Difference between revisions of "GRO J1744-28"
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= Type = | = Type = | ||
| − | Transient Low-mass X-ray Binary | + | |
| − | Discovered on 1995 December 2 with the Burst And Transient Source Experiment (BATSE) on-board the Compton Gamma Ray Observatory (<ref name="Kouveliotou96A"/>) | + | * Transient Low-mass X-ray Binary (Neutron Star) |
| + | * Type I and II X-ray bursts and pulsations (next to Rapid Burster one of a few sources where Type II bursts are observed) | ||
| + | * Discovered on 1995 December 2 with the Burst And Transient Source Experiment (BATSE) on-board the Compton Gamma Ray Observatory (<ref name="Kouveliotou96A"/>) | ||
= Coordinates = | = Coordinates = | ||
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* Distance: 7.5-8.5 kpc (<ref name="Augusteijn97"/>, <ref name="Nishiuchi99"/>) | * Distance: 7.5-8.5 kpc (<ref name="Augusteijn97"/>, <ref name="Nishiuchi99"/>) | ||
| − | * Optical companion: G4 III star (<ref name="Gosling07A"/>, <ref name="Masetti14Atel"/>) with M<0. | + | * Optical companion: G4 III star (<ref name="Gosling07A"/>, <ref name="Masetti14Atel"/>) with M<0.3M<sub>sun</sub> and inclination i>15° (<ref name="Gosling07A"/>) |
== Orbit == | == Orbit == | ||
| − | + | Parameters inferred from 2014 outburst (see <ref name="Pintore14Atel"/>, [https://gammaray.msfc.nasa.gov/gbm/science/pulsars/lightcurves/groj1744.html NSSTC Gamma Ray Astrophysics: GRO J1744]) | |
| − | + | ||
| + | * P<sub>orb</sub> = 11.836 days | ||
| + | * T<sub>π/2</sub> = 2456696.19880 (JED) | ||
| + | * a<sub>x</sub> sin(i) = 2.637 light-sec | ||
| + | * no constrains on the longitude of periastron or eccentricity | ||
| + | |||
| Line 30: | Line 37: | ||
GRO J1744-28 is special because it exhibits X-ray bursts and pulsations at the same time. Sources which show X-ray bursts are generally believed to have surface conditions (low B-fields) which do not allow pulsations. | GRO J1744-28 is special because it exhibits X-ray bursts and pulsations at the same time. Sources which show X-ray bursts are generally believed to have surface conditions (low B-fields) which do not allow pulsations. | ||
| − | |||
| − | + | * Pulse period: 2.14Hz <ref name="Finger96A"/> | |
| + | * B = 2–6 x 10<sup>10</sup> G from disk reflection models (<ref name="Degenaar14A"/>) | ||
| + | * B = 5.27±0.06 x 10<sup>11</sup> G from CRSF measurements (<ref name="DAi15A"/>) | ||
| Line 44: | Line 52: | ||
== X-ray Spectrum == | == X-ray Spectrum == | ||
| − | * Spectrum shows typical cut-off powerlaw like expected from accreting X-ray binary | + | * Spectrum shows typical cut-off powerlaw, like expected from accreting X-ray binary |
| − | * Broad iron line at 6-7 keV | + | * Broad iron line at 6-7 keV (disk reflection or fast disk wind <ref name="Degenaar14A"/>) |
=== Cyclotron Features === | === Cyclotron Features === | ||
| − | Cyclotron line in this source is under debate | + | Cyclotron line in this source is under debate. GRO J1744−28 is one of the few LMXBs where a CRSF has been reported below 10 keV (other candidates are X1822−371, E<sub>CRSF</sub>=0.7keV <ref name="Iaria15A"/>, SWIFT J0051.8−7320, E<sub>CRSF</sub>=5keV <ref name="Maitra18A"/>) |
| − | * Fundamental CRSF at 4. | + | * Fundamental CRSF at 4.68±0.05 keV (gabs, XMM-Newton/INTEGRAL, 2014 outburst <ref name="DAi15A"/>) / ∼4.5 keV (gabs, BeppoSAX, 1997 outburst <ref name="Doroshenko15A"/>) |
| − | * Indication of second and third harmonic at 10. | + | * Indication of second and third harmonic at 10.4±0.1 keV and 15.8<sup>+1.3</sup><sub>-0.7</sub> keV in XMM-Newton/INTEGRAL data (using gabs) (<ref name="DAi15A"/>) |
| − | + | * No cyclotron line in low-flux 2017 February outburst (gabs strength upper limit at 0.07keV, 90% CL) (König et al. in prep.) | |
| − | * No cyclotron line in low-flux 2017 February outburst (König et al. in prep.) | ||
'''References''' | '''References''' | ||
Latest revision as of 14:54, 26 September 2019
Other names : 2EG J1746-2852 ([1])
Available data: NuSTAR ObsID 80202027002
Monitoring data: Swift/BAT
Type
- Transient Low-mass X-ray Binary (Neutron Star)
- Type I and II X-ray bursts and pulsations (next to Rapid Burster one of a few sources where Type II bursts are observed)
- Discovered on 1995 December 2 with the Burst And Transient Source Experiment (BATSE) on-board the Compton Gamma Ray Observatory ([1])
Coordinates
RA 17h 44‘ 33.09“ DEC -28° 44‘ 27.0“
Binary system
- Distance: 7.5-8.5 kpc ([2], [3])
- Optical companion: G4 III star ([4], [5]) with M<0.3Msun and inclination i>15° ([4])
Orbit
Parameters inferred from 2014 outburst (see [6], NSSTC Gamma Ray Astrophysics: GRO J1744)
- Porb = 11.836 days
- Tπ/2 = 2456696.19880 (JED)
- ax sin(i) = 2.637 light-sec
- no constrains on the longitude of periastron or eccentricity
Pulsations & Magnetic field
GRO J1744-28 is special because it exhibits X-ray bursts and pulsations at the same time. Sources which show X-ray bursts are generally believed to have surface conditions (low B-fields) which do not allow pulsations.
