The Radial Acceleration The Radial Acceleration Relation of - - PowerPoint PPT Presentation

▶
the radial acceleration the radial acceleration relation
SMART_READER_LITE
LIVE PREVIEW

The Radial Acceleration The Radial Acceleration Relation of - - PowerPoint PPT Presentation

Aug 05, 2023 443 likes •727 views

The Radial Acceleration The Radial Acceleration Relation of Galaxies Relation of Galaxies Federico Lelli Federico Lelli ESO Fellow (Garching, Germany) ESO Fellow (Garching, Germany) In collaboration with In collaboration with Stacy McGaugh

slide-1
SLIDE 1

The Radial Acceleration The Radial Acceleration Relation of Galaxies Relation of Galaxies

Federico Lelli Federico Lelli

ESO Fellow (Garching, Germany) ESO Fellow (Garching, Germany)

In collaboration with In collaboration with

Stacy McGaugh Stacy McGaugh (Case Western Reserve University) (Case Western Reserve University) James Schombert James Schombert (University of Oregon) (University of Oregon) Marcel Pawlowski Marcel Pawlowski (University of California - Irvine) (University of California - Irvine)

slide-2
SLIDE 2

Federico Lelli (ESO Fellow) The Radial Acceleration Relation of Galaxies

Database for 175 Late-Type Galaxies at z~0 (spirals and dwarf irregulars): astroweb.case.edu/SPARC Lelli, McGaugh, Schombert 2016, AJ

slide-3
SLIDE 3

Federico Lelli (ESO Fellow) The Radial Acceleration Relation of Galaxies

175 HI Rotation Curves from Literature

  • 30 years of radio interferometric observations
  • PhD theses from the University of Groningen

Begeman 1987; Broeils 1992; Verheijen 1997; de Blok 1997; Swaters 1999; Noordermeer 2005; Lelli 2013 + other studies

WSRT

slide-4
SLIDE 4

Spitzer

Federico Lelli (ESO Fellow) The Radial Acceleration Relation of Galaxies

175 HI Rotation Curves from Literature

  • 30 years of radio interferometric observations
  • PhD theses from the University of Groningen

Begeman 1987; Broeils 1992; Verheijen 1997; de Blok 1997; Swaters 1999; Noordermeer 2005; Lelli 2013 + other studies

Homogeneous Photometry at 3.6 μm

  • Optimal tracer of the stellar mass: M* = ϒ*

L

  • Smaller variations of ϒ* in the NIR than optical

Verheijen 2001; Bell & de Jong 2001; Martinsson+2013; Meidt+2014; McGaugh & Schombert 2014; Schombert & McGaugh 2014; Querejeta+2015; Röck+2015; Herrmann+2016; Norris+2016.

WSRT

slide-5
SLIDE 5

Federico Lelli (ESO Fellow) The Radial Acceleration Relation of Galaxies

Widest possible range of disk properties

Dwarf Irrs Spirals

5 dex LSBs HSBs

Mgas/Mbar

4 dex

Basically any known galaxy type with a rotating HI disk.

slide-6
SLIDE 6

Example: High-Mass, High-Density Spiral

gas disk

Federico Lelli (ESO Fellow) The Radial Acceleration Relation of Galaxies

total bulge

Vflat

Spitzer 3.6 μm

∇2Φbar(R,z) = 4πG ρbar(R,z)

  • Vertical Structure:

Disks: exp(-z/hz) with hz∝hR Bulges: spherical symmetry

  • Stellar mass-to-light ratio:

ϒ* = 0.5 M⊙/L⊙ for disks ϒ* = 0.7 M⊙/L⊙ for bulges

slide-7
SLIDE 7

Example: Low-Mass, Low-Density Dwarf

gas disk total

Federico Lelli (ESO Fellow) The Radial Acceleration Relation of Galaxies

Vflat

Spitzer 3.6 μm

∇2Φbar(R,z) = 4πG ρbar(R,z)

  • Vertical Structure:

Disks: exp(-z/hz) with hz∝hR Bulges: spherical symmetry

  • Stellar mass-to-light ratio:

