The erosita All-Sky Survey and possible synergisms with SPHEREX M.Salvato, for the erosita collaboration
Outline Why surveying the (extragalactic) X-ray sky erosita on SRG: Scientific drivers and perspectives: Comparison with other X-ray surveys Expectations for Clusters and AGN erosita/spherex erosita Science Book Merloni t al. 2012 (arxiv:1209.3114) www.mpe.mpg.de/erosita
erosita Main science driver: Cluster Cosmology and the growth of LSS ESA/Planck, z > 1000 Millennium Simulation Vikhlinin et al. 2009 time A signature of clusters is the existence of hot (~10 7 K) ICM Clusters of galaxies are the largest gravitational bound structures, sensitive tracers of LSS Cosmological constraints with (well calibrated) ROSAT samples of <100 obj. Not simply a deeper ROSAT survey! erosita: ~100,000 galaxy clusters total Peak at z ~ 0.3, M 500 ~ 10 14 M sol X-ray data alone will give: Sky position, Spectrum (flux, T X, z, abundances..), Morphology (R 500, z, M gas, substructures )
The erosita instrument PI: Peter Predehl; PS: A. Merloni (MPE) www.mpe.mpg.de/erosita 7 identical telescopes (Wolter- I/ pnccd- cameras) 54 nested mirror shells Focal length 1.6 m F.o.V. = 0.81 sqdeg Total weight ~800 kg Images credits: MPE HEW on axis ~16.5, survey average ~26 Energy range: 0.3-10 kev Spectral energy resolution: 138 ev @ 6 kev (~XMM)
More than the successor of ROSAT Effective area Instrument grasp On-Axis Effective area [cm2] Average Effective area x FOV[cm2deg2] Energy[keV] Energy[keV] Effective area at 1keV comparable with XMM Newton (1400 cm2) But! Factor ~7-8 larger surveying speed 5
A fast surveys machine ~4 4 years dedicated to all sky survey (with estimated 70-80% efficiency)
erosita on SRG: The mission ART-XC IKI erosita MPE Navigator NPO Lavochkin - erosita hardware/calibration/assembly/tests almost over. - Launch: Fall 2017 from Baykonour (Zenit+Fregat) - 3 Months: flight to L2, verification and calibration phase - 4 years: 8 all sky surveys erass:1-8 (scanning mode: 6 rotations/day) - 3.5 years: pointed observation phase, including ~20% GTO. 1 AO per year - Proprietary data rights shared 50/50 between MPE (Germany) and IKI (Russia) German (MPE) half: proprietary period maximum 2 yrs Periodic Release of German all-sky data
erosita Extragalactic sky Image credits: MPE, erosita_de consortium, XMM-XXL Wide-area census of galaxy clusters (10 5 ) and active galactic nuclei (10 6 )
erosita SurveyS in context Point sources (AGN) Extended sources (Clusters) erass:1 All sky: ~10-14 (0.5-2 kev) [erg/cm 2 /s] 2 10-13 (2-10 kev) [erg/cm 2 /s] Poles: 3x10-15 (0.5-2 kev) [erg/cm 2 /s] 4 10-14 (2-10 kev) [erg/cm 2 /s] All sky: 3.4 x 10-14 (0.5-2 kev) Poles: 1.1 x 10-14 (0.5-2 kev) Merloni et al. 2012
erosita will detect ~100k clusters with >50 net counts Pacauld,Clerc+2015 Log Mass (solar masses) 15 15 14 14-2 -1 0 Log redshift ~ 1,700 clusters with precise Temperature (to <10%), up to z~0.08 ~23,000 clusters with accurate redshift determination, up to z~0.45 will detect all massive clusters as z<1, reaching higher z and lower masses at the poles Borm et al. 2014; Pillepich et al2012
even more AGN (~3 million) L* For log LX>45 @z~1 > 10 6 cts @ 4-20 kev (r For log LX>45 @z~3 > 10 6 cts @2-8 kev(rf) erosita will cover uniformly the redshift range 0<z<3 Ideal! Large samples available to study AGN at different L, z, N H, M *, SFR, stacked AGN templates vs. L-z ; X-ray Baldwin effect; Narrow/Broad Iron Kα emission line M.Salvato, vs. LX SPHEREX, and Pasadena more 2016
