惑星の種の大きさを測りたい?

~ 1 μm~ 1000 km

2020年度日本天文学会研究奨励賞受賞記念講演
受賞対象研究：「原始惑星系円盤におけるダスト成長過程に関する理論的・観測的研究」

片岡章雅（国立天文台）

今日のお話shaped protoplanetary disk.

•

原始惑星系円盤から、ダスト散乱に起因したミリ波偏光が受かるはずだ！ (Kataoka et al. 2015)

The Astrophysical Journal Letters, 831:L12 (6pp), 2016 November 10

Kataoka et al.

netary disk. The object is optically thin everywhere.

d ring. This corresponds to point B in Figure 6. By
the vectors are in the radial direction in the inner
ion ring. This is due to the net ﬂux from the azimuthal
being larger than the net ﬂux in the radial direction.
responds to point A in Figure 6. This double-rings a unique feature of the polarization due to dustg, and thus this will be a clue to distinguish theion mechanism.

•

ALMAで観測したら偏光を検出できたし、散乱由来の予想とばっちり合ってた (Kataoka et al. 2016b)

The Astrophysical Journal Letters, 844:L5 (5pp), 2017 July 20

Polarization from Lopsided Protoplanetary Disks

Kataoka et al.
−1

In the left panel,colorscale represents the polarized intensity in units of mJy beam with a log scale, the gray contours show the continuum emission,
However, we cannot rule out the Figure
grain1.alignment
withthetheand from
the whiteshow the polarization vectors. Note that the lengths of the polarization vectors are set to be the same. The levels of the contours are (3, 10, 30,
ow calculate
the expecteda vectors
lopsidedpoloidal magnetic
ﬁelds.polarization
In the case
of
the
1.3
mm
image,
100, 300, 600, 900, 1200, 1500, 1800)×σI(=185 μJy beam−1) for Stokes I. Polarization vectors are plotted where the polarized intensity is larger thanmimic
the welopsidedstructureobservedwith−1of thehowever,interpretdisk
it with(c) 3σtheself-scattering• The gray contours display thePI=0.128 mJy beam . In the right panel, the colorscale displays the polarization fraction overlaid with the polarization vectors.
(e.g.,
Fukagawa
et al.which2013),
wecontinuum
further
add withanvectors
thermaldust emission,
providesthe polarization
emission
the same levels of the left panel. The colorscale is only shown with the same threshold of the polarization vectors in the left panel.
to theminor axis.(e.g.,
However,could
be alsolly parallel
Gaussiandistribution
Pérezthere
et al.
2014)
as somecontributions of (b) the alignment withthe radiationﬁelds to in the grain size and its effects on
possibility
is the difference
power-law size distribution with a power of −3.5 and thethe polarization, which enhances thethepolarization
at the the radiative torque efﬁciencyalignmentvectors
efﬁciency;
maximum grain size 150 μm, which is the most efﬁcient grain
2
⎞
⎡ and
⎤
north–west(alongthe majoraxis) whilegrain size if the grain size is smaller⎛ ( Rsouth–east⎞ regionsdecreases
with decreasing
size to scatter the thermal emission and make it polarized at the

R
)
d
1
⎟
decreasing
north–eastTherefore,and⎜⎜ polarization⎟⎟ ⎥ fraction
thanatthethe
wavelength.
if the peak emission of Stokes I
observed wavelength of λ = 0.87 mm. The density distribution
4max
4min
exp ⎢  the⎟⎢⎣ 2regions
south–west⎝ Gd(along⎠ ⎥⎦the minoris⎠axis).
mainly coming from grains smaller than the wavelengths, itis based on a previous modeling of the continuum at the same
The wavelength dependence in thepolarization
fractionin efﬁciency and thus the polarizawould
decrease thealignment
wavelength (Muto et al. 2015). The density distribution of dust2⎡2 ⎤ et⎡is strong
the(Kataoka
al. 2015),
⎛ z⎞⎤
tion
fraction(e.g.,
Cho & Lazarian 2007; Lazarian &grains Σd is taken to be a Gaussian distribution in radial and⎛r ⎞
1 case of⎢the1self-scattering1rdwhile itexp
is weaker
the grain⎟ ⎥case ⎜in theexpof⎢ (3 )⎜ alignment.
⎟ ⎥ . Therefore,azimuthal direction as
Hoang2007).
⎢⎣ is 2that⎢⎣ 2 ⎝interpretation⎝ The⎠ ⎥⎦ direction
hg ⎠ ⎥⎦
wdazimuthal
Q hmost2thenaturalthealignmentwith theof the polarization vectors as showng⎡⎛ (q - q )2 ⎞ ⎤radiation ﬁelds provides the axisymmetricpolarizain the azimuthal
outer regions
indicates the poloidal magnetic ﬁelddFigure 4. Total polarization fraction as a functionof=the⎢Sobserved
wavelengths.
⎜
⎟⎟ ⎥
exp
S
+
S
S
(
)
thetionbroadof wavelengths,
azimuthal conﬁguration,
contrast
dust
d
0,min
0,max
0,min
vectorsrange
on bothwhile theofself-scattering⎜
while the radial The
direction
on
the
inner
ring
Akimasa
Kataoka(NAOJ)
2
total polarization fraction is derived by integrating⎢
2f
⎝
⎠ ⎥⎦
⎣each Stokes I, Q, and U

