PoS(MQW6)069 http://pos.sissa.it/ ce. near future the research in this To stimulate the general discussion tions formulated during the general ess and contributions to high energy tiago, CHILE ive Commons Attribution-NonCommercial-ShareAlike Licen † ∗ [email protected] discussion. astrophysics made by studies of microquasarsI in our have Galaxy. underlined some ofarea of the astrophysics. questions Here that I will present guide the viewgraphs in and the ques In the last talk of the conference I summarized the main progr Speaker. On leave from CEA-Saclay. France ∗ † Copyright owned by the author(s) under the terms of the Creat c VI Microquasar Workshop: Microquasars and Beyond September 18-22 2006 Società del Casino, Como, Italy I.F. Mirabel E-mail: Microquasars: Progress made and open questions European Southern Observatory. Alonso de Cordova 3107. San

PoS(MQW6)069 I.F. Mirabel sar winds ? c Center region, where the the left. On the right is shown 63 and LS I +61 303) of the − 9 naries radiate the highest energy -even using the VLT in the near source 1E 1740.7-2942, which is ed by pulsar winds or relativistic er of collimated jets that are the trace e nature of the compact object and bserved from X-1 located in hat 1E 1740.7-2942 is a stellar-mass ies and that the very energetic gamma- rs. The flux, spectrum shape and time terpart of the donor in this putative away from the compact source up to distance of a 2 Chandra and INTEGRAL images of the Galactic Center region on 6cm compact counterpart of the high energy source at the cent Recent observations have shown that some compact stellar bi Multiwavelength observations have shown that two (PSR B125 Figure 1 shows the Chandra and INTEGRAL images of the Galacti λ Figure 1: Microquasars: Open questions the of synchrotron electrons and possible positrons streaming most luminous source in thea hard source X of rays relativistic is jets thevariability that famous in extend Einstein up the to X-rays a arethe few similar light Galactic to yea Center those region, that would whichblack be supports hole o the binary. hypothesis However, t and until mid-infrared-, an today unambiguous it optical or hasblack infrared not hole coun binary. been found 2. Gamma rays from compact binaries: microquasar jets or pul light in the universe.whether The the challenge very has high been energyjets to gamma (Figure determine rays 2). th are ultimately power few light years. 1. The microquasar 1E 1740.7-2942 still a mystery three gamma-ray binaries known so far are binar PoS(MQW6)069 I.F. Mirabel : Pulsar winds are Right ck holes. They are based y source (LS 5039) is also her than a microquasar. As : Microquasars are powered by they are not microblazars. energies. High resolution maps trum. Due to the shrink of the wer energies as a function of the Left 303. s a function of the orbital phase. LBA images of the radio emission which would provide support to the e other hand, it would be interesting jets spin as a function of the orbital n of pulsar winds with the wind from tic gamma-rays. bservations at radio wavelengths that stic particles in collimated jets would rge distances in a comet-shape tail, as has , the temperature increases with angular s wind with the companion-star outflow may rgetic gamma-rays. ) via mass accretion from a companion star. The 3 Alternative models for very energetic gamma-ray binaries. At this time it is an open question whether the third gamma-ra These TeV binaries do not require Doppler boosting, namely, Three methods have been proposed to determine the spin of bla compact objects (neutron orjets stellar-mass boost black the holes energy of stellar winds to the range of very ene Figure 2: Microquasars: Open questions momentum. 2) the Fe line at 6.7 keV, which is skewed towards lo on measurements of: 1)inner accretion the disk temperature in of rapidly rotating the (Kerr) continuum black spec holes powered by rotation of neutronbeen stars; shown in the to be wind the flows caseproduce away for very to LS energetic I gamma-rays. la +61 303. Interactionof thi rays from these two sources may bethe produced companion by star. the interactio In fact,support in this the meeting idea were that presentedexpected o LS from I the +61 pulsar wind 303show model may (right a be panel relativistic of a wind Fig. gamma-rayHowever, from 2), no pulsar pulsations V the rat have so compact far object been detected that from spins LS I a +61 powered by a pulsar wind orboost a microquasar the jet, energy where of relativi theat wind radio from wavelengths the would stellar tellphase companion whether or to the their TeV position direction angle of ina the the search sky for remain TeV the emission same. from On confirmedmicroquasar th black jet hole mechanism binaries, for the production of very energe 3. Perspectives to determine the spin of black holes PoS(MQW6)069 I.F. Mirabel has been estimated 1 − erg s 39 d 4U 1543-47 have moderate et al.