Satellite Galaxies (Observation) Open Questions No answers Michael Balogh Department of Physics and...
-
Upload
christian-russell -
Category
Documents
-
view
218 -
download
0
Transcript of Satellite Galaxies (Observation) Open Questions No answers Michael Balogh Department of Physics and...
![Page 1: Satellite Galaxies (Observation) Open Questions No answers Michael Balogh Department of Physics and Astronomy University of Waterloo.](https://reader030.fdocuments.net/reader030/viewer/2022032607/56649edb5503460f94bea69c/html5/thumbnails/1.jpg)
Satellite Galaxies (Observation)
Open QuestionsNo answers
•Michael Balogh•Department of Physics and Astronomy
•University of Waterloo
![Page 2: Satellite Galaxies (Observation) Open Questions No answers Michael Balogh Department of Physics and Astronomy University of Waterloo.](https://reader030.fdocuments.net/reader030/viewer/2022032607/56649edb5503460f94bea69c/html5/thumbnails/2.jpg)
High-level Outstanding Questions
• Why are we spending two days talking about satellite galaxies? -- PvD
• (How) does galaxy formation depend on “environment”? (phenomenological question)
• What are the physical processes driving satellite galaxy evolution (physical question)?
![Page 3: Satellite Galaxies (Observation) Open Questions No answers Michael Balogh Department of Physics and Astronomy University of Waterloo.](https://reader030.fdocuments.net/reader030/viewer/2022032607/56649edb5503460f94bea69c/html5/thumbnails/3.jpg)
High-level Outstanding Questions
• (How) does galaxy formation depend on “environment” Quenched fraction depends on Mstar, Mhalo, DR.
The qualitatively holds for any reasonable proxy (?)
Is Mstar the right thing to use? Vc? Mstar/r2? (Cheung et al. 2012)
Woo et al. (2013)
![Page 4: Satellite Galaxies (Observation) Open Questions No answers Michael Balogh Department of Physics and Astronomy University of Waterloo.](https://reader030.fdocuments.net/reader030/viewer/2022032607/56649edb5503460f94bea69c/html5/thumbnails/4.jpg)
High-level Outstanding Questions
• What are the physical processes driving satellite galaxy evolution Strangulation, ram-pressure, harassment, assembly bias,
tidal stripping All certainly occur – proportion will depend on halo mass,
epoch, Mstar, etc.
![Page 5: Satellite Galaxies (Observation) Open Questions No answers Michael Balogh Department of Physics and Astronomy University of Waterloo.](https://reader030.fdocuments.net/reader030/viewer/2022032607/56649edb5503460f94bea69c/html5/thumbnails/5.jpg)
High-level Outstanding Questions
• (How) does galaxy formation depend on “environment” SFH depends on host halo mass and DR. Older stellar populations in denser regions
• What are the physical processes driving satellite galaxy evolution Strangulation, ram-pressure, harassment, assembly bias,
tidal stripping All certainly occur – proportion will depend on halo mass,
epoch, Mstar, etc.
• There. The basic questions are answered. All that’s left are details.
![Page 6: Satellite Galaxies (Observation) Open Questions No answers Michael Balogh Department of Physics and Astronomy University of Waterloo.](https://reader030.fdocuments.net/reader030/viewer/2022032607/56649edb5503460f94bea69c/html5/thumbnails/6.jpg)
High-level Outstanding Questions
• Do the details matter? Probably.
Very difficult to explain why quenching is not 100% efficient at z=0
Maybe difficult to explain why it is equally efficient at z=1! Could indicate a problem with fundamental understanding of
SF/feedback laws
Weinmann et al. (2010)
![Page 7: Satellite Galaxies (Observation) Open Questions No answers Michael Balogh Department of Physics and Astronomy University of Waterloo.](https://reader030.fdocuments.net/reader030/viewer/2022032607/56649edb5503460f94bea69c/html5/thumbnails/7.jpg)
Outstanding Questions(Details)
1. What do the established correlations at z=0 look like at higher redshift?
2. What is the SFH of satellite galaxies? Does this depend on anything?
3. What role is played by dynamics, of galaxy or halo?
4. What other quantities are relevant: HI and molecular gas? Morphology?
![Page 8: Satellite Galaxies (Observation) Open Questions No answers Michael Balogh Department of Physics and Astronomy University of Waterloo.](https://reader030.fdocuments.net/reader030/viewer/2022032607/56649edb5503460f94bea69c/html5/thumbnails/8.jpg)
1. What do the established correlations at z=0 look like at higher redshift?
![Page 9: Satellite Galaxies (Observation) Open Questions No answers Michael Balogh Department of Physics and Astronomy University of Waterloo.](https://reader030.fdocuments.net/reader030/viewer/2022032607/56649edb5503460f94bea69c/html5/thumbnails/9.jpg)
The Local Universe
Woo et al. (2013)
• Note the range of fq is only 0.4-0.8 over most of the parameter space.
