The WHIQII Survey (WIYN High Image Quality Indiana-Irvine Survey) Erik Tollerud UC Irvine Betsy Barton (UCI), Liese Van Zee (Indiana University), Jeff Cooke(UCI)

WHIQII Survey Imaging: WIYN Minimo w/ ~.7” seeing Spectroscopy: Keck I - LRIS 9 fields, 213 objects ~1 Å/pix , R ~ 4000 123 emission line objects 48 LCBGs

LCBGs Luminous: B < -18.5 Compact: rh <~ 3.5 kpc) Blue: B-V <~0.6, emission line spectra 20% by #, 45% by SF @ z~1 (Noeske et al. 2006) WHIQII fraction ~ 10-18% at 0.4 < z < 1 to B < -17

Metallicities Strong O/Hbeta → R23 + O32 → log(O/H)+12 Kewley & Ellison 08: metallicity calibrations still systematically inconsistant/uncertain McGaugh 1991 best for local compact galaxies (van Zee 2005) Comparison sample: Moustakas & Kennicutt 06

Size independent of O/H

LCBGs have high Ionization Parameter

Conclusions LCBGs undoubtledly heterogeneous – some dwarfs, some bulges/low-L spirals. Surprising lack of metallicity correlations. …apparently compact objects are not necessarily dwarf galaxies. Ionization parameter higher than local field – side effect of compactness. R23 vs. O32 is a useful empirical comparison plane even without calibration.

Hoyos 05 Comparison Hoyos et al. 05 found 17 extremely metal-poor LCBGs in DEEP2 and TKRS by selecting on [OIII] 4363 Their fraction is 17/(1536+3900) ~ 0.3% Can be at best 1 or 2 of WHIQII galaxies by number density arguments

Rh vs. O/H MZR residuals

R vs O/H both branches

Luminosity-Metallicity (LZ)

Imaging Samples WIYN (Kitt Peak) MiniMo 2002- 2004 11 10' x 10' fields Seeing ~ 0.7” Tenish candidates per field

Sample Spectra

Spectroscopy Keck I: LRIS (Low Resolution Imaging Spectrometer ) 9 fields, 213 objects ~1 Å resolution 123 emission line objects 48 LCBGs

Sample Objects 62573 24253 34354 10868

Object 24253 S/N = 2.4 z=0.62 B=-20.1 M*=2 x 1010 B-V=.52 log(O/H)+12=8.85 → [O/H] = .19 (KK=8.99,MGl=7.58) 1”

Object 62573 S/N = 5.1 z=0.44 B=-19.8 M*=8 x 109 B-V=.53 log(O/H)+12=8.84 → [O/H] = .18 (KK=8.98,MGl=7.51) 1”

Object 34354 S/N = 6.77 z=0.57 B=-19.3 M*=1 x 109 B-V=.25 log(O/H)+12=8.49 → [O/H] = -.17 (KK=8.59,MGl=8.15) 1”

Object 10868 S/N = 6.6 z=0.44 B=-19.1 M*=3 x 109 B-V=.44 log(O/H)+12=8.32 → [O/H] = -.34 (KK=8.40,MGl=8.42) 1”

Size vs. Luminosity

LCBGs History HST imaging suggestive of starbursting dwarfs (Koo et al. 1992, Guzman et al. 1998) HDF and others find blue galaxy evolution (Lilly et al. 1995, Ellis 1997) HST and VLT spectra suggest faint disk? (Hammer et al. 2001) 26 HST UDF objects: 90% dwarf, 10% bulges (Noeske et al. 2006) 27 CFHT objects: roughly half are unlikely to fade to dwarfs (Barton & van Zee 2006) Hoyos et al. 05/07: some are very metal poor (~.1 solar), fade to dSphs