erosita un/obscured AGN: 30000sqdeg erass:8, all-sky using XBG models from Gilli+07 Total NH>10^21 At 0.5-2keV: 0.2-0.5/sqdeg CT AGN 6000-15000 all sky (Akylas+12)
erosita sources: Can we follow them up? D/R split SDSS DES IKI(R) Image courtesy of K. Nishikawa (NAOJ)
What SPHEREX can do for erosita point-like sources Improve on multi wavelength association
Go Red! By construction, AGN easier to pick up at redder bands. Number of sources in 1.6 sqdeg i band 25mag Irac ch1 24mag 1E+06 3E+05 In optical, easier to pick up the wrong counterpart to an X- ray source Number of sources in erosita circle ~15 ~5 All-sky better than patchwork for (homogeneity)
Wise colors and magnitude prior for ROSAT/eROSITA ctps Salvato,Buchner+ New Bayesian code based on Budavari & Szalay (2008) applicable to N catalogs simultaneously, possibility to use PRIORS (Magnitude, colors ) 11643 ROSAT ctp in DR12 9026 QSO 240 AGN 2200 GAL with Em.Lines 280 Stars eboss/spiders (P.I: Merloni, Nandra): ~8,000 new redshifts of RASS & XMMSL AGN (~complete for r>17 RASS sources) erosita follow-up over a ~2000 deg2 area in NGC: reach >80% completeness for erass:4 (~50,000 spectra) Dwelly, Salvato+ 2016 The Code works!
erosita_de and MOS: Future South: VISTA/4MOST (2021-2026) 4MOST is in the south ;-) 4MOST will confirm clusters up to z~1, (while SPIDERS only goes to z~0.6) 4MOST will be able to pack fibers more closely to be able to confirm clusters (dense in their core) SPHEREX will make our associations more secure for the fainter Xray sources! and obscured AGN Complete, systematic follow-up of both Clusters and AGN from erosita: reach >80% completeness for erass:8 VISTA ~700k AGN spectra 0<z<6 1.4M galaxies in ~60k X-ray selected clusters
What SPHEREX can do for erosita point-like sources Improve on multi wavelength association and identification of obscured AGN improve on SED fitting (photo-z)
96 bands will improve photoz in high-z sources see e.g. Alhambra, newfirm, J-pas and more Hsu, Salvato+ 2014 (see also e.g.cardamone+10, Salvato+09) This is true for every kind of galaxy, not only for those hosting an AGN!
Once that association and redshifts are correct, then you can: improve on stellar masses select obscured AGN at high-z via specific em.lines SED stacking analysis for specific X-ray subsamples (and viceversa) Variability (transients, changing look AGN at high-z)
For erosita clusters: identification of over-densities (to be tested) photoz in sky region without other multi wavelength data available improved stellar mass computation X-ray properties of mass-selected samples
Wishes list (for the moment): Deblended photometry using PS, DES positional priors Tool for repeating the process for surveys to come of for specific areas of the sky. Addition of Galex (for rejecting false high-z solutions in photoz), VHS/UKIDSS (for the continuum below the emission lines)
PI: Peter Predehl; PS: A. Merloni (MPE) Core Institutes (DLR funding): MPE, Garching/D Universität Erlangen- Nürnberg/D IAAT (Universät Tübingen)/D SB (Universität Hamburg)/D Astrophysikalisches Institut Potsdam/D erosita collaboration Industry: Media Lario/I Mirrors, Mandrels Kayser- Threde/D Mirror Structures Carl Zeiss/D ABRIXAS Mandrels Invent/D Telescope Structure pnsensor/d CCDs IberEspacio/E Heatpipes Associated Institutes: RUAG/A Mechanisms MPA, Garching/D HPS/D,P MLI IKI, Moscow/Ru + many small companies USM (Universität München)/D AIA (Universität Bonn)/D MPE: Scientific Lead Institute, Project Managment Instrument Design, Manufacturing, Integration & Test Data Handling & Processing, Archive etc.