Searching for Intracluster Light

Far....

Quantifying the ICL as a Function of Cluster Morphology
(Feldmeier etal 2002, 2004)

• KPNO 2.1m + T2KA CCD (20' FOV)
• Filter: Washington M (like V but cuts out night sky lines)
• Flat field using "super sky flats" (Morrison etal 1994, 1997)
• Aggressive masking to eliminate stellar wings and background sources
• Limits: S/N=5 @ mu(V)=26.5, S/N=1 @ mu(V)=28.3

Abell 1413 slight excess of  light at large radius, no significant substructure (HST ACS image - lensing!)
MKW 7 again, slight excess of light at large radius, also broad, diffuse plume seen.

Abell 1234 mu(v)=24-26 mu(v)=26-27 mu(v)=27-28 extended diffuse envelope
Abell 1914 mu(v)=24-26 mu(v)=26-27 (binned) significant luminosity in tidal debris!

Speculation/Comments: ICL morphology seems linked to cluster type Some correlation beween ICL amount and cluster type Only seeing tip of the iceberg!

(from Ciardullo etal 2003)

...and Near:

Need to reach 0.1% of sky over degree scales. The Burrell Schmidt 24/36" wide field telescope atop Kitt Peak Case owned/operated SITe 2048x4096 CCD delivers 1.5o x 0.75o FOV Closed tube minimizes scattered light Upgrades and Engineering (aka "Schmidt Happens!") Directed by Paul Harding Installation and optimization of CCD camera Redesign of Newtonian mount Internal Flocking/Baffling to reduce scattered light Coming in Spring 2006: 2nd CCD: full 1.5o x 1.5o FOV Improved AR coatings (0.15%)

• 3 dark runs in Spring 2004 (6 weeks total)
• Image Virgo's core
  
• 75 stacked Virgo fields, plus > 100 offset skies for flat fielding
• achieved a limiting surface brightness of 28.5 mag/arcsec² in V
• 1.5 mag/arcsec² fainter than earlier work (Malin 1994; Weil et al 1997; Katsayannis et al 1998)
• calibrated, quantitative photometric solution with a well-understood error model.
• The Virgo "Cat Scan"

We see: long streams (>100 kpc) orbital arcs extended halos common envelopes tidal debris everywhere! hierarchical evolution Analysis (in progress): how much? compare to PNe  halo structure ICL-galaxy connection dwarfs