Swi$ Observa-ons of Cometary X ray and UV Emission

Transcription

1 Swi$ Observa-ons of Cometary X ray and UV Emission Dennis Bodewits 1,2, M.J. Mumma 2, G.L. Villanueva 2,3, S.M. Immler 4, W. Landsman 2, J. A. Carter 5 and A. M. Read 5 (1) NASA Postdoctoral Fellow, Dennis.Bodewits@nasa.gov, (2) NASA GSFC, Greenbelt MD 20771, USA, (3) Dept. of Physics, The Catholic University of America, Washington, D. C., USA, (4) Dept. of Astronomy, University of Maryland, College Park, MD 20742, USA (5) Department of Physics and Astronomy, University of Leicester, Leicester LE1 1RH, UK

2 Overview IntroducYon Highlights Grism Spectroscopy of Comets Summary

3 Solar System Origins Comets: remnants of early solar system Might have brought water to Earth Trace evoluyon of organic ma\er in space How did the composiyon of pre cometary ices varied with distance from the young Sun? Study gaseous composiyon, chemistry and evoluyon in/of comets.

4 Comets Nucleus 1 10 km AcYve within ~5 AU Large gas cloud coma Stardust H2O + γ OH + H Comet Lulin Bodewits et al 2009 OH + γ O + H H2O parent, OH daughter, O granddaughter Chemistry of most other gases poorly known SpaYal distribuyon gives clues

5 Carbon Chemistry puzzle H2O, C2H6, CH3OH, HCN, C2H2, CH4, H2CO, CO,.. The observed volatile composition could be related to the formation region of the comets. UV/OpYcal: fragments OH, C2, CN, C3, NH,.. Rich Poor Villanueva, ACM 2008 Swif is uniquely suited to measure to carboneous composiyon of faint comets A Hearn et al 1985 IR: Parent species

6 Swif s View of Comets Comet Origins Dust (ConYnuum) Atoms S, C, O, H Ions He +, He 2+, O 6+,.. Op-cal Energy UV FUV EUV Wavelength X ray Molecules NH 2, C 3, C 2, NH, OH, CS, H 2 Molecular ions CO +, H 2 O +, CO 2+,.. Heavy Ions C 5,6+, O 7,8+,.. Solar Processing Wind

7 Cometary X rays?! Solar wind charge exchange with cometary gas Cometary X ray emission can be used to measure the state and composiyon of the solar wind (Bodewits et al 2007)

8 First Simultaneous X ray/uv image of a comet Astronomy Picture of the Day Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer February 21 The Swift View of Comet Lulin Credit: NASA, Swift, Univ. Leicester, DSS (STScI/AURUA), Dennis Bodewits (NASA/GSFC), et al. APOD Feb 21, 2009 Bodewits et al (2009), Carter et al (in prep)

9 First lightcurve of a comet interacyng with a CME Comet Tempel 1 Observed during Deep Impact Lisse, Bodewits et al 2007 Willingale et al 2006 Mason et al 2007

10 73P C: The Crumbing Comet UVOT discovered that largest remainder is syll falling apart D. Bodewits, S. Immler et al.

11 Grism Spectroscopy of Comets GRISM = grayng prism Slitless spectrometer in UV/OpYcal great for comets Sample extended coma in one shot SpaYal and spectral informayon No slit so very faint comets can be observed UVOT: Angstrom OH and CO 2+, CS, NH, CN, C 2, C 3,.. But.. Not simple to interpret 1 direcyon spayal, 1 direcyon spayal+spectral Stacked sequence of narrowband images

12 Grism Image of Comet Lulin x λ

13 Image Processing Rotate and find 0 th order Find 0 th Order: Wavelength MoYon Remove Background and 0 th order image Remove Stars

14 Grism Analysis: Model Image Stacked image model For every species: Isotropic distribuyon Molecular bands Space Space & wavelength

15 Grism Analysis

16 Grism Spectrum of comet Lulin

17 Results: water producyon rate Bodewits et al (submieed) Water producyon rate on Jan 28, ± 0.6 x and 8.7 ± 0.7 x molecules/s

18 Lulin was regular in its fragment species composiyon Bodewits et al (submieed)

19 Grism Spectroscopy of Extended Sources

20 Conclusions Swif is very well equipped to study the composiyon, chemistry and evoluyon of gas around comets X ray: interacyon with solar wind. Only instrument that can monitor gas producyon and X rays simultaneous (Lulin) UVOT: broadband observayons of macroscopic processes. FOV well matched to lifeyme of gases Grisms measure the water producyon and mixing rayos of various fragment molecules in faint/distant comets that are not accessible from Earth Great for supporyng comet missions: Wild 2 (Stardust), future missions EPOXI to 103P/Hartley 2, Stardust NEXT to 9P/Tempel 1

21 Swi$ is very well equipped to predict the future THANK YOU! Monthly Horoscope This is what your stars say in March