make or break: hi & optical views of galaxy disks
DESCRIPTION
Make or Break: HI & Optical Views of Galaxy Disks. Dissecting and tracking disk galaxies Connecting optical and HI views back to First Light (EoR) Matching HI telescopes with counterpart optical survey engines. Matthew Bershady U. Wisconsin. Disk Galaxy Assembly. …didn’t happen this way:. - PowerPoint PPT PresentationTRANSCRIPT
US SKA Nov’08
Make or Break: HI & Optical Views of Galaxy
Disks
Matthew BershadyU. Wisconsin
Dissecting and tracking disk galaxies
Connecting optical and HI views back to First Light (EoR)
Matching HI telescopes with counterpart optical survey engines
US SKA Nov’08
Disk Galaxy Assembly
1<z<2 ??? today
Disks are fragiledestroyed in major mergers; heated in minor mergers
Dry vs wet mergersWet mergers can make new disks; must happen early to yield old, cold disks today
Large disks today - stirred, not shaken streams not train-wrecks
…didn’t happen this way:
UDF
US SKA Nov’08
Blue Cloud and Red Sequence
Some galaxies evolve from blue cloud to form the red sequence.
Most stars are made in the blue cloud but end up in the red sequence.
Identify which are stirred, which are shaken:
Tag environment For those that are stirred:
Monitor smooth & continuous…
accretion growth star-formation
gas consumption
Red sequence
Blue cloud
e.g., Bell et al.’03,’07
growth and destruction
US SKA Nov’08
Connect Optical and HI Views
Are these two trends self-consistent?
Confirm SFR with a single, direct measure from z=0 to z=1 and higher (H)
Measure HI(z) and HI mass-function directly
Determine SFR as function of both dynamical and HI mass
Identify the individual galaxies, e.g., at the knee of the HI mass-functionBaugh’04
Heavens et al’04
SDSS M*
H, OII, LUV
US SKA Nov’08
Go beyond the co-moving integral
Are these two trends self-consistent?
Confirm SFR with a single, direct measure from z=0 to z=1 and higher (H)
Measure HI(z) and HI mass-function directly
Determine SFR as function of both dynamical and HI mass
Identify the individual galaxies, e.g., at the knee of the HI mass-function
large disks
Baugh’04
Heavens et al’04
US SKA Nov’08
Trace Key Observables in the Blue Cloud
Dynamical mass HI mass (+molecular) Star-formation rate (SFR) Stellar mass (dynamically calibrated) Abundances
Dynamical mass - baryonic mass - metallicity
correlationsEfficiency of processing baryons in gravitational wells
pro
cess
ing
baryons
US SKA Nov’08
The Nearby Universe (z<0.1)
H velocity fields Stellar velocity
dispersions Optical-mid-IR SEDs HI synthesis maps
Marc Verheijen - Kapteyn / GroningenKyle Westfall - U. Wisconsin Rob Swaters - U. Maryland David Andersen - HIA / VictoriaThomas Martinsson - Kapetyn/Groningen
The DiskMass Project
Dissecting disk galaxies and establishing a stellar mass zeropoint
US SKA Nov’08
The DiskMass Project
What are the shapes of dark halos?
How massive are spiral disks?
Are they maximal? What’s the stellar mass-to-
light ratio (M/L) in disks?
Breaking the Disk-Halo Degeneracy
Maximum disk M/LK = 0.75
degenerate solutions
Sub-maxium disk M/LK = 0.22
UGC 6918 high surface-brightness disk
US SKA Nov’08
Sample Properties:
50x50 kpc: SDSS
A wide range of physical size and disk morphology
Normal Face-on Spirals from UGC
US SKA Nov’08
Large range in SF histories:
Factors of 60 in LK
10 in R
6 in LB/LK
US SKA Nov’08
Optical Survey Engines
SparsePak FFU 82 fibers, 4.’’7
diameter 72’’ FOV = 11,000 WIYN 3.5m (Bershady et al.’04,’05)
PPak IFU 331 fibers, 2.’’7 diam. 75’’ FOV = 8000 Calar Alto 3.5m (Verheijen et al.’05)
Customized integral field units…
gas
stars
US SKA Nov’08
Connecting mass and fuel to consumption
Radio synthesis maps (Westerbork + VLA)
Baryon reservoir Halo mass at large radii
US SKA Nov’08
SFR: H + Spitzer High-resolution 2D optical kinematics: stars + gas
Connecting mass and fuel to consumption
US SKA Nov’08
Mapping the Cosmic History of Disks
• Track blue cloud in a range of environments across look-back time
Clusters are nodes in the cosmic web Large volumes around clusters probe
the largest dynamic range in environments
• Find the primeval disks at “First Light” – driving part of the Epoch of Re-ionization (EoR)
0<z<1.5
7<z<12 globularclusters
US SKA Nov’08
At z=0.5, the red sequence is well-formed
MS0451: z=0.54, =1354 km/s, Lx=40e44 ergs/s
WIYN Long-Term Variability SurveyCrawford et al. 2006, 2008
US SKA Nov’08
At z=0.9, the blue cloud dominates
. . . even in rich clustersCL1604: z=0.9, =982 km/s, Lx=2e44 ergs/s
WIYN Long-Term Variability SurveyCrawford et al. 2006, 2008
US SKA Nov’08
HI View: State of the Art:
Verheijen et al. 2007 (van Gorkum)
NB: 200h of 1000h total to come!