惑星形成途中のダストサイズは~100µmである。今までの理解とぜんぜん違う！（おもしろい！）(Kataoka et al. 2016a, Kataoka et al. 2017, Ohashi
and Kataoka 2019, Ueda, Kataoka, et al. 2021… )星・惑星形成におけるミリ波偏光
ダスト整列による偏光理論•

偏光観測の例

星・惑星形成領域のミリ波放射は、~10-100K程度の熱放射。
••（よって、シンクロトロン偏光などは受からない）

熱放射偏光の有力なメカニズム
は、ダストの整列

Linear polarization

Akimasa Kataoka (NAOJ)

et al. 2006
Fig. 1. (A) Sketch of the axisGirart
directions:
red/bluearrows show the direction of the redshifted/
blueshifted lobes of the molecular outflow,
probably driven by IRAS 4B (8); solid lines show
the main axis of the magnetic field; and dashedlines show the envelope axes. The solid triangles

原始惑星系円盤におけるミリ波偏光
円盤偏光予測•HD 163296

ALMA前の時代•

観測結果：偏光非検出

原始惑星系円盤全体の大きさは100 au くらい ~ 1秒角くらい•分解能が1秒角切れば偏光見える？

•

トロイダル磁場の証明ができるはず•

SMA,CARMAで円盤の偏光が全然受からない…

Figure 2. Comparison between the Cho & Lazarian (2007) model and the SMA 340 GH
at full resolution (left), a simulated observation of the model with the SMA (center), an(left) or the polarized flux (center, right), and the blue vectors indicate the percentage
rows compare the model prediction (center) with the observed SMA data (bottom) in ea
are the same in both rows, either multiples of 10% of the peak flux (0.9 Jy beam−1 ) in
2.4 mJy beam−1 . The size and orientation of the synthesized beam are indicated in the(A color version of this figure is available in the online journal.)

Fig. 11.—Simulated observations. Degree of polarization is calculated for the radiation from th
we should be able to detect it given that we recover most of
Figure 2. Comparison
between the
ChoWeingartner& Lazarian (2007) modeland the SMA
340Figures
GHz observations
HD 163296.theThedata
top rowshowse.g., Draine
and
1997,
the Stokes
I flux.
2 and 3of comparewiththethe predic
at full
resolution (left),a simulated
observation
ofsight.
the model
withplot
the SMA(center),
and theof
2008 SMA observations (right). The gray scale shows
disk
symmetry
axis
and
the
line
of
We
the
directionfiducial
model
predictions(described
4.1 below).
Lazarian
ChoandandLazarian(left) or the polarized
flux 2007,(center, right),
the blue
vectors indicate the percentage and directionof polarized
flux
at half-beam
Hughesetinal.Section
2009,
2013intervals. The
The
upper
right panel
figureamountandleft to rig
polarization
for
three
different
wavelengths
andtwo
differentrows compare themodelprediction(center) withthe observed
SMA
data (bottom)
in eachofofeach
the four
Stokesdisplays
parametersthe(I, Q,U, V, from2007…
−1 ) in polarized
directionofobserved
flux
for eachsource,thewhere σ
are
the
same
in
both
rows,
eithermultiples
of
10%
of
the
peak
flux
(0.9
Jy
beam
Stokes I or inincrementsof 2σ
for Q, whileU, and V,
viewing
angles.
The
lines
represent
thedirectionofpolarization.
2.4 mJy beam−1 . The size and orientation of the synthesizedbottom
beam arerow
indicatedin the lower
left ofeach panel.
presents
contourmaps
for each of the individual
Since
weversion
assumethatmagneticfield
isjournal.)
azimuthal,the direction(A colorof thisAkimasa
figure isavailable
intheonlineStokesparameters.
The emission in Stokes Q and U (linear
Kataoka (NAOJ)

ミリ波散乱偏光の光源問題
Self-scattering

VLT/SPHERE (Avenhaus et al. 2018)

IR scattered light

disk

Infrared

The Astrophysical Journal Letters, 748:L22 (7pp), 2012 April 1

radio scattered light(self-scattering)

Muto et al.

