Difference between revisions of "Scutum X-1"

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(Created page with "Also known as: 3A 1833-078 [http://simbad.u-strasbg.fr/simbad/sim-id?Ident=Sct+X-1+&NbIdent=1&Radius=2&Radius.unit=arcmin&submit=submit+id Simbad] '''Monitoring Data''': [ht...")
 
m (Kuehnel moved page Sct X-1 to Scutum X-1)
 
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Latest revision as of 11:48, 18 April 2018

Also known as: 3A 1833-078 Simbad

Monitoring Data: [1]], [Swift/BAT

Coordinates

Simbad

RA 18h 35' 25.83" DEC -07° 36' 50.1"


Binary system

Distance

Determined by [1]: ~10 kpc

Orbit

Period: known upper limits ([2]):
For Mcomp = 13 M and Rcomp = 500 R : Porb > 2 yr
For Mcomp = 1.2 M and Rcomp = 100 R : Porb > 0.8 yr

Optical Companion

Names : 2MASS J18352582-0736501 ([2])
Type : Red giant or red supergiant ([2])

The figure below was obtained from [2].
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Available data

  • XMM-Newton: 30 ksec observation of close by radio pulsar (Oct 2005)
  • Chandra: HRC-I image of AX J183518-0754 (3 ksec)
  • RXTE: < 20 ksec observations (Aug 1997); part of Galactic Bulge Monitoring (C. Markwardt)
  • ASCA: 20" off-axis obsevartions <30ksec in Galactic Ridge Monitoring (Apr 1994, Oct 1997)
  • BeppoSAX: GRB observations close by


Description

Sct X-1 is symbiotic X-ray binary discovered by a sounding rocket ([3]).
It is an eclipsing system at a distance of ~10 kpc ([1]), composed of an accreting pulsar ([4]) and a near-IR counterpart, a late type giant or a supergiant.
The position of the x-ray source was found with XMM-Newton data ([2]).
The X-rays are most likely due to wind-fed accretion or due to an elliptical orbit ([2]).


Flux

Between 0.5 and 10 keV, Sct X-1 has a luminosity of 1.4 x 1033 d2kpc ([2]).


Spectrum

The source has a hard spectrum with a low-energy cutoff and an photon index ranging between 1.5 ([5]) and 2.0 ([2]), and a variable absorption from 0.8 x 1022 cm-2 ([5]) to (2 - 4) x 1023 cm-2 ([2]) in the low energy band. These variations in absorbtion are associated with the stellar wind accretion ([2]). It is not clear yet if there is an iron K fluorescence line at 6.4 keV ([5], [2]).
The figure below was obtained from [2].
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Pulse Profile

Sct X-1 shows a pulse period of: 112.86 ± 0.08 sec ([2]).

The figure below (obtained from [2]), shows the double-peaked pulse profile.
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Pulse Period Evolution

The source has had a steady spin down rate of 3.9 x 10-9 s s-1 averaged over 17 yr (see figure below obtained from [2]).

3522

References

  1. 1.0 1.1 Koyama, K., Kawada, M., Kunieda, H., et al., 1990, Nature, 343, 148 (NASA ADS)
  2. 2.00 2.01 2.02 2.03 2.04 2.05 2.06 2.07 2.08 2.09 2.10 2.11 2.12 2.13 2.14 Kaplan, D. L., Levine, A. M., Chakrabarty, D., et al., 2007, ApJ, 661, 437 (NASA ADS)
  3. Hill, R., Burginyon, G., Grader, R., et al., 1974, ApJ, 189, L69 (NASA ADS)
  4. Yamauchi, S., Koyama, K., 1993, PASJ, 45, 449 (NASA ADS)
  5. 5.0 5.1 5.2 Koyama, K., Kunieda, H., Takeuchi, Y., et al., 1991, ApJ, 370, L77 (NASA ADS)