• Is there any difference between central/satellite for the same Mstar and Mhalo?
Wetzel et al. (2012)
Central
s
![Page 10: Satellite Galaxies (Observation) Open Questions No answers Michael Balogh Department of Physics and Astronomy University of Waterloo.](https://reader030.fdocuments.net/reader030/viewer/2022032607/56649edb5503460f94bea69c/html5/thumbnails/10.jpg)
z=1 clusters• GCLASS: 10 z~1 clusters from
SpARCs• Deep GMOS spectroscopy:
complete for M>2x1010MSun
![Page 11: Satellite Galaxies (Observation) Open Questions No answers Michael Balogh Department of Physics and Astronomy University of Waterloo.](https://reader030.fdocuments.net/reader030/viewer/2022032607/56649edb5503460f94bea69c/html5/thumbnails/11.jpg)
z=1 clusters• GCLASS: 10 z~1 clusters from SpARCs• Deep GMOS spectroscopy: complete for
M>2x1010MSun
![Page 12: Satellite Galaxies (Observation) Open Questions No answers Michael Balogh Department of Physics and Astronomy University of Waterloo.](https://reader030.fdocuments.net/reader030/viewer/2022032607/56649edb5503460f94bea69c/html5/thumbnails/12.jpg)
z=1 groups
• GEEC2 sample: X-ray groups (M~6x1013) in COSMOS
• Suggestive of steep mass function for passive galaxies
Mok et al. (2013)
![Page 13: Satellite Galaxies (Observation) Open Questions No answers Michael Balogh Department of Physics and Astronomy University of Waterloo.](https://reader030.fdocuments.net/reader030/viewer/2022032607/56649edb5503460f94bea69c/html5/thumbnails/13.jpg)
Redshift evolution
• Quiescent fractions are high out to z=1 W
oo e
t al. (2
01
3)
ICBS, zCOSMOS, GEEC/GEEC2, GCLASS
Massive clusters (>1014)
Large Groups (0.5-1 x 1014)
Small groups (<5x1013)
log(Mstar) ~ 10.5
Field
![Page 14: Satellite Galaxies (Observation) Open Questions No answers Michael Balogh Department of Physics and Astronomy University of Waterloo.](https://reader030.fdocuments.net/reader030/viewer/2022032607/56649edb5503460f94bea69c/html5/thumbnails/14.jpg)
• We have only begun to sparsely sample the parameter space at z>0.5
1. What do the established correlations at z=0 look like at higher redshift?
![Page 15: Satellite Galaxies (Observation) Open Questions No answers Michael Balogh Department of Physics and Astronomy University of Waterloo.](https://reader030.fdocuments.net/reader030/viewer/2022032607/56649edb5503460f94bea69c/html5/thumbnails/15.jpg)
2. What is the SFH of satellite galaxies?• What are the relevant timescales for
“environment quenching”?
![Page 16: Satellite Galaxies (Observation) Open Questions No answers Michael Balogh Department of Physics and Astronomy University of Waterloo.](https://reader030.fdocuments.net/reader030/viewer/2022032607/56649edb5503460f94bea69c/html5/thumbnails/16.jpg)
Ages of Quiescent galaxies
Smith et al. (2012)
• High s/n spectral analysis of Coma galaxies shows dwarf galaxies of fixed s are older near the cluster centre.