The Astrophysical Journal Letters, 815:L26 (7pp), 2015 December 20

The Astrophysical Journal Letters, 729:L17 (6pp), 2011 March 10

Subaru/HiCIAO

S2 S1
S3
S4

HashimoGemini/GPI

S8
S7

S5

S6

millimeterN
1″ =144AU

1″ =144AUE(Muto et al. 2012, Hashimoto et al. 2011)

Kataoka et al. 2015

1

Akimasa Kataoka (NAOJ)(Rapson et al. 2015)10(mJy/arcsec 2 ) 100

Figure 1. Near-infrared (H band) PI and I images of AB Aur. Left: the HiCIAO PI image with a coronagraphic occulting mask of 0.!! 3 diameter. The multstructures we refer to as S1 to S8 are identified in the top right inset, of which S7 and S8 are newly found. Right: the CIAO reference PSF-subtracted I ima software mask of 1.!! 7 diameter (Fukagawa et al. 2004). In contrast to the original image, this image shown here is not divided by the square of the radia
from the star. The field of view in both images is 7.!! 5 × 7.!! 5. The solid circles in the left bottom inset in both images represent the spatial resolution of 0.!! 06
respectively.

散乱偏光の理論予測

ALMA 観測100 AU

Cycle 3 観測提案書 (PI:Kataoka)cf.) Kataoka et al. 2015

Kataoka, et al. 2016b

ミリ波自己散乱から何がわかるのか？
angle of 90 and the albedo ! =  /(+  ) as a function of maximum grain size.
sca

abs

sca

law of n(a) / a 3.5 . The wavelengths are assumed to be 1.3 mm for the left panel andthe maximum grain size which has the most efficient polarization by 90 scattering.

1.2

rved
ped protoplanetary disk.

1

e amaxPω

0.8

Prediction of polarization fraction
3.1 mm0.87 mm (Band 3)(Band 7)0.34 mm(Band 10)7 mm
(Band 1)•

ダストサイズが波長とコンパラな時しか偏光は受からない•→偏光が受かったらダストサイズ

0.6
0.4
0.2

が測定できる。

ary disk. The object is optically thin everywhere.

0
wavelength
ng. This corresponds to point B in Figure 6. By
e vectors arein thetoradialdirection in the inner
ation
due
90
0.001
0.01
0.1
1
ring. This is due to the net ﬂux from the azimuthal
ingonlylarger than
the net ﬂux
in the radial direction.
Maximum grain size [cm] Kataoka et al., 2015
tpondswhen
theto point A in Figure 6. This double-ringfeature of (§2.2)
the polarization due to dust
geuniquealbedoand thus this will be a clue to distinguish theattering(§2.3).
mechanism.
(grain size) ~ λ/2π
detected.
arizationfrom Lopsided Protoplanetary Disks
Fig. 4.— The polarization times the albedo P ! against the maxcalculate the expected polarizationfrom a lopsided
olarization
effiimumgrain size. This figure represents the sensitive grain size
mimic the lopsided disk structure observed
with
g.,of
Fukagawa
et al. 2013), we further for
add andetection of polarization. Each line corresponds to the wavewavelengths
Gaussian distribution (e.g., Pérez et al. 2014) as