(2005). Right panel: Image 10 eeting it has been proposed that es were presented. Refining the -ray outbursts from the compact 3). may affect the X-ray continuum, 2 that produced in real time syn- +105 contains a spin- mated that more than 30% of the 98). hat relativistic and non-relativistic odic oscillations (QPOs), which is ≥ d relativistic jets. Clearly, SS 433 also one of the most powerful jet ely inefficient. The evidences reside ilities rather than as orbiting “blobs”. ed and X-ray wavelengths. In SS 433 black holes, namely, the mass and the ccretion disk. ill an open question whether the power c outflow and radiation that from other nvironment. They are: 1) The moving ted by the relativistic jets as observed at y different models. 4 Left panel: Jet-powered nebula around Cygnus X-1 from Gallo In SS 433 a mechanical luminosity of the relativistic jets of In last years there have been increasing evidences showing t b) It is still uncertain how the forest of warm absorber lines In this field there are stilla) the The following physics basic of caveats: QPOs is still not fully understood. In this m In this meeting new exciting insights on the spin of black hol 20cm of the nebula W50 that hosts SS 433, from Dubner et al. (19 λ at Figure 3: Microquasars: Open questions they are due to global modes that arise as spontaneous instab and therefore the estimates of the temperature of the inner a 4. Dark outflows and super-Eddington sources mass outflows from accreting compact objectsmostly may be in radiativ the interaction ofX-ray jets the from jets the with microquasars thechrotron XTE interstellar bow J1550-564 shocks and e H1743-32 far awaybinary, from and the 2) sources The and large longradio scale after continuum interstellar wavelengths X in structures Cygnus infla X-1 and SS 433 (Figure analysis of the continuum spectrumning it near was the found maximum that rate, GRSspins. whereas 1915 GRO J1655-40, It LMC is X-3, interestingsources. an However, that due the to the source smallof with number relativistic maximum statistics jets it is spin is a is st function of the spin, as predicted b angular momentum. 3) the maximum fixa frequency of function quasi-peri of the basicspin. parameters that define astrophysical from spectral lines of ions ofmore H, than He, 50% and of Fe the ataccreted energy optical, mass is infrar is not being radiated ejected andis in it a the has super-Eddington form been source of esti of massive stellar winds mass an with anysotropi PoS(MQW6)069 I.F. Mirabel 05 that was followed si- that the jet phenomenology ers ? l mass of compact objects in oscillations in this source, the ery Large Array (Figure 4, left x. At that time it was assumed panel: multiwavelength simultane- ion between insta- ource (ULX). It may be used as a retion disk and the onset of jets was . et al (2004; Figure 4 right panel), to e jets became clear because the ejec- ation had been suddenly blown away l). The triggers of jets are instabilities t states). The X-ray spike in the central us transitions have now been observed in ture of the instability that produced such ) are prolific, why no one has been identified ⊙ the genesis of jets; Right panel: Unified model for 5 100 M ≥ 1 hour of simultaneous multiwavelength observations of ∼ Left panel: Superluminal ejection in GRS 1915+105; central In 1994 it was observed a mayor ejection event from GRS 1915+1 Four years later was obtain further insight into the connect A comprehensive phenomenological model based on the notion 2) If black holes of intermediate mass ( The following questions remain open: 1) What is the relation between massive winds and warm absorb Figure 4: Microquasars: Open questions 5. Disk-jet coupling binaries can be determined? multaneously with BATSE on the Comptonpanel). Observatory The and connection the between V thetion inner took disk-corona place and at th thethat time the of high a energy sudden electrons dropin producing in the the form the hard of 20-100 X-ray collimated keV radi relativistictransition flu jets. remains unknown. The physical na bilities and the formation of jets. In in the or the Magellanic Clouds, where the dynamica GRS 1915+105 during the frequently observed 30-40 min X-ray connection between sudden drops of the x-rayobserved flux again from in the acc several occasionsin (Figure the 4, accretion central disk pane (transitionpanel from marks low-hard the to onset high-sof of a shock through a compact, steady jet is part of the accretionwhich process I was refer later the reader proposed for by a Fender detailed description. Analogo probe of ULX’s in external galaxies. black hole accretion-jet phenomena (Fender et al 2004). viewing angle would be classified as an ultraluminous X-ray s ous observations of instabilities in the accretion disk and PoS(MQW6)069 d radio I.F. Mirabel However, no such QPOs urvive in a region of 10 light me