1. ESA/ESTEC 26-27 Feb. 2007 Effects of X-ray and UV Radiation from Very Young Sun on Biomolecules Angela Ciaravella INAF – Osservatorio Astronomico di Palermo aciaravella@astropa.unipa.it Network Activity JRA Astrophysicists, Chemists, Physicists, Biologists….. EUV and X-ray emission from Sun & stars Modeling of planet atmosphere …….. Experimental EUV and X-ray

2. Conditions in the Early Solar System Very intense and hard radiation from the young Sun Energetic radiation from the early Sun is manly in term of EUV and X-ray emission and energetic particles. Heavy bombardment by: Comets, Meteorites and Micrometeorites main carriers of organic material 4.2 - 3.9 × 10 9 yr ago = 1000 × today value Solar Corona ( 1-2 × 10 6 K) Yohkoh-SXT 3-40 Å band Magnetic confined plasma in loops ….. seeds of life on the Earth

3. Today X-ray Sun 10 -4 10 -5 10 -6 10 -7 10 -8 3 × 10 26 (0.1 keV) @ min = 10 27 erg/sec 5 × 10 27 (0.2 keV) @ max

4. Flares and CMEs Mass 10 13 - 10 16 g Speed >2700 km/sec (480km/sec) Energy 10 32 erg Rate 0.8 up to 6 day Sometime What about solar type stars? Einstein, ….CHANDRA, XMM ….we learned a lot ….. Analysis of the flare decay parameters of the flaring structure L, n, B A flare occurs when energy stored in magnetic fields is suddenly released produces a burst of radiation from radio waves to X and Gamma rays

5. Sun @ min Sun @ max Main Sequence Solar Type Stars Early X-ray Sun: more active, hard and bright …but today is a modest X-ray source (L X = 10 27 – 10 30 erg/sec)  X-ray emission fades much more rapidly than UV.  The variations depends on the hardness of radiation: the hardest the fastest ( Micela 2002 ).  In the 1-10 keV range, X photons @ Earth were >10 3 times higher than today when the Sun was only 10 8 yr old.

6. Young Stars are Very Active in X-ray ● energetic radiation, very huge daily or weekly X-ray flares ( Feigelson \& Montmerle 1999;Feigelson et al. 2003) ● T Tauri show flares emitting at 8 keV for more than two days large size of the flaring structures ( L » R * ) not found in more evolved stars X-rays from the flare can heat up the planet-forming disk ………… L X = 10 31 – 10 33 erg/sec (Favata et al. 2005).

7. Survival ►Amino acids implanted in icy mixtures and irradiated with UV and X-ray quiescent & energetic transient Protection ►Amino acids will be implanted in icy mixtures deposited onto different substrates assumed to be analogues of dust grain materials The role of mineral material of the dust aggregates in protecting both passively and actively the prebiotic chemicals will be studied. Clays can protect DNA molecules from X-ray and UV radiation (Ciaravella et al. 2004; Scappini et al., 2004) Complexity ►The survival of biological molecules can be function of their complexity Irradiation of biological compounds of increasing complexity molecular complexity sustainable in space ► High energy irradiation may induce photo-degradation as well as an increase in molecular complexity. Investigate whether and in which conditions the radiation may induce formation of more complex molecular structures. The Experimental Plan

8. X-ray, UV, Vis 2 -10 4 eV (1- 7000 A). 32 m stainless-steel vacum beam line class 1000 clean_room (Barbera et al 1999). The Laboratory Facilities The Astrobiology Lab The XACT Facility  High vacuum (10 -10 mbar) Chamber  Class 100 Clean room  HI Lyα lamp  X-ray source (1.5 – 10 keV)  Cryostat ( 10 K )  Lasers, Detectors …

9. Upgrade of the X-ray source to simulate transient events (higher fluxes in the 1.5 -15 keV range) Contract personnel Supplies and running cost Travel Estimate Time and Cost The experimental plan is a 3 yr project k€ 100 90 30