lengths of 0.34 mm, 0.87 mm, 3.1, and 7 mm. The band numbers

870 μm, the positive regions almost completely disappear.
StokesU shows two positive and two negative regions at
3.1 mm. The negative blobs disappear at 1.3 mm, while thepositive regions connect, and at 870 μm, the positive regions
turn into a single, large region.
4
F. Bacciotti e
For the Stokes V images (Figure 2), 3.1 mm appears to be
purely noise. For both 1.3 mm and 870 μm, StokesV has anegative ﬂux blob offset to the top-right of the Stokes I
F. Bacciottintensity, and this blob 4is signiﬁcantly brighter in 870 μm.
The Astrophysical Journal Letters, 831:L12 (6pp), 2016 November 10 Although circular polarization can in principle be produced by Kataoka et al.
L30 W. R. F. Dent etscattering
al.
of linearly polarized light off non-spherical grains
4
Hull
et al.
HD 142527
IM LupCWwellTau(e.g., Tazaki
et al. 2017), StokesV has not beencharacterized for ALMA, so its detection could be spurious
IM Lupand will not be discussed in detail in this paper.
The central polarization vectors for 1.3 mm and 870 μm are
55°. 4 ±0°. 96 and 55°. 3 ±0°. 41, respectively. The major axisof HL Tau’s disk is 138°. 02 ± 0°. 07 (ALMA Partnership et al.
2015), indicating the polarization vectors are ∼7° from being
perpendicular to the major axis. We would expect thepolarization to be perfectly perpendicular to the major axis.
The reason for this small 7° discrepancy is uncertain, but could
indicate asymmetry in the disk.
The right panels of Figure 2 show P for each wavelength.
For 1.3 mm and 870 μm, there is a slight asymmetry for P
along the major axis of1%the disk, with the southeast morepolarized than the northwest. For 1.3 mm, the absoluteAUdifference between the 200
two
P peaks along the major axis(a)is0.0013 ± 0.0014, which is not statistically signiﬁcant. The
asymmetry for 870 μm is more apparent, although the southeast
HL TauHD 163296
DG Taupart of the disk −1
does not peak (i.e., it is still increasing at the
Figure 1. In the left panel, the colorscale represents the polarized intensity in units
witha log scale,the grayThecontours
show
the continuum emission,edgeofofmJy
thebeamdetectedpolarized
emission).
P peaktowardand the white vectors show the polarization vectors. Note that the lengths of thethepolarization
are setbe the same.
The alevels
the (a)contours are (3, 10, 30,
northwestvectors
is 0.0077
±to0.0010.
Drawingline offromthe−1
I. Polarization
vectors theare center
plotted ofwhere
the polarized
intensity is larger than100, 300, 600, 900, 1200, 1500, 1800)×σI(=185 μJy beam ) for Stokesnorthwest
peak throughthe disk,
at the same−1
fraction
overlaid withpolarization±
vectors.
TheP gray
3σPI=0.128 mJy beam . In the right panel, the colorscale displays the polarization
radius on
the southeastside,theP=0.0094
0.0010.
risescontours display thecontinuum emission with the same levels of the left panel. The colorscale is only
shown withtheedgesameof the polarization
vectors in the left panel.
to ∼0.0115
at theofthresholdthe disk. Therefore,
the P asymmetry
along the major axis for 870 μm is ∼0.002–0.004. These
are relatively
moderate, butwith
the fact
that they
possibility is the difference in the grain size and its effects on asymmetries
power-lawsize distribution
a powerof −3.5 and theboth at 1.3
mm sizeand 870they
the alignment efﬁciency; the radiative torque efﬁciency appearmaximum
grain
150μm
μm,suggests
which isthecould
most efﬁcient grain
be a real feature. If we consider total polarization PT =decreases with decreasing grain size if the grain size is smaller Contours:
size to scatter the thermal
emission and make it polarized at theContours:
Q 2 + U 2 + V 2 I , the asymmetry
is similar; for 1.3 mm, it isIntensity
P
Polarization
than the wavelength. Therefore, if the peak emission of Stokes Polarized
I 0.0012
observed
wavelengthof fraction
λ = P0.87
mm. The density distributionfrac
± 0.0014, while for 870 μm it is ∼0.001–0.004.
is mainly coming from grains smaller than the wavelengths, it Yangis etbasedon ashowed
previousof thethecontinuumat the sameal. (2017)that modelingasymmetry along
major
would decrease the alignment efﬁciency andFigure
thus
the polariza- axis
(Muto
et al. 2015). The
densityindistributionof dustiswavelength
not disk
expectedscattering-induced
polarizationan
