Eric GawiserYale University

The MUSYC Census of Protogalaxies at z=3

MUSYC E-HDFS UBR composite

Protogalaxies at z=3: TLAs• LBG=Lyman Break Galaxy selected via Lyman break, blue continuum (starburst)

• LAE=Lyman Alpha Emitter selected via strong emission line (early stage of star formation)

• DRG=Distant Red Galaxy selected via Balmer break in observed NIR

• AGN=Active Galactic Nucleus selected in X-rays, Mid-infrared and/or via LBG-like colors

• DLA=Damped Lyman Absorption system selected in absorption, N(HI)>1020 cm-2

Demographics of ProtogalaxiesGoals:

• Cosmological quantities (e.g. cosmic star formation rate density) should be summed over all objects, not just Lyman Break Galaxies, which trace the bright end of the (rest-frame ultraviolet) luminosity function

• Determine if the progenitors of typical galaxies like the Milky Way are found amongst the zoo at z=3.

Approaches:

1. Go deeper with one selection technique until you detect all of the galaxies.

Example: dim Lyman Break Galaxies in HUDF.

Drawback: spectroscopic confirmation impossible so little can be learned about population found.

• Apply all selection techniques in same volume of the universe to measure overlaps in populations and get a full census.

Drawback: need a carefully designed multiwavelength survey.

MUSYC(Multiwavelength Survey by Yale-Chile)

www.astro.yale.edu/MUSYCGawiser et al 2005, ApJS, astro-ph/0509202

Eric Gawiser (Yale, P.I.) Pieter van Dokkum (Yale, P.I.)Paulina Lira (U. Chile)José Maza (U. Chile)Meg Urry (Yale)Martin Altmann (U. Chile)F.J. Castander (IEEC-Barcelona)Daniel Christlein (U. Chile/Yale)Paolo Coppi (Yale)Harold Francke (U. Chile Ph.D. student)Marijn Franx (Leiden)David Herrera (Yale)Leopoldo Infante (P.U. Catolica)Sheila Kannappan (U. Texas)Charles Liu (CUNY/AMNH)Danilo Marchesini (Yale) Rene Méndez (U. Chile)Ryan Quadri (Yale Ph.D. student)Ned Taylor (Leiden Ph.D. student)Ezequiel Treister (U. Chile Ph.D. student)Shanil Virani (Yale Ph.D. student)Sukyoung Yi (Yonsei)

MUSYC: A Square-degree Survey of the Formation and Evolution of Galaxies and their Central Black Holes

Science Projects:

1. Census of protogalaxies at z=3

2. AGN demographics at 0<z<6

3. Proper motion + color survey for white and brown dwarfs

4. Groups and clusters at z<1

5. Recent star formation in ellipticals

6. Low surface-brightness galaxies

7. Quasar lensing statistics

8. Public outreach (Hayden Planetarium)

Extragalactic Atlas of the Hayden Planetarium’s Digital Universe

Download from www.haydenplanetarium.org and run on your laptop for classes and

personal sense of awe

Survey Mag. Limit # of galaxies with redshifts

# of quasars with redshifts

SDSS r'<21 229293 374724

2dF R<19 gals,

R<21 qsos

50748 22431

MUSYC (UBVRIzJHK photo-z’s)

R<26 277341 obj.

(90% galaxies)

~500

Origin of the Lyman break

Steidel & Hamilton 1992

Lyman Break Galaxy (LBG)

LBG in E-CDFS, R=22.8, z=3.38 strong Ly emission (EW=60Å, SFRUV ≥350 M/yr)

numerous chemical absorption features (6 hr IMACS exposure)

Ly

SiII

OI/SiII

CIIFeII

SiIV

SiII

CIV

MUSYCGawiser et al 2005

U B NB5000 V RLyman Emitter (LAE)

Gawiser et al 2006, ApJL submitted(MUSYC plus Caryl Gronwall, Robin Ciardullo, John Feldmeier)

LAE in E-CDFS, R=25.7, z=3.085 Ly EW=200Å, SFR≥30 M/yr (6 hr

IMACS exposure)

Lyman Alpha Emitters probe the z=3 luminosity function much deeper than Lyman break galaxies (R<25.5)

UVR colors of confirmed LAE are consistent with those of LBGs

Confirmed LAEDisagrees with claims of red LAEsby Stiavelli et al 2001, Campos et al 1999

Confirmed LBG

ConclusionsMUSYC data release (images and catalogs):

www.astro.yale.edu/MUSYC and Gawiser et al. 2005, ApJS, astro-ph/0509202 LAEs probe the z=3 luminosity function deeper than LBG

samples but have similar colors, revealing rapid SF. All protogalaxy families (including LAEs undergoing

possible first burst of star formation) have dark matter halo masses of 1011M. Typical (unbiased) z=3 dark matter halos have 109M. Was galaxy formation supressed in those halos?