Transcript ppt - CANDELS

CANDELS
Cosmic Assembly Near-infrared Deep
Extragalactic Legacy Survey
Co-PIs:
Sandra Faber
University of California Santa Cruz
Harry Ferguson
Space Telescope Science Institute
CANDELS
Cosmic Assembly Near-infrared Deep
Extragalactic Legacy Survey
CANDELS Team:
100 scientists
12 countries
Major nodes: UCSC, STScI, ROE,
NOAO, UCI, UMich, MPIA,…
What WFC3-IR can do
What WFC3-IR can do
But the WFC3 diffraction limit is 2-3 times softer than ACS
Photometry gains
Existing
space and
ground
Photometry gains
New WFC3
Exposure Strategy
“Wedding cake” strategy: three layers of J+H
UDFs: 50-100 orbit depth over
~0.004 sq deg
DEEP:
8 orbit depth over
~0.04 sq deg
WIDE:
2 orbit depth over
~0.2 sq deg
Highlights
 Imaging data for 250,000 galaxies from z = 1.5 - 8
 WFC3 bridges the Balmer break out to z ~ 2.5
 WFC3 cuts through dust
 Spitzer Extended Deep Survey, SEDS: IRAC 26 AB (5); means
stellar masses measured to ~3  109 M to z ~ 7
 Overlapping ACS parallels: panchromatic imaging from V  H;
new ACS imaging in UDS, deeper/multicolor ACS imaging in
COSMOS and EGS . . . . . photoz’s!
 UV in GOODS-N: 100 orbits of F275W, F336W
 Every pointing observed at least
twice:
AGN
beyond z ~ 1.5
 Search for variable
 First search for SNe
Survey comparisons
ERS: 9 WFC3 pointings to J+H depth of 4 orbits
Deep: 30 WFC3 pointings to J+H depth of 8 orbits
Wide: 162 WFC3 pointings to J+H depth of 2 orbits
Deep vs. ERS: 5 times more galaxies, 0.6 mag deeper
Wide vs. ERS: 8 times more galaxies, 0.6 mag shallower
Wide + Deep will be the prime finding fields for
first JWST spectroscopy
Three WIDE Fields
COSMOS:
10h 00m +2 deg
14h
EGS:
18m
+53 deg
UDS/UKIDSS/SXDS:
2h 18m -5 deg
Three WIDE Fields
SEDS/IRAC
region
ACS parallel
array
WFC3-IR
primary
array
WIDE FILTERS AND EXPOSURE TIMES:
WFC3-IR: 2 orbits of J+H, at two different epochs for SNe discovery
ACS parallels: 4 orbits of V+I, provides low-z SNe rejection
Two DEEP Fields
GOODS-N:
12h 37m +62 deg
GOODS-S:
03h 30m -28 deg
GOODS-S strategy
ERS2
Deep
region
“Skirt”
region
GOODS-S strategy
WFC3 array
1 orbit
GOODS-S strategy
WFC3 array
1 orbit
ACS parallel
array
GOODS-S strategy
GOODS-S strategy
GOODS-S strategy
GOODS-S exposure maps
J and H-band
Y-band
Deep
region
DEEP FILTERS AND EXPOSURE TIMES:
WFC3-IR: 4 orbits each of Y, J, H, 10 different epochs for SNe discovery
ACS parallels: minimum 14 orbits F814W for secure high-z identifications
GOODS-S exposure maps
F814W, I-band: needed to identify high-z galaxies
Deep
region
Goal: ≥ 28,000 s
in Deep region
Magnitude and mass limits
Area
sq deg
# WFC3 Exposure, orbits
tiles
Y
J
H
Eff. Exposure, orbits
V
I
z
Wide
0.2
162
--
2/3
4/3
4/3
8/3
--
Plus existing ACS
Deep
0.04
30
3
4
4
>3
>14
5
Incl existing ACS
UDF
0.004
3
~40 ~40 ~50
50+ 50+ 50+
Incl existing ACS
Point source limits
Wide
5- AB mag
--
27.0 27.1
5- AB mag
28.7 28.6
--
Plus existing ACS
29
Incl existing ACS
Deep
27.8 28.0 28.0
>29 >30
UDF
29.1 29.5 29.3
30+
Stellar mass @ z~2
30+ 29.4+ Incl existing ACS
M1500, z~7
Wide
109 M
~ -20
Deep
4  108 M
~ -19
UDF
1.4  108 M
~ -18
109 M
Observing schedule
Summary
 Orbit Totals:
 GOODS fields: 483
 EGS: 90
 UDS: 88
 COSMOS: 88
 SNe Follow-up: 152
 Test orbit: 1
 Total: 902 orbits
 Phase II Program IDs
 GOODS-S: 12060-12062
 EGS: 12063
 UDS: 12064
 SNe: 12099
 Public website:
 http://candels.ucolick.org
 Data releases:
 V0.5: builds summed multi-drizzled
images as images come in using
existing instrumental and
astrometric calibrations. Available
within days.
 V1.0: improved versions of V0.5
images based on all data,
additional quality control, and
improved calibrations. Available
within 3 months after last field data
are obtained.
 V2.0: archival version. One year
after last data.
 Value-added data products:
 Re-reduced existing ACS images
multi-drizzled with new data
 Serving all public ancillary data
Supernovae prospects
Supernovae prospects
Dark energy
differences
Supernovae prospects
Supernovae
evolution
HST lifetime
z   candidates
New
WFC3
Yan et al. 2010
Importance of SEDS/IRAC
At z  ,  candidate galaxies in
Deep
At z  ,  candidate galaxies in
Deep
60
objects
here
At z  ,  candidate galaxies in
Wide
100
objects
here
50
objects
here
Merger signatures at z  
Courtesy J. Lotz
Structural parameters at z  
Simulated data
radii
Gini
Sersic n
M20
axial ratio
Useful limit: H ~ 24 AB mag
in Wide survey.
This is 2 x 109 M at z ~ 2.
Half light radius in kpc
Galaxy radii vs. color at z  
Bluecloud
galaxies
Courtesy M. Mozena
RADII OF EARLY-TYPE (PASSIVE) GALAXIES
 UMass measurements at z=0, z=0.4 and z=2
Simulation by Naab et al. 2009 (small points)



Courtesy of M. Giavalisco
Sersic indices at z  
Sersic index
Red
galaxies
Blue
galaxies
WFC3
regime
Courtesy M. Mozena
Fireworks UDF Catalog
zspec = 1.998
log(mass) = 10.689
Old stars?
V
i
Fireworks ERS2 Catalog
zspec = 2.431
log(mass) = 10.210
H
3”
Old stars?
V
i
H
Hydro-ART Simulations (Ceverino et al. 2010)
z = 2.33 log(mass) = 10.20
Raw, no dust
V
i
With dust (absorption and scattering)
H
3”
Old stars
V
i
H
z-band
H-band
z-H
z-band
H-band
z-H
Guo et al. in prep.
PSF-matched
color maps
Simulated “lookback slices”
Back in time
Theoretical completeness
Two SAMs compared: mass completeness in Wide
Bernyk, Croton et al.
Somerville et al.
CANDELS theory group:
Darren Croton, Romeel Dave, Aaron Dutton, Avishai
Dekel, Joel Primack, Rachel Somerville, Risa Wechsler,
and their collaborators…
GOODS-S exposure maps