- Pulse period: 2.14Hz [7]
- B = 2–6 x 1010 G from disk reflection models ([8])
- B = 5.27±0.06 x 1011 G from CRSF measurements ([9])
Outbursts
- 1995 December: Discovery and first report of Type II X-ray bursts ([7])
- 1996 December: Similar burst characteristics ([10]), CRSF report at 5keV in BeppoSAX data (not yet proven) ([11])
- 2014 February: Outburst after 18 years of quiescence ([12], no CRSF), CRSF report at 5keV, 10keV and 15keV in XMM-Newton/INTEGRAL data, still under debate ([9])
- 2017 February: Fourth outburst with ~two orders of magnitude lower luminosity (Koenig et al. in prep.)
X-ray Spectrum
- Spectrum shows typical cut-off powerlaw, like expected from accreting X-ray binary
- Broad iron line at 6-7 keV (disk reflection or fast disk wind [8])
Cyclotron Features
Cyclotron line in this source is under debate. GRO J1744−28 is one of the few LMXBs where a CRSF has been reported below 10 keV (other candidates are X1822−371, ECRSF=0.7keV [13], SWIFT J0051.8−7320, ECRSF=5keV [14])
- Fundamental CRSF at 4.68±0.05 keV (gabs, XMM-Newton/INTEGRAL, 2014 outburst [9]) / ∼4.5 keV (gabs, BeppoSAX, 1997 outburst [11])
- Indication of second and third harmonic at 10.4±0.1 keV and 15.8+1.3-0.7 keV in XMM-Newton/INTEGRAL data (using gabs) ([9])
- No cyclotron line in low-flux 2017 February outburst (gabs strength upper limit at 0.07keV, 90% CL) (König et al. in prep.)
References
- ↑ Kouveliotou et al., 1996, Nature, Volume 379, Issue 6568, pp. 799-801 (1996) (NASA ADS)
- ↑ Augusteijn, T. & Greiner, J., et al., 1997, ApJ 486, 1013 (NASA ADS)
- ↑ Nishiuchi, M. et al., 2018, ApJ, Vol. 517, Issue 1, pp. 436-448. (NASA ADS)
- ↑ 4.0 4.1 MNRAS, Vol. 380, Issue 4, pp. 1511-1520. (NASA ADS)
- ↑ Masetti et al., ATel, No.5999, March 2014 (NASA ADS)
- ↑ Pintore, F. et al., ATEL, No.5901, Feb 2014 (ATEL)
- ↑ 7.0 7.1 Finger, M. H. et al., Nature, Volume 381, Issue 6580, pp. 291-293 (1996) (NASA ADS)
- ↑ 8.0 8.1 Degenaar et al., 2014, ApJL, Vol. 796, Issue 1, article id. L9, 6 pp. (2014) (NASA ADS)
- ↑ 9.0 9.1 9.2 9.3 D'Ai, A. et al., MNRAS, Volume 449, Issue 4, p.4288-4303 (NASA ADS)
- ↑ Woods, P. M. et al., ApJ, Vol. 517, Issue 1, pp. 431-435 (NASA ADS)
- ↑ 11.0 11.1 Doroshenko et al., 2015, Monthly Notices of the Royal Astronomical Society, Volume 452, Issue 3, p.2490-2499 (NASA ADS)
- ↑ Younes, G. et al, ApJ, Vol. 804, Issue 1, article id. 43, 16 pp. (2015) (NASA ADS)
- ↑ Iaria et al., 2015, A&A, Volume 577, id.A63, 14 pp. (NASA ADS)
- ↑ Maitra et al., 2018, Monthly Notices of the Royal Astronomical Society: Letters, Volume 480, Issue 1, p.L136-L140 (NASA ADS)