Intracluster Light: a luminous tracer for dark matter in clusters of - PowerPoint PPT Presentation

Intracluster Light: a luminous tracer for dark matter in clusters of galaxies Mireia Montes In collaboration with: Ignacio Trujillo, Sarah Brough July 5th, 2018 ICL Mireia Montes

What does the ICL tell us? • History of the assembly of the galaxy cluster When? Age of the stars Who? Metallicity of the stars • Properties of the underlying dark matter halo Shape and extent ICL Mireia Montes

In previous episodes… • 6 galaxy clusters observed with HST ( Lotz et al. 2017, 140 orbits/ cluster) • Redshift range 0.3 < z < 0.55 • Multiwavelength observations ( F435W, F606W, F814W, F105W, F125W, F140W, F160W ) MACS J0717.5+3745 ~31 mag/arcsec 2 (3x3 arcsec 2 , 3 σ ) ICL Mireia Montes

In previous episodes… MACSJ1149.5+2223 • [Fe/H] ICL =-0.5 to -0.3 (0.3-0.4 Z ☉ ) • M = 10 9.5 - 10 10 M ☉ • Ages between 2-6 Gyr younger than the BCG(s) • z<1 Consistent with being formed by Montes & Trujillo 2014, 2018 ICL Mireia Montes

In previous episodes… ICL Mireia Montes

In previous episodes… ICL as a tracer of DM? Slope of the stellar mass density profile of the Pillepich+2014, 2018 halo (3D) correlates with the total halo mass 3D Slope of stellar mass density “ …with power-law slopes of the radial mass density distribution as shallow as the dark matter’s” Pillepich+2018 IllustrisTNG M 200 Montes & Trujillo 2018 ICL Mireia Montes

ICL as a tracer of DM? Gravitational lensing Total mass (Stellar + DM) Detailed DM distribution within clusters!! Jauzac et al. (2014, 2015a) ICL Mireia Montes

ICL as a tracer of DM! A2744 ICL X-rays MASS M0416 M0416 50 75 100 125 140 kpc ICL Mireia Montes

Modified Hausdorff distance (MHD) Hausdorff distance: maximum distance among two sets of points Modified Hausdorff distance: More robust to outliers!! It gives us the mean difference in distance between the tracer and the model, in kpc Huttenlocher et al. (1993) ICL Mireia Montes

Modified Hausdorff distance (MHD) A2744 ICL vs. Circle (R) 10"= 45.4 kpc Different lens inversion techniques => uncertainties in the mass maps Montes & Trujillo 2018 (in prep) ICL Mireia Montes

ICL as a tracer of DM! Merging or recently A2744 merged clusters X-rays do not follow the potential of the cluster X-rays vs. Mass Montes & Trujillo 2018 (in prep) ICL Mireia Montes

ICL as a tracer of DM. Surprising? NO! Massive halos t end to accrete more and more luminous satellites (Gao+2004) Hey! Remember… Those satellites tend to deposit their stars at large radii (Cooper+2015) Less concentrated stellar radial profiles! ! D - 2 n i o s l a w o n d n A ICL Mireia Montes

ICL: luminous tracer of DM in clusters of galaxies AS1063 10"= 49.2 kpc ICL Mireia Montes

For the future… + ICL • Large survey of 3000 galaxies (8 clusters) • Integral-field spectroscopy providing stellar populations and dynamics of the whole galaxy in 2D!! Ho et al. 2016 • Study the ICL in the SAMI clusters with HSC@ Subaru We need to reduce the data carefully!! Thanks ICL Mireia Montes

Fraction of light in ICL For discussion SB cut? But it has some problems B Evolution of the fraction driven by passive evolution of stellar populations ( B band vs V band) V Difference in depths BCG + ICL fit? V Montes & Trujillo 2018 ICL Mireia Montes