1. 870 µm ALMA maps of the Class
II protoplanetary
IM Lup. The forpeak valuesof the total intensity (Stokes I),
polarized
intensity (P ), and polarization fraction images are 120.74 mJy beam , 1.37 mJy beam , and 0.011, respectively. The rms noise values inaxisymmetricdisk,
axisymmetry
must
be broken if thetaken
Gaussiantion fraction (e.g., Cho & Lazarian 2007;
Lazarian& thermal
Σared is= so
the total intensityand polarized intensity
dust grainsemission images
100µJy beam toand be= 22 aµJy beam, respectively. distribution in radial and
The black ellipses in the lower-left corners of all panels represent the ALMA synthesized beam (resolution element), which measures 0. 50 ⇥polarizationdue ofto161 scattering
evenetthough
the total
0. 40 at a position angle of 76.9 , corresponding
to a linear
resolutionisof ⇠really
72 au direction
at a distance±as
10 pc (Gaia Collaboration
al. 2016).
azimuthal
Hoang 2007).
Top: Polarization map of IM Lup. Contours are the total intensity thermal dust emission, plotted at 3, 8, 16, 32, 64, 128, 256, 512, 1024 ⇥ .
Grayscale is the polarized thermal dust emission,plotted (Stokes
starting at 3 I .) Linesegments are
the polarization orientationof the other hand,
intensity
is highly
axisymmetric.
On thedust vectors
emission, with lengths
proportional to the polarization fraction P. Bottom left: Grayscale is the total intensity thermal dust
The azimuthal direction of the polarization
as shown
emission; contours are the polarized intensitythe
P , plotted
at
0.06,
0.1,
0.2,
0.3,
0.4,
0.5,
0.6,
0.7,
0.8,
0.9
⇥
the
peak
of
1.37
mJy
beam
.
Bottompolarization ⎡ along
the minor = axis
is expected ⎛to be
Grayscaleis the total
intensity thermal dust emission; contours are
the polarization fraction P
P/I, plotted at levels of⎞⎤
1. ALMA
polarimetricobservations
atpoloidal
3.1 mmright:(top,
Kataokaetal.
2percentage
in theFigure
outerregions
indicates
the Figure
magneticﬁeld
0.005,
0.006,
0.007,
0.008,
0.009,
0.01.
The
coordinates
andthegrayscaleareidentical
in
the
two
bottompanels.
The
ALMAdata used
to intensity(and1.
Sub-mmcontinuumpolarizationin
HD163296.
The
top
panels
show
(a)
the
total
(b)
the
polarization at band 7 iqq)
asymmetric
if
the
dust
disk
is
optically
thick
and
has
a
d
make
figure areshow
availablethein the online version of this publication.
2017), 1.3 mm (middle), and 870 μm (bottom), where theredthisvectors⎢S0,min + (S0,max - S0,min ) exp ⎜⎜ -(c)
⎥
⎟
S
=
d
⎟ ⎥(b). The lower panels are (c) t
conﬁguration,
while
the radial
direction
on rotated).
the inner
ringareregion.
as ellipses
representations
ofwidththe threein theillustration,
total intensity
signiﬁcantangular(forrings
a cartoon
seeimage,
Figuremarked
6 2f 21–3 in>3σ polarization
morphology(i.e., vectors
have
notSuperimposed
been
Vector⎢⎝⎠ are⎣ the HL
⎦ shown at their actual angledlengthsthe
are linearly
proportional
to P. The
color
scale
shows
the(d)
polarized
flux intensity
andthepolarization
angle,etbothpolarization
vectors
superimposed.
In (c), the vectors
al. with2017).
Tau disk
is known
to be opticallyindicates
toroidalmagnetic
ﬁeld.
There
has
been
no in Yang
◦ is multiplied
intensity, which is masked to only show 3σ detections.
Stokes
I contours
in to the2. Linearlypolarized
P andpolarization(d) theof
vectorrotation
relativemeanatof 870
44.1μmby a factor
theintensity
relative
twist.
Polarization
fractionfraction
and anglep a
thick(Carrasco-González
al.emphasize2016), but
no2of⎞et3, to⎛Figuremechanism
locallytorotatethedirectionthemagneticﬁeldeach panel are shown for [3, 10, 25, 50, 100, 200, 325, 500, 750, 1000] × sI ,rr()
cminorDG
Tau(panels
as in(beams
Fig.
1. Polarizationang
polarized
flux and5σ per beam
(250µJy).
are⎜and3-arcsec
au)
across.
Resolution
isof∼0.2 arcsec
areshown lower left).
asymmetryis Images
detectedalongthe(315
axis.(c),(d)).
The lackContours
,
1
´ exp
(
)
sI is 44, 154,atandleast
460 μJyat
bm−1
for at3.1
mm, 1.3 mm,
870of
μm,
where
⎟
by 90°.
Therefore,that
position,thelevelsmechanism
2 thick
indicatethejetDisk near-side lies towards the receding jeasymmetryfor P alongtheoptically
minor axis implies
vectors have 1/2 beam spacing, withlengths proportional
to thepolarization
fraction.
respectively.
2r⎠ orientation.
⎝w
should be different from the grain alignment.
−1
total intensity is I > 10 mJy beam
for CW Tau and I > 30 mJy be(c)