• Can be matched with infall models if quenching is relatively slow (t~1Gyr)• No strong constraint on
when the quenching occurred
![Page 17: Satellite Galaxies (Observation) Open Questions No answers Michael Balogh Department of Physics and Astronomy University of Waterloo.](https://reader030.fdocuments.net/reader030/viewer/2022032607/56649edb5503460f94bea69c/html5/thumbnails/17.jpg)
Ages of transition galaxies: Red disks
• Disks in NFPS are redder near cluster centre
• Gradient can be matched with slow (t~2.5 Gyr) strangulation model if quenching initiates at large radius
• A delay results in a gradient somewhat too steep
Taranu et al. (2013)
![Page 18: Satellite Galaxies (Observation) Open Questions No answers Michael Balogh Department of Physics and Astronomy University of Waterloo.](https://reader030.fdocuments.net/reader030/viewer/2022032607/56649edb5503460f94bea69c/html5/thumbnails/18.jpg)
SFR distribution
Salim et al. (2007)
Wetzel et al. (2013)
• Matching detailed SFR distribution and quenched fraction simultaneously is difficult
• Success here with a delay+rapid quenching model
• Requires understanding the SF calibration at <0.1 Msun/year
![Page 19: Satellite Galaxies (Observation) Open Questions No answers Michael Balogh Department of Physics and Astronomy University of Waterloo.](https://reader030.fdocuments.net/reader030/viewer/2022032607/56649edb5503460f94bea69c/html5/thumbnails/19.jpg)
Quiescent galaxies at z=1
Muzzin et al. (2012)
• Average D4000 in GCLASS quiescent galaxies shows no dependence on environment at z=1
• Requires environment-quenching rate to evolve similarly to mass-quenching rate
![Page 20: Satellite Galaxies (Observation) Open Questions No answers Michael Balogh Department of Physics and Astronomy University of Waterloo.](https://reader030.fdocuments.net/reader030/viewer/2022032607/56649edb5503460f94bea69c/html5/thumbnails/20.jpg)
Transition galaxies at z=1?
• GEEC approach is to use colours rather than SFR
• Is there a population of “green” galaxies between the two sequences?
Mok et al. (2013)
![Page 21: Satellite Galaxies (Observation) Open Questions No answers Michael Balogh Department of Physics and Astronomy University of Waterloo.](https://reader030.fdocuments.net/reader030/viewer/2022032607/56649edb5503460f94bea69c/html5/thumbnails/21.jpg)
Infall models at z=1
• High red fraction at z=1 seems to require shorter delay, consistent with (1+z)-1.5
Mok et al. (in prep)
tdelay=3Gyr
tdelay=3(1+z)-
1.5
![Page 22: Satellite Galaxies (Observation) Open Questions No answers Michael Balogh Department of Physics and Astronomy University of Waterloo.](https://reader030.fdocuments.net/reader030/viewer/2022032607/56649edb5503460f94bea69c/html5/thumbnails/22.jpg)
Infall models at z=1
Mok et al. (in prep)
• Fairly short quenching timescale, t<0.25Gyr, needed to match the transition population
Transition
Passive
![Page 23: Satellite Galaxies (Observation) Open Questions No answers Michael Balogh Department of Physics and Astronomy University of Waterloo.](https://reader030.fdocuments.net/reader030/viewer/2022032607/56649edb5503460f94bea69c/html5/thumbnails/23.jpg)
Spectral line analysis
Mok et al. (in prep)
• But H d absorption is weak: any quenching model predicts it to be stronger
quenching
frosting• Requires ~10 bursts per Gyr
• Makes limit on quenching timescale even tighter
![Page 24: Satellite Galaxies (Observation) Open Questions No answers Michael Balogh Department of Physics and Astronomy University of Waterloo.](https://reader030.fdocuments.net/reader030/viewer/2022032607/56649edb5503460f94bea69c/html5/thumbnails/24.jpg)
2. What are the relevant timescales for “environment quenching”?
• I don’t know.• We can probably still do a better
job at z=0, carefully measuring SFR and ages, more sophisticated modeling
• Potentially a lot of constraining power in doing the same tests at z>0.5, with much more data
![Page 25: Satellite Galaxies (Observation) Open Questions No answers Michael Balogh Department of Physics and Astronomy University of Waterloo.](https://reader030.fdocuments.net/reader030/viewer/2022032607/56649edb5503460f94bea69c/html5/thumbnails/25.jpg)
3. What is the role of dynamics? Galaxy or halo.
![Page 26: Satellite Galaxies (Observation) Open Questions No answers Michael Balogh Department of Physics and Astronomy University of Waterloo.](https://reader030.fdocuments.net/reader030/viewer/2022032607/56649edb5503460f94bea69c/html5/thumbnails/26.jpg)
Galaxy dynamics
Oman et al. (2013)
• Would like to use velocity information to identify galaxy orbits. e.g. Balogh et al. (1999); Nobel et al. (2013)
![Page 27: Satellite Galaxies (Observation) Open Questions No answers Michael Balogh Department of Physics and Astronomy University of Waterloo.](https://reader030.fdocuments.net/reader030/viewer/2022032607/56649edb5503460f94bea69c/html5/thumbnails/27.jpg)
Galaxy orbits
Oman et al. (2013)
Radial velocity vs position for galaxies with different infall ages.
![Page 28: Satellite Galaxies (Observation) Open Questions No answers Michael Balogh Department of Physics and Astronomy University of Waterloo.](https://reader030.fdocuments.net/reader030/viewer/2022032607/56649edb5503460f94bea69c/html5/thumbnails/28.jpg)
Galaxy orbits
Oman et al. (2013)
Radial velocity vs position for galaxies with different infall ages.
