Transcript INTEGRAL AO-1: preliminary results

The INTEGRAL Galactic Sky
Synergy 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 optimised for
imaging (17keV-10MeV)
 SPI optimised for spectra
(20keV-8MeV)
IBIS
SPI
Credit: ESA
 IBIS and SPI are main
instruments
 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
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 days100Ms (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…
421 sources from 3rd catalog
139 others (more recent IGR and known sources)
Around 400 more ‘under inspection’
18-60 keV band
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)
 NSs and BHCs in LMXB
(59+14)
 NSs and BHCs in HMXB
(49+4)
 CVs
21
OK,AGILE
OK,AGILE
 ? still under ispection

AGNs
136 in cat3, OK, AGILE
The AGILE SKY. From Pittori et al.2009
PSR J1826-1334
LSI +61303
Cyg X-3
PSR J1509-5850
PSR J1420-6048 Eta Car
Vela PSR
Crab
PSR/PWN
The light curve of the Crab emission
as seen by INTEGRAL/SPI nonscattered 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.
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 grays:
PSR B0531+21 (Crab)
PSR B1509-58
PSR B0540-69


Different lightcurve shapes
HE-spectra of Crab and B0540 similar

Maximum Lg below 30 INTEGRAL
MeV
profile:

Lx/Lg GeV larger than for older pulsars
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 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)
Key range!
synchrotron
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
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)
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
Middle age Pulsar: Vela
INTEGRAL 2.1 Msec
IBIS / ISGRI
PSR
P1
6.2 σ
(ZN2)
P2
IBIS, 5.1 Msec
INTEGRAL
TOTAL
γ = 1.86 ± 0.03
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 J14206048. 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)
LSI +61 303,
45 – 95 keV
“ON” (phase 0.3 – 0.8)
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
1. 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?)
IGR J174544-2619
2 hr flare
IGR J16318-4848
XMM
INTEGRAL/IBIS
R.
Walter et al., A&A 411, L427, 2003
V. Sguera et al., ApJ 646, 453 2006