Gamma-ray binaries: from low frequencies to high resolution Benito Marcote PhD Student October 15, 2014
Gamma-Ray Binaries Binary systems which host a compact object orbiting a high mass star that have the non-thermal maximum of the Spectral Energy Distribution in γ-rays (Paredes et al 2013, Dubus 2013) System Main star P/ days Cygnus X-3 WR 02 Cygnus X-1?? O97Iab 56 MWC 656?? Be 604 PSR B1259 63 095Ve 12367 HESS J0632+057 B0 Vpe 3150 LS I +61 303 B0 Ve 265 1FGL J10186 5856 O6V 166 LS 5039 O65V 39 Green: X-ray binaries with gamma-ray emission Red: known gamma-ray binaries SED of gamma-ray binaries versus HMXRBs Benito Marcote bmarcote@amubes Astrolunch - ASTRON/JIVE 2/14
Gamma-Ray Binaries Young non-accreting pulsar scenario Strong shock between both winds: Relativistic pair plasma wind from the pulsar Stellar wind from the massive companion star Originally proposed by Maraschi & Treves (1981), re-proposed by Dubus (2006) Radio flux dominated by the synchrotron emission at GHz Orbital motion Wind standoff Star Pulsar V Zabalza et al: GeV-TeV em Coriolis turnover Shocked pulsar wind Shocked stellar wind Model for LS 5039 from Zabalza et al (2012) Fig 1 Sketch of the proposed scenario at the periastron of a close-orbit system similar to LS5039 The region of the CD where significant turbulence, and therefore wind mixing, are expected to take place is indicated with a wavy line The red regions indicate the two proposed emitter locations Benito Marcote bmarcote@amubes Astrolunch - ASTRON/JIVE 3/14 o t w e 2 a p r d e s t t e o m t t e o w b i a l u b l
The gamma-ray binary LS 5039 LS 5039 O65 V star (23 ± 3 M ) d = 25 ± 05 kpc e = 035 ± 004 P orb = 390603 ± 000017 d Light-curve: TeV: periodic outbursts GeV: periodic outbursts X-rays: periodic outbursts radio: not periodic Small variability AU 03 02 01 00 01 02 03 04 Casares et al (2005) 04 03 02 01 00 01 02 03 AU Benito Marcote bmarcote@amubes Astrolunch - ASTRON/JIVE 4/14
The gamma-ray binary LS 5039 50 50 S ν / mjy S ν / mjy 20 10 5 50 20 10 5 VLA 1998 VLA 2002 GMRT 2004-2008 GMRT/WSRT 2013 None Averaged values SSA fit to averaged values SSA+Razin fit to averaged values 02 05 1 2 5 10 20 ν / GHz S ν / mjy 20 10 5 2013 Jul 19 2013 Jul 21 SSA fit to Jul 19 SSA+Raz fit to Jul 21 Fit to averaged values 02 05 1 2 5 10 20 ν / GHz Averaged spectrum explained by a synchrotron self-absorption emission Slightly differences in simultaneous spectra (WSRT+GMRT data) Benito Marcote bmarcote@amubes Astrolunch - ASTRON/JIVE 5/14
The gamma-ray binary LS I +61 303 LS I +61 303 B0 Ve star (125 ± 25 M ) d = 20 ± 02 kpc e = 072 ± 015 P orb = 26496 ± 0003 d P super = 1667 ± 8 d Outbursts at all frequencies X-ray TeV: correlated(?) Radio TeV: correlated Optical Radio: correlated GeV TeV: anticorrelated Frail & Hjellming (1991), Casares et al (2005), Gregory (2002) Benito Marcote bmarcote@amubes Astrolunch - ASTRON/JIVE 6/14
Radio emission of LS I +61 303 LS I +61 303 exhibits a large variability at radio frequencies Emission orbitally modulated (P orb 265 d) No 1, 1998 RELATIONSHIP BETWEEN 2CG 135]1 AND LSI ]61 303 424 423 STRICKMAN ET AL Vol 497 OSSE range than was observed The OSSE integral Ñux 100 from 50È300 kev during VP 325 is (43 ^ 11) ] 10~4 photons cm~2 s~1, while the integral of the ASCA best-ðt 10 9 June 94 (097) 26 June 94 (062) power-law models extrapolated to the same energy range are (10 ^ 04) 100 ] 10~4 and (05 ^ 02) ] 10~4 photons cm~2 s~1 for radio phases 02 and 042 respectively These are inconsistent10 11 June 94 (006) 28 June 94 (070) at the 28 p and 34 p levels, assuming that the spectrum 100 does not change (in particular, does not harden signiðcantly) from 10 to 300 kev Since the relatively 10 12 June large 94 (009) OSSE Ðeld of view 1 July does 94 (079) not exclude the nearby QSO 0241]622 as a possible source of 100 emission, we have also plotted the result of EXOSAT (2È10 kev) observations of the QSO (Turner & Pounds 1989), 10 15 June 94 (019) 2 July 94 (084) corrected for its position in the OSSE collimator response Note that the 17 100photon index power-law spectrum used to model the EXOSAT data is consistent with the OSSE result 10 17 June 94 (028) 3 July 94 (088) When we look 100at an overall view of the spectra from this region, no clear picture emerges However, the fact that OSSE and COMPTEL 10 18 June results 94 (031) fall signiðcantly 5 July above 94 (095) an extrapolation of the ASCA spectra and that the OSSE and 100 COMPTEL spectra are consistent with the X-ray spectrum of QSO 