![Page 1: GEMS Collaboration Meeting Baltimore, Jan 20-21, 2003](https://reader035.vdocuments.mx/reader035/viewer/2022070415/56814f56550346895dbd01c7/html5/thumbnails/1.jpg)
GEMS Collaboration Meeting
Baltimore, Jan 20-21, 2003
What do we want to accomplish?
Get to know each otherTake stock of our status quo
–Data, software (tools),goals,...
Better define data productsPrioritize science goals
–Define approach–Clarify team responsibilities–(Re-)define schedule
GEMS vs. Other current activities
![Page 2: GEMS Collaboration Meeting Baltimore, Jan 20-21, 2003](https://reader035.vdocuments.mx/reader035/viewer/2022070415/56814f56550346895dbd01c7/html5/thumbnails/2.jpg)
2
Galaxy Population over the last 10 Gyrs
How many stars have formed since z~1.2 ?
– In which Galaxies? – Mostly during in star-bursts, or “quiescently”?– Which galaxies are “old” already?
How did the clustering of galaxies evolve ?– Mass clustering vs. galaxy bias.– Always a morphology-density relation?
When and how did bulges and disks form ?– How did the merger rate evolve?– Is there an „angular momentum“ problem– Do disks grow inside out?
What makes AGNs light up?– Dramatic drop in AGN lum. density since z~1
![Page 3: GEMS Collaboration Meeting Baltimore, Jan 20-21, 2003](https://reader035.vdocuments.mx/reader035/viewer/2022070415/56814f56550346895dbd01c7/html5/thumbnails/3.jpg)
3
What Data do we Need ?(to tackle this via “look-back” observations)
Galaxy properties as a function of:– Redshift/Epoch with t/tH ~1
Note: z=1.2 t look-back = 10 Gyrs
– Luminosity– Spectral Energy Distribution (SED)– Internal structure (size, bulge-to-disk, etc.)– Environment a multi-dimensional parameter space
+ account for large-scale fluctuation in the galaxy and mass distribution.
+ include “typical” galaxies at all epochs i.e. reach below L* at all redshifts
![Page 4: GEMS Collaboration Meeting Baltimore, Jan 20-21, 2003](https://reader035.vdocuments.mx/reader035/viewer/2022070415/56814f56550346895dbd01c7/html5/thumbnails/4.jpg)
4
Survey Requirements
Several 10,000 galaxies with– Redshifts to z>1 (good to a few
percent)
– Faint flux limit mr~24
– SEDs, including (rest-) UV and optical
Several large fields– Co-moving size > 5 Mpc
High-resolution (0.1”) imaging– typical scale lengths are 0.3 asec– two-color rest-frame B at all z
![Page 5: GEMS Collaboration Meeting Baltimore, Jan 20-21, 2003](https://reader035.vdocuments.mx/reader035/viewer/2022070415/56814f56550346895dbd01c7/html5/thumbnails/5.jpg)
5
Existing Faint Surveys
CFRS – Lilly, LeFevre, et al. – I<22.5, 591 galaxies
CNOC2– Yee, Carlberg etal.– R<21.5, z<0.55,2000 galaxies
HDF– Williams etal., Cohen etal. – redshifts for 200 objects
Medium Deep Survey – Keck spectroscopy
![Page 6: GEMS Collaboration Meeting Baltimore, Jan 20-21, 2003](https://reader035.vdocuments.mx/reader035/viewer/2022070415/56814f56550346895dbd01c7/html5/thumbnails/6.jpg)
6
CFRS Luminosity Function
