The Wide Field Xray Telescope Andrew Ptak NASAGSFC

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The Wide Field X-ray Telescope Andrew Ptak (NASA/GSFC) for the WFXT team http: //wfxt.

The Wide Field X-ray Telescope Andrew Ptak (NASA/GSFC) for the WFXT team http: //wfxt. pha. jhu. edu

Why WFXT? The only soft X-ray all-sky survey has been the ROSAT All-Sky Survey

Why WFXT? The only soft X-ray all-sky survey has been the ROSAT All-Sky Survey (RASS) Chandra and XMM-Newton are not survey instruments e. Rosita is slated to launch in 2017 but has ~ 30” avg. PSF Athena WFI will have 1. 4 -2 m 2 eff. area but will have a 40’ FOV and may only spend ~ 1 year on surveys Brandt & Alexander (2015) We need a dedicated survey mission to cover large areas (> 100 sq. deg. ) with flux depths matched to LSST and WFIRST: WFXT would be the X-ray SDSS

XB oo t es WFXT: The SDSS for X-rays na Athe AGN

XB oo t es WFXT: The SDSS for X-rays na Athe AGN

Typical X-ray Survey Exposure Maps XMMCOSMOS AEGIS-X XMM-XXL Survey (PI: Pierre) Full XXL area

Typical X-ray Survey Exposure Maps XMMCOSMOS AEGIS-X XMM-XXL Survey (PI: Pierre) Full XXL area = ~ 50 deg 2 WFXT

e. Rosita Will be launched as part of Russian Spektrum Roentgen Gamma (SRG) satellite

e. Rosita Will be launched as part of Russian Spektrum Roentgen Gamma (SRG) satellite to L 2, planned for Feb 2017 Will detect ~ 105 clusters, 106 AGN 27” HEW FOV-averaged spatial resolution 0. 75 deg. FOV effective area ~ 2 X XMM-Newton WFXT

WFXT Key Features Constant PSF (<= 5” HPD) across 1 degree FOV 2 Effective

WFXT Key Features Constant PSF (<= 5” HPD) across 1 degree FOV 2 Effective area ~ 15 X Chandra at 1 ke. V (goal 10000 cm ) Bandpass: ~ 0. 4 -7 ke. V Dedicated survey mission, calibrated data products released with no proprietary period Science goals: discovery and characterization of groups and clusters up z~1 -2, evolution of AGN and growth of earliest AGN, star forming galaxies traced up to z>1, halo stars, SNR and compact Galactic objects Will serve as a target finder for future X-ray missions

Grasp = Aeff x FOV measured at 1. 5 ke. V in cm 2

Grasp = Aeff x FOV measured at 1. 5 ke. V in cm 2 deg 2 Grasp measures survey speed Better angular resolution results in better efficiency and source identification. WFXT Athena e. ROSITA ROSAT XMM Chandra Grasp 5000 -9000 1150 630 900 50 HPD (“) 3 -5 5 27 25 -60 15 -25 1 -5

WFXT Surveys = 3000 X C-COSMOS = 1000 X CDFS

WFXT Surveys = 3000 X C-COSMOS = 1000 X CDFS

XMM COSMOS survey (2 deg 2) (Cappelluti et al. 2009) XMM - 1. 5

XMM COSMOS survey (2 deg 2) (Cappelluti et al. 2009) XMM - 1. 5 Msec 1 deg

Chandra COSMOS survey (1 deg 2) (Elvis et al. 2009) Chandra - 1. 8

Chandra COSMOS survey (1 deg 2) (Elvis et al. 2009) Chandra - 1. 8 Msec Bands (ke. V) [0. 5 -2] [2 -4. 5] [4. 5 -7]

WFXT simulation (one tile from the medium survey) WFXT - 13 Ksec Bands (ke.

WFXT simulation (one tile from the medium survey) WFXT - 13 Ksec Bands (ke. V) [0. 5 -1] [1. 0 -2] [2. 0 -7]

The Bullet cluster (z=0. 3, T=14 ke. V) observed with WFXT Deep survey: 400

The Bullet cluster (z=0. 3, T=14 ke. V) observed with WFXT Deep survey: 400 ksec z=0. 5 z=1. 0 z=1. 5 10’ Joana Santos (INAF, Osservatorio Astrofisico di Arcetri) and the WFXT Team

Survey Spatial Resolution • • • Improve sensitivity for point and extended sources, AGN/cluster/group

Survey Spatial Resolution • • • Improve sensitivity for point and extended sources, AGN/cluster/group discernment at any redshift Minimize source confusion, especially in Deep survey Efficient identification of optical counterparts, Chandra-like id accuracy (<1” radius error circle, >90% correct IDs), essential for 5 x 106 AGN and 2× 105 clusters Detect sharp features of the ICM (shocks, cold fronts, cavities) Resolve cool cores of z>1 clusters (essential for cosmological applications, reliable mass proxy) WFXT

Telescope Design See Pareschi et al. Poster discussing technique to reach WFXT area and

Telescope Design See Pareschi et al. Poster discussing technique to reach WFXT area and Fo. V requirements with a FOVaveraged HPD < 5” The Wolter New Process design with short segments will enable < few arcsec on-axis performance with < 5” over much of the Fo. V WFXT