alternative models: air beamed jet 4, central panel). These time cs of the central cluster of mas- ic explosions or some form by wn that QPOs of maximum fix posed that the black hole in this ic dissipation at larger scales. alle et al. (2006) show that some anel of Figure 4 being considered gy of natal explosions during the oth teams reach similar results and n our Galaxy can be used as nearby ass black holes. In particular, the ck model) versus pointing flux. aptive optics at infrared wavelengths va. This result is consistent with the hole. mposition found in the atmosphere of l black holes are found the same three ly. Could the presence and absence of holes which indicates that the radiating g GRBs are associated with hypernovae holes of all mass scales. tivistic jets (Figure 5). 6 . However, there are following puzzles: ⊙ in Cygnus X-1 and GRS 1915+105 have not receive a large M ⊙ 6 10 10 M × ≥ exhibit similar time delays between the X-rays, infrared an ∗ European and American teams have been studying the kinemati Jet production models: MHD centripetal (inner) plus magnet 1) How could a massive cluster of massive stars be formed2) and s Observing with the VLT, QPOs of about 15 min were reported. Two flow model: collimated MHD flow plus super-relativistic p In previous publications I had proposed that microquasars i The question on whether all black holes form through energet Jet models: Discontinuous ejections of blobs (internal sho 3) The flares in Sgr A For microquasars, and GRBs have been proposed the sa In the three astrophysical manifestations of astrophysica in observations of the disk-jet coupling in accreting black 6. The black hole at the Galactic Center Microquasars: Open questions the quasars 3C120, 3C279 and 3C390, the diagram in the right p sive stars with the VLT and Keckfrom respectively, the where ground using ad becomes competitive withestimate space a astronomy. black B hole mass of 3 linear momentum during formation (Figure 6). years radius from the ? 8. Microquasar - GRB connections probes of the collapsarkinematics model of for microquasars the canformation formation be of of black used holes. stellar-m to For instance, constrainthe from donor the the star chemical ener and co runawaymicroquasar velocity was of formed GRO through J1655-40 a it very energetic was . pro have been observed sofrequency far are with only Keck. observed sporadically but Inthese not QPOs microquasars permanent be it due is to chance kno ? basic ingredients: a black hole, an accretion disk, and rela direct collapse is related to the(type question Ib/c). on whether The all recent lon observationslong-lasting of GRBs GRB can 060614 be by associated Dellafinding with that V very the black faint holes superno of wavelengths as observed indelays the are flares comparable, irrespective of of the GRS massplasma of 1915+105 has the detached (Figure black from the gravitational field of the black 7. Microquasars and beyond PoS(MQW6)069 I.F. Mirabel owing no luminous supernova gnus X-1 and the parent association of ned at its birth place and did not received a 7 The three manifestations of astrophysical black holes. Figure 5: Left panel: R-band light curve of the GRB 060614 afterglow sh (Della Valle et al.massive stars 2006). Cygnus OB3 showing Rightstrong that panel: kick. the microquasar Proper remai motion of of Cy Figure 6: Microquasars: Open questions PoS(MQW6)069 I.F. Mirabel d black hole astrophysics ndamental properties of the stars, tion as was stellar astrophysics in ived. mpirical correlations become more eaching the physical understanding adiate their energy, empirical corre- ck holes will be determined. As in black hole astrophysics. Using cor- io fluxes, noise spectrum, and QPOs rays and radio waves, quasi-periodic osity is a function of size and temperature. rameters that describe astrophysical black 8 At present, black hole astrophysics is in an analogous situa Different empirical correlations between the X-ray and rad [1] Della Valle,M. et al. 2006, Nature[2] 444, 1050 Dubner, G. et al. (1998), Astron.[3] J. 116, Fender, 1842 R. et al. (2004), MNRAS[4] 355, 1105 Gallo, E. et al.(2005), Nature 436,[5] 819 Merloni, A. et al. (2003) MNRAS, 345, 1057 as a function of black holerobust, mass independently have of been proposed. the models, Ifstellar these the astrophysics, e in mass black and hole spin astrophysics the of lumin bla the first decades of the XXof the century. interior At of that stars time, andlations the well way such before by as r which the they HR produce diagram andsuch were r as found their and mass. used Analogous torelations approaches derive among fu are observables taking such place as in oscillations, the flickering radiated frequencies, fluxes in etc, x- fundamental pa Microquasars: Open questions 9. Empirical correlations and analogies between stellar an holes such as the mass and spin of the black holes are being der References