With projection, most of the information is lost
![Page 29: Satellite Galaxies (Observation) Open Questions No answers Michael Balogh Department of Physics and Astronomy University of Waterloo.](https://reader030.fdocuments.net/reader030/viewer/2022032607/56649edb5503460f94bea69c/html5/thumbnails/29.jpg)
Group Dynamics
Balogh & McGee (2010)
• Do properties of the halo other than its mass matter?• From SDSS, any
scatter in passive fraction appears to be small
![Page 30: Satellite Galaxies (Observation) Open Questions No answers Michael Balogh Department of Physics and Astronomy University of Waterloo.](https://reader030.fdocuments.net/reader030/viewer/2022032607/56649edb5503460f94bea69c/html5/thumbnails/30.jpg)
Global Group dynamics
Hou et al. (2013)
• No evidence for strong dependence on group dynamical state
![Page 31: Satellite Galaxies (Observation) Open Questions No answers Michael Balogh Department of Physics and Astronomy University of Waterloo.](https://reader030.fdocuments.net/reader030/viewer/2022032607/56649edb5503460f94bea69c/html5/thumbnails/31.jpg)
4. What are the correlations with other key quantities: HI, molecular gas, morphology?
![Page 32: Satellite Galaxies (Observation) Open Questions No answers Michael Balogh Department of Physics and Astronomy University of Waterloo.](https://reader030.fdocuments.net/reader030/viewer/2022032607/56649edb5503460f94bea69c/html5/thumbnails/32.jpg)
Morphology
• Several studies have indicated that any transformation requires bulge growth
• e.g. from 116 X-ray groups (photoz membership) in COSMOS:
George et al. (2013)
![Page 33: Satellite Galaxies (Observation) Open Questions No answers Michael Balogh Department of Physics and Astronomy University of Waterloo.](https://reader030.fdocuments.net/reader030/viewer/2022032607/56649edb5503460f94bea69c/html5/thumbnails/33.jpg)
Is HI a more sensitive probe?
Gavazzi et al. (2013)
• Gavazzi et al.: Ha imaging + ALFALFA in Virgo
• Galaxies become HI deficient faster than their sSFR declines
• Tracking the change in molecular and neutral gas relative to SFR could be very powerful
![Page 34: Satellite Galaxies (Observation) Open Questions No answers Michael Balogh Department of Physics and Astronomy University of Waterloo.](https://reader030.fdocuments.net/reader030/viewer/2022032607/56649edb5503460f94bea69c/html5/thumbnails/34.jpg)
Progress?
• Important to add the cosmic time variable into the detailed z=0 correlations.
• Greatest scope for advance is in SDSS-like surveys covering 0.5<z<2• Need high spatial completeness of mass-
selected samples• Requires multiobject spectrographs on
wide-field, large aperture telescopes
![Page 35: Satellite Galaxies (Observation) Open Questions No answers Michael Balogh Department of Physics and Astronomy University of Waterloo.](https://reader030.fdocuments.net/reader030/viewer/2022032607/56649edb5503460f94bea69c/html5/thumbnails/35.jpg)
ngCFHT
• Concept introduced to the CFHT community at the 2010 Users Meeting in Taipei
• Followed up with workshop in March 2013, over 100 participants from Canada, France, China, Taiwan, Japan, India, Korea, Brzil, Australia, USA
Create a new and expanded partnership to
1. replace the 3.6m telescope with a 10m-class telescope, mounted on the existing pier and within the volume of the current dome.
2. install a dedicated wide-field (1.5 deg2) multi-object spectrograph that can simultaneously collect spectra for more than ~3000 sources.
3. do this by the early 2020s and immediately begin spectroscopic surveys.
![Page 36: Satellite Galaxies (Observation) Open Questions No answers Michael Balogh Department of Physics and Astronomy University of Waterloo.](https://reader030.fdocuments.net/reader030/viewer/2022032607/56649edb5503460f94bea69c/html5/thumbnails/36.jpg)
Survey N(z) Depth Comp
GAMA 300k R<19.8 >90%
DEEP2 60k R<24.1 60%
VVDS 100k35k
I<22.5I<24
25%20%
zCOSMOS 20k I<22.5 66%
VIPERS 100k I<22.5 40%Survey N(z) Depth Comp.
Wide 7.4M I<23.5 10%
Med 2.5M I<24.25 >90%
Deep 30k I<26 >90%
Clusters >1000 I<23.5 >90%
Virgo 500k I<23.6 >90%
ngCFHT
Existing: