Massive star-forming clumps at low and high redshift How can we study them with ELT? Matteo Messa, Angela Adamo, Göran Östlin
Overview Star formation is a hierarchical process - Star clusters and star-forming clumps - Ubiquitous (in star-forming galaxies) - Tracers of the star-formation process 10 pc YMC in the MW 4 kpc ~1 kpc Spiral arm of M51 SF region in LMC
High-redshift clumps Star formation at high redshift Chain - Galaxies dominated by bright clumps Mass: 10 8 -10 9 M ☉ - Clump cluster - Size: 1 kpc e.g. Elmegreen+2007, Elmegreen+2009, Guo+2012, Tacconi+2013 Double - Clumps are larger and more massive clump than in local universe - Different Galaxy-scale properties Tadpole - Gas-rich - Highly turbulent - Rotational supported e.g. Förster Schreiber+2009, Spiral Wisnioski+2015, Girard+2018 Elliptical Elmegreen+2005
High-redshift clumps Star formation at high redshift - Galaxies dominated by bright clumps Mass: 10 8 -10 9 M ☉ - - Size: 1 kpc e.g. Elmegreen+2007, Elmegreen+2009, Guo+2012, Tacconi+2013 - Clumps are larger and more massive than in local universe - Different Galaxy-scale properties - Gas-rich - Highly turbulent - Rotational supported e.g. Förster Schreiber+2009, Wisnioski+2015, Girard+2018 - Survival and migration of clumps shape galaxies: - Formation of bulge Bournaud+2007
High-redshift clumps Star formation at high redshift - Lensed systems: resolving below kpc sizes - “Cosmic Snake” galaxy (Cava+2018), z=1 - Same clumps at different resolutions: 10 times difference in mass - High-definition allows study at sub-galactic scales: testing evolution of clumps Cava+2018
High-redshift clumps Star formation at high redshift - Lensed systems: resolving below kpc sizes - “Cosmic Snake” galaxy (Cava+2018), z=1 - Same clumps at different resolutions: 10 times difference in mass - High-definition allows study at sub-galactic scales: testing evolution of clumps - Sensitivity - To study less massive clumps - Until now: imaging (clumps are too faint for spectroscopy) Elmegreen+2009
Low-redshift clumps Star formation at low redshift: LARS galaxies - Analogs of high-z Lyman-break galaxies, study their Ly-α emission - Redshift = 0.028 – 0.18 - Multi-band observations with HST Mass down to ~10 5 M ☉ Sizes down to ~10 pc scale
Low-redshift clumps Star formation at low redshift: LARS galaxies - Testing the effect of different resolutions - Nearby galaxy ESO 338-IG04: resolved down to cluster scales Kpc-size clumps Resolved single clusters Resolved clumps dominating the galaxy < 10 pc 10-100 pc 100-400 pc Larger sizes Brighter luminosities Lower SFR densities Messa+submitted
Low-redshift clumps Star formation at low redshift: LARS galaxies - SFR – size relation - Comparison to sample at various redshifts - Denser than clumps at z=0 (SINGS) - Σ SFR,cl similar to clumps in z=1-3 galaxies (Livermore+2012,2015) - Less dense than z=3-6 compact star-forming regions (Bouwens+2017,Vanzella+2017) Messa+submitted
Low-redshift clumps Star formation at low redshift: LARS galaxies - Clumpiness: - Fraction of UV light in clumps - Higher at lower resolution LARS01 Messa+submitted
Low-redshift clumps Star formation at low redshift: LARS galaxies - Clumpiness: - Fraction of UV light in clumps - Higher at lower resolution - In function of galactic-scale properties Consistent with - V shear /σ 0 : rotational over dispersion velocities - Σ SFR instability theories Dispersion dominated Rotation dominated Messa+submitted
Studying clumps with ELT What do we need to study clumps across redshifts? - High spatial resolution - High sensitivity - Large field of view (multiplex capability) ELT-MOSAIC can address this! High–redshift galaxies: - NIR spectroscopy à rest frame optical (Hα, Hβ, optical lines) - Gas kinematics - Ionization state - Metallicity - TALK by Lorenza Della Bruna tomorrow
Studying clumps with ELT High redshift galaxies: - Current facilities: KMOS z~1 galaxies: m K <24, M * >10 9 M ☉ - - ELT-MOSAIC: lower luminosities (M * ~ 10 8 M ☉ ) - - More irregular and clumpy galaxies - Sub-kpc scale HDM 2’’ 0’’.075 kpc scale Stott+2016 HUDF
Studying clumps with ELT High redshift galaxies - Lensed systems: sub-kpc scale 30-pc-scale clumps Cava+2018
Studying clumps with ELT High redshift galaxies - Lensed systems: sub-kpc scale FIBERS, HMM: 0’’.6: Interesting high-z compact sources e.g. Bouwens z~6 low-lum galaxies
Studying clumps with ELT Low redshift galaxies - Sub-kpc scale - Combination HDM+HMM - Gas dynamics at the same scales as small clumps - NIR lines - See POSTER by Katie Hollyhead
Conclusions - Clumpy star formation at high-z - Reflecting the galaxy properties - Important for galaxy evolution across redshifts - Studying clumps in local galaxies - To test the galactic-scale properties - ELT-MOSAIC - Spectroscopy of clumpy high-redshift galaxies at sub-kpc scale - Spectroscopy of lensed galaxies at ~10 pc scale
Recommend
More recommend
