A pulsar wind nebula associated with PSR J2032+4127 as the powering source of TeV J2032+4130 Javier Mold´ on Netherlands Institute for Radio Astronomy Extreme Astrophysics in an Ever-Changing Universe Crete, June 16, 2014 Collaborators • J. M. Paredes, Universitat de Barcelona • V. Zabalza, The University of Leicester • V. Bosch-Ramon, Universitat de Barcelona • M. Rib´ o, Universitat de Barcelona • J. Mart´ı, Universidad de Ja´ en • M. Kramer, Max-Planck-Institut f¨ ur Radioastronomie • A. G. Lyne, Jodrell Bank Centre for Astrophysics, The University of Manchester • B. W. Stappers, Jodrell Bank Centre for Astrophysics, The University of Manchester Extreme Astrophysics Collaborators 2 The gamma-ray sky http://tevcat.uchicago.edu/ • VHE (> 100 GeV) sky as seen by Cherenkov telescopes. ∼140 sources • 46 extragalactic. 61 galactic. ∼30 unidentified Extreme Astrophysics Introduction 3 First unidentified source: TeV J2032+4130 • Observed by HEGRA in 1999-2001 • Significance of 6.1σ • Steady flux on yr timescales • Extended with radius 6.2 ± 1.2 ± 0.9 arcmin • Hard spectrum with index −1.9 ± 0.1stat ± 0.3/rmsys • Integral flux > 1 TeV at the level of ∼5% Crab [Aharonian et al. 2002, A&A 293, L37] Extreme Astrophysics Introduction 4 TeV counterpart (MAGIC) [Albert et al. 2008, ApJ, 675, L25] • Extension of the energy spectrum down to 400 GeV. No spectral break • Extension of the source: ∼5 arcmin (assuming Gaussian shape) • No flux variability over several yr, compatible with HEGRA (not Whipple) Extreme Astrophysics Introduction 5 TeV counterpart (VERITAS) [Aliu et al. 2014, ApJ 783, 16] Extreme Astrophysics Introduction 6 PSR J2032+4127 [Camilo et al. 2009, ApJ 705,1] • Fermi: GeV pulsar LAT PSR J2032+4127 [Abdo et al. 2009, Sci 325, 840] • P = 143 ms, τc = 0.11 Myr, E˙ sp =2.7 × 1035 erg s−1 • GBT: radio pulsar same position and period GeV pulsar, and a Be star Extreme Astrophysics Introduction 7 Field around PSR J2032+4127 Suzaku VLA 6 cm [Murakami et al. 2011, PASJ, 63, 873] Extreme Astrophysics [Butt et al. 2008, MNRAS 385, 1764] Introduction 8 Observations • VLA • June 28, 2010 • Two frequency bands centered at 4.4 and 7.8 GHz • D configuration • EVN • Observations on 2010, 2011, and 2014 • 1.6 GHz • Pulsar gating • Chandra • Archival data, 0.5-10 keV band, 48.7 ks observation on 2004 July 12 with the Advanced CCD Imaging Spectrometer (ACIS) detector. Extreme Astrophysics Observations 9 Observations • VLA • June 28, 2010 • Two frequency bands centered at 4.4 and 7.8 GHz • D configuration • EVN • Observations on 2010, 2011, and 2014 • 1.6 GHz • Pulsar gating • Chandra • Archival data, 0.5-10 keV band, 48.7 ks observation on 2004 July 12 with the Advanced CCD Imaging Spectrometer (ACIS) detector. Extreme Astrophysics Observations 9 Observations • VLA • June 28, 2010 • Two frequency bands centered at 4.4 and 7.8 GHz • D configuration • EVN • Observations on 2010, 2011, and 2014 • 1.6 GHz • Pulsar gating • Chandra • Archival data, 0.5-10 keV band, 48.7 ks observation on 2004 July 12 with the Advanced CCD Imaging Spectrometer (ACIS) detector. Extreme Astrophysics Observations 9 VLA VLA: Extended radio emission Extreme Astrophysics VLA 9 δJ2000 Extended radio emission: a PWN 280 + PSR J2032+4127 VLA 4.4 GHz +41◦ 270 18s 16s Extreme Astrophysics 14s αJ2000 12s 20h 32m 10s VLA 10 δJ2000 Extended radio emission: a PWN 280 + PSR J2032+4127 VLA 4.4 GHz VLA 7.9 GHz +41◦ 270 18s 16s Extreme Astrophysics 14s αJ2000 12s 20h 32m 10s VLA 10 Radio spectrum Flux density [mJy] 4.0 1.0 GMRT GBT VLA GBT 0.1 1 2 3 Frequency [GHz] 4 5 6 7 8 9 • Pulsar spectrum: Sν = (0.36 ± 0.02)(ν/GHz)−1.6±0.1 mJy • Insignificant contribution from the pulsar: α = −0.4 ± 0.4 Extreme Astrophysics VLA 11 EVN EVN: Pulsar proper motion Extreme Astrophysics EVN 11 δJ2000 PSR J2032+4127 proper motion 280 +41◦ 270 18s 16s µα cos δ = −2.0±2.0 mas yr−1 µδ = −10.8 ± 2.0 mas yr−1 Extreme Astrophysics 14s αJ2000 12s 20h 32m 10s αJ2000.0 = 20h 32m 13.125 ± .002s δJ2000.0 = +41◦ 270 24.44 ± 0.02” EVN 12 δJ2000 PSR J2032+4127 proper motion 280 +41◦ 270 18s 16s µα cos δ = −2.0±2.0 mas yr−1 µδ = −10.8 ± 2.0 mas yr−1 Extreme Astrophysics 14s αJ2000 12s 20h 32m 10s αJ2000.0 = 20h 32m 13.125 ± .002s δJ2000.0 = +41◦ 270 24.44 ± 0.02” EVN 12 δJ2000 PSR J2032+4127 proper motion 280 +41◦ 270 18s 16s µα cos δ = −2.0±2.0 mas yr−1 µδ = −10.8 ± 2.0 mas yr−1 Extreme Astrophysics 14s αJ2000 12s 20h 32m 10s 2D velocity: 90–190 km s−1 at 1.7–3.6 kpc EVN 12 Galactic velocity vrad [km s−1 ] 0 −40 • Components of the Galactic and −80 peculiar velocity of PSR J2032+4127. −120 −160 vcir [km s−1 ] 360 • The grey areas indicate the 320 280 expected Galactic velocity for young stars. 240 200 160 • (II) Assuming radial velocity of: vz [km s−1 ] 0 +100 km/s (dashed line) -100 km/s (dotted line) −40 −80 vpec [km s−1 ] −120 160 The velocities are not compatible with the expected ones from Galactic rotation 120 80 40 0 1.5 2.0 2.5 3.0 Distance [kpc] Extreme Astrophysics 3.5 4.0 EVN 13 Galactic velocity vrad [km s−1 ] 0 −40 • Components of the Galactic and −80 peculiar velocity of PSR J2032+4127. −120 −160 vcir [km s−1 ] 360 • The grey areas indicate the 320 280 expected Galactic velocity for young stars. 240 200 160 • (II) Assuming radial velocity of: vz [km s−1 ] 0 +100 km/s (dahsed line) -100 km/s (dotted line) −40 −80 vpec [km s−1 ] −120 160 The velocities are not compatible with the expected ones from Galactic rotation 120 80 40 0 1.5 2.0 2.5 3.0 Distance [kpc] Extreme Astrophysics 3.5 4.0 EVN 14 Widefield 360 320 δJ2000 Contours: JVLA 4.4 GHz Black Cross: EVN, pulsar Black dots every 5000 yr 280 +41◦ 240 40s Extreme Astrophysics 20s 32m 00s αJ2000 20h 31m 40s EVN 15 Widefield VERITAS Contours: JVLA 4.4 GHz Black Cross: EVN, pulsar Black dots every 5000 yr Red ellipse: Fermi 0 36 MAGIC δJ2000 320 280 +41◦ 240 HEGRA 40s Extreme