high density low density Rayleigh-Taylor Test: High density medium starts on top of low density medium and they mix (oil+vinegar) Springel (2010)

Transcription

1 GAS MIXES high density Springel (2010) low density Rayleigh-Taylor Test: High density medium starts on top of low density medium and they mix (oil+vinegar)

2 HOT HALO highest resolved density nth= 50x10 5 M (310 pc) 3 DISK GAS nth= 10 cm -3 STARS FORM FROM COOL, DENSE GAS T max = K; n min = 10 cm-3 (resolved density) Inherit kinematics and chemistry from parent gas

3 HOW DOES THAT WORK? Not well: Massive cooling instabilities lead to many unstable clumps

4 Behroozi+ (2010) weak lensing satellite dynamics strong lensing ABUNDANCE MATCHING COMPARED TO OTHER OBSERVATIONS

5 COOLING OFF COOLING ON All SN energy from 1 star particle input at the same time THERMAL FEEDBACK IN PHASE DIAGRAM all SN energy packed into 1 particle at 1 time (Dalla Vecchia & Schaye 2012) DALLA VECCHIA & SCHAYE (2012)

6

7

8 g1536: g5664: 7x10 11 M 5x10 11 M g511r5: 6.5x10 11 M

9 GREG STINSON (MPIA, HEIDELBERG) A CRITICAL MASS SCALE IN GALAXY FORMATION

10

11 p + n 0 H He γ p + n 0 n 0 p + γ p + H n 0

12 "Sun poster" by Kelvinsong

13 GEORGY + (2013)

14 CAN WE DESCRIBE GALAXY FORMATION SO WELL?

15 TIMESCALES T DYN = 1 4πGρ =26.8 Myr ( n cm -3)-1/2 Typical density of a star: 1 g / cc t dyn = 15 minutes Typical density of a galaxy: 0.1 m p / cc t dyn = 100 Myr

16 NiHAO

17 GARRISON-KIMMEL (2014)

18 3X10 10 M 2X10 11 M 100 kpc 7X10 11 M 1X10 12 M 100 kpc

19 BURSTY STAR FORMATION 7X10 11 M

20 M :2X10 7 M M H :2X10 10 M 3X10 7 M 3X10 10 M M 2X10 9 :2X10 8 M M M 2X10 11 H :8X10 10 M M STAR FORMATION M HISTORIES 2X10 10 :6X10 9 M M M 7X10 11 H :3X10 11 M M M :5X10 10 M M H :2X10 12 M 2X10 11 M 3X10 12 M

21 BURST FREQUENCY T DYN=26.8 Myr ( n cm -3)-1/2 6 / 500 Myr ~ 1 / 100 Myr n~0.1 cm -3 This is closest to the ISM density It takes the ISM this long to recollapse Are the burst amplitudes crazy?

22 ARE BURSTS OBSERVED?

23 GALAXY STAR FORMING MAIN SEQUENCE?? BRINCHMANN+ (2004)

24 H α - UV GALAXY SURVEY 11 MPC LOCAL VOLUME SURVEY LEE, KENNICUTT ET AL (2008) LOG(SFR) M B (~M )

25 GALAXY STAR FORMING MAIN SEQUENCE FIREWORKS (WUYTS+ 2008)

26 GALAXY STAR FORMING MAIN SEQUENCE SIMULATED SFR IS MEAN OF PREVIOUS 15 MYR

27 IMPACT ON DISK STRUCTURE

28 MILKY WAY PROGENITORS VAN DOKKUM+ (2013)

29 WHERE DOES OUTFLOW GO?

30 5 G1 E N QSO G2 A E F B C D COS HALOS OVI Figure 1: An illustration of our sampling technique and data. (A) An SDSS composite image of the field around the QSO J with two targeted galaxies, labeled G1 and G2, which are both in the star-forming subsample. (B) The complete COS count-rate spectrum (counts s 1 ) versus observed wavelength. The panels below concentrate on the redshifted O VI OBSERVATIONS TUMLINSON+ (2011)

31 CREATES HOT HALO N OVI AT 100 KPC STINSON+ (2012)

32 MISSING BARYONS? WERK+ (2014)

33 CORE OR CUSP? DENSITY PROFILES

34 NFW DENSITY PROFILE α=-1 unresolved γ=-3 Density profile of dark matter

35 PONTZEN & GOVERNATO (2012) FLATTENING CUSPS

36 VARYING POTENTIAL Changes in potential change the orbits of particles

37 2X10 11 M ALSO SEE PONTZEN & GOVERNATO (2012) DO BURSTS AFFECT THE GALAXY S SHAPE? THERE IS NO CENTER SINCE STELLAR FEEDBACK KEEPS MOVING ENOUGH GAS TO AFFECT POTENTIAL

38 WARNING: PRELIMINARY ANALYSIS FLATTENING DEPENDS ON MASS

39 MEDIUM MASS M halo =10 11 M

40 LOW MASS M halo =3x10 10 M

41 12 M M =10 H I G H M A S S ( M I L K Y W AY ) halo

42

43 DM only α α IS PROFILE S INNER SLOPE DARK MATTER α PROFILES with feedback at z=0

44 DARK MATTER ONLY Fairly constant independent of mass

45 WITH STELLAR FEEDBACK trend with mass lots of scatter

46 AS FUNCTION OF STELLAR MASS same trend maybe less scatter? Mass of stars

47 STAR FORMATION EFFICIENCY even less scatter? Star formation efficiency

48 ALL SIMULATIONS WITH FEEDBACK TOGETHER

49 STELLAR FEEDBACK LIMITS STAR FORMATION AND FLATTENS DM DENSITY PROFILE LOWER STELLAR MASS HALOS HAVE FLATTER DICINTIO+ (2014) PROFILES

50 SUMMARY Stars drive outflows Bursty star formation histories Creates Circum-galactic medium (CGM, gas halo) Change DM profile cusps to cores and back again

51 MISSING SATELLITES PROBLEM Far fewer satellite substructures found around Milky Way than CDM predicts

52 with MUGS overcooled Nickerson+ (2012)

53 Nickerson+ (2011) WHY SUBHALOS FAIL Low mass potentials not deep enough to hold ionized 10 4 K gas

54 VAN DEN BOSCH+ (2001) DARK MATTER OBSERVED BARYONS BARYONS HAVE MUCH LESS LOW ANGULAR MOMENTUM MATERIAL THAN DARK MATTER: WHERE DID IT GO? ANGULAR MOMENTUM DISTRIBUTION