different definition of quenching: here, quenching is O type star disappears. [OIII] flux decrease very quickly, 10-100Myr. We can select fast-quenching galaxies by this method, but not slow-quenching galaxies.
Different indicator of SFR have different timescales.
In this paper, the sample are just central quenched galaxies, since OIII aperture is 3’’.
Galaxies in this sample are mostly spiral, so disappear of OIII is not from mergers.
Galaxies in this sample tend to reside in higher environment density. Satellite galaxy fraction of galaxies in this sample is slightly higher than normal SF galaxies.
AGN duty cycle: 0.1-1 Myr.
SFR may oscillate, quench, then recover.
If you want to quench galaxy in short timescale, you need to do something to molecular gas, to prevent forming stars?
Peng: environment quenching can not quench galaxy in this short time (this paper, 10 Myr).
Passive sequence is a garbage can for those quenched galaxies after .
Quenching timescale is related to redshift. Higher redshift, quenching faster.
Simulation: S0 is from merger of elliptical????
Bulge: prevent gas collapse to form stars, morphological quenching.
specific angular momentum is correlated to mass
标度律？
from kinematic data, calculate angular momentum, from photometry???
size of bulge~1kpc, is the resolution of IllustrisTNG high enough to resolve bulge of individual galaxy?
B/T with SSFR, for my sample, and background.
quenching mechanism: morphology quenching (gravitational quenching) (bulge), bar quenching, AGN quenching (it is said that low luminous AGN plays a strong influence in quenching, very powerful).
Q-parameter: don’t collapse? Jeans instability.
Estimating gas masses ad dust-to-gas ratios from optical spectroscopy: using optical spectroscopy to derive gas content. This method able us to measure faint galaxies.
Catching Galaxies in the act of quenching star formation : quenching galaxy fraction at a given epoch is 5%~10%. Fast quenching process. A probable work to do.
assembly bias: bias between DM halo and stars.
what determines the DM halo bias? spin? substructure?
Clustering of SDSS DR7 galaxy groups may reveal DM halo distribution.
To qualify the clustering of galaxies, we introduce TWO-POINT CORRELATION FUNCTION . (Mo, 2010 book)
Group-galaxy cross-correlation function (Davis, Peebles, 1983). To enlarge the amount of galaxies.
Projected correlation function, eliminate redshift: wp(rp).
Two sub sample: depend on setting a threshold for halo mass. For Mhalo>13, and Mhalo<13 (depend on the brightness of galaxies.)
Here the cluster color means the color of its central galaxy.
Red groups are more clustered than blue groups, for low mass halos (luminosity based halo mass).
New pipeline: PYMORTH (Bernardi et al., 2017), new pipeline for luminosity. Bernardi only gives luminosity, using mass-luminosity relation (Mendel, 14), we can calculate stellar mass. “Truncated”. This pipeline may have big problem, the difference between stellar mass of two catalog can be 2 dex! Luis: my 5 year old daughter can figure out …..
Offset by GROUP FINDER in observation: this finder assumes that the brightest galaxies are the centers of clusters.
The origin double schechter function, is not good for low mass galaxies. The mass function of SF is single schechter function. The mass function of passive galaxies is not.
Illustris TNG : 10^12~10^15: total mass of halos.
高能的indirect detection，因为flux很小。反而低能( eV）的可以direct detection，因为flux很大。分界线大概是knee的位置。
对于不同component，能谱knee一下的slope是差不多的。
高能粒子的探测是通过secondary particles来进行的。越低越高，secondary particle越少，中间大气比较多。探测的是muon和其他带电粒子。
LHAASO，80000m2. 四川。
Ultra-High Energy CR, >10^18eV. can only be detected indirectly. 有两种方法：一种是用一堆telescope去观测secondary particles产生的light，另一种是用探测器array探测secondary muons。探测器array里面是一堆pure water. High-energy comes into the cavity, create cherenkov radiation. AUGER detector, very large.
UHECR cuts off at 10^20eV. E>10^20eV protons encountering a CMB photon.?????
E>10^18.5eV comes from extragalactic origin.
High energy particles can penutrate differently. Lights travels farthest. (photon can also be UHECR).
fig, pennutration.
Where does UHECR come from?
theoretical analysis requires LL GRB model.
Conclusion:
w2LL GRB from silicon rich progenitors, or from hypernova model can explain the Auger spectrum and composition.
Physical model is more important than a well-fitted model without physical meaning.