# Presentation: 531994

## INTEGRAL

*Science Highlights*

## Mission Status

*Spacecraft*
*3.5 years in orbit*
*Nominal operation*
*> 10 yr of on-board fuel remaining*
*Instruments*
*Small degradation of SPI and JEM-X early in mission*
*Stable operation since mid-2004*
*Mission Extension*
*Approved by ESA through 2008 with recommendation to continue to 2010.*
*NASA participation beyond FY06 tbd (MO&DA Senior Review)*
*Ongoing International GO program*
*NASA supported US participation*
*Administered by NASA INTEGRAL GOF*

## Observing Program, Data Rights

*Currently in mission cycle 3*
*25% of data reserved for Core Program*
*Deep Galactic central region exposure*
*Norma, Scutum, Sagatarius,  spiral arms*
*Galactic plane scan*
*20% for cycle 4 and beyond, but will institute key projects*
*All data are proprietary for 1 year*
*Lots of discussion about waiving this for cycle 4+ CP, but no policy change as yet*
*NASA mirrors public data archive*

## Primary Instruments

***Primary Instruments***

- 2x10-5

- 30 kbs

- , 106 s

***17***

## Primary Instruments

***Primary Instruments***

- ~1 mCrab, 100 ks, 20-100 keV

- Systematics: achieves statistical limit for ~100 ks

## Sky Coverage

*Emphasis on Galactic plane, particularly inner  ****40**o*

## e+e- Annihilation Radiation

*511 keV line and Ps continuum trace the Bulge, FWHM ~8**o*
*Hard to reconcile w/known populations?*
*No evidence for 511-kev point sources (e.g. Bulge XRBs)*
*SN Ia ? (why no disk component)?*
*Dark matter? *
*Surprisingly, small disk component (B:D ~6****3)*
*No evidence for asymmetry*
*~10**-3 **cm**-2.**s**-1, **=10**43 **annihilations per sec*

## e+e- Annihilation Radiation

*Narrow line profile*
*Constrains explosive origin scenarios*
*Ambient ISM *
*Suggests T~8000K, n~0.3 cm**-3** *
*Ps fraction ~0.9*
*No redshift or doppler*
*Recall that Nova Mus 91 line was at ~480 keV*
*Constant intensity*

## Galactic Nucleosyntheis

- Diehl et al. 2006, Nature, 439, 45

**SNR:  1.9 ******** 1.1 ctry****-1**
**SFR = 2.8 ******** 0.8 M****o**** yr****-1**

- SPI

**Comptel**

***Galactic Nucleosyntheis***

*26**Al*

## Galactic Nucleosyntheis

- SPI(1.173 MeV &1.333 MeV):              F = 4 10-5  cm-2 s-1 per line
- (Harris et al. 2005)

**60****F/****26****Al**

***Galactic Nucleosyntheis***

- 26Al:  SNII, novae, AGB
- 60Fe: SNII
- Ratio observed (1/9);  may need additional W26Al source (WR stars?)

*44**Ti:  Cas A, detected at 68 & 78 keV, but not at 1.1 MeV;  Given COMPTEL detection, implies V**** 10**3 **km/s*

## Galactic Plane Monitoring: HMXBs

*Bulge region monitored ~1x per orbit*
*Deep exposure of GC region in Core Program*
*Eventually ~20 Msec near GC*
*Hard X-ray selected catalog list*
*~200+ sources*
*~25% “new”*
***50% of these highly absorbed*
*Slow rotators (100-1000 sec)*

*IBIS mosaic: 20-50 keV, 1 Msec, ~40**o**x20**o*

## Hidden HMXB Population? 

*Map of INTEGRAL detected Galactic XRBs. Gray scale indicates nominal density of HMXB content.*
*Highest density is centered on spiral arms, notably  Scutum, Norma and Sag. Significant enhancement to overall sample in those regions.*
*HMXBs roughly trace SF, but take ~10’s of Myr to form*

- Lutovinov et al 2004

*Lutovinov et al 2005*

## NH Distribution

*Derived, and “cataloged” galactic NH column density towards INTEGRAL HMXB sample*
*In a number of cases, evidence for local absorption supports this discrepancy*
*Tendency for high absorption is clear*

- Lutovinov, et al 2004; Grebenev et al 2004; Sidoli et al 2004; + few other ATels

## Sample Broad-Band Spectra

*Sample spectra from Lutovinov et al 2005 Most objects have characteristic HMXB SED*
*AX J183800-0655 BH?*
*High absorption is evident in low-energy continuum*
*Typically little or no flux below ~5 keV*
*Where high-SN X-ray data is available, spectral features indicative of Compton thick media*

