1 / 40

nigel douglas university of groningen

measuring kinematics in elliptical galaxies. nigel douglas university of groningen. (spiral) galaxy dynamics. neutral gas (stars, H II regions). Braun 2002. rotation curve decomposition. RotCurve (cwru.edu). early-type galaxy dynamics. stellar spectroscopy. Statler et al 99.

mfargo
Download Presentation

nigel douglas university of groningen

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. measuring kinematics in elliptical galaxies nigel douglas university of groningen

  2. (spiral) galaxy dynamics neutral gas (stars, HIIregions) Braun2002

  3. rotation curve decomposition RotCurve (cwru.edu)

  4. early-type galaxy dynamics stellar spectroscopy Statleret al99

  5. IFU (integral field unit) Oosterloo priv comm

  6. discrete tracers of kinematics • globular clusters • satellites • PNe • stars

  7. stellar streams Ibata et al. 2004

  8. PNe • easy to detect • easy to measure radial velocity linewidth  21 km/s • ubiquitous at 2.5 20 per 109 LB e.g. 750 for NGC 3379

  9. PNe v stars • by assumption PNe follow stars • how true is this? • PNe age and population synthesis

  10. techniques for acquiring PNe radial velocities: • imaging+spectroscopy • perot-fabry • slitless spectroscopy

  11. imaging + spectroscopyngc 5128 Hui, Ford, Ciardullo, Jacoby 1993 Hui, Ford, Freeman, Dopita 1995 Peng, Ford, Freeman 2004

  12. fabry-perot ngc 3384 68 PNe Tremblay, Merritt, Wiilliams 1995

  13. slitless spectroscopy:the PN spectrum

  14. slitless spectroscopy NGC 5128 Slitless spectroscopy(1) trials at AAT 1995

  15. Slitless spectroscopy(2) cf Hui et al 1995 24 PNe compared

  16. Slitless spectroscopy(3) Fehrenbach 1947 Douglas & Taylor 1999

  17. CDI at WHT: M94 modified ISIS 1997-2001 NGC 7457 NGC 5866 Douglas et al. 2000

  18. CDI at VLT: NGC 4697 MB = -19.8 D = 10.5 Mpc UT1 + FORS1 1999/2000 14 hrs: 535 PN to 3 Reff Méndez et al. 2001

  19. Bibliography: PNe velocitieswith slitless spectroscopy CDI (rotating spectrograph): Douglas & Taylor 1999 Douglas, Gerssen et al 2000 CDI (mirror and grism): Méndez, Riffeser et al 2001 PN.S (simultaneous CDI): Douglas, Arnaboldi et al 2002 Romanowsky, Douglas et al 2003

  20. PN.S design

  21. PN.S grating

  22. PN.S mask

  23. instrument efficiency = 72% •  total system efficiency = 33% • three 36 Å [O III] filters ( -1400 .. +3400 km/s) • field of view = 11.4’ x 10.3’ • dispersion 1.29 pxl/Å • built by prime optics, RSAA, ASTRON Douglas et al 2002

  24. sample data 5’ x 2’ field in M31 (H. Merrett et al.)

  25. pn.spectrograph project pn.s team: n. douglas, n. napolitano (groningen) k. kuijken (leiden) a. romanowsky, m. merrifield, h. merrett (nottingham) m. arnaboldi (turin) m. capaccioli (naples) k. freeman (rsaa) o. gerhard (basel)

  26. PN.S programme • sample of 12 bright, round E galaxies: • B  12.5, E2 or rounder, • v < 1300 km/s • 100 - 400 PNe per galaxy, to 5-15 Reff • ~ 8 hours to reach m5007 = 28.0

  27. NGC 3379 E1 , MB = -20.0 D = 11 Mpc WHT+PN.S: March 2002 3 hrs : 197 PN velocities to 7 Reff , v = 20 km/s

  28. Surface brightness profiles PNe stars (Capaccioli et al. 1990)

  29. NGC 3379: Dispersion profile long-slit data (Statler & Smecker-Hane 1999) 29 PNe (Ciardullo, Jacoby & Dejonghe 1993) 110 PNe 197 PNe Isotropic singular isothermal halo isotropic constant-M/L Hernquist model Sluis et al. also confirmed with ~60 PNe

  30. “Science three” dispersion profiles isotropic constant-M/L Hernquist model Romanowsky et al. 2003 (refs for long-slit: Bender et al 1994)

  31. PN.S limitations • - single wavelength: • poor discrimination • utilises 0.1% of spectrum • + undispersed H-alpha camera

  32. M-CDI: masked counter-dispersed imaging past narrow band surveys at D > 10 Mpc: poor returns in follow-up spectroscopy apply counter-dispersed imaging (don’t need good astrometry) but utilise all information

  33. PNe in M87 UT2+FORS2/MXU: 28-30 Apr 2001 MCDI 1400B VPH grism 6 fields @ 1 hr each: 200 PN velocities to 5 Reff , v =15 km/s Ciardullo et al. 1998

  34. NGC3377 future developments:

  35. NGC3377 future developments: wavelength tagging detectors

  36. NGC3377 future developments: spectrum of an entire galaxy

  37. NGC3377 future developments: non-radial velocities

More Related