SED fitting workshop

Cosmology School, Kraków 2022

Katarzyna (Kasia) Małek

Mahmoud  (Misha) Hamed 

National Centre for Nuclear Research, Warsaw, Poland

Outline

  • Part 1 - what's the SED stands for?
  • Part 2 - introduction to CIGALE
  • Part 3 - hands on

K. Malek, M. Hamed "CIGALE workshop", Cosmology School, Kraków, 2022

Part One
SED?

Credit: https://www.almaobservatory.org/

Centaurus A (NGC 5128)

Credit: https://www.almaobservatory.org/

Centaurus A (NGC 5128)

Credit: https://www.almaobservatory.org/

Centaurus A (NGC 5128)

Credit: https://www.almaobservatory.org/

Centaurus A (NGC 5128)

Credit: https://www.almaobservatory.org/

Centaurus A (NGC 5128)

Credit: https://www.almaobservatory.org/

Centaurus A (NGC 5128)

Credit: https://www.almaobservatory.org/

Centaurus A (NGC 5128)

Colour composite image, revealing the lobes and jets originates from the active galaxy’s central black hole. This image was obtained with three instruments: 

  • submm (870micron) LABOCA/APEXPEX (Chile)
  • X ray data from Chandra X-ray Observatory
  • optical observations (2.2-m WFI, MPG/ESO, Chile)  show the background stars and the galaxy’s characteristic dust lane in close to "true colour".

Centaurus A (NGC 5128)

Credit: ESO Centaurus A LABOCA

Multiwavelength imagery of DustPedia galaxy NGC 368 and Six of the enigmatic blue and dusty gas rich galaxies revealed in Clark et al., 2015

Spectral Energy Distribution

  • Galaxies emit electromagnetic radiation over the full possible frequency/ wavelength range,
  • analysis of this radiation is the main means through which astronomers study galaxies and thus learn about their formation and evolution,
  • the distribution of energy over wavelength/frequency is called the Spectral Energy Distribution (SED).

K. Malek, M. Hamed "CIGALE workshop", Cosmology School, Kraków, 2022

Spectral Energy Distribution

  • Galaxies emit electromagnetic radiation over the full possible frequency/ wavelength range,
  • analysis of this radiation is the main means through which astronomers study galaxies and thus learn about their formation and evolution,
  • the distribution of energy over wavelength/frequency is called the Spectral Energy Distribution (SED).

K. Malek, M. Hamed "CIGALE workshop", Cosmology School, Kraków, 2022

Spectral Energy Distribution

  • Galaxies emit electromagnetic radiation over the full possible frequency/ wavelength range,
  • analysis of this radiation is the main means through which astronomers study galaxies and thus learn about their formation and evolution,
  • the distribution of energy over wavelength/frequency is called the Spectral Energy Distribution (SED).

K. Malek, M. Hamed "CIGALE workshop", Cosmology School, Kraków, 2022

But one has to remember, that ..

… we are working (almost only) with broad band photometry

Credit: D. Burgarella

K. Malek, M. Hamed "CIGALE workshop", Cosmology School, Kraków, 2022

Credit: https://ned.ipac.caltech.edu/level5/March13/Lagache/Lagache2.html

The ULIRG is observed at redshift z=0.66 and is represented here in the rest-frame (from Galliano 2004).

K. Malek, M. Hamed "CIGALE workshop", Cosmology School, Kraków, 2022

The SED of galaxy is shaped by nearly every physical property of the galaxy, and among others:

 

  • the initial mass function (IMF),
  • the star formation history (SFH),
  • stellar populations (SSP),
  • the metal content (Z),
  • chemical compositions and their evolution,
  • dust characteristics (amount, attenuation law, etc.),
  • the grain size distribution,
  • the star-dust geometry,
  • the interstellar radiation field,
  • etc.

 

K. Malek, M. Hamed "CIGALE workshop", Cosmology School, Kraków, 2022

Some of the fundamental properties of galaxies (SFH, IMF, metallicity, stellar mass..) are easier to measure than others, and each provides important clues regarding the formation and evolution of galaxies. 

 

These quantities, measured from the SEDs of galaxies, have provided the foundation for our modern understanding of galaxy formation and evolution.

