1 / 20

Star Formation History of M100: Swift/UVOT

Star Formation History of M100: Swift/UVOT. Alison Newell, Ignacio Ferreras & Mark Cropper Mullard Space Science Laboratory, University College London. Scope of talk. Describe current UV Imaging Surveys M100 (NGC 4321) Describe the data Models of Unresolved Stellar Populations

nancy
Télécharger la présentation

Star Formation History of M100: Swift/UVOT

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Star Formation History of M100: Swift/UVOT Alison Newell, Ignacio Ferreras & Mark Cropper Mullard Space Science Laboratory, University College London

  2. Scope of talk • Describe current UV Imaging Surveys • M100 (NGC 4321) • Describe the data • Models of Unresolved Stellar Populations • Further Work

  3. UV Imaging Surveys • Galex • 5 arcsec , FUV, NUV • XMM-OM & Swift UVOT • 2 arcsec, 3 UV + 3 Optical

  4. Gain in spatial resolution – M81 Galex (2 UV colours) Swift-UVOT (3 UV colours)

  5. Swift/UVOT 30 cm modified RC telescope 17x17 arcmin FoV Photon counting detectors 1700 – 6000 Å

  6. OM/UVOT & GALEX filter bandpassesUVOT: UVW2,UVM2,UVW1,UGALEX: FUV,NUV

  7. M100 Basic Properties • Grand design barred Sc Spiral • Nearby, well studied • Central region • Spiral arms • Nearly face-on, ~16 Mpcs • Optical, Hα, CO maps • Spitzer-SINGS • HST – central • GALEX – NUV only • Herschel UVOT 6 colour M100

  8. UVOT Images M100 • Observed 2005 November 5 • UVOT Software – combine and register • Max count rate 1.47 c/s/pixel (B)

  9. Source Detection Process Background • SExtractor – 3σ • UVW2 image used for detections – 1928 Å • Background subtraction complex – stellar emission spiral arms • SF regions: extended, crowded

  10. Photometry Kron elliptical apertures Kron - magnitude Small circular aperture for colours SE Double image mode Large errors on optical images Use SDSS images

  11. SDSS images M100 DR 7 • Observed 2003 January 28, 2004 January 28 • Exposure time 53.9s • 4 separate images • SWARP – combine and register

  12. SDSS Photometry 2 runs, 2 frames 3 arcsec apertures 4 catalogues - amalgamated Removed: Foreground stars Background galaxies

  13. Catalogue • 428 sources with 3 UV colours • ~ 91% have SDSS u,g,r colours, ~ 50% i,z • ~ 2.5 sources per kpc2

  14. Radial Distribution UVW2 Similar for UVM2, UVW1 HII Cepa & Beckman (1996) Sharp edge at 50’’ Sharp fall off at 150 “ Disk edge

  15. Models • Unresolved • 1 px ~ 0.5arcsec ~ 50pc • Age, metallicity, dust • Bruzual & Charlot 2003 models • Simple Stellar Population

  16. C-M Plot

  17. CC plots metallicity UV SDSS

  18. CC plots - dust Degeneracy Model – low dust, young population Cover the UV extent with UVW2 – UVW1 Break degeneracy for older populations

  19. Future work • Comparison with other models • Composite models – more complex analysis • Star formation rate • Radial trends • Comparison with Spitzer SINGS Complementary approach to GALEX

  20. Summary • Swift/UVOT photometry • Described M100 data, some properties • Compared data with Bruzual & Charlot 2003 models • Determined young dust free regions with solar Z • Identified future work

More Related