Randall Smith (NASA/GSFC)

The X-ray Universe 2008 – Granada Opening the window of x-ray spectroscopy Randall Smith (NASA/GSFC)

Constellation-X Science Objectives Black Holes Observe hot matter spiraling into Black Holes to measure their spin and test the effects of General Relativity Trace their evolution with cosmic time, their contribution to the energy output of the Universe and their effect on galaxy formation Large Scale Structure Use clusters of galaxies to trace the locations of Dark Matter and follow the formation of structure as a function of distance Search for the missing baryonic matter in the Cosmic Web Cycles of Matter and Energy Study dynamics of Cosmic Feedback (outflow of mechanical energy, radiation, and chemical elements from star formation and black holes to the interstellar and intergalactic medium) Study the creation and dispersion of elements in supernovae, the equation of state of neutron stars, stellar activity, proto-planetary systems and X-rays from solar system objects

Mission Implementation • 4 Spectroscopy X-ray Telescopes (SXTs) each consisting of a Flight Mirror Assembly and a X-ray Microcalorimeter Spectrometer (XMS) • Covers the band-pass from 0.6 to 10 keV • Angular resolution requirement of 15 arc sec (goal of 5 arc sec HPD) • Field of View 5 x 5 arc min (64x64 pixels, goal of 10 x 10 arc min FOV) • Count rates: 1/4 crab or 1,000 ct/sec/pixel at full energy resolution with low dead-time.

Mission Implementation 4 Spectroscopy X-ray Telescopes 1.3 m • 4 Spectroscopy X-ray Telescopes (SXTs) each consisting of a Flight Mirror Assembly and a X-ray Microcalorimeter Spectrometer (XMS) • Covers the band-pass from 0.6 to 10 keV • Angular resolution requirement of 15 arc sec (goal of 5 arc sec HPD) • Field of View 5 x 5 arc min (64x64 pixels, goal of 10 x 10 arc min FOV) • Count rates: 1/4 crab or 1,000 ct/sec/pixel Flight Mirror Assembly Representative Gratings • Two additional systems extend the bandpass: • X-ray Grating Spectrometer (XGS) covers from 0.3 to 1 keV (included in one or two SXT’s) • Hard X-ray Telescope (HXT) band-pass covers from 6 to 40 keV (not shown) • All instruments operate simultaneously XGS CCD Camera X-ray Microcalorimeter Spectrometer (XMS)

X-ray Micro-calorimeter array layout • Central, core array: • Individual TES • 32 x 32 array with 5 arc sec pixels • 2.75 arcmin FOV • 2.5 eV resolution (FWHM) • Fast (~ 300 sec time constant) • Outer, extended array • 4 absorbers/TES • Extends array to 64 x 64 pixels (4096) with 1792 readout channels • 5.5 arcmin FOV • < 10 eV resolution • 1-2 msec time constant 5.5 arcmin

Micro-calorimeter Progress Multiplexed Readouts are essential to reduce the number of amplifiers • Demonstrated a 2 x 8 time division readout with a spectral resolution of ~3 eV average (~2.6 eV best pixel) For outer part of array require position sensitive arrays • fabricated and tested the first Position Sensitive TES’s with spectral resolution 5 eV (meets requirement of <10 eV) NIST MUX facility with GSFC TES TES mulitiplexing Energy resolution of 2.6 eV Position Sensistive TES Arrays

Enabling Technology: Thin, Segmented X-ray Mirrors • Efficient X-ray imaging requires grazing incidence mirrors • Precisely figured hyperboloid/paraboloid surfaces • The angular resolution state of the art is Chandra with 0.5 arc sec • Small number of thick, highly polished substrates leads to a very expensive and heavy mirror with modest area • Constellation-X requires a collecting area at least an order of magnitude larger than Chandra • 15 arc sec angular resolution requirement (5 arc sec goal) • Lightweight segmented approach based on ASCA and Suzaku technology • 10,000 thin glass reflectors, shaped to the correct figure

Technology Progress: X-ray Telescope Demonstrated < 15 arc sec angular resolution of thin glass mirror segments with X-ray test Error budget understood and now working towards 5 arc sec mission goal NuSTAR will utilize Con-X glass forming process and in doing so demonstrate production line approach with 3,000 glass pieces at GSFC X-ray image 14.7 arc sec HPD as predicted by optical metrology Mirror segment pair on cradle in GSFC X-ray test facility NuSTAR optic

X-ray Grating Spectrometer (XGS) • XGS key requirements: • Effective area >1000 cm2 from 0.3 to 1 keV (or even 1.25 keV) • Spectral resolving power >1250 over full band • Two concepts under study for the grating arrays: • Blazed transmission fixed grating • Off-plane deployed reflection grating • CCD detectors: • Back-illuminated (high QE below 1 keV), • Fast readout with thin optical blocking filters Deployed reflection gratings Colorado Fixed blazed gratings MIT