K. Malek, M. Hamed "CIGALE workshop", Cosmology School, Kraków, 2022

Credit: M.Hamed

K. Malek, M. Hamed "CIGALE workshop", Cosmology School, Kraków, 2022

K. Malek, M. Hamed "CIGALE workshop", Cosmology School, Kraków, 2022

young stellar populations

starsze populacje gwiazdowe

Polycyclic aromatic hydrocarbon 

starsze populacje gwiazdowe

old stellar populations

hot dust

cold dust

synchrotron emission (AGN)

hot gas

K. Malek, M. Hamed "CIGALE workshop", Cosmology School, Kraków, 2022

astrophysics full of colours!

GALEX (UV)

(Credit: NASA)

Herschel( Credit: NASA)

VLT (optical) (Credit: ESO)

AKARI (MIR-FIR)

(Credit: JAXA)

GEMINI (opt)

 Spitzer (NIR-MIR)

 (Credit: NASA)

CFHT (Credit: cfht)

HOW TO FIT SED?

HOW TO FIT SED?

Credit: D. Burgarella

K. Malek, M. Hamed "CIGALE workshop", Cosmology School, Kraków, 2022

HOW TO FIT SED?

K. Malek, M. Hamed "CIGALE workshop", Cosmology School, Kraków, 2022

HOW TO FIT SED?

K. Malek, M. Hamed "CIGALE workshop", Cosmology School, Kraków, 2022

HOW TO FIT SED?

Stellar & dust emissions fitted separatly

K. Malek, M. Hamed "CIGALE workshop", Cosmology School, Kraków, 2022

HOW TO FIT SED?

Credit: D. Burgarella

K. Malek, M. Hamed "CIGALE workshop", Cosmology School, Kraków, 2022

HOW TO FIT SED?

to use all the data in a consistent way

K. Malek, M. Hamed "CIGALE workshop", Cosmology School, Kraków, 2022

What we can model?

we can do it under the assumption of the energy balance 

  • stellar populations,
  • dust emission/evolution,
  • gas content,
  • etc

K. Malek, M. Hamed "CIGALE workshop", Cosmology School, Kraków, 2022

https://github.com/bd-j/prospector

K. Malek, M. Hamed "CIGALE workshop", Cosmology School, Kraków, 2022

https://github.com/bd-j/prospector

K. Malek, M. Hamed "CIGALE workshop", Cosmology School, Kraków, 2022

https://github.com/bd-j/prospector

K. Malek, M. Hamed "CIGALE workshop", Cosmology School, Kraków, 2022

https://github.com/bd-j/prospector

sSFR=SFR/Mstar

K. Malek, M. Hamed "CIGALE workshop", Cosmology School, Kraków, 2022

https://github.com/bd-j/prospector

K. Malek, M. Hamed "CIGALE workshop", Cosmology School, Kraków, 2022

https://github.com/bd-j/prospector

K. Malek, M. Hamed "CIGALE workshop", Cosmology School, Kraków, 2022

Credit: https://github.com/bd-j/prospector

K. Malek, M. Hamed "CIGALE workshop", Cosmology School, Kraków, 2022

K. Malek, M. Hamed "CIGALE workshop", Cosmology School, Kraków, 2022

STAR FORMATION HISTORY 

K. Malek, M. Hamed "CIGALE workshop", Cosmology School, Kraków, 2022

K. Malek, M. Hamed "CIGALE workshop", Cosmology School, Kraków, 2022

Dust emission + dust re-emission: dust radiates energy absorbed in the UV and optical at relatively low, mid-IR to sub-mm wavelengths.

dust attenuation

Credit: Boquien et al., 2019

K. Malek, M. Hamed "CIGALE workshop", Cosmology School, Kraków, 2022

DUST ATTENUATION

(absorption and scattering of star light by dust)

K. Malek, M. Hamed "CIGALE workshop", Cosmology School, Kraków, 2022

Credit: M. Hamed

K. Malek, M. Hamed "CIGALE workshop", Cosmology School, Kraków, 2022

Credits: NASA

a key component of the interstellar medium (ISM)

  • dust particles are formed as a product of stellar evolution, 
  • they are formed in the environment of evolved stars and  then they are ejected into the interstellar medium,
  • their sizes range from a few nm to a few μm,
  • the main building block is carbon, including graphite + silicate,
  • its presence in galaxies is "noticeable" as
    • emission in the IR wavelenghts,
    • modification of the stellar continuum (UV - NIR) 

Credit: D. Donevski

K. Malek, M. Hamed "CIGALE workshop", Cosmology School, Kraków, 2022

dust attenuation

K. Malek, M. Hamed "CIGALE workshop", Cosmology School, Kraków, 2022

AGN emission 

Credit: Boquien et al., 2019

K. Malek, M. Hamed "CIGALE workshop", Cosmology School, Kraków, 2022

Toba et al., 2021

x-ray eROSITA

K. Malek, M. Hamed "CIGALE workshop", Cosmology School, Kraków, 2022

Credit: Guang, KM et al., 2022

Radio LOFAR

 

