LEGA-C. The Physics of Galaxies 7 Gyr Ago. Arjen van der Wel Max Planck Institute for Astronomy, Heidelberg

Transcription

1 LEGA-C The Physics of Galaxies 7 Gyr Ago Arjen van der Wel Max Planck Institute for Astronomy, Heidelberg

2 How do galaxies assemble their stellar bodies? Collection of large samples at large lookback times Redshift surveys Multi-wavelength photometric surveys Hubble Space Telescope surveys Deep spectroscopic surveys

3 How do galaxies assemble their stellar bodies? Collection of large samples at large lookback times Redshift surveys Multi-wavelength photometric surveys Hubble Space Telescope surveys Deep spectroscopic surveys

4 How do galaxies assemble their stellar bodies? Collection of large samples at large lookback times Redshift surveys Multi-wavelength photometric surveys Hubble Space Telescope surveys Deep spectroscopic surveys

5 How do galaxies assemble their stellar bodies? Collection of large samples at large lookback times Redshift surveys Multi-wavelength photometric surveys Hubble Space Telescope surveys Deep spectroscopic surveys

6 Where we are now We have a detailed census and phenomenological description Madau & Dickinson (2014): of 3.9 Gyr. Half of the stellar mass observed today was formed before a redshift z =1.3. About 25% formed before the peak of the cosmic star-formation ratedensity,andanother 25% formed after z =0.7. Less than 1% of today s stars formed during the epoch of SFR history and Mass Function integrations agree: 40-60% of stars formed before and after z = 1

7 How do galaxies assemble their stellar bodies? Collection of large samples at large lookback times Redshift surveys Multi-wavelength photometric surveys Hubble Space Telescope surveys Deep spectroscopic surveys

8 How do galaxies assemble their stellar bodies? Collection of large samples at large lookback times Redshift surveys Multi-wavelength photometric surveys Hubble Space Telescope surveys Deep spectroscopic surveys

9 Evolution of the Size Distribution CANDELS + 3D-HST: van der Wel et al. (2014a)

10 Evolution of the Size Distribution CANDELS + 3D-HST: van der Wel et al. (2014a)

11 Evolution of the Size Distribution CANDELS + 3D-HST: van der Wel et al. (2014a)

12 Where we are now We have a detailed census and phenomenological description No change in M* (in Schechter) over 10 Gyr Evolution in number density Quenching Star formation inside-out Assembly through merging

13 Where we are now We have a detailed census and phenomenological description No change in M* (in Schechter) over 10 Gyr Evolution in number density Quenching Star formation inside-out Assembly through merging allowing us to make sweeping statements, e.g., The majority of all stars formed in disk galaxies with similar mass as the present-day Milky Way (van der Wel et al. 2014b)

14 How do galaxies assemble their stellar bodies? Collection of large samples at large lookback times Redshift surveys Multi-wavelength photometric surveys Hubble Space Telescope surveys Deep spectroscopic surveys

15 How do galaxies assemble their stellar bodies? Collection of large samples at large lookback times Redshift surveys Multi-wavelength photometric surveys Hubble Space Telescope surveys Deep spectroscopic surveys

16 Large Early Galaxy Astrophysics Census 128-night Public Spectroscopic Survey with VLT / VIMOS Observations: December Spring 2018 >3000 z=0.6-1 galaxies (K-selected, UltraVISTA Muzzin+13) 20hr integrations; typical S/N = 20/Å R = 2500, λ = Å Stellar ages and metallicities Dynamical masses Gas-phase metallicities

17 Large Early Galaxy Astrophysics Census 128-night Public Spectroscopic Survey with VLT / VIMOS Observations: December Spring 2018 >3000 z=0.6-1 galaxies (K-selected, UltraVISTA Muzzin+13) 20hr integrations; typical S/N = 20/Å R = 2500, λ = Å Stellar ages and metallicities Dynamical masses Gas-phase metallicities

18 Large Early Galaxy Astrophysics Census 128-night Public Spectroscopic Survey with VLT / VIMOS Observations: December Spring 2018 >3000 z=0.6-1 galaxies (K-selected, UltraVISTA Muzzin+13) 20hr integrations; typical S/N = 20/Å R = 2500, λ = Å Stellar ages and metallicities Dynamical masses Gas-phase metallicities

19 Large Early Galaxy Astrophysics Census PI: Arjen van der Wel (MPIA) Survey Manager: Kai Noeske (MPIA) Survey Scientists: Rachel Bezanson (Arizona) Dynamics Anna Gallazzi (Arcetri) Chemical abundances Camilla Pacifici (STScI) Star formation histories Co-I s: Eric Bell (Michigan) Gabe Brammer (STScI) Stephane Charlot (IA Paris) Priscilla Chauke (MPIA) Marijn Franx (Leiden) Ivo Labbe (Leiden) Michael Maseda (Leiden) Juan Carlos Munoz (ESO) Adam Muzzin (Cambridge) Hans-Walter Rix (MPIA) David Sobral (Lisbon) Jesse van de Sande (Sydney) Pieter van Dokkum (Yale) Vivienne Wild (St. Andrews) Christian Wolf (ASU)

20 Typical spectrum from redshift surveys

21 What LEGA-C Spectra Reveal z = 0.70 Stellar mass: M* = 1.4 +/- 0.5 x Msol 16 ACS image

22 What LEGA-C Spectra Reveal z = 0.70 Stellar mass: M* = 1.4 +/- 0.5 x Msol 16 ACS image

23 What LEGA-C Spectra Reveal Ca Ca Hδ Ca G Hɣ Fe Ca z = 0.70 Stellar mass: M* = 1.4 +/- 0.5 x Msol 16 Stellar velocity dispersion: 154 +/- 6 km/s Dynamical mass: 1.5 +/- 0.3 x Msol Fe Fe Hβ Fe Mean stellar age: 2.9 +/- 0.3 Gyr Metallicity: 65% +/- 7% solar

24 We now have collected 23% of the data - High Sersic index - Low Sersic index - Inclined disks

25 Spectral Properties vs. Structure High-Sersic index galaxies

26 Spectral Properties vs. Structure Low-Sersic index galaxies

27 Star Formation History Distribution of age indicators: D4000 and Hδ Kauffmann+03 (SDSS; z < 0.1)

28 Star Formation History Distribution of age indicators: D4000 and Hδ 530 LEGA-C galaxies

29 Spectral Properties vs. Structure Face-on and Edge-on Disks

30 Summary and Outlook LEGA-C is a 128-night survey with VLT/VIMOS: deep continuum spectroscopy of >3000 galaxies at z = LEGA-C will reveal the physics of galaxy formation by measuring the evolution of stellar populations over the past 7 Gyr Observations started in 11 months ago; we have collected 23% of data First Data Release (spectra) by June 1st, 2016 Second Data Release (spectra + phys. parameters) by Dec 1st, 2016

31 Resolved stellar kinematics at z = 1 van der Wel & van der Marel 2008