え？~100 µm?
The Astrophysical Journal Supplement Series, 245:2 (50pp), 2019 November

Sadavoy et al.

1

1

I

1

P

1

00

00

I

P
frac

多くの円盤が、波長0.9 mmで自己散乱偏光を示す
1

frac→ 多くの円盤のダストサイズは100µm?

Figure 3. The 14 continuum sources with polarization detections. Background images show the Stokes I maps on a logarithmic color scale (see Appendix A for theﬂux scale), and the black line segments show the normalized e-vectors. Sources with ‡are outside of the inner third of the primary beam FWHM. The blue and red
arrows indicate the outﬂow position angle, if known (see Section 4.1 for details). The gray bars show the major-axis position angle of the continuum sources detectedin polarization, except IRAS 16293B, as this source is near face-on and does not have a well-constrained continuum position angle. For VLA 1623 A, we show twogray bars: the ﬁlled one shows the position angle of the compact disk from Harris et al. (2018), and the open one shows the position angle of the extended disk.

The polarization fraction in the south region is as high as
sub-mm observations found an upper
limit rofand
1 per
centthetoetradial
the
total
on-source
20,max
h,
where
θ are
andTheazimuthalcoordinates,◦ although some 15 m
Piétual. (2014)
andthetimeoneof jet, ijetwas=S49
reportedof
13.9±0.7%,
whichishigherthan
thepredicted
value(e.g.,
Kataoka et al. 2016, Hull et al. 2018,
Bacciotti
et
al.
2018,
Dent
al.
2019,
Stephensetpolarization
fraction ineta 1 arcsec
beam(Hughesetal.
2009).
Pinte
were
flaggedinthesecondsessionwhile
thetargettran
2. LinearlypolarizedP
andapolarizationand S0,min are Figure
theHartigan
maximumand(2004).
minimum
surfaceat posi- fraction
et al.
Theintensity
same
fit density
gives
disk
in
ijet
Cho & Lazarian 2007). The high fractionofpolarizationmeans
11
et al. (2018) and Teague et
have
also
recently
found
to
the
zenith.
3 al. (2018)
andDG(c),(d)).
inFig. 1.with
Polarization◦◦ center andthe center of the
ring,
θTau
fd represent
theContours
width
d and
tion
angle,
PA(panels= 60.7±1.9, in goodasagreement
hig
that
the
alignment
efﬁciency
maybe
higherthan
expected
or
the
disk
dynamical evidenceof massiveet
planets
in2019the system. indicate the jet
al. 2017, Kataoka et al.long-to-short2017, Ohashi
et
al.
2018,
Sadavoyal.
Thesystem
was
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represent
w
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2014),
andalmostper201
axis ratio of elongated dust
grainsislargerthan−1
In this paper, we present ALMA observations of polarized
dust
of
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is Imean> 10frequency
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2004).
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the assumed value (Cho & Lazarian emission2007). of
Alternatively,theHD163296 at 870 µm with a resolution of ∼0.2arcsec –338.432,jet
348.494, and 350.494
Akimasa Kataoka (NAOJ)−2 GHz,◦ each having 31.25
values are Piétu
taken
toTau,
bethe andΣ0,maxcm
Σ0,high polarization fraction observed in the southwest region(2014)
the=0.6
oneflux
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For etDGal.
integrated
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199

個人的な経験と着想に至った経緯•

学部：京大 (2006-2010)

䜂䛾䛷,㣕㦌SMART䜢⏝䛔䛯
X⥺㍤Ⅼ䛾᫬㛫ኚ໬ゎᯒ䕿ᕷᕝᖾᖹࠊ∦ᒸ❶㞞ࠊ⠛ᮌ᪂࿃ࠊఅぢ┤ⱱࠊᶫᮏ♸ᶞࠊΏ㑓ⓡᏊ䚸 ໭஭♩୕㑻ࠊ▼஭㈗Ꮚ

•野辺山電波観測実習 / すばる実習 / 京大課題演習太陽ி㒔኱Ꮫ⌮Ꮫ㒊䚸ி㒔኱Ꮫ኱Ꮫ㝔⌮Ꮫ◊✲⛉㝃ᒓኳᩥྎkitai@kwasan.kyoto-u.ac.jp

Abstract
X⥺㍤Ⅼ䠄XBP䠅䛸䛿䚸X⥺㡿ᇦ䛷ኴ㝧䜢ぢ䛯䛸䛝䛻䚸ኴ㝧඲య䛻䜋䜌୍ᵝ䛻Ⅼᅾ䛧䛶䛔䜛㍤Ⅼ䛷䛒䜛䚹⣸እ⥺㡿ᇦ䛷䜒ほ 䛩䜛䛣䛸䛜䛷䛝䚸䛭䛾ሙྜ䛿Coronal Bright Point䛸䜒࿧䜀䜜䜛䚹኱䛝䛥䛿2୓km䛛䜙3୓km䛾䜒䛾䛜ከ䛔䠄Dere 2008䠅䚹௒ᅇ䛿2007ᖺ10
᭶10᪥䛻ほ 䛥䜜䛯1䛴䛾XBP䛻ὀ┠䛧䚸ኴ㝧䛾ྛᒙ䛷䛾ほ 䜢䜂䛾䛷䚸㣕㦌SMARTᮃ㐲㙾䜢⏝䛔䛶⾜䛔䚸XBP䛾ᵓ㐀䜢ゎᯒ䛧䛯䚹䛭䛾⤖ᯝ䚸XBP䛜䝹䞊䝥ᵓ㐀䜢ᣢ䛴䛣䛸䚸ග⌫䛷☢ሙ䛾cancellation䜢㉳䛣䛧䛺䛜䜙ᾘ⁛䛧䛶䛔䛟ᵝᏊ䜢ᤊ䛘䛯䚹

•

修士：京大（2010-2012, 指導教員：野村英子さん）

㼲1. ほ

㼲3. ྛἼ㛗䛷䛾⤖ᯝᑐ㇟

SOT(Na filter;StokesV;ᴟᛶ䛿ⓑ䛜ṇ䚸㯮䛜㈇):☢ሙ䛾cancellation

20”

