1 / 41

The origin of E+A galaxies

The origin of E+A galaxies. Tomo Goto Japan Aerospace Exploration Agency. January. In Chile. In Japan. The origin of E+A galaxies. Strong Balmer absorption No [OII], no Hα Post-starburst A star + absorption lines E+A galaxies K+A galaxies. Tomo Goto Japan Aerospace Exploration Agency.

chelsi
Download Presentation

The origin of E+A galaxies

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. The origin of E+Agalaxies Tomo Goto Japan Aerospace Exploration Agency Tomo Goto

  2. January In Chile In Japan

  3. The origin of E+Agalaxies • Strong Balmer absorption • No [OII], no Hα • Post-starburst A star + absorption lines • E+A galaxies • K+A galaxies Tomo Goto Japan Aerospace Exploration Agency Tomo Goto

  4. What caused star burst? What stopped it? Cluster related. Found to live in cluster region (MORPHS, Dressler & Gunn 83) Dust enshrouded star formation.(Poggianti et al. 1999; Smail et al. 1999) Merger/Interaction (Zabludoff et al 1996) Still puzzles Very rare(21/11113 in LCRS). Phase is short(1Gyr). Million spectra of SDSS provide good opportunity to address this 20-year-old puzzle. Galaxy evolution in action. Two puzzles on E+A(post-starburst) Tomo Goto

  5. Morphological Butcher-Oemler effect in CE(Goto, et al. 2003, PASJ, 55,755) color morphology More blue galaxies in higher redshift The Morphological BO Effect Tomo Goto

  6. SDSS will produce Imaging of 10,000 sq.deg r~23.1 In 5 optical bands (ugriz) Spectra of and in 5 years Using 2.5m telescope at APO. Sloan Digital Sky Survey (SDSS) Tomo Goto

  7. Tomo Goto

  8. Tomo Goto

  9. Evolution is difficult to observe. Elliptical Galaxy@z=0 Important Transition Stage popIII galaxy@z=10 ? Spiral galaxy@z=0 It is important to observe galaxy evolution in action.=> E+As Tomo Goto

  10. Not much information on past SFH • Truncation of SF: galaxy evolution in action Tomo Goto

  11. HδEW>4Å (2.42%) 4 categories. E+A: Hα<1σ, [OII]<1σ, No emission lines. (0.04%) HDS+[OII]: Hα<1σ, [OII]≧1σ (0.09%) HDS+Hα: Hα≧1σ, [OII]<1σ (0.04%) HDS+em:Hα≧1σ, [OII]≧1σ, Significant emission lines.(2.25%) How to find E+AsGoto, T. et al. 2003, PASJ, 55, 771 Goto, T. 2005, MNRAS, 357, 937 The largest catalog of 564 E+As out of 650,000 galaxies. Tomo Goto

  12. E+A Spectra Tomo Goto

  13. E+A Atlas Images Tomo Goto

  14. HDS+em Spectra Tomo Goto

  15. HDS+em Sample Atlas Images Tomo Goto

  16. [OII] has been used as SF indicator. Could be dust? Metallicity effect? Possible 52% contamination in high-z work HDS+Hα Spectra Tomo Goto

  17. HDS+Hα Atlas Images Tomo Goto

  18. HDS+[OII] Spectra • Could be self-absorption? • HI gas cloud? Tomo Goto

  19. HDS+[OII] Atlas Images Tomo Goto

  20. Cluster Related(ram pressure, tidal interaction with cluster potential, …etc; Dressler et al. 1999; Poggianti et al. 1999) Dusty Starburst(2/15 of E+As have radio SF; Miller et al. 2002; Smail et al. 1997;) Interaction/Merger(tidal features in 5/21 E+As in Zabludoff et al. 1996) Three Scenarios for E+A Tomo Goto

  21. E+A E+A is K+A “E+A” is sometime called “K+A” because of its disk-like morphology. However,… Previous sample might be contaminated by HDS+Hα Tomo Goto

