NHXM: a New Hard X-ray NHXM: a New Hard X-ray imaging imaging

and polarimetric Mission and polarimetric Mission

Giorgio Matt Giorgio Matt (Dip. Fisica, Università Roma Tre, Italy)(Dip. Fisica, Università Roma Tre, Italy)

on behalf of the NHXM teamon behalf of the NHXM team

A short history 1/2A short history 1/2

• Italian Space Agency (ASI) recognized in its long term plan hard X-ray focusinghard X-ray focusing and X-ray X-ray polarimetrypolarimetry as strategic activities (i.e. technologies which potentially address outstanding scientific issues and in which Italy can have a leading role).

• Simbol-XSimbol-X was identified as the refernce mission for the former technology

• Unfortunately, on March 2009 Simbol-X was cancelled by CNES for budgetary reasons. Simbol-X science remains valid, however, even considering the newly approved X-ray missions

A short history 2/2A short history 2/2

• The ASI Phase A study was called New Hard X-ray New Hard X-ray MissionMission and included also the study of HEXIT-Sat, that was successfully carried out in parallel with Simbol-X

• Phase B Industrial contract for optics approved in Italy in any case with NHXM as the new reference mission and is proceeding well

• The ASI Phase A study of a polarimetric mission, Polarix, was also completed successfully

• A new mission concept combining broad band A new mission concept combining broad band spectroscopy, imaging and polarimetry (for the time spectroscopy, imaging and polarimetry (for the time being maintaining the name NHXM) was therefore being maintaining the name NHXM) was therefore proposed to ASI in September 2009proposed to ASI in September 2009

NHXM ParametersNHXM Parameters

NHXM Focal PlanesNHXM Focal Planes

3 mirror modules with a hybrid focal plane

• Silicon based detector (MOS CCD or DEPFET)

• CdTe array

• Anticoincidence system (NaI or CsI)

1 mirror module with a photoelectric imaging polarimeter(2 detectors, working in the 2-10 and 6-35 keV ranges)

NHXM in a contextNHXM in a context

• NuStar (NASA SMEX). First hard X-ray (6-79 keV) mission with focusing telescopes

(HPD@30 keV: 60”). Energy resolution ΔE~1 keV.

Launch in 2011.

•ASTRO-H (JAXA). Broad-band (0.3-80 keV) focusing telescopes (HPD@30 keV: 100”). Non focusing soft γ-ray detector in the 10-600 keV band. High energy resolution (calorimeter) in

the 0.3-12 keV range. Launch in 2013.

• GEMS (NASA SMEX). Non imaging X-ray (2-10 keV) polarimeter. Launch in 2014.

NHXM in a context NHXM in a context

NHXM in a contextNHXM in a context

Polarimetric sensitivityPolarimetric sensitivity

Soft X-ray channel

Hard X-ray channel

Two polarimetric channels (2 – 10 keV and 6 – 35 keV) for an effective diagnostic of the emission mechanisms

Simultaneous Simultaneous spectroscopic and spectroscopic and polarimetric polarimetric observations !!!observations !!!

Science with NHXMScience with NHXM

BH census and accretion BH census and accretion physicsphysics

Non-thermal emission and Non-thermal emission and acceleration mechanismsacceleration mechanisms Radiative processes in strong Radiative processes in strong

electromagnetic electromagnetic and gravitational fieldsand gravitational fields

These three broad topics define the core These three broad topics define the core scientific objectives of NHXMscientific objectives of NHXM

NHXM and the CXBNHXM and the CXBIR selected AGN, how large the obscuration is? Only high energy X-ray observations can tell, thus assessing the real power of the active nucleus and probing the BH growth in these galaxies and its feedback.

HEW<20” HEW<20” >65% CXB resolved @30keV>65% CXB resolved @30keV

CDFS 1 Msec NHXM simulations (10-40 keV)

• Chandra sources (red contours);

• IR selected CT AGNs (blue circles) at z=0.5-2 assuming NH=1024 cm-2 and a reasonable IR/X-ray luminosity ratio

CXB fraction and CT AGNCXB fraction and CT AGN

Geometry of the Geometry of the torus:torus:

the polarization angle will give us the orientation of the torus, to be compared with IR results, and with the ionization cones (Goosmann & Matt 2010)

NHXM NHXM NuStarNuStar Astro-HAstro-H 20-40keV 20-40keV

..

