Lightcones for Munich Galaxies

Bruno Henriques

OutlineOutline

1. Model to data - stellar populations and photometry

2. Model to data - from snapshots to lightcones

4. Results - all-sky cones

3. Results - pencil beams

April 21, 2023

Luminosity of a stellar population

Stellar Population Synthesis

Metallicity + Age +IMF

Dust Model

3

€

Aλ = −2.5log1− exp−τ λ secθ

τ λ secθ

⎛

⎝ ⎜

⎞

⎠ ⎟

Mass to LightMass to Light

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Direct comparison to observed frame apparent magnitudesTest SED fitting / K-corrections

Reliability of assumed star formation histories

Test determinations of mass

Full Emission SpectraFull Emission Spectra

The inclusion of the TP-AGB phase means that intermediate-age

populations will contribute significantly to the near infra-red emission from galaxies (Marasto 2005, Charlot & Bruzual 2007)

In past evolutionary population synthesis codes,

the K-band was mostly determined by old

populations (e.g. Bruzual & Charlot 2003, PEGASE,

Starburst99)

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Test the impact of stellar populations modelling in the observed galaxy properties.

K

Ji z

(see also Henriques, Maraston, Monaco et al. (2010))

Different Stellar populationsDifferent Stellar populations

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z=0

z=5.7

z=1.4

The semi-analytic is built on top of the dark matter distribution and has outputs only at given snapshots.

to lightcones

From snapshot/box output

(despite galaxy properties being computed in smaller steps ~ 6 Myr )

LightconesLightcones

Comoving distance

Redshifts - snapshots

(zi+zi-1)/2<z<(zi+zi+1)/2

dcom

zi

zn

LightconesLightcones

Mass to light

obs_frame

rest_frame

only few replications, distant in redshift

Number Counts & ZdistNumber Counts & Zdist

bright near-by and faint distant galaxies

Intermediate redshifts dominated by faint

objects

First tests can be performed directly in the observed frame with only few derivations applied to data.

Henriques, White, Lemson, et al. 2012

Rest-frame Colours and LFsRest-frame Colours and LFs

Optical-near-infrared color, separates passive

from dust obscured galaxies

Large differences

between stellar populations

More informative tests can be done for rest-frame properties in order to obtain a comprehensive picture.

Allsky LightconesAllsky Lightcones

Selection in iAB< 21.0 - 100deg2 - comparable to modern wide surveys

BOSSBOSS

observed-frame color selection criteria can be

matched

The model can be used to analyze the selection in

terms of fundamental quantities Maraston, Pforr, Henriques, et al. 2012

Stellar Mass of Massive EllipticalsStellar Mass of Massive Ellipticals

The numbers of massive galaxies are similar in model and data reflecting the slow evolution of these objects at

later times

ConclusionsConclusions

Narrow and wide lightcones constructed to match modern surveys.

Wide photometric coverage that can be used to test derivation of fundamental quantities from observations.

Large range of properties can be closely compared with available data to identify possible tensions in theory.

Simulations to Observations Simulations to Observations

Boxes to cones

Mass to light

MotivationMotivation

Because we should. The physics of galaxy formation are complex but observations suggest they must obey simple relations.

Why use a phenomenological approach to study galaxy formation?

Still, we do not have a good understanding and cannot work from first principles, so models must be

observationally based.

Fast method to compute the evolution of the galaxy population across cosmic time for samples as large as modern surveys.

Many aspects of the physics that govern galaxy formation depend simply on galaxy and dark matter properties as indicated by

observed scaling relations.

Tully-Fisher

BlackHole-BulgeMass

SFR-Gas

Scaling RelationsScaling Relations

Even if direct simulations reach high resolution and significant volumes they face the same problems due

to un-resolved physics!

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TB-AGB

TB-AGB + RHeB

SSP

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Van der Wel, Franx, Wuyts, et al. 2006

Chandra Deep Field - South

ACS+IRAC+J&H filters

Older then the Universe! Undetected in MIPS!

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Maraston, Daddi, Renzini, et al. 2006

What are the implications for galaxy formation models?

MUSYC – Gawiser et al. 2006GOODS – Giavalisco et al. 2004

Optical to mid-infrared data

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Marchesini 2009Marchesini 2009

CB07

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BC03

CB07

M05

Henriques, Maraston, Monaco, et al. (Astro-ph: 1009.1392)