Megan E. Eckart

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The SEXSI Survey Recent Progress

• Megan E. Eckart
• Caltech
• with Fiona Harrison, David Helfand, Daniel
  Stern, Luke Kotredes

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Overview

• Introduction to the SEXSI sample and optical
  followup
• Highlights of the optical/X-ray sample
  composition
• Spitzer data
• high-z type 2 quasar candidates
• SEDs of spectroscopically IDd sources

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SEXSI Survey

• Study dominant contributors to XRB
• 1034 2-10 keVsources from 27 Chandra
  pointings (2 deg2)
• R-band imaging
• 438 spectroscopic redshifts from Keck

Harrison et al. 2003, ApJ, 596, 944-956 (Paper 1)
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SEXSI Survey
Harrison et al. 2003, ApJ, 596, 944-956 (Paper 1)
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Redshift Distribution

• Peak z 0.7
• 34 narrow-lined Lxgt1044 sources(type-2 quasar
  candidates)
• nine z gt 2, obscured type-2 quasar candidates

Eckart et al. 2006, ApJS, 165, 19-56 (Paper 3)
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Fraction Obscured

• SEXSI - excellent statistics over flux range
• 50 obscuredindependent of luminosity

Fraction with log(NH) gt 22
log (Unobscured 2-10 keV Luminosity erg s-1)
Eckart et al. 2006, ApJS, 165, 19-56 (Paper 3)
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Spitzer Data

• Spitzer data over five SEXSI fields (IRAC
  MIPS)
• 250 SEXSI X-ray sources covered
• 140 with spectroscopic ID
• 62 of total X-ray sources are in wedge
• 86 of BLAGN
• 67 of NLAGN
• 28 of ELG
• 15 of sources with Lxlt10 43.5 erg s-1

- wedge from Stern et al. (2005)
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High-z QSO 2
- quadrant split from Martinez-Sansigre, Lacy et
al. (2005)
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High-z QSO 2
- quadrant split from Martinez-Sansigre, Lacy et
al. (2005)
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BLAGN SEDs

• Many BLAGN fit a typical quasar SED (Elvis et
  al. 1994)
• BUT, there are many that fit a star forming
  template better in mid-IR/optical (Devriendt et
  al. 1999 template plotted above)

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NLAGN SEDs

• Bad match to both templates
• (would match an absorbedAGN spectrum )

• Fits star forming template in IR

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ELG SEDs

• Overwhelming majority (but not all) of ELG fit
  starforming template

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In Progress

• Synthesis of spectrally identified and
  unidentified SEDs
• X-ray stacking of Spitzer sources
• with Chandra nondetections
• Acknowledgements Fiona Harrison, David Helfand,
  Dan Stern, Luke Kotredes

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