Transcript WSRT’s contributions to knowledge of neutron stars and

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
Early in 1971 Braes and Miley started
observing X-ray sources with the
Westerbork Synthesis Radio Telescope
(WSRT), at 1415 MHz
1973 Cambridge Conference on the “Physics and Astrophysics
of Compact Objects”: Luc Braes is in the 2nd row, 4th from the left
Braes &
Miley
1972
IUA
Symp.
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?
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)
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
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-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
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)
March 27
April 03
April 09
April 16
April 23
April 27
Microquasar GRS 1915+105: Black hole
>10 solar masses with an ~2 solar mass
K-giant companion in 33,5 day orbit
Discovered by Bruce Margon (1978)
SS433
SS 433
Vermeulen,Schilizzi
The Mother of all
Micro-quasars
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)
Westerhout 50, the”beam bag” produced by the precessing beams
of SS433
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 MicroQuasar!!
The jet-powered optical nebula of Cygnus X-1
(Russell, Fender, Gallo and Kaiser, 2008, MNRAS)
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)
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!