Constellation-X Science Objectives Black Holes Observe hot matter spiraling into Black Holes to test the effects of General Relativity Trace their evolution with cosmic time, their contribution to the energy output of the Universe and their effect on galaxy formation Large Scale Structure Use clusters of galaxies to trace the locations of Dark Matter and follow the formation of structure as a function of distance Search for the missing baryonic matter in the Cosmic Web Cycles of Matter and Energy Study dynamics of Cosmic Feedback (outflow of mechanical energy, radiation, and chemical elements from star formation and black holes to the interstellar and intergalactic medium) Creation and dispersion of the elements in supernovae, The equation of state of neutron stars, Stellar activity, proto-planetary systems and X-rays from solar system objects

Black Hole Questions Addressed by Constellation-X • What are the demographics of black hole spin? • How did black holes form/grow? (MBH vs s) • Is spin an important energy source? • Is General Relativity the correct theory of gravity in the strong-field regime? • How does accretion actually work? • Does MHD turbulence drive disk accretion? • How do accretion disks drive jets? • How does “Quiescent Accretion” differ?

Primary method… measure black hole spin using the width/profile of the broad iron line… Rapidly-spinning Non-spinning KERRDISK model Brenneman & Reynolds (2006) • Feature : Spin measurement independent of mass or distance • Theoretical assumption : X-ray reflection / iron line emission truncates at the innermost stable circular orbit (ISCO conjecture).

Con-X simulation with 1 million photons in 2-10keV bandConstrains a>0.90 for amodel=0.95 15ks observation of broad Fe line for F2-10keV=510-11 erg/s/cm2 • Need fewer counts if… • Iron is super-solar (e.g., as in MCG-6-30-15) • Emission is centrally concentrated • z>>0 15ks for F2-10keV=510-11 erg/s/cm2 EW=180eV, r-3

Disk hugging corona : orbiting hot spots Iron line intensity as function of energy and time. Arcs trace orbits of disk material around black hole… can be compared with predicted GR orbits Con-X simulation (assuming 3x107 Msun black hole) Theoretical Armitage & Reynolds (2003)

Keplerian orbit of a single “hot spot” a=0.98 i=30o R=30 R=3 R=2.5 R=6 R=15

A procedure for testing GR… • Fit each track for (r,a) assuming Kerr metric • Kerr metric  a(r)=constant r=3rg; a=0.95; M=3107 Msun

Black Holes & Accretion Disks • Theory: Magnetic turbulence drives disk accretion • But how to prove it? • Magnetic fields also drives winds… • Magnetic winds originate close to black holes, are dense, and should be variable on short (dynamical) timescales. • Need resolution, collecting area  Constellation-X.

Black Holes & Accretion Disks • Theory: Magnetic turbulence drives disk accretion • But how to prove it? • Magnetic fields also drives winds… • Magnetic winds originate close to black holes, are dense, and should be variable on short (dynamical) timescales. • Need resolution, collecting area  Constellation-X. • We can detect wind absorption lines in just 3 seconds. • 3 seconds is the orbital period at 200 R_Schwarzschild. • Only magnetic winds can originate there. • Black holes are arguably “cleaner”, but many neutron stars and white dwarf disks can be studied in the same way.

Where are the Baryons: Searching in the UV and X-ray Bands • Many of the predicted baryons have notbeen detected in the local Universe • Most are thought to reside in a hot 106 – 107 K intergalactic medium • Major challenge is to detect this warm-hot intergalactic medium The Constellation-X Advantage: Large area (XMS), High resolution (XGS) and >10× the line resolving power of Chandra and XMM-Newton

How Many Filaments are There? Cen & Fang 2006

Plasma Diagnostics with Constellation-X The Constellation-X energy band contains the K-line transitions of 25 elements allowing simultaneous direct abundance determinations using line-to-continuum ratios X-ray spectroscopic workhorse: the He-like triplet  density and temperature diagnostics A Selection of He-like Transitions Observed by Constellation-X The spectral resolution of Constellation-X is tuned to study the He-like density sensitive transitions of Carbon through Zinc

How do clusters form and grow?(how is the gas heated and enriched in heavy elements)? • Merger processes that form clusters have kinetic energies up to 1063 -1064 ergs and are the most energetic events since the Big Bang, • Major mergers have variations in gas velocity and gas is hot (e.g., the Bullet cluster: 3000- 4000 km s-1 ; Markevitch et al. 2002) • With high-throughput, spatially-resolved spectroscopy with the calorimeter, Con-X can determine subcluster velocities and: • Measure redshifts of subclusters from X-ray spectra (LOS velocity) • Measure velocity in plane of sky from shocks or density/temperature jumps across cold fronts

How do more typical minor cluster mergers proceed? Temperature Map Ascasibar & Markevitch (2006) • Supersonic mergers like the Bullet cluster merger are relatively rare: more common are minor mergers • Minor mergers cause “sloshing” and cold fronts. • Con-X will observe velocity differences on the scale of ~200-300 km/s, which is the expected scale in these mergers (e.g., Ascasibar & Markevitch 2006) -- bringing observational tests to models of how structure is formed.

