Kinematics of Circumgalactic Gas: Quasars Probing the Inner CGM of - PowerPoint PPT Presentation

Kinematics of Circumgalactic Gas: Quasars Probing the Inner CGM of z=0.2 Galaxies Crystal Martin & Stephanie Ho (UC Santa Barbara) Glenn Kacprzak (Swinburne) Chris Churchill (NMSU) What Matters Around Galaxies?

Consider the Cool Gas Illustration of the Milky Way Halo (Putman, Peek & Joung 2012 ARA&A

Strength of Mg II Absorption Depends on Azimuthal Angle Outflow Accretion ß 200 kpc à Minor Axis Major Brook+2011 Axis Above: Bordoloi+2011 (zCOSMOS Stacks) See Also: Bouché+2012 (10 galaxies at low redshift; bimodal) Lan+2014 (2000 SDSS pairs at z ≈ 0.5) Does the CGM spin like the disk? e.g., Steidel+2002 (z ≈ 0.6)

New Observations • 50 star-forming galaxies redshift at z ≈ 0.2 (from SDSS) • All have background quasar with b = 90 kpc (inner CGM) • Keck/LRIS spectroscopy of MgII absorption (quasar sightline) • Measurements of galactic rotation curve (APO and Keck) • High-resolution infrared imaging with Keck/NIRC2 Star-forming Galaxies

Quasars Probing Galaxies: Outflow Example Galaxy Spectrum Kacprzak, CLM, Bouche + 2014 Mg II Doublet -- Quasar Sightline Fitted Model: V = 40-80 km/s; SFR = 5-15 Msun/yr; h = 0.1-0.9

Viewed at Disk Inclinations > 45 ° CLM+2017

Geometrical Considerations: 1. Azimuthal Angle PARADIGM Disk Minor Axis DATA Disk Minor Axis Disk Major Axis Disk Major Axis

Which Sightlines Show Mg II Absorption? 100 Mg II detection 100 No Mg II detection LRIS Sightline Less certain 80 80 Minor Axis (kpc) Minor Axis (kpc) 60 Same Distribution? 60 CLM+2017 No. P ≈ 10% 40 40 b α b 20 α 20 0 0 20 40 60 80 100 0 0 20 Major Axis (kpc) 40 60 80 100 Major Axis (kpc)

Absorption Strength Depends on Azimuthal Angle 100 Mg II detection 100 No Mg II detection Mg II detection Less certain 80 No Mg II detection Less certain 80 Minor Axis (kpc) Minor Axis (kpc) 60 Absorption is weaker at 60 intermediate azimuthal angles. 40 40 b α b 20 α 20 0 0 20 40 60 80 100 Major Axis (kpc) 0 0 20 40 60 80 100 Major Axis (kpc)

Equivalent Width Dependence of Mg II Absorption 300 mA < W 2796 < 1000 mA W 2796 > 1000 mA 100 mA < W 2796 < 300 mA 100 100 100 Mg II detection Mg II detection Mg II detection Less certain 80 80 80 Minor Axis (kpc) Minor Axis (kpc) Minor Axis (kpc) 60 60 60 40 40 40 b b b α α α 20 20 20 0 0 0 0 20 40 60 80 100 0 20 40 60 80 100 0 20 40 60 80 100 Major Axis (kpc) Major Axis (kpc) Major Axis (kpc) Opt. Depth ( t < 1): Optical Depth ( t ≈ 1-10): Optical Depth ( t >> 1): Similar Mg + column Largest velocity spread Large velocity spread at density at all ( a ,b) large a and all b at small a and small b

Interpretation of Spatial Variation in W 2796 Gas Disturbed by Galactic Small differences Selects Gas Rotating Wind ( q =30 o -40 o ) in metal column with Disk 100 100 100 Mg II detection Mg II detection Mg II detection Less certain 80 80 80 Minor Axis (kpc) Minor Axis (kpc) Minor Axis (kpc) 60 60 60 40 40 40 b b b α α α 20 20 20 0 0 0 0 20 40 60 80 100 0 20 40 60 80 100 0 20 40 60 80 100 Major Axis (kpc) Major Axis (kpc) Major Axis (kpc) Opt. Depth ( t < 1): Optical Depth ( t ≈ 1-10): Optical Depth ( t >> 1): Similar Mg + column Largest velocity spread Large velocity spread at density at all ( a ,b) large a and all b at small a and small b

Major Axis Sightlines Kinematics of Gas Near the Disk Plane Ho, CLM, et al 2017, ApJ, 835, 267 1. Halo gas rotates in same direction as galactic disk. 2. Circular orbits would produce a larger Doppler shift. 3. Inflow in the disk plane can explain observed kinematics.

Mg II Doppler Shifts & Galactic Rotation Ho, CLM, et al 2017, ApJ, 835, 267

Doppler shifts in quasar sightlines correlated with disk rotation Ho, CLM, et al 2017, ApJ, 835, 267 Galaxy Rotation Curves Mg II in Quasar Sightlines • .

Some of the absorption components are not on circular orbits Ho, CLM, et al 2017, ApJ, 835, 267 Galaxy Rotation Curves Mg II in Quasar Sightlines • .

Models for Individual Sightlines • Disks cannot produce absorption on both sides of V sys . Ho, CLM, et al 2017, ApJ, 835, 267 • Thin disks produce a narrow profile. • Fitting disks models has awkward implications (H eff ≈ r vir ).

Inflow Model Predicts Sign of Disk Inclination Ho, CLM, et al 2017, ApJ, 835, 267

Where is the Mg II Doppler Shift Correlated with the Direction of the Disk Rotation? O: Aligned X : Not Aligned At low impact : Systemic parameter, alignment persists to larger azimuthal angles. Major Axis Sample

Geometrical Considerations: 2. Disk Inclination At each position, we compare Mg II Doppler shift to projected disk rotation. Find V (MgII) < V (disk) X : Not rotating in direction of galactic disk

Detecting Kinematic Signatures of Disk Accretion Stewart et al. (2013) v b < 75 kpc ≈ 0.5 R VIR

Take Away Points: Kinematics of the z≈0.2 CGM 100 Mg II detection • Small impact parameter No Mg II detection Less certain 80 sightlines find large, R ≈ 80 +/- Minor Axis (kpc) 60 10 kpc, disks of cool gas. 40 • The gas is not primordial b α 20 because it’s detected in Mg II. 0 0 20 40 60 80 100 • Requires a substantial inflow Major Axis (kpc) velocity. • Inflows contribute to prolonging disk star formation. • Angular momentum matters in the CGM, and observations can measure it. Borthakur+2015, COS-GASS

Looking Forward: 1. Comparison to Gas Disks in EAGLE Disk at z=0.271; disk radius ≈ 50 kpc 25 r = 50 kpc | j particle | ( × 10 − 3 pkpc * km/s) 20 15 10 5 0 0 20 40 60 80 100 r shell (kpc) Stephanie Ho , Monica Turner, Joop Schaye, CLM

Looking Forward : 2. How is the Minor Axis Gas Disturbed? CLM+2012; Kornei+2012 • Typical z≈0..4-0.9 galaxies have outflows with h ≈ few. Gas observed down the barrel is near the galaxy (1-10kpc). Gravity pulls much of it back. • At z≈0.2, we are looking at the CGM a few Gyr later. Winds have disturbed the CGM above the disk plane. • 100 kpc @1000 km/s in 10 8 yr • 100 kpc @100 km/s in 10 9 yr