Astrophysics 20s 32m 00s αJ2000 20h 31m 40s EVN The past trajectory of PSR J2032+4127 coincides with the measurement of the CoG of the TeV emission measured with MAGIC, which is compatible with the measured positions from HEGRA and VERITAS 16 Chandra Chandra: diffuse X-ray emission Extreme Astrophysics X-ray 16 Diffuse X-ray emission 290 280 δJ2000 Contours: JVLA 4.4 GHz Cross: EVN, pulsar Red Crosses: Chandra 270 +41◦ 260 20s 16s 12s αJ2000 Extreme Astrophysics 20h 32m 08s X-ray 17 Diffuse X-ray emission 290 280 δJ2000 Contours: JVLA 4.4 GHz Cross: EVN, pulsar Red Crosses: Chandra Color scale: diffuse Chandra 270 +41◦ 260 20s 16s 12s αJ2000 Extreme Astrophysics 20h 32m 08s X-ray 18 X-ray/gamma-ray correlation • Correlations of the X-ray and gamma-ray fluxes with E˙ and τc : • E˙ sp = 2.7 × 1035 erg s−1 ⇒ LX = 7.4 × 1030 erg s−1 or FX = 2.2 × 10−14 erg cm−2 s−1 • τc = 0.11 Myr ⇒ Fγ /FX ∼ 1000 ⇒ Lγ = 7.4 × 1033 erg s−1 [Mattana et al. 2009 ApJ 694 12] Extreme Astrophysics Correlation 19 X-ray/gamma-ray correlation • Correlations of the X-ray and gamma-ray fluxes with E˙ and τc : • E˙ sp = 2.7 × 1035 erg s−1 ⇒ LX = 7.4 × 1030 erg s−1 or FX = 2.2 × 10−14 erg cm−2 s−1 • τc = 0.11 Myr ⇒ Fγ /FX ∼ 1000 ⇒ Lγ = 7.4 × 1033 erg s−1 [Mattana et al. 2009 ApJ 694 12] Extreme Astrophysics Correlation 19 Diffuse X-ray emission 290 The diffuse emission could be: • Partially from the PWN itself. 0 δJ2000 28 • Unrelated source. Field young stars? 270 • e− escaping from the shock? +41◦ 260 20s 16s 12s αJ2000 Extreme Astrophysics 20h 32m 08s Correlation 20 Scenario • High speed pulsar forms a shock at ∼ 100 . • High energy particles are accelerated and escape the shock region. • If leptonic, they could be the responsible of the TeV source through IC in the Thomson regime off CMB and IR galactic photons with energy density uCMB−IR ∼ 1 eV. • Diffusion coefficient of D ∼ 1026 cm2 s−1 , tdiff ∼ 30 − 50 kyr. • Particles are advected by the shocked flow in the opposite direction to the pulsar motion. These relativistic particles produce radio (detected) and X-ray emission (not detected yet). • The size of the TeV source is compatible with a projected velocity of ∼ 100 km s−1 . Extreme Astrophysics Scenario 21 Conclusions • The radio morphology strongly resembles that of a PWN. • The positional coincidence between the pulsar and the origin of this elongated radio structure suggests a physical association. • This is supported by the proper motion of the pulsar, opposite to the radio structure. • The pulsar space velocity is not compatible with the Galactic rotation. Probably formed with a kick. • The absence of diffuse X-ray emission overlapping the elongated radio structure could be explained by the low flux expected. • The extended X-ray emission detected with Chandra and Suzaku remains unclear. (Associated with the Be stars in the field?). Extreme Astrophysics Conclusions 22
© Copyright 2024 ExpyDoc