Segmented Optics Courtesy of W. Zhang (GSFC) Tuesday Jan 20, 2009 WFXT

Segmented Optics Courtesy of W. Zhang (GSFC) Tuesday Jan 20, 2009 WFXT

WFXT Performance Requirements Parameter Requirement Goal Area (1 ke. V) 7, 000 cm 2

WFXT Performance Requirements Parameter Requirement Goal Area (1 ke. V) 7, 000 cm 2 10, 000 cm 2 Area (4 ke. V) 2, 000 cm 2 4, 000 cm 2 Field of View 1 deg 2 PSF HPD 5” 3” Pixel Size ~ 1” (24 μm) ~ 1” Energy Band 0. 2 -4 ke. V 0. 1 -6 ke. V Energy Resolution E/ΔE > 10 E/ΔE > 20 Time Resolution <3 s <1 s WFXT

log. N-log. S AGN dominate source counts down to ~ 10 -17 ergs s-1

log. N-log. S AGN dominate source counts down to ~ 10 -17 ergs s-1 cm-2 , ~ 10000 sources deg-2 AGN can be selected by finding an Xray counterpart but must be careful at Chandra Deep Field depths -> Total Galaxies Lehmer et al. (2012) WFXT

Quasar Surveys Courtesy of G. Richards

Quasar Surveys Courtesy of G. Richards

AGN Z>6 Evolution Very wide range of predictions for z>6 AGN: Observations of significant

AGN Z>6 Evolution Very wide range of predictions for z>6 AGN: Observations of significant samples at z>6 would constrain the physics of early BH formation disentangling between several scenarios e. g. providing info on mass of BH seeds, accretion mechanisms

AGN and Galaxies WFXT surveys will detect ~ 107 AGN, 105 galaxies Athena would

AGN and Galaxies WFXT surveys will detect ~ 107 AGN, 105 galaxies Athena would detect ~ 600, 000 AGN in its 1 -year notional survey (Aird et al. 2013)

High-Z AGN • • Simulated 400 ksec spectrum of highly obscured, high redshift AGN

High-Z AGN • • Simulated 400 ksec spectrum of highly obscured, high redshift AGN NH =1024, Γ=1. 82, EWline =1 ke. V. 530 counts total Strong iron line and allows an accurate redshift determination from the X-ray data alone. • • WFXT Pessimistic case assumes an exponential decline towards high -z in the space density of AGN at all luminosities. Synergistic: Euclid, LSST and WFIRST identify the WFXT sources, WFXT picks out the AGN (especially high-z, obscured)

Synergy with Wide-Area Surveys WFXT is the only X-ray mission that will match, in

Synergy with Wide-Area Surveys WFXT is the only X-ray mission that will match, in area and sensitivity, the next generation of wide-area O/IR and radio surveys z=6 Medium Survey QSO z=6 Deep Survey QSO WFXT

Source Identification (Optical) LSST 10 yr (ugrizy) LSST ~1 wk Pan STARRS (gvrizy) WFXT

Source Identification (Optical) LSST 10 yr (ugrizy) LSST ~1 wk Pan STARRS (gvrizy) WFXT 20, 000 Wide 3000 Medium 100 Deep SDSS (gvriz) CDFS 2 Msec IDs (Luo et al.

Source Identification (NIR) WFIRST HLS 2400 deg 2 Euclid DS 40 deg 2 Euclid,

Source Identification (NIR) WFIRST HLS 2400 deg 2 Euclid DS 40 deg 2 Euclid, 15000 deg 2 VISTA/Viking, 20000 deg 2 20, 000 Wide 3000 Medium 100 Deep VISTA/VHS, 20000 deg 2 WFXT

The potential of a WFXT survey With 13 ks: ~L* clusters at 13 ksec

The potential of a WFXT survey With 13 ks: ~L* clusters at 13 ksec exposure z=1. 6 detected with ~ 500 counts. With 400 ks: the simulated Spiderweb cluster detected 4 with > 10 counts. Redshifts measured with ~600 counts for the 17 Proto-cluster at z=2. 1 (400 ksec) brightest z=1. 6 clusters in this field Completely X-ray based cluster redshift survey!

The potential of a WFXT survey With 13 ks: ~L* clusters at 13 ksec

The potential of a WFXT survey With 13 ks: ~L* clusters at 13 ksec exposure z=1. 6 detected with ~ 500 counts. With 400 ks: the simulated Spiderweb cluster detected 4 with > 10 counts. Redshifts measured with ~600 counts for the 17 Proto-cluster at z=2. 1 (400 ksec) brightest z=1. 6 clusters in this field Completely X-ray based cluster redshift survey!

Science with WFXT: Clusters of galaxies Not just a cluster counting machine: • •

Science with WFXT: Clusters of galaxies Not just a cluster counting machine: • • Characterize ICM properties and measure mass proxies for thousands of clusters at z>1. • • Trace the epoch of entropy injection and metal enrichment of the ICM. • • Study the intense dynamics of proto-cluster assembly at z~2. • • Multi-λ synergies: a vast scientific legacy for decades to come • • Path finder follow-up studies with ELTs, Athena X-IFU, ALMA, . . .

