V. Tudose (UvA, AIRA), R. Fender (Soton, UvA), M. Garrett (JIVE), J. Miller-Jones (UvA), Z. Paragi (JIVE), R. Spencer (Jodrell),

G. Pooley (Cambridge), M. van der Klis (UvA), A. Szomoru (JIVE)

e-VLBI observations of a microquasar in e-VLBI observations of a microquasar in outburst : Cygnus X-3outburst : Cygnus X-3

Special acknowledgements : R. Campbell (JIVE) and C. Reynolds (JIVE)

Real-time VLBI: e-VLBIReal-time VLBI: e-VLBI

Data transferred in real-time over optical fibers

e-VLBI : the real thing !e-VLBI : the real thing !

enables very rapid access to the data

provides the ability to make informed decisions wrt the subsequent observations

improves the decision making process wrt potential follow-ups

avoids embarrassing situations…..

5 km of tape (~1000 $) on Onsala control room floor due to incorrectly mounting on drive

Cre

dit:

A. R

oy

Oooops…

Mar

ti e

t al

. 200

1

Cygnus X-3Cygnus X-3

1997 Feb 6 1997 Feb 8 1997 Feb 11

Mioduszewski et al. 2001

Miller-Jon

es et al. 2004

15 GHz

5 GHz

d ~ 9 kpcP = 4.8 hcompact object: unknowncompanion : WN Wolf-Rayet

First open call European e-VLBI First open call European e-VLBI observations*observations*

2006 March 16 (dark Epoch)

2006 April 20 (Epoch I)

2006 May 18 (Epoch II)

Cygnus X-3

VX

V

6 antennae : Onsala (SW), Torun (PL), Jodrell Bank (UK), Cambridge (UK), Medicina (IT) and Westerbork (NL)

frequency : 5 GHz (6 cm)

transfer rate : 128 Mbit/s

7 h

12 h

*For the results of the e-VLBI observations of GRS 1915+105 see the poster by Rushton et al.

Mar 16 Apr 20 May 18

Epoch I Epoch IIdark Epoch

Tudose et al., submitted

peak flux : 3.4 mJy/beamrms noise : 0.03 mJy/beamcontour levels:(-15,15,25,35,45,55,65,75,85,95) x rms

Cygnus X-3Cygnus X-3

peak flux : 18.2 mJy/beamrms noise : 0.2 mJy/beamcontour levels:(-15,15,25,35,45,55,65,75,85,95) x rms

Tudose et al., submitted

Cygnus X-3Cygnus X-3

Distribution of the electric vector PAs Fractional linear polarization

2006 April 20

Epoch

101 ± 3

748 ± 17

150 ± 2

60 ± 6

87 ± 917.5 ± 0.3 X 8.8 ± 0.5

Flux density

(mJy)

PA

(degree)

Size

(mas2)

2006 May 18

Component

single

A

B

C

RA (J2000)DEC

(J2000)

20h32m25.771437s

20h32m25.771628s

20h32m25.771051s

20h32m25.771525s

+40°57'27''.92800

+40°57'27''.96566

+40°57'27''.95621

+40°57'27''.93000

23.2 ± 0.7 X 10.6 ± 2.5

38.4 ± 2.1 X 30.7 ± 8.1

19.4 ± 1.1 X 12.2 ± 2.3

69 ± 13

82 ± 22

55 ± 7

Data fittingData fitting

uv-plane fittinguv-plane fitting

Cyg

nu

s X

-3C

ygn

us

X-3

Gallo et al. 2003

during Epoch I the core of Cyg X-3 was quenched

Cygnus X-3

ConclusionsConclusions

on Epoch I the core of Cyg X-3 was in deep quenching; 3 upper limit to the flux density is 0.4 mJy

on Epoch II almost 40 % of the radio emission of Cyg X-3 at large scale is missing at e-VLBI scale

evidence in Cyg X-3 for interaction of the jet with the surrounding medium

e-VLBI will ultimately improve our knowledge of transient sources