What matter(s) around galaxies? Shining a bright light on the cold phase of the CGM Cantalupo et al., Nature , 2014 Sebastiano Cantalupo ETH Zurich In collaboration with: MUSE GTO Team (ETH, CRAL, Leiden, AIP, Toulouse, Gottingen) + Cosmic Structure Formation group at ETH & J. Xavier Prochaska, Sammy B. Slug, Piero Madau, Fabrizio Arrigoni-Battaia, Joe Hennawi , Martin Haehnelt Sebastiano Cantalupo – What Matter(s) Around Galaxies - June 2017 14/06/2007
Talk Outline & Key Questions What are the morphological and physical properties of the CGM on both small and large scales? (key questions #2 and #3) Introduction: detecting the CGM/IGM in emission Observational surveys (NB, MUSE, MOSFIRE) and inferred properties of the CGM Cantalupo et al., Nature , 2014 How do galaxies affect cooling in the CGM? (key question #4) Open questions/Summary Sebastiano Cantalupo – What Matter(s) Around Galaxies - June 2017 14/06/2007
Detecting Cosmic Gas “Classical” approach: in absorption. quasar • pro: ability to detect low-density gas including metals. • con: typically only 1D information (or sparse 2D) LLS/DLAS = “Dark” galaxies? Filaments? IGM? CGM? ... difficult to say without direct detection. Direct detection in emission : Fluorescent Ly α ( Hogan & Weymann 1987;Gould & Weinberg 1996; Zheng & Miralda-Escude 2005; Cantalupo+05,07; Kollmeier+06,10; Cantalupo+12 ) external fluorescent QSO ionizing flux emission fluorescent emitters HI HI Absorption part (1D info) ionized region HII recombina- (HII) tions Self-shielded gas (slab): “mirror” emission -> ~60% of incident ionizing radiation “converted” to Ly α (but see Cantalupo+05). Fully ionized gas: proportional to gas density squared. Sebastiano Cantalupo – What Matter(s) Around Galaxies - June 2017 14/06/2007
How bright is fluorescent emission: simulations Simulated Ly α images at z~2.5 (20Å NB; no noise/PSF) centred on a ~10 13 M sun halo hydro-simulation (RAMSES) + Radiative Transfer ( RADAMESH , SC+12 ) QSO fluorescence Cantalupo+12 log(SB) (cgs/arcsec 2 ) -17 NB & -18 MUSE 1h MUSE medium -19 MUSE deep -20 MUSE UVB+Stars FOV +QSO UVB+Stars -21 2 4 6 2 4 6 8 8 cMpc cMpc UVB fluorescence 1) Look around bright quasars How to detect it? 2) “Stack” for statistical detection (see Sofia Gallego’s talk) 3) Integrate for 100+ hours away from quasars Sebastiano Cantalupo – What Matter(s) Around Galaxies - June 2017 14/06/2007
Highlights from Narrow-Band imaging survey of Quasar fields at z~2.3 Compact fluorescent emitters without CGM in emission around a bright galaxy stellar counterparts (“Dark galaxies”) SC+12 qso (3’) SC+12 Morphology and SB compatible with “cold filaments” Giant Quasar Nebulae: + other 25 QSOs (FLASHLIGHT Keck+GMOS survey; the Slug 1’ (500kpc) Cantalupo+, in prep.; Arrigoni-Battaia+, in prep.; see next talk) main results: - Giant Nebulae (>100kpc) are rare in NB surveys (<10%) qso - Morphology and “kinematics” compatible with CGM/IGM but SB is too high for expected gas densities —> dense clumps required (see later). Cantalupo+14, Nature Sebastiano Cantalupo – What Matter(s) Around Galaxies - June 2017 14/06/2007
Are Giant Nebulae really rare? A MUSE snapshot survey around z~3.5 QSOs ~350 kpc 45” Targets: brightest radio-quiet QSOs at 3<z<4 (and two radio-loud, R1 & R2) Exposure times: 1h only total integration (“snapshot” survey) “White-light” images obtained by collapsing the datacube along the wavelength direction. Borisova, Cantalupo+, 2016 Sebastiano Cantalupo – What Matter(s) Around Galaxies - June 2017 14/06/2007
MUSE observations of QSOs at z~3.5: 100% detection rate of giant nebulae! ~350 kpc 45” Targets: brightest radio-quiet QSOs at 3<z<4 (and two radio-loud, R1 & R2) Exposure times: 1h only total integration (“snapshot” survey) Optimally extracted pseudo-NB images with QSO PSF-subtraction obtained with CubExactor (Cantalupo in prep.) All nebulae larger than 100 kpc with various morphologies. Borisova, Cantalupo+, 2016 Sebastiano Cantalupo – What Matter(s) Around Galaxies - June 2017 14/06/2007
