The INTEGRAL Galactic Sky Synergy with AGILE P. Ubertini, A. Bazzano, A. Tarana on behalf of the IBIS Survey Team 1
OUTLINE IBIS and its capabilty The IBIS view of the Galactic Gamma–ray Sky The IBIS AGILE Galactic source OK 2
INTEGRAL overview IBIS and SPI are main instruments IBIS optimised for imaging (17keV-10MeV) SPI optimised for spectra (20keV-8MeV) IBIS is the primary survey instrument Wide FOV (30x30 degrees) ISGRI detector mainly operates 17-600 keV Sensitivity <0.5mCrab for deep exposures JEM-X and Credit: ESA IBIS SPI Coded aperture mask - multiplex advantage - monitoring of many sources while simultaneously searching for other new ones.
IBIS: hunting new γ-ray sources Takes advantage of the large FOV (~1000sq deg) for source detection Unbiased search of the IBIS datasets: 6+ years of operations Looking for weak persistent sources only visible on long timescales: spans a duration of > 1600 days100Ms (with no basic systematic errors! i.e. 4.5sigma limit averall) Looking for transient sources on various timescales (s to y) Follow-up of new and unidentified sources in other waveband Overall analysis of all the sources: Spectra, timing, states Go through this quickly – all demonstrated later 4
The soft gamma-ray sky according to IBIS… 421 sources from 3rd catalog 139 others (more recent IGR and known sources) Around 400 more ‘under inspection’ More than 700 !!! 4th catalog almost ready 18-60 keV band
Source populations CAT 3 – E>17 keV 6
Source populations above 100 keV 7
IBIS GALACTIC Sources MAGNETARs (4+3) PSRs and PWN (13) OK,AGILE NSs and BHCs in LMXB (59+14) NSs and BHCs in HMXB (49+4) OK,AGILE CVs 21 ? still under ispection AGNs 136 in cat3, OK, AGILE
The AGILE SKY. From Pittori et al.2009 LSI +61303 Cyg X-3 PSR J1826-1334 PSR J1509-5850 Eta Car Vela PSR Crab PSR J1420-6048
PSR/PWN
The light curve of the Crab emission as seen by INTEGRAL/SPI non-scattered events. The 0.1–1 MeV gamma-ray events used for the polarization analysis were selected from within the phase interval 0.5–0.8 of the pulsar period (shaded). The gamma-ray polarization vector superimposed on a composite image of the Crab from Chandra (X-ray/blue) and HST (optical/red). The vector is drawn so as to pass through the position of the pulsar. The limits on the direction of the vector are indicated by the shading. The direction of the polarization vector shows a remarkable alignment with the inner jet structure. Image credits NASA/CXC/ASU/J. Hester et al. (2002) Ap. J 577, L49 (X-ray) and NASA/HST/ASU/J. Hester et al. (2002) Ap. J 577, L49 (Optical) The data are consistent with a linearly polarized beam with the electric vector at an angle of 123°±11° closely aligned with the pulsar spin orientation angle which has been estimated to be 124°.0±0°.1. The polarization is 46%±10%. The errors are dominated by non-statistical effects. The angle is measured from North, anti-clockwise on the sky.
Young Pulsars Three young pulsars (< 10 kyr) so far studied at hard X-rays/soft g-rays: PSR B0531+21 (Crab) PSR B1509-58 PSR B0540-69 Different lightcurve shapes HE-spectra of Crab and B0540 similar Maximum Lg below 30 MeV Lx/Lg GeV larger than for older pulsars INTEGRAL profile: Slowikowska et al. 2007
PSR B1509-58 in MSH 15-52 (G320-1.2) Pulse profile consistent with e.g. BATSE, RXTE, but, INTEGRAL timing plus imaging gives results on the PWN, see Forot et al. 2006 ISGRI 20 – 300 keV power law with a= −2.12 up to 160 keV Possible break at this energy
The emerging population of pulsar wind nebulae in soft-γ rays PSRB 0540-69 as a test case (Campana et al. 2008) synchrotron Key range! Up to know very little was known about PWN above 20 keV, yet soft gamma-rays are important diagnostic as they probe the end part of the synchrotron emission and show that particle acceleration is taking place near the pulsar Results on other PWN Name Dominance (IBIS range) Crab PWN PSR B0540-69 PWN Vela PWN PSR J1811-1925 PWN AXJ 1838-0655 PSR PSR J1833-1034 PWN PSR J1846-0258 PWN Archival X-ray data allowed to separate the pulsar and PWN emission in a number of systems including PSR B0540-69 The result is that the INTEGRAL emission is often dominated by PWN (Dean et al. 2009)
Middle age Pulsar: Vela INTEGRAL 2.1 Msec IBIS / ISGRI PSR P1 P2 INTEGRAL TOTAL γ = 1.86 ± 0.03 6.2 σ (ZN2) IBIS, 5.1 Msec PWN PWN, EGRET PSR
the second middle age Pulsar : PSRJ1420-6049 INTEGRAL mosaic in the energy range 20-40 keV a faint signal of 5 sigma is detected consistent with the position of PSR J1420-6048. This pulsar belongs to the middle aged class where the PWN interacts with the reverse shock of the Supernova Remnant. Interestingly, NO INTEGRAL counterpart to the Rabbit PWN candidate, Horns et al., ASS 309,215,2007
The PWN KeV to TeV connection ..and now GeV!!! AGILE AGILE AGILE AGILE From Mattana et al. 2009, Dean et al., 2009
Microqsos LSI +61 303 a Be in a HMXB 20 – 95 keV: “OFF” (phase 0.8 – 1.3) “ON” (phase 0.3 – 0.8) Microqsos
LSI +61 303, “ON” (phase 0.3 – 0.8) 45 – 95 keV 45 – 205 keV
AGL J2032+4102 ?=CYG X-3 Transition from the ultra-soft to the Hard state observed with INTEGRAL Apparently, the ultrasoft state precedes the emission of a jet, which is apparent in the radio and hard X-ray domain Beckman et al, 2008 A&A During the ultrasoft state, the soft X-ray spectrum is well-described by an absorbed (NH = 1.5 × 1022 cm−2) black body model, whereas the X-ray spectrum above 20 keV appears to be extremely low and hard (≃ 1.7). During the transition, the radio flux rises to a level of > 1 Jy, and the soft X-ray emission drops by a factor of ∼ 3, while the hard X-ray emission rises by a factor of ~14 and becomes steeper (up to Ѓ= 4).
Hard X-ray emission from Eta Carinae Tavani M. et al, ApJ accepted From Leyder et al., 2008
NSs in HMXBs: Examples of important unexpected INTEGRAL discoveries and possible association with Gamma ray source the highly absorbed (mostly transient) binary systems as a new class of HMXB: slow pulsar (100-1000s period) in a giant cocoon (Nh often >23) the super-giant fast transients: a new (sub) class of super-giant HMXB (wind accretion in blobs?) V. Sguera et al., ApJ 646, 453 2006 IGR J174544-2619 2 hr flare R. Walter et al., A&A 411, L427, 2003 XMM INTEGRAL/IBIS IGR J16318-4848 See Vito Sguera talk