Blue cloud
Red sequence
z=0.2
Westerbork
45’
US SKA Nov’08
HI View: State of the Art
Solid detections for 42 sources in 2 x 0.4 deg2 fields
expect 200 sources in 1000h
Limited spatially-resolved kinematic information
H offers detailed kinematic supplement + SFR map
t=80 min, 3.5m telescope (CA)
16x16 array of 1” fibers (PMAS)
A963 - Westerbork
A2192 (z=0.19) - VLA MHI=7x109 Msun
Verheijen & Dwarakanath ‘08
US SKA Nov’08
Optical Follow-up at z>0.2
Scale 4m-class IFU observations to 8m-class telescopes comparable S/N in t=10h, 10 times angular
resolution, twice the luminosity Stellar kinematics out z=0.2 H out to z=1 w/ NIR and AO
Best example: VLT / Sinfoni also Keck / OSIRIS and Gemini / NIFS
Multi-object IFU ? Only example in optical: VLT / FLAMES-GIRAFFE
Fiber+lenslet coupled spectrograph15 units + 15 sky fibers, 25’ patrol field2” x 3” arcsec units: 20 square microlenses (0.52” sampling)11000<< 39000, 370-950 nm range
Flores et al.’04
Eisenhauer et al.’03Larkin et al.’06McGregor et al. ‘99
US SKA Nov’08
Multiplex at high-z:
VLT / GIRAFFE
This is a powerful instrument . . . . . . But note: isovels heavily smoothed.Enough sampling?
Science: emission-line kinematics of distant galaxies.
Flores et al.’06
US SKA Nov’08
Finding First Light
Science Goal: Discover how rapidly the first galaxies form.
When is reionization complete?
The frontier is z>7. The achievable flux limit for SALT is about z=10 (Ly @1.35 m)
Instrument Requirements:
Fabry-Perot imaging: =2500 z=8: we expect > 30 sources in 12
hours z=9-10: expect ~30 sources in 53-
1600 hours Simultaneous optical FP to cull
interlopers (redshifted [OII]3727 if NIR-line is H).
Follow-up optical-NIR MOS at >4000:
eliminate remaining interlopers (split [OII]3727 doublet);
determine kinematics to make dynamical mass estimates;
constrain winds and outflows.
H Ibrightnesstemperature:Reionization
z = 12.1 9 .2 7.6
LyIn theJ band
Barton et al. ‘04
Furlanetto et al.
Sim
ulat
ions
2’x2’8m tel
US SKA Nov’08
Robert Stobie Spectrograph (RSS)@ prime focus
Wisconsin-Rutgers-SAAOOptical: Nordsieck, Williams, O’Donoghue NIR: Sheinis, Wolf, Bershady & Nordsieck
SALT: Southern African Large Telescope
US SKA Nov’08
SALT: Tilted, rotating Arecibo
Tracker
Bream
Payload
Primary Mirror
Concrete Pier
RSS
spherical aberrationcorrector
US SKA Nov’08
RSS: Optical + NIR beams
Dewar
Pre-Dewar
Camera
F-P
doublet
gratings
pupil
filters
Pol-BS
Vis-Camera
Vis F-P’s
Vis-gratings
Nordsieck
Sheinis
Williams
US SKA Nov’08
Dewar
Pre-Dewar
Camera
F-P
doublet
collimatorSlit
gratings
Detector
pupil
filters
Dichroic-BS
RSS Optical layout/Components
US SKA Nov’08
Emission-line Sensitivies
SALT RSS Visibile and NIR beam, 1 arcsec2 aperture
H from 0<z<1.75 to 0.1 Mo/yr
Star-formation rates Nebular abundances H/[NII], [OIII]/HRedenning H/H
Lyfrom 2.6<z<12 to 1 Mo/yr
First Light / EoR5, 1h=4000, 1 arcsec2
US SKA Nov’08
Future Possibilities…toward SKA
HI surveys of disk galaxies Arecibo, pointed (GASS++): z~0.3 Westerbork, EVLA, blind: z~0.2-0.4 MeerKAT, BigKAT, ASKAP, blind: z~0.3-0.6 EoR ???
3D Optical Spectroscopic Follow-up of HI surveys
Spatially resolved ionized-gas kinematics & abundancesz<0.2-0.3: minor investment in existing 4m-
class facilities, z>0.3: major investment in new 8m-
class instrumentation Stellar kinematics
z<0.2-0.3: major investment in new 8m-class instrumentation
z>0.3: 30m-class optical telescope + spectrograph
2D Optical Discovery of First LightRedshifts to z=10
same instrument
$0.5-1M
$10-15M
$1G
$10M