eric gawiser yale university the musyc census of protogalaxies at z=3 musyc e-hdfs ubr composite
TRANSCRIPT
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
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)
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?