GRS 1915+105

GRS 1915+105

A near-infrared (K band) light curve for V1487 Aquilae, adapted from Neil et al. (2007)[1]
Observation data Epoch J2000.0      Equinox J2000.0
Constellation	Aquila
Right ascension	19^h 15^m 11.6^s[2]
Declination	+10° 56′ 44″[2]
Characteristics
Evolutionary stage	Microquasar[3]
Spectral type	KIII[4]
Astrometry
Parallax (π)	0.120 ± 0.009 mas[3]
Distance	28,000 ly (8,600+2,000 −1,600[3] pc)
Details
Black hole
Mass	12.4+2.0 −1.8[3]^[contradictory] M☉
Other designations
V1487 Aquilae, Granat 1915+105, Nova Aquilae 1992, Granat 1915+10, INTEGRAL1 112
Database references
SIMBAD	data

GRS 1915+105 or V1487 Aquilae is an X-ray binary star system containing a main sequence star and a black hole. Transfer of material from the star to the black hole generates a relativistic jet, making this a microquasar system. The jet exhibits apparent superluminal motion.

It was discovered on August 15, 1992 by the WATCH all-sky monitor aboard Granat.[5] "GRS" stands for "GRANAT source", "1915" is the right ascension (19 hours and 15 minutes) and "105" reflects the approximate declination (10 degrees and 56 arcminutes). The near-infrared counterpart was determined by spectroscopic observations.[6]

The binary system lies 11,000 parsecs away[7] in Aquila. The black hole in GRS 1915+105 is 10 to 18 solar masses[8]^[contradictory]. The black hole rotates at least 950 times per second, giving it a spin parameter >0.82 (1.0 is the theoretical maximum).[9][10]

Galactic superluminal source

A sequence of MERLIN observation of the X-ray binary GRS 1915+105 taken over a few days.

In 1994, GRS 1915+105 became the first known galactic source that ejects material with apparent superluminal motion velocities.[11]

Observations with high resolution radio telescopes such as VLA, MERLIN, and VLBI show a bi-polar outflow of charged particles, which emit synchrotron radiation at radio frequencies. These studies have shown that the apparent superluminal motion is due to a relativistic effect known as relativistic aberration, where the intrinsic velocity of ejecta is actually about 90% the speed of light.[7]

Growth regulation

Repeat observations by the Chandra X-Ray Observatory over the period of a decade have revealed what may be a mechanism for self-regulation of the rate of growth of GRS 1915+105. The jet of materials being ejected is occasionally choked off by a hot wind blowing off the accretion disk. The wind deprives the jet of materials needed to sustain it. When the wind dies down, the jet returns.[12]

See also

• GRO J1655-40

References

1. Neil, Ethan T.; Bailyn, Charles D.; Cobb, Bethany E. (March 2007). "Infrared Monitoring of the Microquasar GRS 1915+105: Detection of Orbital and Superhump Signatures". The Astrophysical Journal. 657 (1): 409–414. arXiv:astro-ph/0610480. Bibcode:2007ApJ...657..409N. doi:10.1086/510287. S2CID 15959057.
2. Liu, Q. Z; Van Paradijs, J; Van Den Heuvel, E. P. J (2007). "A catalogue of low-mass X-ray binaries in the Galaxy, LMC, and SMC (Fourth edition)". Astronomy and Astrophysics. 469 (2): 807. arXiv:0707.0544. Bibcode:2007A&A...469..807L. doi:10.1051/0004-6361:20077303. S2CID 14673570.
3. Reid, M. J; McClintock, J. E; Steiner, J. F; Steeghs, D; Remillard, R. A; Dhawan, V; Narayan, R (2014). "A Parallax Distance to the Microquasar GRS 1915+105 and a Revised Estimate of its Black Hole Mass". The Astrophysical Journal. 796 (1): 2. arXiv:1409.2453. Bibcode:2014ApJ...796....2R. doi:10.1088/0004-637X/796/1/2. S2CID 9800558.
4. Abubekerov, M. K; Antokhina, E. A; Cherepashchuk, A. M; Shimanskii, V. V (2006). "The mass of the compact object in the low-mass X-ray binary 2S 0921-630". Astronomy Reports. 50 (7): 544. arXiv:1201.4689. Bibcode:2006ARep...50..544A. doi:10.1134/S1063772906070043. S2CID 40984265.
5. Castro-Tirado, A. J; Brandt, S; Lund, N (1992). "Grs 1915+105". IAU Circ. 5590: 2. Bibcode:1992IAUC.5590....2C.
6. Castro-Tirado, A. J; Geballe, T. R; Lund, N (1996). "Infrared Spectroscopy of the Superluminal Galactic Source GRS 1915+105 During the September 1994 Outburst". Astrophysical Journal Letters. 461 (2): L99. Bibcode:1996ApJ...461L..99C. doi:10.1086/310009. S2CID 122041186.
7. Fender, R. P; Garrington, S. T; McKay, D. J; Muxlow, T. W. B; Pooley, G. G; Spencer, R. E; Stirling, A. M; Waltman, E. B (1999). "MERLIN observations of relativistic ejections from GRS 1915+105". Monthly Notices of the Royal Astronomical Society. 304 (4): 865. arXiv:astro-ph/9812150. Bibcode:1999MNRAS.304..865F. doi:10.1046/j.1365-8711.1999.02364.x. S2CID 144364.
8. Greiner, J. (2001). "GRS 1915+105". arXiv:astro-ph/0111540.
9. Jeffrey E. McClintock; Rebecca Shafee; Ramesh Narayan; Ronald A. Remillard; Shane W. Davis; Li-Xin Li (2006). "The Spin of the Near-Extreme Kerr Black Hole GRS 1915+105". Astrophysical Journal. 652 (1): 518–539. arXiv:astro-ph/0606076. Bibcode:2006ApJ...652..518M. doi:10.1086/508457. S2CID 1762307.
10. Jeanna Bryne. "Pushing the Limit: Black Hole Spins at Phenomenal Rate". space.com. Retrieved 2017-11-25.
11. Mirabel, I. F; Rodríguez, L. F (1994). "A superluminal source in the Galaxy". Nature. 371 (6492): 46. Bibcode:1994Natur.371...46M. doi:10.1038/371046a0. S2CID 4347263.
12. "An Erratic Black Hole Regulates Itself" (Press release). NASA. 2009-03-25. Archived from the original on 2017-07-09. Retrieved 2009-04-16.

External links

• A Very Massive Stellar Black Hole in the Milky Way Galaxy November 28, 2001 (ESO)
• Image V1487 Aquilae
• O maior buraco negro estelar da Via Láctea (The biggest stellar black hole of the Milky Way) - in Portuguese.
• MICRO-QUASAR WITHIN OUR GALAXY
• The micro quasar GRS 1915+105 INTEGRAL Science Data Centre