ϒ* = 0.5 M⊙/L⊙ for disks ϒ* = 0.7 M⊙/L⊙ for bulges

slide-8
SLIDE 8

Federico Lelli (ESO Fellow) The Radial Acceleration Relation of Galaxies

  • 1. Basic Data & Structural Relations: Lelli+2016a, AJ
  • 2. Baryonic TF Relation: Lelli+2016b, ApJL
  • 3. Central Density Relation: Lelli+2016c, ApJL
  • 4. Radial Acceleration Relation (I): McGaugh+2016, PRL
  • 5. Radial Acceleration Relation (II): Lelli+2017a, ApJ
  • 6. Testing DM Halo Profiles: Katz+2017, MNRAS
  • 7. Testing Emergent Gravity: Lelli+2017b, MNRAS
slide-9
SLIDE 9

Federico Lelli (ESO Fellow) The Radial Acceleration Relation of Galaxies

  • 1. Basic Data & Structural Relations: Lelli+2016a, AJ
  • 2. Baryonic TF Relation: Lelli+2016b, ApJL
  • 3. Central Density Relation: Lelli+2016c, ApJL
  • 4. Radial Acceleration Relation (I): McGaugh+2016, PRL
  • 5. Radial Acceleration Relation (II): Lelli+2017a, ApJ
  • 6. Testing DM Halo Profiles: Katz+2017, MNRAS
  • 7. Testing Emergent Gravity: Lelli+2017b, MNRAS
slide-10
SLIDE 10

Federico Lelli (ESO Fellow) The Radial Acceleration Relation of Galaxies

For all galaxies: ϒdisk = 0.5 M⊙/L⊙ ϒbulge = 0.7 M⊙/L⊙ ~2700 independent points at difgerent R

Total Acceleration: V2

  • bs /R = -∇Φtot

Baryonic Force: V2

bar /R= -∇Φbar

∇2Φbar= 4πG ρbar

McGaugh+2016, PRL Lelli+2017, ApJ

Radial Acceleration Relation

slide-11
SLIDE 11

Federico Lelli (ESO Fellow) The Radial Acceleration Relation of Galaxies

For all galaxies: ϒdisk = 0.5 M⊙/L⊙ ϒbulge = 0.7 M⊙/L⊙

Total Acceleration: V2

  • bs /R = -∇Φtot

Baryonic Force: V2

bar /R= -∇Φbar

∇2Φbar= 4πG ρbar

gobs= gbar 1−e

−√gbar/g0

gobs=√gb ar g0

gobs=gb ar

McGaugh+2016, PRL Lelli+2017, ApJ

Radial Acceleration Relation

slide-12
SLIDE 12

Very different galaxies but ONE relation

V2

bar /R= -∇Φbar

∇2Φbar= 4πG ρbar

Federico Lelli (ESO Fellow) The Radial Acceleration Relation of Galaxies

V2

  • bs /R = -∇Φtot
slide-13
SLIDE 13

Building up the Radial Acceleration Relation

Federico Lelli (ESO Fellow) The Radial Acceleration Relation of Galaxies

Lelli et al. (2017), ApJ

Large Diversity in Rotation Curves Regularity in Acceleration Plane

slide-14
SLIDE 14

Federico Lelli (ESO Fellow) The Radial Acceleration Relation of Galaxies

Is There Any Intrinsic Scatter?

Uncertainties drive scatter! err(gbar) → ϒ*, 3D geometry err(gobs) → Dist, Inc, Vrot

σobs

2 = σerr 2 + σint 2

σobs→ measured rms σerr→ error propagation σint→ consistent with zero!

McGaugh+2016, PRL; Lelli+2017, ApJ

slide-15
SLIDE 15

Federico Lelli (ESO Fellow) The Radial Acceleration Relation of Galaxies

gDM=gtot−gbar=F(gbar) From the observations: For a spherical DM halo: For our fiducial fitting F: M DM(R)= R

2

G F(gbar) M DM(R)= R2 G gbar exp(√gbar/ g0)−1

We can infer the DM profile from the baryons!

slide-16
SLIDE 16

Federico Lelli (ESO Fellow) The Radial Acceleration Relation of Galaxies

gDM=gtot−gbar=F(gbar) From the observations: For a spherical DM halo: For our fiducial fitting F: M DM(R)= R

2

G F(gbar) M DM(R)= R2 G gbar exp(√gbar/ g0)−1

We can infer the DM profile from the baryons!

