Elisabete da Cunha (ESR – IAP) MAGPOP Mid Term Review – La Palma, 12.2006 MAGPOP ESR at the Institut d’Astrophysique de Paris MAGPOP Mid Term Review La

Elisabete da Cunha (ESR – IAP)

MAGPOP Mid Term Review – La Palma, 12.2006

MAGPOP ESR at the Institut d’Astrophysique de Paris

MAGPOP Mid Term ReviewLa Palma, 7 – 8 December 2006

Elisabete da Cunha (Early Stage Researcher)



SHORT PROFILE

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Nationality: Portuguese

Previously at the Faculty of Sciences of the University of Porto (Portugal): degree (July 2005) in Physics/Applied Mathematics (Astronomy)

Broad background in Physics and Mathematics Cosmology, Extragalactic Astronomy, Observational Astronomy, …

MAGPOP Research Training Network:

3 year PhD project (10.2005 – 10.2008) Node: Institut d’Astrophysique de Paris, CNRS, Université Pierre et Marie Curie – Paris VI, France Supervisor: Stéphane Charlot Modelling and interpreting galaxy spectral energy distributions



SCHOOLS

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École Doctorale d’Île de France École Doctorale d’Île de France (Doctoral School):(Doctoral School):

1st year: Numerical simulations and parallel calculus Evolution of local and distant galaxies Dynamics of galaxies

2nd year: Data analysis Cosmology Introduction to telescope time proposals

MAGPOP Budapest Summer School (08.2006):MAGPOP Budapest Summer School (08.2006):

Observational Astronomy (ground- and space-based) Stellar population synthesis models Galaxy formation and evolution models Practical sessions:

Virtual Observatory Telescope time proposals



ACTIVITIES & CONFERENCES

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IAP activities:IAP activities:

Annual Thesis Day: where PhD students present their work to other researchers and students in the IAP.

Weekly seminars on several subjects.

Weekly Jornal Club with the Galaxy Group at the IAP.

Conferences & Meetings:Conferences & Meetings:

MAGPOP Network Meeting in Toledo, Spain (02.2006)

ENAA 2006: National Meeting of Portuguese Astronomical Society in Espinho, Portugal (07.2006)



RESEARCH PROJECTS

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Simple model for the infrared emission by dust in galaxies: with S. Charlot (IAP), D. Elbaz (CEA Saclay).

Simple model for the full spectral energy distributions of galaxies from the ultraviolet to infrared: with S. Charlot (IAP), D. Elbaz (CEA Saclay).

Infrared cosmological background/first stars and galaxies: with S. Charlot (IAP), E. Vangioni (IAP), K. Olive (Univ. Minnesota), F. Daigne (IAP).

Current projects and collaborators:Current projects and collaborators:



MODELLING GALAXY SPECTRA

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Modelling the SED:Modelling the SED: Star formation history Dust content

PhD Thesis: Modelling and interpretation of the spectral energy distributions (SEDs) of galaxies from ultraviolet to infrared wavelengths with simple models.

UVOptica

l

DU

ST

Infrared

STARS

ULIRG

Starburst

Disk

Elliptical






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We are developing a simple, versatile model to interpret consistently the spectra of galaxies at ultraviolet, optical and infrared wavelengths in terms of a set physical parameters describing the star formation history and the dust content.This model will be applied to the analysis of large samples of galaxies.

Ultraviolet and optical emission:Ultraviolet and optical emission:

Stellar populations synthesis models (Bruzual & Charlot) to describe stellar emission + simple prescription for the attenuation by dust (Charlot & Fall).

Infrared emission:Infrared emission: Develop a simple, physically motivated model for the IR emission, which allows one to interpret the mid- and far-infrared emission by dust in galaxies consistently with the emission at shorter wavelentghs.

consistently connected




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Dust luminosity:Dust luminosity:

The total luminosity reradiated by dust grains in a galaxy equal to the total luminosity they absorb from stars.

Influence of the finite lifetimes of stellar birth clouds on the absorption of radiation: photons emitted by stars that live longer than the birth clouds (~10 Myr) propagate only through the ambient ISM before they escape from the galaxy.

giant molecular clouds in which stars form:

HII region (hydrogen ionized by young hot stars)

+HI region (neutral hydrogen)

interstellar medium (older and colder stars)



MODELLING GALAXY SPECTRA – Infrared

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Dust components:Dust components:

Polycyclic Aromatic Hydrocarbons (PAHs) Organic molecules that have a typical emission spectrum in the mid-infrared (between ~5 and 20 µm).

Very Small Grains (VSGs) Small carbonaceous grains that are heated by the absorption of single photons and reach high temperatures (several hundreds of K).

Big Grains (BGs) Composed mainly of silicates and graphite with sizes up to ~100 nm; these grains are in thermal equilibrium with the radiation field and emit as modified black bodies.




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Example of a Example of a model infrared model infrared galaxy spectrum:galaxy spectrum:

TBGsBC

fµ = LdISM / Ld

total

1 = LPAH / Ld

BC

2 = LVSGs(200K) /

LdBC

3 = LVSGs(80K) /

LdBC

4 = LBGsBC / Ld

BC



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NGC 5713NGC 5713

Spiral galaxy (SABbcp) d=26.6 MpcResult of the fit to ISO and IRAS infrared fluxes to the model library – model SED and comparison with observations.




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NGC 5713NGC 5713

Spiral galaxy (SABbcp) d=26.6 MpcResult of the fit to ISO and IRAS infrared fluxes to the model library – probability density histogram for each parameter of the model.




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NEXT...

Connect with stellar emission models and with constraints on the optical attenuation curve (O. Vince, Budapest Node)

model galaxy spectra in the ultraviolet, optical and infrared

Application of the new model to observed samples of galaxies in the UV, optical and IR (V. Buat, J. Walcher, Marseille Node; T. Heckman, JHU Node).

Extract information about key physical parameters related to the star formation history and the interaction between stellar radiation and dust.

Implications for the evolution of the physical properties of galaxies (MPA Node).

galaxy formation and evolution models

Documents

Elisabete da Cunha (ESR – IAP) MAGPOP Mid Term Review – La Palma, 12.2006 MAGPOP ESR at the Institut d’Astrophysique de Paris MAGPOP Mid Term Review La