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

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

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

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In 1971, the only known X-ray source that showed (variable) radio emission was Scorpius X-1, discovered by Andrew and Purton, 1968, and further studied by Ables (1969). Observations by Hjellming and Wade (1971,ApL 164,L1) and confirmed by Braes and Miley (1971, A&A 14, 160) showed it to have a triple structure, resembling a little Quasar

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Braes & Miley 1972 IUA Symp.

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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 9 th magnitude star HD226868 as the sole possible optical candidate of the RADIO Source. BUT WAS THIS THE X-RAY SOURCE?

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Webster and Murdin (1971, Nature) identified the radio source with the 9 th 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)

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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

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The first pulsating and eclipsing binary X-ray source, Centaurus X-3, was discovered in November 1971 by the UHURU team. The doppler motion showed the companion to be a massive star > 16Msun, and the eclipse duration indicated that the star is a blue supergiant, like HD 226868. This made the possibility that Cyg X-1 is a black hole in a similar binary system, suddenly very likely.

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The appearance of the radio source of Cyg X-1 just after the X-ray transition

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The discovery of this coincidence, made by the UHURU team in the spring of 1972, showed that the radio and the X-ray source are the same object, and that Cyg X-1 indeed is a High-Mass X-ray binary, and that it most likely contains a black hole

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Nature 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 der Laan-modelfor an expanding bubble of relativistic electrons with magnetic fields, this is the first Micro-Quasar ( 22 years before this name was invented) Nature 237, 506, 30 June 1972

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Cyg X-3 is a 4.8- hour period X-ray binary, and is a 4.8 hour period IR source, at a distance of 10 Kpc. In 1993 van Kerkwijk et al. (Nature) found it to have a Wolf-Rayet (He *) companion. It has radio jets. It is at times the brightest radio source in the sky.

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March 27 April 03 April 09 April 16 April 23 April 27 Radio outburst of the black-hole X-ray binary GRS1915+105 in 1994: Blobs moving on the sky with apparently super-luminal velocities 1,2c to 1,7c (VLA). This is a well-known relativisitic projection effect, seen in quasar jets. This led to the name Micro-quasar (Mirabel and Rodriguez, 1994, Nature 371,46)

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Microquasar GRS 1915+105: Black hole >10 solar masses with an ~2 solar mass K-giant companion in 33,5 day orbit

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The black-hole X-ray binary GRS 1915+105: radio blobs moving out with relativistic velocities (VLA) The blobs move on the sky with apparently superluminal velocities (1,2c to 1,7c), this is a well-known relativistic projectioneffect seen also in quasar-jets. This led to the name Micro-quasar (Mirabel and Rodriguez 1994,Nature 371,46)

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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) SS 433 The Mother of all Micro-quasars A ~10 Msun Black hole with ~15 Msun donor, in 13d orbit (Fabrika &Cherepaschuk 2013) Discovered by Bruce Margon (1978)

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Westerhout 50, thebeam bag produced by the precessing beams of SS433

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Optical behaviour of SS 433 during the May/June 1987 campaign, Aslanov, Cherepaschuck, Goranskij, Rakhimov and Vermeulen, AA 270, 200, 1993 [13-day binary]

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Gallo, Fender, Kaiser, Russell, Morganti, Oosterloo and Heintz, 2005, Nature 436, 819: WSRT observations at 1.4 GHz: Discovery of the Jet-powered nebula of Cygnus X-1: Cygnus X-1 is a Micro-Quasar!

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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!!

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H-alpha picture of the jet-powered nebula of Cyg X-1 taken with the Isaac Newton Telsc. (Gallo et al.,2005)

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

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From Mirabel and Rodriguez 1999, Ann.Rev. A&A: Several sources to be added: e.g. Cyg X-1 (black Hole) and Sco X-1 (NS)

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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!