Nucleosynthesis and Explosion Mechanisms in Supernovae through Con-X studies of Supernova Remnants Core Collapse SNe • ~ 3/4 of all SNe • M(progenitor) > 8 solar masses • Predominant producers of O, Ne, Mg • Leave compact remnants • Gaseous remnants highly structured and asymmetric • Precise explosion mechanism unknown Thermonuclear SNe • ~ 1/4 of all SNe • White dwarfs that grow to near the Chandrasehkar mass • Predominant producers of Fe • Gaseous remnants relatively symmetric • Progenitor systems and precise explosion mechanism unknown

Tycho: Con-X Simulations Chandra Con-X sim Well sampled spectra, on scale of Con-X PSF. Remnant size and characteristic knot size well matched to 15” HPD.

NGC 891 A 50 ks simulated observation of the hot halo gas in the edge-on spiral galaxy NGC 891. The solid line shows 0.3 keV gas model shifted by 600 km/s (assuming halo circular velocity of 300 km/s based on disk measurements). Dark Matter Distribution in Spiral Galaxies • Rotation curves of cold gas and stars prove existence of dark matter halos. Since stars and gas are confined to the plane of the galaxy, the rotation curves probe only 2D distribution of dark matter • By measuring the T and r distribution of hot gas surrounding the galaxy, as well as its rotational velocity, the 3D distribution of dark and luminous matter in the galaxy can be determined • Expected rotation velocities are ~ 300 km s-1 - well within Constellation-X capabilities Credit: Diana Worrall

Does the metal-enriched gas in starburst superwinds escape? • Heavy elements created in stars & supernovae end up in hot, X-ray emitting, gas seen in superwinds (106 K < T < 108 K). • Ejected metals may be the source for the metals of the Intergalactic Medium (IGM),. • Proving that starburst superwinds can eject metals into the IGM requires measurements of the velocity of the hot metal-enriched gases • Con-X will measure gas velocities in superwinds. Current X-ray telescopes lack the necessary spectral resolution. The starburst galaxy M82 and its superwind as seen by the three Great Observatories. Chandra ACIS-S thermal X-ray emission (blue); Spitzer 8μm (red);HST ACS Hα+[N II] (yellow);HST ACS B-band (cyan) [image credit: Hubble Heritage/NASA].

Velocity measurements in superwinds with Con-X • Hydrodynamical simulations of superwinds predict soft X-ray emission from gas with 400 km/s < v (km/s) < 2000 km/s • Escape velocities for local superwind galaxies and Lyman Break Galaxies with M* > 1010 Msun are in the range 300 – 700 km/s. • In 100 ks exposures, in the faintest regions of currently-detected superwinds, Con-X calorimeter can measure: • individual X-ray line redshifts: σv ~ 30-90 km/s • Con-X will able to map the velocity as a function of position in nearby superwinds of different mass, allowing us to test whether vX > vescape as a function of galaxy mass. Simulated Con-X XMS spectrum of a small region within a superwind For any line with > 40 counts the line redshift can be determined to the accuracy shown above.

The two order of magnitude increase in capability of Constellation-X is well matched to that of other large facilities planned for the 2010-2020 decade JWST LST X-ray ALMA Constellation-X Constellation-X: A future astrophysics great observatory IR Sub-mm GSMT Optical

Summary • Constellation-X is a facility class observatory that opens the window of X-ray spectroscopy with a two order of magnitude gain in capability that will make major advances in the study of virtually all classes of astrophysical objects, and will specifically: • Follow the formation of large scale structure through observations of clusters of galaxies and search the Cosmic Web to find the missing hot Baryons • Study the processes that drive Cosmic Feedback, the formation of the elements and their distribution throughout the Universe • Revolutionize our understanding of how Black Holes evolve with cosmic time, and observe matter orbiting close to the event horizon • We are realizing the payoff from many years of well focused technology investments and mission implementation studies that demonstrate the mission is ready to proceed • We are poised to make a robust case to the upcoming decadal survey that Constellation-X is the highest priority for the next large astrophysics observatory • http://constellation.gsfc.nasa.gov

Randall Smith (NASA/GSFC)

Randall Smith (NASA/GSFC)

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