  22. Environment of E+A Galaxies Goto, T. 2005, MNRAS, 357, 937 Not by cluster, not by large-scale structure Tomo Goto

  23. Cluster related(ram pressure, tidal interaction, merging…etc; Dressler et al. 1999; Poggianti et al. 1999) Dusty Starburst(2/15 of E+As have radio SF; Miller et al. 2002; Smail et al. 1997;) Interaction/Merger(tidal features in 5/21 E+As in Zabludoff et al. 1996) Three Scenarios for E+A Tomo Goto

  24. Optical-Infrared color: r-K E+As are not dustier. (c.f., 5 dusty starbursts in Smail et al. are ~1mag redder.) Tomo Goto

  25. Radio Estimated SFR Goto, T. 2004, A&A, 427, 125 No evidence that E+As are not dusty starbursts. Tomo Goto

  26. Cluster related(ram pressure, tidal interaction, merging…etc; Dressler et al. 1999; Poggianti et al. 1999) Dusty Starburst(2/15 of E+As have radio SF; Miller et al. 2002; Smail et al. 1997;) Interaction/Merger(tidal features in 5/21 E+As in Zabludoff et al. 1996) Three Scenarios for E+A Tomo Goto

  27. Hδ_EW vs Time Tomo Goto

  28. u-gvs HδEW(current SF vs recent SF) Young E+As: closer to burst (130-470 Myrs) Tomo Goto

  29. Young E+A Spectra (HδEW>7Å) Tomo Goto

  30. Atlas Image of Young E+As Tomo Goto

  31. Naccompanying galaxies More accompanying galaxies for young E+As at <100kpc scale. Goto, T. 2005, MNRAS, 357, 937 Tomo Goto

  32. Cluster related(ram pressure, tidal interaction, merging…etc; Dressler et al. 1999; Poggianti et al. 1999) Dusty Starburst(2/15 of E+As have radio SF; Miller et al. 2002; Smail et al. 1997;) Interaction/Merger(tidal features in 5/21 E+As in Zabludoff et al. 1996) Three Scenarios for E+A Tomo Goto

  33. 178 Ultra Luminous Infrared Galaxy (ULIRG) 1012Lsun< Lir<1013LsunLargest Sample of ULIRG before ASTROF Goto, T. 2005, MNRAS, 360, 322 Tomo Goto

  34. Not every meger is E+A. Goto, T. 2005, MNRAS, 360, 322 Tomo Goto

  35. Morphological Butcher-Oemler effect in CE(Goto, et al. 2003, PASJ, 55,755) color morphology More blue galaxies in higher redshift The Morphological BO Effect Tomo Goto

  36. Passive Spiral Galaxies in the SDSS(Goto et al. 2003,PASJ,55,757) Spiral but no star formation. What are these? Tomo Goto

  37. Close this Window Optical-IR color --- not dustier Yamauchi, Chisato & Goto, TomotsuguAre passive spiral galaxies truly 'passive' and 'spiral'? A near-infrared perspective.Monthly Notices of the Royal Astronomical Society352 (3), 815-822.doi: 10.1111/j.1365-2966.2004.07966.x PS do not look like dusty star forming galaxies. Yamauchi & Goto 2004 MNRAS, 352, 815 Tomo Goto

  38. The Environment of Passive Spirals(Goto et al. 2003,PASJ,55,757) Passive spirals may be a smoking gun in cluster galaxy evolution. Tomo Goto

  39. Morphology Radius Relation(Goto et al. 2003, MNRAS, 346, 601,) SFR :Gomez et al. 2003 Tomo Goto

  40. E+As are in all environment including the field. E+As are not cluster/LSS origin. Optical-IR color is not redder; radio SFR<10Msun/yr. E+As are not likely to be Dusty Starburst. Excess in Naccompanyinggalaxies . Merger/interaction is most likely to be responsible for the E+As. Consistent with E morphology. The Origin of E+As Tomo Goto

More Related