A M U LT I - WAV E L E N G T H V I E W O F LY M A N - A L P H A N - PowerPoint PPT Presentation

A M U LT I - WAV E L E N G T H V I E W O F LY M A N - A L P H A N E B U L A E : S T U DY I N G T H E G L OW I N G C G M I N D E N S E E N V I R O N M E N T S M O I R E P R E S C OT T ( N E W M E X I C O S TAT E U N I V E R S I T Y ) G A B R I E L B R A M M E R ( S T S C I ) , A R J U N D E Y ( N OAO ) , J O H A N F Y N B O ( DA R K C O S M O L O G Y C E N T R E ) , AG NA R H A L L ( N M S U ) , C RY S TA L M A RT I N ( U C S B ) , I VA M O M C H E VA ( S T S C I ) , PA L L E M Ø L L E R ( E S O )

LY M A N - A L P H A N E B U L A E — T H E O P P O RT U N I T Y • Ly 𝛽 nebulae are a unique Q2) What are the window into: morphological and physical properties • the CGM in emission over 10s or 100s of kpc of the CGM? 40 kpc • an active phase of Credit: M. Prescott & galaxy formation Q3) What are the A. Dey 2010 (precursors to galaxy physical processes groups/clusters) that shape the CGM • To leverage this on both large (kpc) opportunity, need to know and small (pc) 80 what is lighting them up scales? kpc — not always obvious! Credit: NASA/CXC/SAO

LY M A N - A L P H A N E B U L A E — T H E C H A L L E N G E AGN • Ly 𝛽 nebulae are challenging to interpret: • in massive halos, messy, energetic regions Cantalupo+2005 Resonant • many processes at Scattering Zheng et al. 2010 work — shock-heating, gravitational cooling, resonant scattering, Mori+2004 and AGN/SF photoionization Millennium Simulation, Springel et al. 2005 • difficult to disentangle, Gravitational given uncertainties in Cooling both data and models Faucher-Giguere+2010 Shock-heating

A M U LT I - WAV E L E N G T H V I E W O F LY M A N - A L P H A N E B U L A E • Using multi-wavelength data on individual Ly 𝛽 nebulae as a window into the CGM in dense regions: • Environment — census of nearby galaxies (& AGN) • Kinematics — map out how the gas is moving • Physical conditions — metallicity, density, source of ionization

A M U LT I - WAV E L E N G T H V I E W O F LY M A N - A L P H A N E B U L A E • Using multi-wavelength data on individual Ly 𝛽 nebulae reveals a more complete picture of the CGM in dense regions: • Environment — census of nearby galaxies (& AGN) galaxy redshifts, multi-wavelength coverage to find AGN • Kinematics — map out how the gas is moving • Physical conditions — metallicity, density, source of ionization

E N V I R O N M E N T: LY M A N - A L P H A N E B U L A E L I V E I N OV E R D E N S E R E G I O N S Steidel et al. 2000 • Environments of Ly 𝛽 nebulae 80 kpc overdense on large (~50 Mpc) scales • Early circumstantial evidence: first examples found in surveys of dense regions (Francis+1999, Steidel+2000) • Subsequent follow-up showed Ly 𝛽 Ly 𝜷 Nebula nebulae: • live in overdense regions (Matsuda +2004,2005, Prescott+2008) • are strongly clustered (Yang+2009) • have low space densities (Saito +2006, Prescott 2009, Yang+2010) (also see Cai+2016, 2017) Prescott et al. 2008

E N V I R O N M E N T: LY M A N - A L P H A N E B U L A E L I V E I N OV E R D E N S E R E G I O N S • On smaller scales, the local environment is overdense • Large population LABd05 z=2.656 of associated galaxies and a Ly 𝜷 nearby obscured AGN x4 • Factor of ~4 galaxy overdensity on ~50-100 kpc scales Prescott+2012b Found a similar situation even in a Ly 𝛽 nebula that was previously thought to be alone…

A “ C O O L I N G ” LY M A N - A L P H A N E B U L A ? LABn06 z=3.157 Nilsson+2006 discovered an • unusual Ly 𝛽 nebula: No associated galaxies ➡ No associated AGN ➡ Surface brightness profile ➡ similar to early “gravitational cooling” model predictions Became known as the “best • candidate for a Ly 𝜷 nebula powered by cold accretion” Nilsson+2006 …because what else could it be?

M U C H H A S C H A N G E D S I N C E T H E D I S C OV E RY • New data - 3D-HST spectra, CANDELS imaging, much improved photo-zs, improved LABn06 z=3.157 IRAC/MIPS fluxes, Herschel measurements • New understanding of AGN identification using MIR, X-ray • New theoretical predictions for Ly 𝛽 nebulae powered by “cold accretion” Drastically changed our understanding of this system - ostensibly the poster child of a gravitationally powered nebula Nilsson+2006

• 7 photo-z neighbors within LY M A N - A L P H A N E B U L A D O E S R<10” and dz<0.15 H AV E A S S O C I AT E D G A L A X I E S • 1 has a grism-z with a faint [OII] detection at the redshift 3D-HST of nebula z=3.157 photo-z / grism-z • Still no visible central galaxy, closest galaxy part of a foreground structure (z=1) Ly 𝜷 • Local region (R<10”) is overdense N gal (per deg 2 per mag) LABn06 NMSU student Agnar Hall Prescott+2015b finding similar results

T H E R E I S A N E A R B Y O B S C U R E D AG N • IRAC/MIPS source with power-law MIR SED, consistent with being an obscured AGN • Lower surface brightness Ly 𝛽 emission encircles obscured AGN • AGN redshift poorly constrained, but Obscured highly suggestive of AGN an association Prescott+2015b

AG N C O M I N G O U T O F H I D I N G • The more carefully we look, the more AGN we find ~60-80% AGN • AGN often offset from the Ly 𝛽 emission Ly 𝜷 nebulae • Demonstrates importance of multi- wavelength coverage to get a full census of the local region Overzier+2013

A M U LT I - WAV E L E N G T H V I E W O F LY M A N - A L P H A N E B U L A E • Using multi-wavelength data on individual Ly 𝛽 nebulae reveals a more complete picture of the CGM in dense regions: • Environment — census of nearby galaxies (& AGN) • Kinematics — map out how the gas is moving multiple emission lines, Ly 𝛽 vs. less optically thick lines • Physical conditions — metallicity, density, source of ionization

K I N E M AT I C S - L OW V E L O C I T Y O F F S E T S I N LY M A N - A L P H A N E B U L A E • Velocity offsets of Ly 𝛽 vs. non-resonant lines (e.g., H 𝛽 , [OIII]) encode information about outflow/infall • Low velocity offsets measured for LAEs • Low velocity offsets for embedded galaxies within Ly 𝛽 Prescott+2015a nebulae (including data from Steidel+2010, Yang+2011, Finkelstein +2011, McLinden+2011,2013, Hashimoto+2013, Guaita+2013; see also Yang+2014)

K I N E M AT I C S - L OW V E L O C I T Y O F F S E T S I N LY M A N - A L P H A N E B U L A E • See the same picture within the nebula gas itself • Consistently low velocity offsets (~100 km/s) between Ly 𝛽 and non-resonant HeII Ly 𝜷 CIV HeII CIII] 11 arcsec - 94 kpc 7.4 arcsec = 63 kpc z=1.67 PRG1 Prescott+2015a

K I N E M AT I C S - L OW V E L O C I T Y O F F S E T S I N LY M A N - A L P H A N E B U L A E • Low velocity offsets for LAEs and embedded galaxies in Ly 𝛽 nebulae • Measure similarly low velocity offsets within the diffuse gas in Ly 𝛽 nebulae • Ly 𝛽 roughly tracing Prescott+2015a the systemic (including data from Steidel+2010, Yang+2011, Finkelstein velocity +2011, McLinden+2011,2013, Hashimoto+2013, Guaita+2013; see also Yang+2014)

K I N E M AT I C S — S I G N S O F R OTAT I O N I N LY M A N - A L P H A N E B U L A E Prescott+2015a PRG1 • Large-scale velocity shear suggestive of rotation • Similar to predictions for recently accreted gas (Also see talks by F. Arrigoni-Battaia, D. C. Martin) Stewart+2013

A M U LT I - WAV E L E N G T H V I E W O F LY M A N - A L P H A N E B U L A E • Using multi-wavelength data on individual Ly 𝛽 nebulae reveals a more complete picture of the CGM in dense regions: • Environment — census of nearby galaxies (& AGN) • Kinematics — map out how the gas is moving • Physical conditions — metallicity, density, source of ionization multiple emission lines, emission line diagnostics, comparisons to photoionization models

P H Y S I CA L C O N D I T I O N S — I O N I Z AT I O N Overzier+2013 B1 B1 North • B1 - IFU data, split nebula into two large apertures B1 South • — consistent with z=2.38 AGN photoionization

P H Y S I CA L C O N D I T I O N S — I O N I Z AT I O N • PRG1 — deep spectroscopy SF models from 2 nights on Keck/LRIS allows us to use many spatial apertures across the nebula • — consistent with AGN photoionization AGN models Prescott, Martin, & Dey in prep. (overplotted on Feltre+2016) Ly 𝜷 CIV HeII CIII] 11 arcsec - 94 kpc 7.4 arcsec = 63 kpc z=1.67 PRG1

P H Y S I CA L C O N D I T I O N S — M E TA L L I C I T Y, D E N S I T Y, I O N I Z AT I O N PRG1 PA=52.44 o Z ~ 0.03 - 0.1 Z o Preliminary n H ~ 3 - 10 cm -3 log U ~ -1 to -2 • assuming AGN powering, fit CIV+HeII+CIII] measurements using grid of Cloudy photoionization models Prescott et al., in prep.

P H Y S I CA L C O N D I T I O N S — M E TA L L I C I T Y, D E N S I T Y, I O N I Z AT I O N PRG1 PA=146.0 o Z ~ 0.03 - 0.1 Z o Preliminary n H ~ 3 - 10 cm -3 log U ~ -1 to -2 • assuming AGN powering, fit CIV+HeII+CIII] measurements using grid of Cloudy photoionization models Prescott et al., in prep.