4U 1700-37

4U 1700-37 is one of the stronger binary X-ray sources in the sky, and is classified as a high-mass X-ray binary. It was discovered by the Uhuru satellite.[10] The "4U" designation refers to the Fourth (and final) Uhuru catalog. It is associated with a bright (6.53 V magnitude) blue supergiant star HD 153919, which is orbited by an accreting compact object that must be either a neutron star or a black hole. The X-ray source is eclipsed by the star every ~3.4 days, but no pulsations have yet been observed. The source is one of the ten brightest persistent X-ray sources in the 10-100 keV hard X-ray energy region.

4U 1700-37

Observation data Epoch J2000      Equinox J2000
Constellation	Scorpius
Right ascension	17^h 03^m 56.77311^s[1]
Declination	−37° 50′ 38.9150″[1]
Apparent magnitude (V)	6.51 (- 6.57) - 6.60[2]
Characteristics
Spectral type	O6Iafcp[3]
U−B color index	−0.727[4]
B−V color index	+0.253[4]
Variable type	Ellipsoidal + HMXB[2]
Astrometry
Radial velocity (Rv)	−75.00 ± 7.4[5] km/s
Proper motion (μ)	RA: 2.80[1] mas/yr Dec.: 4.71[1] mas/yr
Parallax (π)	0.36 ± 0.57[1] mas
Distance	6910 ± 1120 ly (2120 ± 343[6] pc)
Orbit[7]
Period (P)	3.4118 ± 0.0001 d
Eccentricity (e)	0.17 ± 0.06
Periastron epoch (T)	JD 2443702.62 ± 0.21
Argument of periastron (ω) (primary)	54 ± 24°
Semi-amplitude (K1) (primary)	10.06 ± 0.66 km/s
Details[8]
O star
Mass	58 ± 11 M☉
Radius	21.9+1.3 −0.5 R☉
Luminosity	660,000 L☉
Temperature	35000 ± 1000 K
X-ray object
Mass	2.44 ± 0.27 M☉
Other designations
V884 Sco, CD−37° 11206, HD 153919, HIP 83499, SAO 208356[9]
Database references
SIMBAD	data

Evidence of Compton cooling during an X-ray flare recorded by the Chandra X-ray telescope strongly suggests that the compact object is a neutron star;[11] if verified it would be among the most massive known, and near the boundary of the theoretical maximum.

References

1. van Leeuwen, F.; et al. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. S2CID 18759600.
2. Samus, N. N.; Durlevich, O. V.; et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)". VizieR On-line Data Catalog: B/gcvs. Originally Published in: 2009yCat....102025S. 1. Bibcode:2009yCat....102025S.
3. Sota, A.; Apellániz, J. Maíz; Morrell, N. I.; Barbá, R. H.; Walborn, N. R.; Gamen, R. C.; Arias, J. I.; Alfaro, E. J. (2014). "The Galactic O-Star Spectroscopic Survey (GOSSS). II. Bright Southern Stars". The Astrophysical Journal Supplement Series. 211 (1): 10. arXiv:1312.6222. Bibcode:2014ApJS..211...10S. doi:10.1088/0067-0049/211/1/10. S2CID 118847528.
4. Kozok, J. R. (1985). "Photometric observations of emission B-stars in the southern Milky Way". Astronomy and Astrophysics Supplement Series. 61: 387–405. Bibcode:1985A&AS...61..387K.
5. Kharchenko, N. V.; et al. (2007). "Astrophysical supplements to the ASCC-2.5: Ia. Radial velocities of ~55000 stars and mean radial velocities of 516 Galactic open clusters and associations". Astronomische Nachrichten. 328 (9): 889. arXiv:0705.0878. Bibcode:2007AN....328..889K. doi:10.1002/asna.200710776. S2CID 119323941.
6. Megier, A.; Strobel, A.; Galazutdinov, G. A.; Krełowski, J. (2009). "The interstellar Ca II distance scale". Astronomy & Astrophysics. 507 (2): 833. Bibcode:2009A&A...507..833M. doi:10.1051/0004-6361/20079144.
7. Pourbaix, D.; et al. (2004). "S_B⁹: The ninth catalogue of spectroscopic binary orbits". Astronomy and Astrophysics. 424 (2): 727–732. arXiv:astro-ph/0406573. Bibcode:2004A&A...424..727P. doi:10.1051/0004-6361:20041213. S2CID 119387088.
8. Clark, J. S.; Goodwin, S. P.; Crowther, P. A.; Kaper, L.; Fairbairn, M.; Langer, N.; Brocksopp, C. (2002). "Physical parameters of the high-mass X-ray binary 4U1700-37". Astronomy & Astrophysics. 392 (3): 909–920. arXiv:astro-ph/0207334. Bibcode:2002A&A...392..909C. doi:10.1051/0004-6361:20021184. S2CID 119552560.
9. "HD 153919". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 4 September 2017.
10. Jones, C.; Forman, W.; Tananbaum, H.; Schreier, E.; Gursky, H.; Kellogg, E.; Giacconi, R. (1973). "Evidence for the Binary Nature of 2U 1700-37". The Astrophysical Journal. 181: L43. Bibcode:1973ApJ...181L..43J. doi:10.1086/181181.
11. Martinez-Chicharro, M.; Torrej ́on, J. M.; Oskinova, L.; F ̈urst, F.; Postnov, K.; Rodes-Roca, J. J.; Hainich, R.; Bodaghee, A. (2018). "Evidence of Compton cooling during an X-ray flare supports a neutron star nature of the compact object in 4U1700−37". Monthly Notices of the Royal Astronomical Society: Letters. 473 (1): L74–L78. arXiv:1710.01907. Bibcode:2018MNRAS.473L..74M. doi:10.1093/mnrasl/slx165. S2CID 56539478.

External links

• Seifina, Elena; Titarchuk, Lev; Shaposhnikov, Nikolai (2016). "X-Ray Spectra of the High-Mass X-Ray Binary 4U 1700-37 Usingbepposax, Suzaku, Andrxteobservations". The Astrophysical Journal. 821 (1): 23. arXiv:1603.05504. Bibcode:2016ApJ...821...23S. doi:10.3847/0004-637X/821/1/23. S2CID 119118682.
• Jaisawal, G. K.; Naik, S. (2015). "Broad-band spectroscopy of the eclipsing high-mass X-ray binary 4U 1700-37 with Suzaku". Monthly Notices of the Royal Astronomical Society. 448 (1): 620–628. arXiv:1501.01122. Bibcode:2015MNRAS.448..620J. doi:10.1093/mnras/stv029. S2CID 118350876.
• Giménez-García, A.; Torrejón, J. M.; Eikmann, W.; Martínez-Núñez, S.; Oskinova, L. M.; Rodes-Roca, J. J.; Bernabéu, G. (2015). "An XMM-Newton view of FeKα in high-mass X-ray binaries". Astronomy & Astrophysics. 576: A108. arXiv:1501.03636. Bibcode:2015A&A...576A.108G. doi:10.1051/0004-6361/201425004.
• Islam, Nazma; Paul, Biswajit (2016). "Orbital evolution and search for eccentricity and apsidal motion in the eclipsing HMXB 4U 1700−37". Monthly Notices of the Royal Astronomical Society. 461 (1): 816–824. arXiv:1606.01059. Bibcode:2016MNRAS.461..816I. doi:10.1093/mnras/stw1299. S2CID 118605899.