High spatial resolution extragalactic study with ALMA at 2020

HIGH SPATIAL RESOLUTION
EXTRAGALACTIC STUDY WITH
ALMA AT 2020
Satoki Matsushita (ASIAA)
Topics:
• Circum-AGN Molecular Gas Study at 1 mas
• Submm H2O Maser Disk VLBI Observations
Circum-AGN Molecular Gas Study at 1 mas
--- High Spatial Resolution Extragalactic Study with
ALMA at 2020
Circum-AGN Molecular Gas Study
at 1 mas
 Circum-AGN molecular gas:
 Fuel for the AGN activities.
 Obscuring material.
 Dynamics can be dominated by
Super Massive Black Holes (SMBHs).
 Imaging the circum-AGN molecular gas at 1 mas:
 Help to understand the AGN fueling mechanism.
 Possible to estimate SMBH masses.
 Sphere of influence for ~1 x 106 Mo BH
 ~ 0.4 pc.
 1 mas at 16 Mpc (~ Virgo Cluster)
 ~ 0.08 pc (5 times smaller resolution than sphere of influence)
 Good enough to image the gas dynamics under SMBH
gravitational field.
 Circum-AGN molecular gas is expected to be warm, more
than several hundred Kelvin.
12CO(1-0)
12CO(2-1)
12CO(3-2)
NGC 5194 (Sy 2)
810 pc
Isaac Newton Telescope
INT-WFC
Sakamoto et al. 1999,
ApJS, 124, 403
Matsushita et al. 2004,
ApJL, 616, L55
NGC 1097 (Sy 1)
1 kpc
1 kpc
VLT MELIPAL + VIMOS
Kohno et al. 2003,
PASJ, 55, L1
Hsieh et al. 2008,
ApJ, 683, 70;
Hsieh et al. 2011, ApJ,
736, 129
Hsieh et al. 2011, ApJ,
736, 129
NGC 1068 (Sy 2)
SDSS
Tsai et al. 2012,
ApJ, 746, 129
Krips et al. 2011,
ApJ, 736, 37
Tsai et al. 2012,
ApJ, 746, 129
Circum-AGN Molecular Gas Study
at 1 mas
 Recent Herschel-PACS observation
toward the nucleus of NGC 1068:
 Moderate excitation gas:
n(H2) ~ 105.6 cm-3, T ~ 170 K
 High excitation gas:
n(H2) ~ 106.4 cm-3, T ~ 570 K
Krips et al. 2011
Circum-AGN CO
J=1-0, 2-1, & 3-2
SMA & PdBI Obs.
Hailey-Dunsheath et al. 2012,
ApJ, 755, 57
Circum-AGN Molecular Gas Study
at 1 mas
 Extended ALMA (E-ALMA)
 Additional 5 antennas at baselines up to 200 km.
(300 km is too long / too less sensitive for several
hundred Kelvin line imaging)
 59 12m antennas (ALMA 50 + ACA 4 + E-ALMA 5).
 CO(3-2) with dV = 100 km/s.
1σ sensitivity ~ 150 K (14.5 µJy) with 100 hr integ.
Possible to detect circum-AGN CO(3-2) with 1 mas
resolution.
 [CI] is another option for atomic line observation,
which may trace closer to SMBH than the CO lines.
Circum-AGN Molecular Gas Study
at 1 mas
 Further Extended ALMA (FE-ALMA)
 Add two 25 m submm single-dish telescopes.
1σ sensitivity ~ 190 K (17.8 µJy) with 24 hr integ.
Submm H2O Maser Disk VLBI Observations
--- High Spatial Resolution Extragalactic Study with
ALMA at 2020
Submm H2O Maser Disk VLBI Obs.
 H2O masers around
SMBHs:
 SMBH mass estimation.
 Galaxy distance
estimation.
 Submm VLBI will be
open for the common
use at 2020.
Miyoshi et al. 1995, Nature, 373, 127
Megamaser Cosmology Project
Braatz, Reid, Condon, Henkel, Lo,
Kuo, Impellizzeri, Gao, Zhao, Constantin, Greene
North Offset (mas)
NGC 6323
UGC 3789
Mrk 1419
NGC 2273
NGC 6264
NGC 1194
East Offset (mas)
J0437+2456
NGC 5765b
Megamaser Cosmology Project
Cepheids
0 Mpc
NGC 6264
Largest
Structures
NGC 6323
ESO 558-G009
Mrk 1419
UGC 3789
J0437+2456
NGC 1194
IC 2560
NGC 4258
Braatz, Reid, Condon, Henkel, Lo,
Kuo, Impellizzeri, Gao, Zhao, Constantin, Greene
Direct Measurement of H0
100 Mpc
200 Mpc
• The technique gives a geometric measurement of H0 independent
of the cosmological model
• One method can be applied to all galaxies out to ~ 200 Mpc
– No “Ladder”
• Conceptually simple
• Independent of all other techniques
Submm H2O Maser Disk VLBI Obs.
 22 GHz H2O maser  321 GHz H2O maser
 An order of magnitude higher frequency.
 An order of magnitude higher angular resolution.
 An order of magnitude distant sources.
 Direct SMBH mass estimation at 2 Gpc (z~0.5).
 Direct distance estimation at 2 Gpc (z~0.5).
 439 GHz & 658 GHz may also be good H2O
masers.
Submm H2O Maser Disk VLBI Obs.
 Extragalactic submm H2O maser has been
detected for the first time.
Peak Continuum Flux Density
= 40.6 mJy/beam
Contours: H2O maser
Greyscale: Continuum
Hagiwara et al. 2013, ApJ, 768, L38
Submm H2O Maser Disk VLBI Obs.
 Line sensitivity can be a problem:
 Phase-Up ALMA – Greenland Telescope (GLT)
baseline sensitivity:
 1σ ~ 50 mJy @ dV = 10 km/s, tintg = 10 s
 Calibration with continuum can be the best way:
 Phase-Up ALMA – Greenland Telescope (GLT)
baseline sensitivity:
 1σ ~ 1.8 mJy @ BW = 16 GHz, tintg = 10 s
Megamaser Cosmology Project
Braatz, Reid, Condon, Henkel, Lo,
Kuo, Impellizzeri, Gao, Zhao, Constantin, Greene
 Imaging can be very challenging.
 Image 1/10 size of NGC 6323 is needed for the submm
H2O maser disk imaging at z ~ 0.5.
NGC 4258
NGC 6323
beam
High Spatial Resolution Extragalactic
Study with ALMA at 2020
 Circum-AGN Molecular Gas Study at 1 mas
 Image molecular/atomic gas inside the SMBH
sphere of influence for galaxies within 50 Mpc.
 Study the AGN fueling mechanisms.
 Extended ALMA is necessary:
 Additional 5 antennas at baselines up to 200 km.
 Submm H2O Maser Disk VLBI Observations
 Estimate black hole mass and distance.
 Study with an order of magnitude distant galaxies
(z ~ 0.5) than the current study (~200 Mpc).
 Calibration with continuum emission will be the
best way.