Science with WFXT: Clusters of galaxies Not just a cluster counting machine: • •

Science with WFXT: Clusters of galaxies Not just a cluster counting machine: • • Characterize ICM properties and measure mass proxies for thousands of clusters at z>1. • • Trace the epoch of entropy injection and metal enrichment of the ICM. • • Study the intense dynamics of proto-cluster assembly at z~2. • • Multi-λ synergies: a vast scientific legacy for decades to come • • Path finder follow-up studies with ELTs, Athena X-IFU, ALMA, . . . ROSAT WFXT z>1 XMM, Chandra z>1

WFXT Cluster sample Cluster counts (Medium + Deep Surveys) Detection: 50 -100 counts T

WFXT Cluster sample Cluster counts (Medium + Deep Surveys) Detection: 50 -100 counts T measurements: 1500 counts T profiles: 15, 000 counts Temperatures critical to cluster cosmology Profiles, cluster physics, exclude central region Large samples allow study of systematics >3, 000 clusters at z>0. 5, from which z can be measured from Fe line WFXT can reach into early groups

AGN X-ray variability with WFXT The 4 Ms CDFS dataset (courtesy of M. Paolilo)

AGN X-ray variability with WFXT The 4 Ms CDFS dataset (courtesy of M. Paolilo) WFXT Deep survey: 400 ks per field, 100 sq. deg - will allow to sample homogeneously broad range of masses and timescales. 30% fluctuations typical in CDFS.

Wide range of science X-ray counterparts to a. LIGO detections GRB afterglows (including orphan

Wide range of science X-ray counterparts to a. LIGO detections GRB afterglows (including orphan / off-axis) Halo stars LMXB and HMXB populations SNR remnants Obscured accretion at high-z Cluster physics: Fe abundance in the ICM, evolution of cool cores in clusters and feedback, low SB regions in the outskirts of clusters Solar System Science Dark Matter search (e. g. , Zandanel et al. 2015) …

WFXT Telescope Layout 3 Telescope Design WFXT was studied by the MSFC Advanced Concepts

WFXT Telescope Layout 3 Telescope Design WFXT was studied by the MSFC Advanced Concepts Office (ACO) in 2012 Optics design optimized for wide-field (e. g. , Burrows, Burg & Giacconi 1992 polynomial perturbation optics design) Mirror: current state-of-the-art technologies are full-shell optics from MSFC and/or Brera (see Pareschi et al. poster) or segmented optics from GSFC Detectors: CCDs baselined in ACO study but more likely would use APS

WFXT Mission Requirements WFXT

WFXT Mission Requirements WFXT

Mass and Power WFXT

Mass and Power WFXT

Mission Parameters o Chandra-like orbit: 16, 000 x 130, 000 km o LEO also

Mission Parameters o Chandra-like orbit: 16, 000 x 130, 000 km o LEO also would be a consideration for lower background, faster To. O response, impact of LEO orbit assessed in ACO study o Total mass 2200 kg (including propellant and launch vehicle adapter) o Structures sized based on FEM analysis o Reaction wheels sized for 12 deg. / min slew rate o Star trackers + ultra-fine sun sensor give 1” pointing knowledge WFXT

ACO Cost Estimate Component Cost ($M) Spacecraft 163 Instruments 181 Reserves (35%) 120 Operations

ACO Cost Estimate Component Cost ($M) Spacecraft 163 Instruments 181 Reserves (35%) 120 Operations 77 Total 541 Not including launch vehicle, optics assumed to be at TRL 3 -4 WFXT

Design Trades • Including a retractable grating • Cost ~ $100 -200 M •

Design Trades • Including a retractable grating • Cost ~ $100 -200 M • Would recover highly-rated Astro 2010 highresolution spectroscopy science below 2 ke. V not feasible with Athena • Discussed in NASA PCOS 2011 X-ray Mission Concept Study report • Orbit: LEO vs Chandra-like • Optics Technology: segmented vs full-shell optics WFXT

Conclusions • Current soft X-ray surveys consist of the RASS, shallow serendipitous source /

Conclusions • Current soft X-ray surveys consist of the RASS, shallow serendipitous source / slew surveys (~ hundreds of sq. deg. ), medium-deep surveys (several sq. deg. ), Chandra deep fields (< 1 sq. deg) that probe cluster, AGN and galaxy evolution, AGN absorption, black hole growth, etc. • Current X-ray satellites limited by FOV and/or background, primary pointed missions • e. Rosita will survey soft X-ray sky at ~ 10 X RASS sensitivity, will detect ~ 10 5 clusters, ~ 106 AGN, 103 -4 galaxies • Athena WFI baseline is to spend ~ 1 year surveying <~ 100 deg 2 • WFXT will survey soft X-ray size at ~ 10 -100 X e. Rosita sensitivity (due to higher grasp, sharper and constant PSF, longer exposures) truly matching deep survey sensitivities for LSST, Euclid and WFIRST • will detect ~ 106 clusters, ~ 107 AGN, 104 -5 galaxies • WFXT