K. Malek, M. Hamed "CIGALE workshop", Cosmology School, Kraków, 2022

KM preliminary results

Radio LOFAR

X-ray Chandra

K. Malek, M. Hamed "CIGALE workshop", Cosmology School, Kraków, 2022

Part Two
CIGALE

The basics of the spectral energy distribution (SED) fitting methods is to reconstruct the stellar (and dust) emission of a galaxy with population synthesis models and SFH of varying complexity with free parameters based on the multi-λ broadband including dust attenuation.


SED fitting a method commonly used to derive physical parameters useful to quantify galaxy evolution, the most popular ones being the SFR and the Mstar.

CIGALE
Code Investigating GALaxy Emission
http://cigale.lam.fr/

K. Malek, M. Hamed "CIGALE workshop", Cosmology School, Kraków, 2022

For each galaxy the best value for each parameter as well as the best fitted model is found using the Bayesian-like statistical analysis (χ 2 ); In the next step, the physical values are calculated based on the probability distribution function (PDF) of the derived parameters of interest

CIGALE
Code Investigating GALaxy Emission
http://cigale.lam.fr/

K. Malek, M. Hamed "CIGALE workshop", Cosmology School, Kraków, 2022

different modules for the SED fitting (but not all of them)

+ X-ray + radio ect

K. Malek, M. Hamed "CIGALE workshop", Cosmology School, Kraków, 2022

Possible models for Cigale

SFH: model composed of two decreasing exponentials; delayed tau model; your own model from the file,
stellar Bruzual and Charlot (2003); Maraston 2005,
nebular computing the nebular emission from the UV to the NIR. It includes both the nebular lines and the nebular continuum.
att. Calzetti et al. (2000) & Leitherer et al. (2002); Charlot & Fall (2000)
IR Dale et al. (2014); Draine and Li (2007); Casey (2012)
AGN Fritz et al. (2006) AGN dust torus emission; Dale et al. (2014), Stalevski et al., (2016) - SKIRTOR (clumpy torus + att)

radio: Synchrotron radio emission based on the radio-IR correlation, a free power–law spectral slope, and the assumption that at 21 cm the spectrum is dominated by non–thermal emission

Part Three
Hands on

https://cigale.lam.fr/

https://cigale.lam.fr/

cd scratch
cd ../cosmos05
cp A* ../cosmosX
cd
cd scratch

# during install anaconda  (https://www.anaconda.com/)  !!!IMPORTANT!!! -> 
# change the target directory to /home/cosmosX/scratch/anaconda3

chmod u+x Anaconda3*
sh ./Anaconda...
source ~/.bashrc
conda update conda
conda update anaconda

conda install git-lfs

conda create -n py39_cigale python=3.9 anaconda
conda activate py39_cigale
git lfs fetch

conda install astropy numpy scipy sqlite sqlalchemy matplotlib configobj

git clone https://gitlab.lam.fr/cigale/cigale.git
cd cigale



python setup.py build
python setup.py develop

cd  

cd /cosmosX/scratch/CIGALE_hands_on

#enviroment

ssh -C4Y cosmosXX@byk.oa.uj.edu.pl

ssh -Y Cen or Cep or Eri or Aqr

 

cp /home/cigale/CIGALE_hands_on .

 

conda activate py39_cigale

 

#enviroment

install anaconda (https://www.anaconda.com/)
chmod u+x Anaconda3-2022.05-Linux-x86_64
sh ./Anaconda...
bash
conda update conda
conda update anaconda

#enviroment
conda create -n py39_cigale python=3.9 anaconda
conda activate py39_cigale

conda install astropy numpy scipy sqlite sqlalchemy matplotlib configobj

sudo apt-get install -y git-lfs

git clone https://gitlab.lam.fr/cigale/cigale.git
cd cigale

git lfs install
python setup.py build
python setup.py develop

 

Boquien  et al. 2019

katarzyna.malek@ncbj.gov.pl

mahmoud.hamed@ncbj.gov.pl

Po pierwsze obserwujemy światło przesunięte ku czerwieni (redshift)

http://www.stsci.edu/~dcoe/BPZ/sedanim.gif

https://ogrisel.github.io/scikit-learn.org/

1+z=λobserv/λemit
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