precise determination of the source position and the identification of the infrared counterpart ([8]). This analysis found an average flux level of 6.4 mCrab in the 20–60 keV band, with short-term flares of up to ~67 mCrab.
[1] obtained a spectral classification of the mass donor based on VLT observations. The group also made a preliminary estimate of the masses of both stars in the system ([9]).
ATel 9412 (26 Aug 2016) reported detection of activity with MAXI with peak fluxes of ~90 mCrab compared to a usual level of ~3 mCrab.
References
- ↑ 1.0 1.1 1.2 Cite error: Invalid
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