![Page 7: GEMS Collaboration Meeting Baltimore, Jan 20-21, 2003](https://reader035.vdocuments.mx/reader035/viewer/2022070415/56814f56550346895dbd01c7/html5/thumbnails/7.jpg)
7
Status quo: Morphologies
![Page 8: GEMS Collaboration Meeting Baltimore, Jan 20-21, 2003](https://reader035.vdocuments.mx/reader035/viewer/2022070415/56814f56550346895dbd01c7/html5/thumbnails/8.jpg)
8
Status quo: bars
![Page 9: GEMS Collaboration Meeting Baltimore, Jan 20-21, 2003](https://reader035.vdocuments.mx/reader035/viewer/2022070415/56814f56550346895dbd01c7/html5/thumbnails/9.jpg)
9
Status quo: Bulge-Disk Fitting:GIM2D(Simard etal 1999)
Data:
somewhat heterogeneous HST imaging
![Page 10: GEMS Collaboration Meeting Baltimore, Jan 20-21, 2003](https://reader035.vdocuments.mx/reader035/viewer/2022070415/56814f56550346895dbd01c7/html5/thumbnails/10.jpg)
10
![Page 11: GEMS Collaboration Meeting Baltimore, Jan 20-21, 2003](https://reader035.vdocuments.mx/reader035/viewer/2022070415/56814f56550346895dbd01c7/html5/thumbnails/11.jpg)
11
Status quo: disk sizes
![Page 12: GEMS Collaboration Meeting Baltimore, Jan 20-21, 2003](https://reader035.vdocuments.mx/reader035/viewer/2022070415/56814f56550346895dbd01c7/html5/thumbnails/12.jpg)
12
Status quo: Disk size functionLilly et al 1998 HST images of CFRS galaxies
![Page 13: GEMS Collaboration Meeting Baltimore, Jan 20-21, 2003](https://reader035.vdocuments.mx/reader035/viewer/2022070415/56814f56550346895dbd01c7/html5/thumbnails/13.jpg)
13
Status quo: merger rate
![Page 14: GEMS Collaboration Meeting Baltimore, Jan 20-21, 2003](https://reader035.vdocuments.mx/reader035/viewer/2022070415/56814f56550346895dbd01c7/html5/thumbnails/14.jpg)
14
Surveys at Hand
COMBO-17 C. Wolf, K. Meisenheimer (co-PIs), E. Bell, C.
Maier, H.-W. Rix, S. Phleps, A. Borch + Edinburgh, Bonn
– Data from WFI at the MPG/ESO 2.2m on La Silla
GEMS – 2-color, deep HST/ACS mosaic ( ~180 x HDF
area)
![Page 15: GEMS Collaboration Meeting Baltimore, Jan 20-21, 2003](https://reader035.vdocuments.mx/reader035/viewer/2022070415/56814f56550346895dbd01c7/html5/thumbnails/15.jpg)
15
GEMS: Key to “internal structure”(Galaxy Evolution from Morphology and SEDs)
Large HST program (125+50 orbits) to image “extended-Chandra-Deep-Field-South”
– 10,000 redshifts from COMBO-17– 9x9 ACS tiles 150 x HDF– V and z
– Limit: mz~27.5
![Page 16: GEMS Collaboration Meeting Baltimore, Jan 20-21, 2003](https://reader035.vdocuments.mx/reader035/viewer/2022070415/56814f56550346895dbd01c7/html5/thumbnails/16.jpg)
16
GEMS 58
1.5% of total
![Page 17: GEMS Collaboration Meeting Baltimore, Jan 20-21, 2003](https://reader035.vdocuments.mx/reader035/viewer/2022070415/56814f56550346895dbd01c7/html5/thumbnails/17.jpg)
17
COMBO-17 (~0.7”) vs. HST/ACS
![Page 18: GEMS Collaboration Meeting Baltimore, Jan 20-21, 2003](https://reader035.vdocuments.mx/reader035/viewer/2022070415/56814f56550346895dbd01c7/html5/thumbnails/18.jpg)
18
..and we do have the redshifts..