A 3D view of the Muse Quasar Nebula 3 (MQN03), 350kpc in size: CubExtractor (Cantalupo, in prep.) + VisIt QSO PSF and continuum subtracted cube 350kpc 2 σ ~1x10 -18 cgs/arcsec 2 10A ~ 600km/s Borisova, Cantalupo+, 2016 Sebastiano Cantalupo – What Matter(s) Around Galaxies - June 2017 14/06/2007
2D Velocity maps: - no clear signs of “rotation” (with some exceptions); - radio-quiet nebulae (1-17) are kinematically “narrow”. Borisova, Cantalupo+, 2016 Sebastiano Cantalupo – What Matter(s) Around Galaxies - June 2017 14/06/2007
How do they compare with other Ly α Nebulae and “haloes”? Circularly averaged SB profile “redshift-corrected” average profile (all scaled to z=3) QSO PSF All giant quasar nebulae have similar SB profile and are consistent with fluorescence (including LBG Stack “halo” of Steidel+11) Borisova, Cantalupo+, 2016 Sebastiano Cantalupo – What Matter(s) Around Galaxies - June 2017 14/06/2007
Inferring the cold gas content of the Giant Nebulae: the Slug case Cantalupo+, Nature, 2014 “Photon-pumping / Ly α “Recombination” case scattering” case Observed SB (gas mostly ionized) (gas mostly neutral) cm -2 cm -2 Inferred N(HI) Inferred N(HII) a a b b NB: depends on Clumping Factor M(HII) ~ M(“cold” H) ~ 10 12 M ⊙◉☊ /C 0.5 M(HI) ~ M(“cold” H) ~ 2.5x10 11 M ⊙◉☊ Sebastiano Cantalupo – What Matter(s) Around Galaxies - June 2017 14/06/2007
Comparison with simulations: more IGM “clumps” needed! Simulation (all) Slug Nebula C=1 “ionized” case Subgrid Clumping a Factor (<1kpc) N(H) cm -2 b Text Slug Nebula Slug Nebula C=50 “neutral” case “ionized” case Subgrid Clumping N(H) a a Factor cm -2 (<1kpc) b b Cantalupo+, Nature, 2014 Sebastiano Cantalupo – What Matter(s) Around Galaxies - June 2017 14/06/2007
Breaking degeneracies with non-resonant lines: MUSE HeII search NB (Ly 𝛃 ) c Cantalupo+, in prep. Sebastiano Cantalupo – What Matter(s) Around Galaxies - June 2017 14/06/2007
Extended HeII detected with MUSE from “part” of the Slug (no rotation!): continuum subtracted cube (9h) 12 + CubEx v1.6 (Cantalupo, in prep.) 6 4 2 150kpc 2 σ ~3x10 -19 c cgs/arcsec 2 10A ~ 600km/s Cantalupo+, in prep. Sebastiano Cantalupo – What Matter(s) Around Galaxies - June 2017 14/06/2007
Why is HeII “missing” from the Slug “tail”? 1) “Tail” Ly α emission due to “photon-pumping / scattering” ruled out by MOSFIRE H α (and preliminary MUSE CIII) detection “tail” Ly α spectrum “tail” Ly α /H α ~10 qso b consistent with Case B Recombination H α spectrum Leibler, Cantalupo+, to be sumbitted Sebastiano Cantalupo – What Matter(s) Around Galaxies - June 2017 14/06/2007
Why is HeII “missing” from the Slug “tail”? High densities required HeII/Ly α 2) High densities and larger distances ~0.08 Expected HeII/Ly α ratio 0 -0.5 (a) -1 log (HeII/Ly α ) -1.5 -2 <0.005! data -2.5 D = 50 kpc “single-density” D = 160 kpc clump scenario -3 D = 350 kpc D = 1 Mpc -3.5 -1 0 1 2 3 4 log(nH/cm -3 ) (a) n clump ~10 2 -10 4 cc ! (depending on data actual distance) (b) (b) <n> cold =0.1 cc <n> cold ~1-10 cc if log-normal σ >2.5 “turbulent/lognormal <n> cold =1 cc density distribution” scenario data Cantalupo+, in prep. Sebastiano Cantalupo – What Matter(s) Around Galaxies - June 2017 14/06/2007
Open Questions and Future Directions What sets the frequency , size and luminosity of the giant quasar Nebulae? (quasar lifetime, opening angle, halo mass, redshift, quasar luminosity,…) What is the origin of the IGM/CGM clumps traced by the Nebulae? (thermal/gravitational instabilities, quasar radiation effects,…) How this affects galaxy and QSO formation? (fast gas accretion, violent disk instability,…) Exploring a larger parameter space: - include lower luminosity quasars; - extend the redshift range to 2<z<3 (not possible with MUSE, KWCI required) Improving our theoretical understanding of IGM “clump-formation”: - hydrodynamical and thermal stability analysis (see Ann-Christine Vossberg’s talk); - detailed comparison with observational data. Moving “away” from quasars: - detect “average” Cosmic Web filaments connecting galaxies and illuminated by the cosmic UVB (>50h-deep exposure with MUSE and/or KWCI required). Sebastiano Cantalupo – What Matter(s) Around Galaxies - June 2017 14/06/2007
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