100”
20”
SMART, Hǂ2007/10/10 22:30:15UT•

星形成領域における磁場観測予測研究（富阪さん・町田正博さん）

HINODE, XRT
2007/10/10 18:49:16UTHINODE, SOT_CaII H
2007/10/10 18:47:17UT

2007ᖺ10᭶10᪥18:00UT㡭䚸䠄–170”,–35”䠅䛻䛒䛳䛯1Ⅼ䛾
XBP䜢ほ 䛧䛯䚹 䛣䛾㍤Ⅼ䛾Ⓨ⏕ᮇ㛫䛿10᭶8᪥15:00UT㡭
䛛䜙11᪥18:30UT㡭䜎䛷䚹௒ᅇ䛾ゎᯒᮇ㛫䛿䚸䛭䛾X⥺ᙉᗘ䛜㧗䛟άືⓗ䛺10᪥18:00UT㡭䛛䜙11᪥6:00UT㡭䜎䛷䛷䛒䜛䚹

10/10 20:52:36

10/10 21:20:34

10/10 22:44:35

10/11 00:24:32

10/11 02:46:36

10/10 21:24:08

10/10 22:59:19

10/11 00:10:47

10/11 02:49:28

EIS(FeXII;velocity map with EIS intensity contour):୰ᚰ㒊䛸ᕥୖ㒊䛷blue shift䚸ྑୗ㒊䛷red shift

20”
10/10 20:52:24

XRT(C filter):䝹䞊䝥ᵓ㐀䛸㠀ᑐ⛠䛺brightening㼲2. ゎᯒ
4䛴䛾ᮃ㐲㙾(䜂䛾䛷SOT,EIS,XRT,㣕㦌SMART)䜢⏝䛔䛶XBP䛾ྛᒙ䛷䛾ື䛝䜢᥈䛳䛯䚹ྛ䚻䛾ᙺ๭䛿௨ୗ䛾㏻䜚䛷䛒䜛䚹
1.SOT:•(1-a:NaV/I filter;ᕥᅗ)ග⌫䛷䛾XBP䛾☢ሙ䛾᫬㛫ኚ໬
(1-b:Ca filter;ྑᅗ)ᙬᒙ䛷䛾XBP䛾intensity᫬㛫ኚ໬

博士：総研大/国立天文台（指導教員：富阪幸治さん）

A. Kataoka et al.: Stat
20”
10/10 20:52:45

10/10 21:20:36

10/10 22:44:57

10/11 00:26:34

10/11 02:46:56

3 hour㼲4. 䜎䛸䜑䛸⪃ᐹ௨ୖ䛾ゎᯒ⤖ᯝ䛛䜙௨ୗ䛾䜘䛖䛺ᵓ㐀䛜⪃䛘䜙䜜䜛䚹
fig.1

•

ダスト空隙率進化（田中秀和さん）

3.XRT(C filter):䝁䝻䝘ᒙ䛷䛾㑄⛣ᒙ~䝁䝻䝘ᒙ䛾㏿ᗘሙゎᯒᕥ䛿intensity䚸ྑ䛿㏿ᗘሙ䜢⾲䛩 intensity᫬㛫ኚ໬䜢ぢ䜛

20”

4.SMART:ᙬᒙ䛷䛾㏿ᗘሙ䛾᫬㛫ኚ໬(filter:Hǂ,Hǂ㼼0.5Å)ńୖᅗ䛾⡆᫆Dopplergram䛛䜙䚸XBP࿘㎶䛿䚸ᙬᒙ䛷䛿ୗ㝆ὶ䛻ᑐᛂ䛧䛶䛔䜛䛣䛸䛜䜟䛛䛳䛯䚹

PD：ハイデルベルク大学
•

fig.3

2.EIS:

SMART⡆᫆Dopplergram:
Hǂ+0.5Å䛛䜙Hǂ–0.5Å䜢ᘬ䛔䛯(SOT_Na contour㉥䛜ᴟᛶṇ䚸㟷䛜ᴟᛶ㈇)

•

fig.2

References
Dere, K. P.. A&A, 491, 561, 2008
Tian, H., Curdt, W., Marsch, E., & He, Jiansen, ApJ, 681, L121, 2007
Asai, A., Shibata, K., Hara, H., & Nitta, N. V., ApJ, 673, 1188, 2008