0241]622, lead to the likelihood that at least some, 10 19 June 94 (035) 7 July 94 (002) and perhaps a signiðcant amount, of the Ñux observed by both OSSE and 100COMPTEL might come from the QSO rather than LSI ]61 303 Cycle-to-cycle variations in the X-ray emission 10 21 June 94 (042) 8 July 94 (007) may also contribute to the observed discrepancy More contemporaneous 01 10 X-ray 100 and01 c-ray data 10 are 100 required to test for the existence of cycle to cycle variability Frequency (GHz) of the LSI ]61 303 system and to better study the X-ray FIG 4ÈMultifrequency radio light curves of LSI ]61 303 observed Strickman FIG period 5ÈTime et recently evolution al of the (1998) reported LSI ]61 303 nonthermal by Paredes radio spectrum et al during (1997a) the outburst of 1994 JuneÈJuly Spectra are labeled according to the date and radio phase of the observation with the VLA corresponding to the radio outburst of 1994 JuneÈJuly Similarly, the low signiðcance of the OSSE light curves Error bars not shown are smaller than the symbol size a function shownof inorbital Figure phase 2 does Ultimately notthe allow high-energy us to usewith temporal wind optical signa- depth e ects dictating the time delay Benito Marcote bmarcote@amubes Astrolunch shock emissivity will depend on the geometrical and radiative tures characteristics to - ASTRON/JIVE between the injection of the electrons and the visibility of associate of the pulsar LSI cavity ]61 303 as the pulsar with orbits the OSSE the radiosource emission We 7/14 Flux Density (mjy)
Results from the GMRT observations GMRT data from Nov 2005 to Feb 2006 100 610 MHz 235 MHz 80 S º = mjy 60 40 20 0 0:0 0:5 1:0 1:5 2:0 Á Benito Marcote bmarcote@amubes Astrolunch - ASTRON/JIVE 8/14
Results at very low frequencies With the GMRT observation at 154 MHz we detected for first time a gamma-ray binary at these very low frequencies ν = 154 MHz Bandwidth 32 MHz Beam: 30 14 arcsec (J2000) 30 0 24 0 18 0 12 0 Point-like source S ν = 37 ± 2 mjy 06 0 +61 00 0 43 m 42 m 41 m 40 m (J2000) 39 m 2 h 38 m Benito Marcote bmarcote@amubes Astrolunch - ASTRON/JIVE 9/14
Results at very low frequencies 6 RSM pointings to LS I +61 303 with LOFAR up to now ν = 149 MHz Bandwidth 78 MHz Beam: 27 15 arcsec g 4 analyzed obs 3 detections > 3σ Point-like source Benito Marcote bmarcote@amubes Astrolunch - ASTRON/JIVE 10/14
Results at very low frequencies Preliminary results from the RSM LOFAR observations Detection of LS I +61 303 in three of four analyzed observations The behavior of the source is variable along the time 100 00 05 φ LOFAR 150 MHz 80 Sν / mjy 60 40 20 0 56350 56400 56450 MJD Benito Marcote bmarcote@amubes Astrolunch - ASTRON/JIVE 11/14
The gamma-ray binary HESS J0632+057 82 The gamma-ray binary candidate HESS J0632+057 HESS J0632+057 B0 Vpe star (16 ± 3 M ) d = 14 ± 05 kpc e = 083 ± 008 4 3 MWC 148 / HESS J0632+057 Porb = 321 d φapa = 047 B A RR005, RM006 P orb = 321 ± 5 d AU 2 Variability at all frequencies TeV: periodic outbursts GeV: periodic outbursts X-rays: periodic outbursts radio:? 1 0 Toobserver φper = 097 Moldón (2012) 4 3 2 1 0 1 AU Benito Marcote bmarcote@amubes Figure 81: Sketch of the orbit of MWC 148/HESS J0632+057 with the position of the compact object during the observations of projects RR005 and RM006 marked as red circles The white dots are plotted every 01 orbital phases The empty squaresmarktheinferiorand superior conjunction of the compact object, which occur at orbital phases 0961 and 0063, respectively Astrolunch The - orbit ASTRON/JIVE was computed using the orbital solution reported in Casares et al 12/14
Radio emission of HESS J0632+057 Radio flux density [µjy] Integral flux (>1 TeV) [10 12 cm 2 s 1 ] 800 600 400 200 0 14 12 10 08 06 04 02 00 02 Phase-folded time [days] 0 50 100 150 200 250 300 EVN 16 GHz WSRT 16 GHz GMRT 13 GHz Swift HESS VERITAS MAGIC Swift < 30 µjy 00 01 02 03 04 05 06 07 08 09 10 Orbital phase Light-curve of HESS J0632+057 in radio (color data, top), X-rays (gray circles) and TeV (color data, bottom) 6 5 4 3 2 1 0 5 4 3 2 1 0 X-ray flux [10 12 erg cm 2 s 1 ] X-ray flux [10 12 erg cm 2 s 1 ] Declination (J2000) 06 +6 00 54 48 42 +5 36 δ offset [mas] 75 50 25 33 m Right Ascension (J2000) 0 25 50 75 75 50 25 0 25 50 75 α offset [mas] 6 h 32 m EVN and WSRT observation in 2014 No detections in any case, with an EVN 3-σ upper-limit of 30 µjy Benito Marcote bmarcote@amubes Astrolunch - ASTRON/JIVE 13/14
Thank You! Benito Marcote bmarcote@amubes Astrolunch - ASTRON/JIVE 14/14