Illustris vs Real Universe: Satellite LF, ksz Effect,

Transcription

1 Illustris vs Real Universe: Satellite LF, ksz Effect, Hyunbae Park (KASI), + Many people SFR of High-z Galaxies (Uleung-Do)

2 Simulation Setup Simulation code : AREPO (moving mesh code) Parameter Boxsize Value 75 Mpc/h # of DM Particles DM Particle Mass M Gas Particle Mass ~ M ΛCDM cosmological initial conditions

3 Stellar Mass Function from Illustris Illustris reproduces the stellar mass function to some level

4 Illustris vs Real Universe Illustris has actual baryons that can be compared directly with observations. e.g.) Hey Hyunbae, I find this interesting trend in my observation. Can you check how it comes out in Illustris? However, things are not so simple let me tell you why.

5 Known Problem of Illustris Due to exaggerated AGN feedback, Illustris galaxies clusters has a lower gas fraction than observed.

6 Topic 1) Satellite Galaxy Luminosity Function Park, C. (KIAS); Hwang, H. S. (KIAS); Park, H.; Lee, J. C. (KASI) Satellite system: To study the star-formation quenching of satellite galaxies Isolated galaxy system: To exclude the impact of merging Early type host: Host type dependance not demonstrated enough before

7 Topic 1) Satellite LF Samples Satellite Galaxies 1) Isolated: All the neighbors within r vir is more than one magnitude fainter in the r-band. 2) z < 0.011; > M r > ) Have known satellites from SDSS observation

8 Topic 1) Satellite LF Non-detection of Faint Satellites SDSS spec. limit MMT spec. limit Very few satellites were confirmed MMT spectroscopy!

9 Topic 1) Satellite LF Cut-off in Observed Satellite LF A sharp cut-off like this has not been seen in other studies.

10 Topic 1) Satellite LF Galaxy Morphologies in Illustris Ellipticals Disk Galaxies Irregulars Illustris galaxies look like real galaxies. We check the early-type systems in Illustris.

11 Topic 1) Satellite LF Finding Early Type Hosts It seems early and late type overlap at low-mass end. This is unphysical! They are well separated in the high-mass end. Luckily, our sample hosts are in the high-mass end!

12 Topic 1) Satellite LF Finding Early Type Hosts Early type Late type If [g-r color] > log[m * /(10 9 M /h)]/ , early type. Or, late type.

13 Topic 1) Satellite LF Results Illustris vs. Observation We did NOT find the LF cutoff in Illustris!

14 Topic 1) Satellite LF Results But, we DID see some galaxies being quenched suddenly!

15 Topic 1) Satellite LF Results z Those galaxies had their gas suddenly stripped away when they made a close encounter with other satellites.

16 Topic 1) Satellite LF Summary for Satellites We did not see the LF cut-off, but we found an interesting way of quenching satellites.

17 Topic 2) Kinetic SZ effect Park, H.; Alvarez, M. (CITA); Bond, J. R. (CITA) in prep. Blueshift Redshift T T (ˆ) = Z d ˆ v c Plasma Doppler-shifts scattered CMB photons, causing extra temperature fluctuations.

18 Topic 2) ksz effect ksz Effect in the CMB Power Spectrum D ksz `=3000 =2.9 ± 1.3 µk 2 (South Pole Telescope; George et al. 2015) The ksz effect occupies a small portion in the CMB power spectrum at high l s.

19 Topic 2) ksz effect ksz Effect & Plasma Density Field D ksz `=3000 =2.9 ± 1.3 µk 2 ~ 5 arcmin The ksz signal depends on how much the plasma density fluctuates along the line-of-sight.

20 Topic 2) ksz effect Baryonic Physics in Plasma 70 Dark Matter 70 FreePlasma Electron >10 50 >10 (Mpc/h) (Mpc/h) (Mpc/h) (Mpc/h) 0 We know much about the dark matter density field, but not the plasma density field. We look into their difference in Illustris.

21 Topic 2) ksz effect Baryonic Suppression in the Density Power Spectrum W 2 e P e /P d z =0 z =0.5 z =1 Free electron z =2 z =4 What goes into l = 3000 signal 0.0 e n e n e,0 n e, k [h Mpc 1 ] (Park et al. in prep.)

22 Topic 2) ksz effect Baryonic Suppression in the Density Power Spectrum W 2 e P e /P d z =0 z =0.5 z =1 Free electron z =2 z =4 0.0 e n e n e,0 n e, k [h Mpc 1 ] ~30 % suppression at all scales due to gas locked in stars and neutral gas in galaxies

23 Topic 2) ksz effect Baryonic Suppression in the Density Power Spectrum W 2 e P e /P d z =0 z =0.5 z =1 Free electron z =2 z =4 0.0 e n e n e,0 n e, k [h Mpc 1 ] Extra suppression at small scales due to star-formation feedback

24 Topic 2) ksz effect Baryonic Suppression in the ksz Signal dd `=3000 ksz /ds `/s[h Mpc 1 ] Suppressed 2.83 μk μk 2 Dark matter case Plasma case D ksz,spt z (Linear in s) `=3000 =2.9 ± 1.3 µk 2 Extra suppression at small scales due to star-formation feedback

25 Topic 2) ksz effect Comparison to Other Simulation Works D ksz `=3000 =2.9 ± 1.3 µk 2 Dl=3000 (μk 2 ) Illustris 1.38 Shaw et al Trac et al Battaglia Dolag et al Roncarelli et al The resulting ksz signal is lower what others papers report. Why?!

26 Topic 2) ksz effect Lack of Gas in Illustris Clusters dd `=3000 ksz /ds `/s[h Mpc 1 ] Suppressed 2.83 μk μk 2 Dark matter case Plasma case z (Linear in s) Galaxies clusters in Illustris has a lower gas fraction than observed. Maybe, Illustris is suppressing the low-z signal too much

27 Topic 2) ksz effect Summary for ksz effect Dark Matter FreePlasma Electron >10 50 (Mpc/h) (Mpc/h) z=2 z= (Mpc/h) 2 60 `/s[h Mpc 1 1 ] Dark matter case Plasma case We2 P e /P d z=0 z = 0.5 z= Free electron ksz dd`=3000 /ds (Mpc/h) 50 > k [h Mpc ] z (Linear in s) We want to check how the low-z suppression appears in other simulations.

28 Topic 3) Star-formation Rate of High-z Galaxies Jung, I. (UT Austin); Park, H.; Finkelstein, S. (UT Austin);+??? in prep. A z~4 galaxy imaged by CANDELS + Spitzer/IRAC Jung et al. (2017) We are just beginning to spatially resolve stellar mass and star-formation rate of z~4 galaxies.

29 Topic 3) SFR of High-z galaxies A Test of A Model for Massive Galaxy Evolution Out In The resolution is quite poor, but we can divid the image into inner/outer part and test the evolution model of high-z galaxies.

30 Topic 3) SFR of High-z galaxies A Test of A Model for Massive Galaxy Evolution Jung et al. (2017) The larger the [central stellar mass density], the larger [SFR out /SFR in ]. The observation is consistent with the model.

31 Topic 3) SFR of High-z galaxies SFR of a Illustris Galaxy at z = 4 SFR map of a Illustris subhalo Subhalos seems to be too large in Illustris, but we can still try doing the analysis. I am still working on this!

32 Lessons from playing with Illustris Illustris disagrees with the real universe in many ways. Whether Illustris agrees with the target observation or not, it is quite tricky to understand what that means. Maybe analyze other similar simulation together to convince people (like the referees)? 70 Free Electron >10 (Mpc/h) (Mpc/h) 0