The INTEGRAL Galactic SkySynergy with AGILE

P. Ubertini, A. Bazzano, A. Tarana on behalf of the IBIS Survey Team

OUTLINE

•IBIS and its capabilty

•The IBIS view of the Galactic Gamma–ray Sky

•The IBIS AGILE Galactic source

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

IBISIBIS

SPISPI

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

The soft gamma-ray sky according to IBIS…

18-60 keV band

421 sources from 3rd catalog139 others (more recent IGR and known sources)Around 400 more ‘under inspection’

More than 700 !!! 4th catalog almost ready

Source populations CAT 3 – E>17 keV

Source populations above 100 keV

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

LSI +61303 Cyg X-3

PSR J1826-1334 PSR J1509-5850

Eta Car

Vela PSRCrab

PSR J1420-6048

The AGILE SKY. From Pittori et al.2009

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 -rays:

PSR B0531+21 (Crab)

PSR B1509-58

PSR B0540-69

Different lightcurve shapes HE-spectra of Crab and B0540 similar

Maximum L below 30 MeV

Lx/L GeV larger than for older pulsarsINTEGRAL profile:Slowikowska et al. 2007

PSR B1509-58 in MSH 15-52 (G320-1.2)

ISGRI 20 – 300 keV Pulse profile consistent with e.g. BATSE, RXTE, but, INTEGRAL timing plus imaging gives results on the PWN, see Forot et al. 2006

power law with a= −2.12 up to 160 keVPossible break at this energy

The emerging population of pulsar wind nebulae in soft-γ rays

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 pulsarArchival X-ray data allowed to separate the pulsar and PWN emission in a number of systems including PSR B0540-69The result is that the INTEGRAL emission is often dominated by PWN (Dean et al. 2009)

Results on other PWNName Dominance (IBIS range)Crab PWNPSR B0540-69 PWNVela PWN PSR J1811-1925 PWNAXJ 1838-0655 PSRPSR J1833-1034 PWNPSR J1846-0258 PWN

synchrotron

PSRB 0540-69 as a test case (Campana et al. 2008)

Key range!

Middle age Pulsar: Vela

INTEGRAL 2.1 MsecIBIS / ISGRI

6.2 σ

(ZN

2)

P1 P2

PSR

INTEGRAL TOTALγ = 1.86 ± 0.03

PWN, EGRET

PSR

PWN

IBIS, 5.1 Msec

the second middle age Pulsar : PSRJ1420-6049

INTEGRAL mosaic in the energy range 20-40 keVa 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!!!

From Mattana et al. 2009, Dean et al., 2009

AGILE

AGILE

AGILE

AGILE

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

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).

Apparently, the ultrasoft state precedes the emission of a jet, which is apparent in the radio and hard X-ray domain

Hard X-ray emission from Eta Carinae

From Leyder et al., 2008

Tavani M. et al, ApJ accepted

NSs in HMXBs: Examples of important unexpected INTEGRAL discoveries

and possible association with Gamma ray source1. 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)

2. the super-giant fast transients: a new (sub) class of super-giant HMXB (wind accretion in blobs?)

R. Walter et al., A&A 411, L427, 2003

XMM

INTEGRAL/IBIS

IGR J16318-4848

V. Sguera et al., ApJ 646, 453 2006

IGR J174544-2619 2 hr flare

See Vito Sguera talk