~1.2´x 2.2´ (0.003 of the total field)
![Page 19: GEMS Collaboration Meeting Baltimore, Jan 20-21, 2003](https://reader035.vdocuments.mx/reader035/viewer/2022070415/56814f56550346895dbd01c7/html5/thumbnails/19.jpg)
19
GEMS: Top-Level Project Steps
Image acquisision, reduction Object Detection+Match-up
Fitting/Morphology quantification
Selection/fitting simulation Structural „master catalog“
Empirical results Link to theoretical predictions Model-dependent results
![Page 20: GEMS Collaboration Meeting Baltimore, Jan 20-21, 2003](https://reader035.vdocuments.mx/reader035/viewer/2022070415/56814f56550346895dbd01c7/html5/thumbnails/20.jpg)
20
GEMS Analysis: Basic Steps
Task Responsible Date
Complete (%)
Data Acquistion
Caldwell, Vick, Peng
100% P ~95% E
Tile Reduction
Caldwell ~90% D~50% E
Object Detection
McIntosh ~90% D ~20% E
Galfit Code Peng Häußler,Jogee
~95% D
GIM2D McIntosh ~95% D
![Page 21: GEMS Collaboration Meeting Baltimore, Jan 20-21, 2003](https://reader035.vdocuments.mx/reader035/viewer/2022070415/56814f56550346895dbd01c7/html5/thumbnails/21.jpg)
21
Task ahead: Fitting 30,000 galaxies
![Page 22: GEMS Collaboration Meeting Baltimore, Jan 20-21, 2003](https://reader035.vdocuments.mx/reader035/viewer/2022070415/56814f56550346895dbd01c7/html5/thumbnails/22.jpg)
22
GEMS vs past work
30-fold number increase Well defined sample with ample
external information z-band ACS imaging
![Page 23: GEMS Collaboration Meeting Baltimore, Jan 20-21, 2003](https://reader035.vdocuments.mx/reader035/viewer/2022070415/56814f56550346895dbd01c7/html5/thumbnails/23.jpg)
23
Our competitive edge
COMBO-17 full catalog not yet published
GEMS mosaic largest HST image mosaic of sufficient depth (perhaps for a while...)
Comprehensive team experienceBUT..... GEMS data instantly public With DEEP and VMOS, the COMBO-17
data will loose their uniqueness within a year
![Page 24: GEMS Collaboration Meeting Baltimore, Jan 20-21, 2003](https://reader035.vdocuments.mx/reader035/viewer/2022070415/56814f56550346895dbd01c7/html5/thumbnails/24.jpg)
24
Top-Level Science Goals
How did stellar disks evolve/grow?– (Disk) size function
– L vs reff , Tully-Fisher
Evolution of bulges/ellipticals– B/D ratios, growth of „old“ pops.
– L vs reff , fundamental plane
Evolution of merger rate vs star burst rate
Did „internal evolution“ play a role?– Bar statistics
When are galaxies AGNs?– Host galaxies
![Page 25: GEMS Collaboration Meeting Baltimore, Jan 20-21, 2003](https://reader035.vdocuments.mx/reader035/viewer/2022070415/56814f56550346895dbd01c7/html5/thumbnails/25.jpg)
What do we want to accomplish?
Get to know each otherTake stock of our status quo
–Data, software (tools), responsibilities
Better define data productsPrioritize science goals
–Define approach–Clarify responsibilities–(Re-)define schedule–set of possible 1.generation papers
GEMS vs. Other current activities
![Page 26: GEMS Collaboration Meeting Baltimore, Jan 20-21, 2003](https://reader035.vdocuments.mx/reader035/viewer/2022070415/56814f56550346895dbd01c7/html5/thumbnails/26.jpg)
26
![Page 27: GEMS Collaboration Meeting Baltimore, Jan 20-21, 2003](https://reader035.vdocuments.mx/reader035/viewer/2022070415/56814f56550346895dbd01c7/html5/thumbnails/27.jpg)
27
Spectroscopy goals for COMBO-17/GEMS
Redshifts – outliers?– present median precision 180 Mpc– GEMS image contains 6 x more galaxies with
good photometry Spectral features
– Balmer emission/absorption lines– AGN vs. star-formation diagnostics
Kinematics– Stellar and emission lines
(stellar) masses from SEDs, spectra and kinematics
Star-formation rates and metallicity
Interaction rates – local velocity dispersion