Purely Empirical Relations (accuracy ~30%). Only inputs are M/L and Poisson’s equation.

slide-17
SLIDE 17

Federico Lelli (ESO Fellow) The Radial Acceleration Relation of Galaxies

Open Issues for ΛCDM models:

  • 1. Why is the RAR scatter so small?

Is this consistent with stochastic hierarchical merging?

slide-18
SLIDE 18

Federico Lelli (ESO Fellow) The Radial Acceleration Relation of Galaxies

Open Issues for ΛCDM models:

  • 1. Why is the RAR scatter so small?

Is this consistent with stochastic hierarchical merging?

  • 2. Why is the RAR outer slope ~0.5?

gobs=√(g0gbar) → Vflat

4 = Mbar / (g0G) → Observed BTFR.

Whatever sets the RAR should also set the BTFR.

slide-19
SLIDE 19

Federico Lelli (ESO Fellow) The Radial Acceleration Relation of Galaxies

Open Issues for ΛCDM models:

  • 1. Why is the RAR scatter so small?

Is this consistent with stochastic hierarchical merging?

  • 2. Why is the RAR outer slope ~0.5?

gobs=√(g0gbar) → Vflat

4 = Mbar / (g0G) → Observed BTFR.

Whatever sets the RAR should also set the BTFR.

  • 3. Why an acceleration scale? What sets its value?

Different roles of g0: baryon-to-DM transition (RAR) & global baryon-to-DM content (BTFR)!

slide-20
SLIDE 20

Conclusions:

Federico Lelli (ESO Fellow) The Radial Acceleration Relation of Galaxies

  • There is a local coupling between baryons

and DM in galaxies over ~5 dex in Mbar.

  • There is an acceleration scale ~10-10 m s-2.
slide-21
SLIDE 21

Questions?

Federico Lelli (ESO Fellow) The Radial Acceleration Relation of Galaxies

slide-22
SLIDE 22

Federico Lelli (ESO Fellow) The Radial Acceleration Relation of Galaxies

Radial Acceleration Relation for ETGs

X-rays ETGs:

gobs from hot gas haloes in hydrostatic equilibrium (Humprey+2006,2009,2012)

Rotating ETGs:

gobs from stellar kinematics + Jeans Axisymmetric Models (Atlas3D - Cappellari+2010)

Dwarf Spheroidals:

gobs from stellar kinematics + Jeans Spherical Models (many many references...)

Lelli+2017a, ApJ

slide-23
SLIDE 23

Federico Lelli (ESO Fellow) The Radial Acceleration Relation of Galaxies

MCMC Fits to Individual Galaxies

Extremely tight relation!

σobs = 0.054 dex (~10%)

err(Vrot) ~ 10%

Pengfei Li et al. (submitted)

slide-24
SLIDE 24

Federico Lelli (ESO Fellow) The Radial Acceleration Relation of Galaxies

Desmond 2017, MNRAS

AM-based Models:

Di Cintio & Lelli 2016 Desmond 2017 Navarro+2017

Numerical Sims:

Keller & Wadsley 2016 Ludlow+2017 Tenneti+2017

Basic Results:

1) Similar relation but shape is model-dep. 2) Scatter is too large:

σobs

2 = σint 2+σerr 2

Can’t forget errors!

A “Natural” outcome of galaxy formation?

3.5σ discrepancy!

slide-25
SLIDE 25

Residuals vs Local Galaxy Properties

Federico Lelli (ESO Fellow) The Radial Acceleration Relation of Galaxies Lelli+2017, ApJ

slide-26
SLIDE 26

Residuals vs Global Galaxy Properties

Federico Lelli (ESO Fellow) The Radial Acceleration Relation of Galaxies Lelli+2017, ApJ

slide-27
SLIDE 27

Alternative versions of the RAR

Federico Lelli (ESO Fellow) The Radial Acceleration Relation of Galaxies