## “Fast Transients”, ~day timescale flares

- IGR J17544-2619

- Negueruela, Smith, et al. 2005, (astro-ph/0511088)

***“******Fast Transients”, ~day timescale flares***
***Hard X-ray selected***
***~10 now known, 4 w/sg primaries***
***~2X previously known sg XRBs***

## Galactic Ridge Emission

*Long standing problem: *
*true diffuse, or integrated point sources? *
*<10 keV X-rays have dominant diffuse component **(although see Revnivstev et al 2006)*
*Diffuse scenarios are problematic:*
*Compton scattering? *
*Where is the radio emission*
*Bremsstrahlung in ISM?*
*Ionization balance?*
*IBIS results indicate that point sources contribute ~90% of inner-Galaxy flux 20-200 keV *

## Diffuse Galactic Emission

*SPI has larger FoV, wider energy bandpass than IBIS *
*Strong et al 2005 find: *
*Hard (>200 keV) excess above integrated (known) point-source flux*
*Ps continuum evident*
*Speculation:*
*AXP populations*

## INTEGRAL – HESS Associations

**Ubertini et al. 2006**

***INTEGRAL – HESS Associations***

**IGR J18135-1751 = HESS J1813-178*** *

*3 INTEGRAL-HESS associations of interest*
*PSR 1259-63,Sgr A* region, &IGR18135-1752  *

*PSR 1259-63, (Be star – ms Pulsar Binary)*
*Sgr A* (extended emission, particle acceleration)*
*IGR18135-1752  (PWN?)*

## Sgr A* - Hard-X-Ray Counterpart?

*Source coincident w/Sgr A**
*IBIS resolution ~10’ inadequate for unambiguous association*
*Early reports of contemporaneous flaring now in doubt*
*Likely that hard-X-rays come from extended emission region ambient to Sgr A**
*Also the TeV source?*
*Also, Sgr B2 “Compton Mirror”*
*Active period?*

## Hard X-ray AGN Survey

*70 hard X-ray selected AGN, 25,000 sq deg, ~mCrab*
*Sub-mCrab on ~7,000 sq deg*
*~7% “new” sources*
*Sy-2’s harder than Sy-1’s*
*~10% Compton thick (NH****10**24**)*
*Less than expected considering DHXRB spectrum*
*~1% of DHXRB (<Z>=0.22)*
*Weak absorption-luminosity dependence (higher Lx, less absorbed, consistent /Swift)*

- Seyfert 2

- Seyfert 1.5

- Blazars

- Seyfert 1

## Hard X-ray AGN Survey

*Log(N) – Log(S) curve for hard-X-ray sample:*
*Consistent w/Euclidian space distribution (but low z sample).*
*Normalization consistent w/Swift and independent INTEGRAL survey **(Krivonos 2005; Tueller private communication)** *
*~1.2****10**-2**deg**-2 **@mCrab*
*With increased high-latitude exposure, expect ~200 AGN*

## SGRs, AXPs

*AXP 1E 1841-045 showed pulsed emission up to ~150 keV **(Kuiper, et al 2004) *
*Lx exceeds spin-down energy by****10**2*
*Broad-band spectral differences*
*SGR 1806-20 and SGR 1900+14 have persistent emission up to 100 keV, with Lx~10^36 erg/s  (20-100 keV)** *

## Gamma-Ray Bursts

*Prompt, GRB localizations are being disseminated at a rate of about 10 per year.  *
*Notable case: GRB 031203 position distributed 20 seconds after its detection*
*In addition to the bursts imaged by IBIS, SPI ACS system is component of the IPN.  *
*Isotropic response, it detects about ~70 bursts/year down to a threshold of 7****10**-8** erg/cm**2**, many localized by triangulation.  *

## Hard-X-Ray, -Ray Background

*Recent Earth-pointing observation: determine cosmic high energy background by using the Earth as an occulter.*
*"Point and shoot" observation; blinded star trackers*
*Complications: reflected emission, cosmic-ray Bremsstrahlung*
*Ongoing analysis ...*

## Lessons Learned

*Don’t squeeze ground calibrations out of development schedule*
*Engage community as extensively and as early on as possible*
*INTEGRAL Core Program encompasses too much key science*
*Usable SW calibrations & backgrounds by time of first data release*
*Liberal data rights policy *
*Scientists should participate at all levels of development *
*Early INTEGRAL SW development “top heavy” w/computer jocks*
*Retain archive & theory research program*
*One pre-launch symposium is adequate*
*Don’t have Russians launch it (politics ...)*