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PHYS 2070 final project

PHYS 2070 final project. 09/04/2013 Kelvin Au. Ngc 6503. Morphological Type: SA(s) cd Right Ascension (J2000): 17hr. 49min. 26.514sec. Declination (J2000): +70deg. 08' 39.63“ Size: 4.7’ x 1.5’ Physical Size (Diameter) ( ly ): 56317.5 Visual (Apparent) Magnitude: 10.83

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PHYS 2070 final project

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  1. PHYS 2070 final project 09/04/2013 Kelvin Au

  2. Ngc 6503

  3. Morphological Type: SA(s)cd • Right Ascension (J2000): 17hr. 49min. 26.514sec. • Declination (J2000): +70deg. 08' 39.63“ • Size: 4.7’ x 1.5’ • Physical Size (Diameter) (ly): 56317.5 • Visual (Apparent) Magnitude: 10.83 • Visual (Absolute) Magnitude: -18.82 • Surface Brightness (m ”-2): 21.6 Aladin, SIMBAD, VizieR, Starry Night Planetarium Software

  4. Starry Night Planetarium Software

  5. Infrared IRAS Survey: 100 Optical Digitized Sky Survey Radio 0408 MHz: HI All-Sky Continuum Survey Orientation Up – North Left – East X-Ray HEAO 1A X-Ray RASS Broad Image Credit: SkyView

  6. Data & observations

  7. Observation conditions • Moon Phase: Waxing Crescent • Moonrise: 08:21:23 CST • Moonset: 21:08:59 CST • Sunrise: 07:43 CST • Sunset: 17:42 CST • SQM: 20.05, 20.03, 20.12 • Focus Displayed: 242 • FWHM of Target 2-11 • Date: February 12/13, 2013 • Image Capture Time: 22:43 CST • Temperature: -9°C • Seeing: Excellent • Cloud Cover: 5% • Sky Glow 1/5 • Transparency: Excellent • FWHM of Focus Star: 4-6 px.

  8. Image Processing Bias • Master Bias • Master Dark • Master Flat • Reducing the Image • Had to split into 3 substacks • Ended up using 24 frames • Final Image Dark Flat

  9. 499 x 426 pixels Orientation Down – North Left – East

  10. 16 Colour LUT Orientation Down – North Left – East Log Up LUT & Negative

  11. Current research & knowledge

  12. Background • The problem with Rotation Curves… • Maximum Disc Hypothesis • Influence of Dark Matter Image Adapted: PhilHibbs, Wikipedia Commons (Binney et al. 1998)

  13. Research Paper Image Adapted: (Bottema 1997) • ‘The maximum rotation of a galactic disc’ (Bottema 1997) • Find quantity of dark matter contained in a galaxy • Assumptions made • Model formulated • Apply to NGC 6503 & NGC 1560 • NGC 6503 being a normal sized galaxy with normal surface brightness (Bottema 1997)

  14. Focus area

  15. Calculate the distance to ngc 6503! (This was way more involved than I was hoping for!)

  16. Use Distance Modulus to find the Distance • Need Apparent Magnitude • Image Measurements • Need Absolute Magnitude • Tully-Fisher Relation

  17. Find Apparent Magnitude of Galaxy • Used contour to find the flux count Gaussian Blur: 5px. Orientation Down – North Left – East

  18. Find Apparent Magnitude of Galaxy • Used contour to find the flux count • Compare magnitude to count of known star for scale Image Credit: ALADIN

  19. Find Apparent Magnitude of Galaxy • Used contour to find the flux count • Compare magnitude to count of known star for scale • Apparent magnitude formula Galaxy: F1=1847180 Comparison Star: F2 =26605.3376, m2 = 14.819 Apparent magnitude: m = 10.08 Compare B Band: 10.90 J Band: 8.201 (This is slightly reassuring!) (VizierR, SIMBAD)

  20. Find Absolute Magnitude of Galaxy • Tully-Fisher Relation (Binney et al. 1998, Rhee et al. 2005)

  21. Find Absolute Magnitude of Galaxy • Tully-Fisher Relation Remember the value as obtained from Rhee et al.’s paper (Rhee et al. 2005)

  22. Finally Assembling the Pieces • Can’t use the apparent magnitude (10.08) that was measured Remember the value as obtained from Rhee et al.’s paper d = 6.76 Mpc. d = 8.09 Mpc. d = 7.32 Mpc. (Rhee et al. 2005)

  23. Finally Assembling the Pieces • Can’t use the apparent magnitude (10.08) that was measured • Compare Calculated Values iflat: 6.76 Mpc. imax: 7.32 Mpc. Rhee et al. (2005): 8.09 Mpc. Starry Night Values: 8.09 Mpc. Literature Values Rhee et al. (2005): 4.4 Mpc. Bottema (1997): 6.0 Mpc. Starry Night: 8.55 Mpc.

  24. Final remarks • The whole apparent magnitude determination was basically pointless • At least it seemed correct • Final distance values – not bad • Error! So much error! • Way more work than I hoped for… • But I learned a lot… (I guess…)

  25. citations Binney J, Merrifield M. 1998. Relative Distance Estimators. In Galactic Astronomy, Princeton University Press. Princeton. 796pp. Bottema R. 1997. The maximum rotation of a galactic disc. 328:517-525. arXiv:astro-ph/970623v1. http://arxiv.org/abs/astro-ph/9706230v1 Rhee M, Broeils A. 2005. HI LINEWIDTHS, ROTATION VELOCITIES AND THE TULLY-FISHER RELATION. Journal of Astronomy and Space Sciences. 22:2:89-112. http://koreascience.or.kr/article/ArticleFullRecord.jsp?cn=OJOOBS_2005 _v22n2_89

  26. citations Aladin Sky Atlas. http://aladin.u-strasbg.fr/aladin.gml SIMBAD Astronomical Database. http://simbad.u-strasbg.fr/simbad/ SkyView. National Aeronautics and Space Administration. http://skyview.gsfc.nasa.gov/ VizieR Service. http://vizier.u-strasbg.fr/viz-bin/VizieR PhilHibbs.GalacticRotation2.svg http://en.wikipedia.org/wiki/File:GalacticRotation2.svg Starry Night planetarium software and ImageJ image software were used.

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