KS 1947+300

From Remeis-Wiki
Jump to navigation Jump to search


Also known as GRO J1948+32 Simbad

Monitoring Data: Swift/BAT MAXI RXTE/ASM

Coordinates

RA 19h 49m 35.49s , DEC +30° 12' 31.8"
RA 19.82653 , DEC +30.20911
l 66.0990 , b +02.0836

Binary System

Distance: 10 kpc (assuming standard luminosity, [1])


Orbit

Parameter Value Unit Reference
Porb 440.415(7) days [2]
Tπ/2 51985.31(7) MJD [2]
a sin i 137.4(1.2) lt-sec [2]
e 0.034(7) [2]
ω 33(3) degrees [2]

Optical companion

Name: not reported in [1]
B0Ve star

Parameter Value Unit Reference
U 14.76(8) mag [1]
B 15.06(5) mag [1]
V 14.16(3) mag [1]
R 13.50(2) mag [1]
I 12.77(4) mag [1]

Description

The binary system was discovered in 1989 by Mir-Kvant/TTM and independently by BATSE in 1994. It is located in the constellation Cygnus and showed a strong outburst in 2000/2001. A few smaller outbursts followed until 2004. The source was in quiescence from then on until 2013, when it underwent an outbrust again, followed by moderate X-ray and optical activity. The 2000/2001 outburst was (among others) monitored by RXTE and BeppoSAX, the 2013 outburst by NuSTAR, Swift and Suzaku.

Spectrum

The spectrum of KS 1947+300 is well described by an absorbed cut-off power law with an additional black body component and a fluorescent iron line ([3], [4]) or a thermal Comptonization model with an additional black body ([2], [5]). During the 2013 outburst, a cyclotron line at 12.2 keV was discovered in NuSTAR data ([4])

Pulse period & profiles

The pulse period is ~18.8 s ([2]). The pulse profiles show a characteristic energy-dependence with a single broad peak at low energies which evolves to a narrow, secondary peak and a broad main peak ([5]). This evolution is rarely seen in X-ray pulsars. In most cases, the pulse profile is more complex at low energies and evolves to a sinusoidal shape at higher energies. The pulse profile is similar in shape to the one observed in IGR J16393-4643 ([6]).

References

  1. 1.0 1.1 1.2 1.3 1.4 1.5 1.6 Cite error: Invalid <ref> tag; no text was provided for refs named Negueruela03
  2. 2.0 2.1 2.2 2.3 2.4 2.5 2.6 Cite error: Invalid <ref> tag; no text was provided for refs named Galloway2004
  3. Cite error: Invalid <ref> tag; no text was provided for refs named Tsygankov05
  4. 4.0 4.1 Cite error: Invalid <ref> tag; no text was provided for refs named Fuerst14a
  5. 5.0 5.1 Cite error: Invalid <ref> tag; no text was provided for refs named Naik06
  6. Cite error: Invalid <ref> tag; no text was provided for refs named Islam15