1 / 4

Spectroscopic Properties of the z=4.5 Ly a -Emitters

Ly a. z=4.5. Ly a. z=4.5. Ly a. z=4.5. Ly a. z=4.5. Spectroscopic Properties of the z=4.5 Ly a -Emitters. Steve Dawson (UCB) in collaboration with Arjun Dey (NOAO) Buell Jannuzi (NOAO) Sangeeta Malhotra (STSci) James Rhoads (STSci) Hyron Spinrad (UCB) Daniel Stern (JPL).

senona
Download Presentation

Spectroscopic Properties of the z=4.5 Ly a -Emitters

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. Lya z=4.5 Lya z=4.5 Lya z=4.5 Lya z=4.5 Spectroscopic Properties of the z=4.5 Lya-Emitters Steve Dawson (UCB) in collaboration with Arjun Dey (NOAO) Buell Jannuzi (NOAO) Sangeeta Malhotra (STSci) James Rhoads (STSci) Hyron Spinrad (UCB) Daniel Stern (JPL) Keck/DEIMOS (Dawson et al. 2004b)

  2. o o o o o o o o o A A A A A A A A A Follow-up Spectroscopy (Dawson et al. 2004a, 2004b) • Keck/LRIS 400-line grating: • lblaze = 8500 • dispersion = 1.86 / pix • DlFWHM ~ 6 (~ 200 km s-1) • Keck/LRIS 150-line grating: • lblaze = 7500 • dispersion = 4.8 / pix • DlFWHM ~ 25 (~ 1000 km s-1) • Keck/DEIMOS 600-line grating: • lblaze = 7500 • dispersion = 0.65 / pix • DlFWHM ~ 3.5 (~ 1000 km s-1) • i • ~ 80 confirming Keck spectra • (selection reliability = 80%) Sample individual spectra Lya Lya [OII] Lya Composite Lya line

  3. Ensemble Results: EW Distribution Max. Lya EW predicted for normal stellar pop. (Charlot & Fall 1993) 20% - 35% of the Lya-emitters in the spectroscopic sample show EW > 240 A. Normal star formation is not powering these sources. What is?

  4. AGN Among the z = 4.5 Population? Lack of detectable X-ray emission (LX < 1042 erg s-1) in deep Chandra ACIS imaging implies: no.(Wang et al. 2004) Lack of high-ionization state emission lines in spectra of restframe UV implies: no. f(HeII) < 0.13 f(Lya) (2s) f(CIV) < 0.08 f(Lya) (2s) No detectable CIV l1549 emission No detectable HeII l1640 emission

More Related