Stardust in the Early Universe Erik Elfgren Luleå University of Technology Swedish National Graduate School of Space Technology

Acknowledgements Supervisors Sverker Fredriksson Johnny Ejemalm Collaborators François-Xavier Désert – Grenoble Bruno Guiderdoni – Lyon

History of the Universe Cosmic Microwave Background Dust My Research Conclusions

Early history History of the Universe Big Bang 13.7 billion years ago Rapid expansion First atoms formed 1 min after the BB 75% H 25% He <1% D, Li, He-3 Duration: 3 min  No heavier elements ?

History of the Universe Decoupling Plenty of high E photons Photons ionize H When T ~ 3000 K Photons can’t ionize  No interaction  Photons unchanged until today  Cosmic Microwave Background (CMB) 300,000 years after Big Bang

History of the Universe The Dark Ages Photons cool Matter contract through gravitation

First Generation of Stars ~1 billion years after Big Bang ~100 times heavier than the Sun ~1 million years before they die Finish as supernovae  Dust Galaxy formation 10 times more Dark Matter  Dark Matter shepherds normal matter History of the Universe Structure Formation

History of the Universe Structure Formation

History of the Universe Structure Formation Star birthStar death Supernova Dust Dust ejection Dust accretion

History of the Universe Summary Big Bang rapid expansion First atoms 1 min Decoupling 300,000 years First stars & galaxies 1 billion years Today 13.7 billion years CMB Dust

Cosmic Microwave Background CMB 300,000 years after BB: T ~ 3000 K 13.7 billion years after BB: T ~ 3 K Everywhere Black Body radiation like the Sun T = K = Microwaves

Cosmic Microwave Background Why is the CMB interesting? Expansion rate  Age of the Universe Amount of Dark Matter, Dark Energy  Shape of the Universe Matter distribution at t = 300,000 years  Closing in on the Big Bang Structure formation  How the first galaxies and stars form Stephen Hawking: “It is the discovery of the century, if not of all time.”

Cosmic Microwave Background How? Temperature map (whole sky)  Power Spectrum = angular correlations

Dust Why is the dust interesting? Absorbs CMB light Absorbs star light Emits radiation similar to the CMB Comes from the first stars Star light CMB light Dust emission Supernova

Supernovae ejects heavier elements such as C, Si, O, N, Fe which condense into dust: CO, SiO 2, Al 2 O 3, … Dust Creation Friction with Gas and Dust High energy photons Cosmic rays  Mean life time Δt = 30 million – 10 billion years Destruction

Dust life times Δt = 10 8, 10 9 and years Dust production Star formation Dust distribution Dark Matter distribution My Research Model

My Research Intensity Like CMB but also Dust Spectrum (CMB) Intensity Observed wavelength

My Research Temporal distribution Dust Distribution 13.5 billion years ago 12.5 billion years ago Relative dust density Time from now

My Research Spatial distribution Dust Distribution Angular correlation 180º/angle

Conclusions Detection with Planck Angular correlation 180º/angle Seems possible

Conclusions Summary First stars  star dust Star dust emit radiation The radiation might be detected with Planck Outlook Collaboration with Lyon Simulation of the first galaxies Dust influence on their properties Supernova Star light CMB light Dust emission Planck detector 1 st starsDust