IS THERE A MAXIMUM MASS FOR
STAR FORMATION?
Picture Credit: NASA, ESA, and The Hubble Heritage Team
Peter Behroozi, STScI
Quenching & Quiescence, 7/17/14
MAKING SENSE OF EVERYTHING
WE KNOW SO FAR ABOUT Q&Q
Picture Credit: NASA, ESA, and The Hubble Heritage Team
Peter Behroozi, STScI
Quenching & Quiescence, 7/17/14
Lots of information
not so much order.
(Most common abstract words for Q&Q)
A guiding principle for organization:
As simple as
possible,
but not si
Cosmic Web
Hot Gas
Cold Gas
GMCs
Stars/BH
Galaxy Formation:#
Studying links between these kinds of matter
Cosmic Web
Hot Gas
Cold Gas
GMCs
Stars/BH
Cosmic Web
Cold Flows
Hot Gas
Cold Gas
Mergers
GMCs
Stars/BH
Cosmic Web
Cold Flows
Hot Gas
Feedback
Cold Gas
Mergers
GMCs
Stars/BH
Key Question: What determines each link’s strength?
Key Findings So Far
10
15
8
4
No Halos
Cosmic Web
GMCs
0.5
0
Star Formation Rate
13
12
11
10
10
0.2
14
10
10
1
log10(SFR)
Cold Gas
•
Hot Gas
Halo Mass [MO]
10
2
z
10
Stars/BH
2.8
-1.1
-5.0
9
10
1
2
4
6
8
10
Time Since Big Bang [Gyr]
Behroozi et al. 2013
or
Moster et al. 2013
12
13.8
Key Findings So Far
10
15
8
4
No Halos
Cosmic Web
GMCs
0.5
0
Star Formation Efficiency
13
12
11
10
10
0.2
14
10
10
1
log10(SFR/MA)
Cold Gas
•
Hot Gas
Halo Mass [MO]
10
2
z
10
Stars/BH
9
10
1
2
4
6
8
10
Time Since Big Bang [Gyr]
-0.3
-2.6
-5.0
12
Behroozi et al. 2013
Halo Mass is Important, Redshift Maybe Less So
13.8
-1
Host Halo
Probability Density [dex ]
Satellite Galaxies
Hot Gas
Cold Gas
GMCs
Stars/BH
1
a = 1.0
a = 0.5
a = 0.25
0.1
1
Rpeak,mass / Racc,host
10
Behroozi et al. 2014
Non-quiescent Satellite SFRs very similar to Central SFRs!
Satellite Galaxies
Host Halo
Hot Gas
Cold Gas
GMCs
Stars/BH
Wetzel et al. 2013
Non-quiescent Satellite SFRs very similar to Central SFRs!
Massive Galaxies
Cosmic Web
Hot Gas
Cold Gas
GMCs
Stars/BH
Watson, Hearin et al. 2014
Massive Galaxies aren’t so different from satellites(!)
Quenched Galaxies
Cosmic Web
Hot Gas
?
Cold Gas
GMCs
Stars/BH
Tumlinson et al. 2013
Plenty of cold gas, just not forming H2(!)
Quenched Galaxies
Cosmic Web
Hot Gas
?
Cold Gas
GMCs
Stars/BH
Tumlinson et al. 2013
Plenty of cold gas, just not forming H2(!)
Merging Galaxies
Cosmic Web
Hot Gas
Cold Gas
GMCs
Stars/BH
Patton et al. 2013
Extra cold gas/H2 = more SFR, but not extra hot gas(!)
Galaxies With AGNs
Cosmic Web
?
Hot Gas
Cold Gas
GMCs
?
?
Stars/BH
Hickox et al. 2013
AGN activity doesn’t automatically quench SFR,#
so there must be a way for incoming cold gas to bypass feedback#
(or does AGN feedback just delay SF?)
Summary
Cosmic Web
Hot Gas
Cold Gas
Cosmic Web
Convenient way#
to combine many results#
in single theory
Hot Gas
Cold Gas
GMCs
GMCs
Stars/BH
Stars/BH
Summary
Host Halo
Cosmic Web
Hot Gas
Hot Gas
Cold Gas
Massive galaxies#
may quench for the same reason#
as their satellites
Cold Gas
GMCs
GMCs
Stars/BH
Stars/BH
Summary
Cosmic Web
Hot Gas
Merging galaxies#
suggest that hot gas may not#
be so important#
Cosmic Web
Hot Gas
?
Cold Gas
Cold Gas
GMCs
Stars/BH
So quenching may just#
be a sign that no more cold#
flows are occurring#
GMCs
Stars/BH
Summary
Cosmic Web
Cosmic Web
?
Hot Gas
Cold Gas
GMCs
Stars/BH
?
?
?
In this scenario,#
AGNs sustain quenching#
but aren’t only cause#
Hot Gas
Cold Gas
GMCs
Stars/BH
?
?