Probing the gaseous environment of star-forming galaxies in - - PowerPoint PPT Presentation

Probing the gaseous environment

• f star-forming galaxies in

absorption and emission

Michele Fumagalli ICC,CEA – Durham University

What matter(s) around galaxies?

• What are the morphological and physical properties of the CGM?
• What are the physical processes that shape the CGM on both large (kpc) and small (pc) scales?

Inflows and outflows at z~3: the open question.

We want to constrain observationally the physical properties of halo gas near star forming galaxies

MF et al. 2011

Inflows and outflows at z~3: the origin of Lyman Limit Systems

To unveil the physical properties of inflows and outflows we need to understand the distribution, metallicity and kinematics of LLSs, and compare results against the predictions of simulations

MF et al. 2011

The redshift evolution of Lyman Limit Systems

Already from the first LLS surveys, it became evident that LLSs are distinct from the IGM and trace the galaxy population

Sargent et al. 1989: “we believe that most of the LLSs are produced by galaxies” MF et al. 2013

The metallicity distribution of z > 2 LLSs: the HD-LLS sample

We have completed a detailed study of the physical properties of 150 LLSs with high-resolution spectroscopy (…a ten-fold improvement over previous samples…)

Prochaska et al. 2015; MF et al. 2016a HD-LLS sample Literature value

(See also Quiret et al. 2016 and recent work by N. Lehner et al.)

LLSs exhibit a spread of metallicity over 5 orders of magnitude, from super-solar to pristine. LLSs have densities comparable to galaxy halos.

MF et al. 2016a

The metallicity distribution of z > 2 LLSs: the HD-LLS sample

Literature value HD-LLS sample

The metallicity distribution is consistent with predictions of cold-flows streaming onto galaxies, which seems in some tension with very efficient outflows.

Prediction from simulations (2011) Observations (2016) MF et al. 2011, 2016a

The metallicity distribution of z > 2 LLSs: implication for theory

(See also Hafen et al. 2016; Shen et al. 2012, 2013)

Connecting strong absorbers to galaxy halos via small-scale clustering

With quasar pairs, we are mapping the gas distribution around galaxies to test the LLS/galaxy association at z~3 and z~2

MF et al. 2014, 2017 in prep Preview of pilot programme at z~3

Connecting strong absorbers to galaxy halos via small-scale clustering

With quasar pairs, we are mapping the gas distribution around galaxies to test the LLS/galaxy association at z~3 and z~2

MF et al. 2017 in prep Preview of programme at z~2

Connecting strong absorbers to galaxy halos with MUSE

Searching directly for galaxies associated with LLSs in emission. The case of Q0956+122.

MF et al. 2016b Wavelength Flux Very metal poor LLS z ~ 3.22 Log NHI ~ 17.4; log nH ~ -3.3 Log Z/Z⊙ = -3.35 ± 0.05 “Pristine” LLS z ~ 3.09 Log NHI ~ 17.2; log nH < -2 Log Z/Z⊙ = < -3.8

“Pristine” LLS in Ly𝛽

Five Ly𝛽 emitters, but 0.4 expected at random. At least three sources aligned with the LLS. Compelling case of pristine gas in a filament feeding galaxies with low SFRs.

“Pristine” LLS z ~ 3.09 MF et al. 2016b

Searching directly for galaxies associated with LLSs in emission. The case of Q0956+122.

Connecting strong absorbers to galaxy halos with MUSE

“Pristine” LLS in Ly𝛽

Five Ly𝛽 emitters, but 0.4 expected at random. At least three sources aligned with the LLS. Compelling case of pristine gas in a filament feeding galaxies with low SFRs.

“Pristine” LLS z ~ 3.09 MF et al. 2016b

Searching directly for galaxies associated with LLSs in emission. The case of Q0956+122.

Connecting strong absorbers to galaxy halos with MUSE

Very metal poor LLS in Ly𝛽

No galaxies or Ly𝛽 emitters detected. Very metal poor gas in the IGM or CGM of galaxies at very low SFR (< 0.2 M/yr). Dependency on density to second order!

Very metal poor LLS z ~ 3.22 MF et al. 2016b

Searching directly for galaxies associated with LLSs in emission. The case of Q0956+122.

Connecting strong absorbers to galaxy halos with MUSE

Searching directly in emission for galaxies associated with DLAs: an example of a metal rich system (J025518+004847) Direct image of a gas-rich large scale (50 kpc) structure with multiple (interacting) galaxies that enrich the surrounding medium

MF et al. 2017b, submitted

Connecting strong absorbers to galaxy halos with MUSE Multiple galaxies inside extended structure

System 10% solar at z ~ 3.25 (DLA) Example of “intermediate” nebulae

Much more to come: MUSE large programme for z ∼ 3 LLSs (197.A-0384(A); PI Fumagalli) MUSE redshift survey in ~25 quasar fields with ~40 LLSs for statistical analysis

• f correlation between LLSs and star forming galaxies (covering factors)

Connecting strong absorbers to galaxy halos with MUSE

See FLASH talk by Ruari Mackenzie for more examples of DLA hosts found with MUSE See talk by Rich Bielby for MgII absorption in a group at z~0.3

The role of gaseous environment around galaxies

Going beyond galaxy-absorber associations…

The role of gaseous environment around galaxies

Going beyond galaxy-absorber associations…

There are not real data!

The role of gaseous environment around galaxies: MUSE’s view of RPS at z~0

MUSE is revolutionizing our view of ram-pressure stripping in clusters

MF et al. 2014 H𝛽 emission from ESO 137-001 in Norma Cluster Real MUSE data At only 300 kpc from central cluster galaxy!

Detailed kinematics studies are now possible, i.e. we can separate RPS from gravitational interactions

Gas velocity (line of sight and dispersion) from ESO 137-001 in Norma Cluster MF et al. 2014

The role of gaseous environment around galaxies: MUSE’s view of RPS at z~0

Moreover, we can study the excitation mechanisms that power emission…

Fossati, MF et al. 2016

The role of gaseous environment around galaxies: MUSE’s view of RPS at z~0

The role of gaseous environment around galaxies: MUSE’s view of RPS at z~0

MF et al. 2014 H𝛽 emission from ESO 137-001 in Norma Cluster Real MUSE data

Moreover, we can study the excitation mechanisms that power emission…

… and the metallicity of HII regions inside and outside galaxies

Fossati, MF et al. 2016

The role of gaseous environment around galaxies: MUSE’s view of RPS at z~0

See more examples in the “MUSE sneaks a peek at extreme ram- pressure stripping events” series

What matter(s) around galaxies?

• What are the morphological and physical properties of the CGM?
• What are the physical processes that shape the CGM on both large (kpc) and small (pc) scales?

The cold phase of the CGM (as traced by LLSs) is primarily photoionised with mean metallicity of 1% solar, and with a 5 order

• f magnitude scatter

We have preliminary indication that optically-thick gas clusters on scales of dark matter halos, although not all LLSs at z~3 may trace the CGM We have uncovered examples of complex associations between optically-thick gas and galaxies at both ends of the metallicity distribution A mix of inflows and outflows are required to reproduce the wide spread in metallicity, although optically-thick gas does not appear to be heavily enriched As we uncover more examples of groups associated to absorbers, we need to consider the role of environmental processes Examples from z~0 reveal complex mix of morphology, excitation mechanisms, and metallicities on kpc scales

Radiation matters too… MUSE detection of UVB at z~0

Talk by Tom Theuns on Thursday afternoon!

MF et al. 2017a

The metallicity distribution of LLSs appears quire robust with respect to ionization corrections. We need to look more into model dependency.

MF et al. 2016a

The metallicity distribution of z > 2 LLSs: the HD-LLS sample

The role of gaseous environment around galaxies

Going beyond galaxy-absorber associations…