2-10 keV Chandra/XMM2-10 keV Chandra/XMM

Gilli et al.

Treister et al.

Gilli et al.

Raban et al. 2009

Accretion physics: Galactic black Accretion physics: Galactic black holesholes

Esin et al. (1997)

Broad band spectroscopy and polarimetry can help answering several important questions for

GBH (some of them apply to AGN too):

is the disc really truncated in the low state?

is the hard X-ray emission in the different states due to a hot

corona, or a jet?

is the broad line really relativistic (vs. Comptonization)

is the hard emission thermal or not thermal?

is the accretion an ADAF in the quiescent state/LLAGN?

Accretion physics in AGN Accretion physics in AGN

Haardt (1997)

Corona geometry via polarimetry (geometrically thick, optically thin disks should not be polarized, while accretion disk coronae should be (Haardt & Matt 1993; Poutanen & Vilhu 1994; Schnittman & Krolik 2010)

Nature of the primary X-ray emission in both highly accreting BH and starved BH (GBH in quiescence/LLAGN)

- Corona physical parameters (T, ) via broadband spectroscopy

Dovciak et al. (2008)

StrongStrong gravitygravity and black hole spin and black hole spin

a=0

Fabian et al. (2000)

Li et al. (2005)

a=1

a=0.,0.5, 0.9, 0.999

Different, independent methods (line profile,

continuum shape, rotation of the polarization angle) can be

applied simultaneously to estimate the black hole spin

The broad band is required !!!

Our own SMBH in a contextOur own SMBH in a context

Sgr A* as a (very) low luminosity accreting BH:

What is the accretion mode?

Does it experience episodes of much larger activity?

~2x1033 erg/s

The strange case of Sgr The strange case of Sgr B2B2SgrB2 is a giant molecular cloud at

~100pc projected distance from the SgrA*, with a radius of 7 pc (3’.5)The spectrum of SgrB2 is a pure The spectrum of SgrB2 is a pure reflection spectrumreflection spectrum

Reflection of what? No bright enough source is there !!!

INTEGRAL Image of GC (Revnivtsev 2004)

The emission from SgrB2 is extended and brighter in the direction of the BH (Murakami 2001).

Is SgrB2 echoing past emission from the BH, which was then active in the past (e.g. Koyama et al. 1996) ???

Sunyaev et al. 1993

Was the GC an AGN a few hundreds Was the GC an AGN a few hundreds years ago?years ago?

X-ray polarimetry can definitively proof or reject this hypothesis. SgrB2 should be highly polarized with the SgrB2 should be highly polarized with the electric vector perpendicular to the line connecting electric vector perpendicular to the line connecting the two sources. the two sources.

Reid et al. (2009)

Measurable with NHXM!

What is the accretion What is the accretion mode?mode?

Narayan et al. (1997)

Is the ADAF the actual accretion mode? is there a difference in the accretion mode

during quiescence and flares?

Is ADAF the accretion mode in low

luminosity AGN?

Sensitive spectroscopy in hard

X-rays is needed!!

A 18-months scientific ASI Phase B study started in December 2009 with A 18-months scientific ASI Phase B study started in December 2009 with the following aims:the following aims:

• Optimize the mission profile

• Streamline the scientific payload requirements and configuration

• Look for strong and significant international collaborations (in the framework

of an Italian-led missions)

• Characterise the background in the new orbit and its impact on the focal plane cameras

• Obtain final scientific design of various payload items and of the mirror optical design

• Development of the front-end electronics (VELA) for the DepFET detectors

• Start the development of a pixelated High Energy Detector in CdTe

• Development of a focal plane camera design, including and anticoincendence system

20

Present statusPresent status

• Simbol-X was shut down, but the discovery space of an Simbol-X-like mission is still extremely wide; it will be further enhanced by the addition of simultaneous imaging polarimetry

• This is achievable by the medium-size NHXM project, exploiting already available technology in mirror and detector manufacturing, well within the next decade

• Both technologies have old and strong roots in Italy, building up on the BeppoSAX, INTEGRAL & XMM heritage

• Strong interest has been expressed also by other International Institutes

• NHXM science will strongly benefit from earlier hard X-ray focusing missions NuSTAR and ASTRO-H and from the polarimetric GEMS mission.

NHXM will be a good precursor for IXONHXM will be a good precursor for IXO

SummarySummary