George Miley and the discovery of Micro-quasars (X-ray binaries with bimodal relativistic jets)

1. George Miley and the discovery of Micro-quasars(X-ray binaries with bimodal relativistic jets) E.P.J. van den Heuvel University of Amsterdam Leiden, June 11, 2013

2. Early in 1971 Braes and Miley started observing X-ray sources with the Westerbork Synthesis Radio Telescope (WSRT), at 1415 MHz

3. 1973 Cambridge Conference on the “Physics and Astrophysics of Compact Objects”: Luc Braes is in the 2nd row, 4th from the left

4. Braes & Miley 1972 IUA Symp.

5. Braes and Miley (1971,Nature 232,246, 1415 MHz) and Hjellming and Wade, 1971, ApJ 168, L21, 2695 MHz) independently discovered a weak radio source that had appeared in the X-ray error box of Cyg X-1 in early April 1971. The precise WSRT position left the 9th magnitude star HD226868 as the sole possible optical candidate of the RADIO Source. BUT WAS THIS THE X-RAY SOURCE?

6. Webster and Murdin (1971, Nature) identified the radio source with the 9th magnitude O9.7 Iab blue supergiant star HD 226868, and discovered in Nov. 1971 this star to be a 5.6 day period spectroscopic binary with a radial velocity amplitude of 64 km/sec (now: 72km/s) [Nature, 7 Jan.1972]. Assuming a “normal” mass of 30 Msun for the supergiant, one finds (since there are no X-ray eclipses), that the minimum mass of the unseen companion is > 6 Msun. As this is larger than the upper mass limit of 3.4 Msun of neutron stars, the companion, if it is the X-ray source, must be a BLACK HOLE .(In the paper they still allow also a supergiant mass 10Msun, which gives a companion>2 Msun)

7. From B.Louise Webster and Paul Murdin, Nature 235,37 (7 Jan 1972), Received 17 Nov. 1971. Orb. Period 5.6 days, velocity ampl. 64 km/s

9. The second great discovery of Braes and Miley: the strong and highly variable radio source Cygnus X-3. As its radio spectral evolution after a large radio outburst exactly follows a “van derLaan-model”for an expanding bubble of relativistic electrons with magnetic fields, this is the first “Micro-Quasar” ( 22 years before this name was invented) Nature Nature 237, 506, 30 June 1972

10. Radio outburst of the black-hole X-raybinary GRS1915+105 in 1994: Blobsmoving on the sky withapparently super-luminal velocities 1,2c to 1,7c (VLA). This is a well-knownrelativisitic “projection” effect, seen in quasar jets. This led to the name Micro-quasar (Mirabel andRodriguez, 1994, Nature 371,46) March 27 April 03 April 09 April 16 April 23 April 27

11. Microquasar GRS 1915+105: Black hole >10 solarmasseswithan ~2 solarmass K-giantcompanion in 33,5 dayorbit

12. Discoveredby Bruce Margon (1978) SS 433 The Mother of all Micro-quasars SS433 Vermeulen,Schilizzi Multi-wavelength campaign on the May/June 1987 outburst WSRT, with NHO and Calar Alto (Spain), Russian 6m Telescope, Bologna, NRAO, Sydney Univ., NRL, etc. (Vermeulen et al.A&A 270,177,1993) A ~10 Msun Black hole with ~15 Msun donor, in 13d orbit (Fabrika &Cherepaschuk 2013)

13. Westerhout 50, the”beam bag” producedby the precessingbeams of SS433

14. Gallo, Fender, Kaiser, Russell, Morganti, Oosterloo and Heintz 2005,Nature: WSRT Radio jet and jet-powered nebula of Cyg X-1 (1.4 GHz) [on Cover of Nature]: Cyg X-1 is a Micro- Quasar!!

15. The jet-powered optical nebula of Cygnus X-1 (Russell, Fender, Gallo and Kaiser, 2008, MNRAS)

16. From Mirabel andRodriguez 1999, Ann.Rev. A&A: Several sources tobeadded: e.g. Cyg X-1 (black Hole) andSco X-1 (NS)

17. Conclusions Braes and Miley in 1971-1972 did breakthrough work with the new WSRT on the discovery of the radio emission of accreting neutron stars and black holes in X-ray binaries: - Discovery of the triple “micro-quasar” structure of Sco X-1 (1971) Discovery of the sudden radio appearance of Cyg X-1 in 1971, allowing its definitive identification with the first ever established black hole in an X-ray binary: HD226868 (1972), (In 2005 found with WSRT to be a micro-quasar). Discovery of the second “Micro-Quasar” Cygnus X-3 (1972) George: Many Thanks!