Introductory Lecture on Astrophysics (for astroparticle physicists) - PowerPoint PPT Presentation

Introductory Lecture on Astrophysics (for astroparticle physicists) Pasquale D. Serpico International School on AstroParticle Physics - Zaragoza 13/07/2010

Disclaimer Disclaimer  Astrophysics is a huge field: In no way I can provide anything close to a general overview, both for the lack of time and competence.  I ’ ll try to give you an overall introduction to concepts, mechanisms & a way of reasoning that those of you unfamiliar with astrophysics should learn in order not to get lost in the astro jargon & zoology.  I ’ ll try to keep in mind that most of you have likely a particle physics background, and may lack even an introduction to key concepts in astrophysics (e.g. virial theorem, shock waves, etc.) Sorry for the experts among you!  Physical basis and impact of these “tools” for astroparticle “applications” are my main guidelines: based on my experience!

References References General Astrophysical Concepts General Astrophysical Concepts   “ “Theoretical Astrophysics Theoretical Astrophysics” ”, , by by T. T. Padmanabhan Padmanabhan (Vol Vol. I: . I: Astrophysical Processes Astrophysical Processes; ; Vol Vol. II.: . II.: Stars Stars & Stellar & Stellar Systems Systems) ) ( Astroparticle Bounds from Stellar Stellar Systems Systems Astroparticle Bounds from   “ “Stars as Laboratories for Fundamental Physics Stars as Laboratories for Fundamental Physics” ”, , by by G. G. Raffelt Raffelt Introduction to High High Energy Astrophysics Energy Astrophysics Introduction to   “ “High High Energy Astrophysics Energy Astrophysics” ”, , by by M. M. Longair Longair (Vol Vol. I: . I: Particles Particles, , Photons Photons and and their their detection; detection; Vol Vol. II.: . II.: Stars Stars, The , The Galaxy Galaxy and the ISM) and the ISM) ( More advanced advanced ( (still accessible still accessible!) !) More   “ “Stellar Stellar Structure Structure and and Evolution Evolution” ”, , by by R. R. Kippenhahn Kippenhahn and A. and A. Weigert Weigert   “ “Galactic Astronomy Galactic Astronomy” ”, , by by J. J. Binney Binney and M. and M. Merrifield Merrifield   “ “Galactic Dynamics Galactic Dynamics” ”, , by by J. J. Binney Binney and S. and S. Tremaine Tremaine   “ “Cosmic Ray Astrophysics Cosmic Ray Astrophysics” ”, , by by R. R. Schlickeiser Schlickeiser   “ “Foundations Foundations of of High-Energy Astrophysics High-Energy Astrophysics” ”, , by by M. M. Vietri Vietri

Outline o of the f the lectures lectures Outline Lecture I: I: Intro Intro & Stellar & Stellar phenomena phenomena Lecture  Introduction Introduction ( (history history, , definition definition and basic and basic concepts concepts) )   Galaxies Galaxies and and Stars Stars: basic : basic notions notions on on structure structure & & evolution evolution   Quick detour to Quick detour to “ “applications applications” ” to astroparticle to astroparticle  Lecture II: II: “ “Non-thermal Non-thermal” ” phenomena phenomena Lecture  Energy losses Energy losses of of charged particles as diagnostic tool charged particles as diagnostic tool   Notions Notions on the on the acceleration acceleration of of particles particles   Some Some notions notions on on galactic galactic and and extragalactic sites extragalactic sites of of  acceleration acceleration

History & some & some “ “definition definition” ” History Astronomy: the oldest natural science, Venus Tablet of King Ammizaduga dealing with positional determination of ~XVII century BC celestial bodies, description of their motion Babylon (nowadays Irak) Astrophysics: deals with physical properties & processes of celestial objects The latter is very young latter is very young, in XIX , in XIX century still doubted it could be possible century still doubted it could be possible! ! The On the subject of stars[…] all investigations which are not ultimately reducible to simple visual observations are necessarily denied to us. We shall never be able to determine their chemical composition or even their density […] I regard any notion concerning the true mean temperature of the various stars as forever denied to us. Auguste Comte, 1835 - Cours de la Philosophie Positive

Physical diagnostics at at distance distance! ! Physical diagnostics The situation changed as a consequence of Lab discoveries: In 1860, German physicist Gustav Kirchoff and chemist Robert Bunsen published their findings: 1. A hot solid object produces light with a continuous spectrum. 1. A hot solid object produces light with a continuous spectrum. 2. A hot tenuous gas produces spectral lines with gas-specific wavelengths 2. A hot tenuous gas produces spectral lines with gas-specific wavelengths 3. A hot solid object surrounded by a cooler tenuous gas produces an almost 3. A hot solid object surrounded by a cooler tenuous gas produces an almost continuous spectrum with gaps at discrete line positions of continuous spectrum with gaps at discrete line positions of Point 2. Point 2. The study of physical properties of celestial objects was now possible via the analysis of their light! • A “new particle” was soon identified thereafter “from the sky”: founder & first & first founder Helium in the solar spectrum (1868 - Janssen & Lockyer) Helium editor of “ “Nature Nature” ” editor of • First observed on Earth in 1882 (by Neapolitan physicist Luigi Palmieri, analyzing lava of Mount Vesuvius) 587.49 nm Birth of “ “Astroparticle Astroparticle” ” Birth of

In the XX century century, , also also the first the first assumption dropped assumption dropped! ! In the XX all investigations […] not […] reducible to simple visual observations are necessarily denied to us. Karl Jansky Jansky, early , early ‘ ‘30: Discovery of Radio Signal of the Milky Way 30: Discovery of Radio Signal of the Milky Way Karl Astrophysics finally possible even with “ “invisible messengers invisible messengers” ”! ! Astrophysics finally possible even with Janky and his antenna - Bell Telephone Reber Radio Telescope Wheaton, IL (1937) Laboratories Holmdel, NJ (near Fermilab site) In the present day, it is routinely accepted that astrophysics In the present day, it is routinely accepted that astrophysics can be performed without light altogether (CRs CRs, neutrinos, , neutrinos, GWs GWs… …) ) can be performed without light altogether (

(Astro)physics with invisible messengers physics with invisible messengers (I, HE) (I, HE) (Astro) Kamiokande Kamiokande Homestake Mine Mine Homestake X-ray astrophysics X-ray astrophysics astrophysics ν astrophysics ν Nobel Prize Prize 2002 2002 Nobel Aerobee Aerobee Rocket Rocket

(Astro)physics with invisible messengers physics with invisible messengers (II, LE) (II, LE) (Astro)

How extreme? ? How extreme Astroparticle Astroparticle: using physics to : using physics to understand astrophysics, which in turn understand astrophysics, which in turn we want to understand to learn about we want to understand to learn about (new?) physics in environments which (new?) physics in environments which are too extreme (density, temperature, are too extreme (density, temperature, distance and time-scales… …) to ) to distance and time-scales reproduce them in the Lab. reproduce them in the Lab. “unusual scales unusual scales” ” by many by many “ orders of magnitude! orders of magnitude! Not crazy to think that some Not crazy to think that some physical laws may lose their physical laws may lose their domain of applicability… … domain of applicability

The Space Age was crucial Age was crucial! ! The Space Atmosphere is opaque Atmosphere is opaque to to most most ‘ ‘invisible invisible’ ’ light light To explore other bands, To explore other bands, (Actually, we’ ’ve rather ve rather (Actually, we one needs to go in space one needs to go in space adapted ourselves to adapted ourselves to or to use or to use indirect techniques indirect techniques detect detect… … what available!) what available!)