䛆fig.1䛇 SOT䛾☢ሙᵓ㐀䜘䜚䚸す䛛䜙+,–,+䛾ᴟᛶ䛾☢ሙ䛜୪䜆䚹
䛆fig.2䛇 –䛾ᴟ䛾ୖ✵䛷☢Ẽreconnection䛜㉳䛝䚸ୖ✵䜈䛸jet䛜ὶ䜜䜛(䛣䜜䛜EIS䛾blue shift䛸ᑐᛂ䛩䜛)䚹
䛆fig.3䛇 –䛸+䛾ᴟ䛜㏆䛵䛝䚸☢Ẽreconnection䛜⤯䛘䛪㉳䛝䚸brightening䛾source䛷䛒䜚⥆䛡䜛䚹䜎䛯+䛾ᴟ䛜䛒䜛ሙᡤ䛷䛿ୗ㝆ὶ䛜㉳䛝䜛(SMART䛾ୗ㝆ὶ䛸ᑐᛂ)䚹䛭䛾ᚋ䚸☢ሙ䛜ᣑᩓ䛧䚸brightening䛜ᙅ䜎䜛䚹௒ᚋ䛾ㄢ㢟
•EIS䛷䛾ᕥഃ䛾blue shift䛾䝯䜹䝙䝈䝮䛾ゎ᫂•brightening䛾ᕥྑ㠀ᑐ⛠ᛶ䛻䛴䛔䛶•ග⌫㠃䛷䛾☢ᴟ䛾⛣ື䛾ཎᅉ

輻射輸送計算による観測モデリング(Cornelis Dullemond氏)
Kataoka, Tanaka, Okuzumi et al, 2013
Akimasa Kataoka (NAOJ)

野辺山観測実習•

天文との出会い。学部２年生で参加。

•

星形成領域の単一鏡電波観測→面白かった
ので天文学に来た•••

https://www.nro.nao.ac.jp/~nro45mrt/html/misc/45school.html

ちなみに守屋さんも同じ年に参加

多分僕です

当時院生の方（樋口さんと島尻さん）に
電波天文について教えてもらう

輝線で見ると物理状態がよくわかること・
単一鏡で見ると結構大まかな構造しかわからないことは理解した。
•

別件ですが直後のすばる実習では今西さん・小宮山さんにお世話になりました。
中島さんも参加者の１人
Akimasa Kataoka (NAOJ)

10

星形成と磁場と偏光•

学部４年生のときに参加した広島の天文学会にて、町田正博さんに「やってみない？」と言われて始まる。

•

課題：町田さんの３次元磁気流体シミュレーションを、富阪さんの輻射輸送計算コード
で擬似観測し、どんな偏光が見えるはずかを計算した
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The total flux measured in our 8
observations is 6.2 T 0.5 janskys (Jy) oarea of 33 square arc sec, where there is adsensitivity to measure the polarization. A
ing optically thin emission, a dust tempera
50 K (19), aTheory
gas-to-dust ratio of 100, andObservations
opacity of 1.5 cmj2 gj1 (20), we estim
total mass traced by the dust to be 1.2
solar masses Ed300 K (d/300 pc), where dadopted distance to the NGC 1333 cloud
can make an estimate of the averaged cdensity EN(H2)^ and volume density En(Hthe region traced by the dust as follows: N
M/(Amm) and n(H2) 0 M/(Vmm), where M
dust mass, mm is the average mass peticle, A is the area of the dust emission, a
1
3
4
–
/
2
( /3)p A / 2 is the volume. Adopting a h
to-hydrogen mass ratio of 30%, we find tmean column density is N(H2) 0 8.2 !
cmj2 and the mean volume density is n
j1 cmj3; both are similar
7 d
4.3 ! 10
Kataoka,
300 Tomisaka, Machida, 2012
Fig. 1. (A) Sketch of the axis directions: red/blue expected values for the observed scales (1With the array configuration and freq
arrows show the direction of the redshifted/
blueshifted lobes of the molecular outflow, used, these SMA observations are not seprobably driven by IRAS 4B (8); solid lines show to dust emission on scales larger thanthe main axis of the magnetic field; and dashed 3000 AU, where models of magnetized clines show the envelope axes. The solid triangles ing clouds expect the magnetic fieldshow the positions of IRAS 4A1 and 4A2. The cross uniform. Therefore, the magnetic field hashows the center of the magnetic field symmetry. modeled by a family of parabolic fun(B)Contour map of the 877-mm dust emission
町田正博さん（当時国立天文台）
富阪幸治さん（当時国立天文台）(Stokes I) superposed with the color image of the Fig. 2. Histogram of the
Akimasa Kataoka (NAOJ)
polarized flux intensity. Red vectors indicate that

ALMA観測研究への参加
L14-2
•

M. F

2013年(D1)頃、深川さん・武藤さんから「CS(7-6)のモ
デリングをしてくれ」と依頼があった。
••「観測屋」と「理論屋」が別れている中で、その間をつなぐモデリングができるようになれば強いだろうと思って二つ返事で参加。

その後議論の中で「ダスト散乱で偏光が見えないか？」となった。芝井・武藤両氏からのアイディア。
•

Fukagawa et al. 2013

結局CSのモデリングは全然やらずに偏光の話をすす Fig. 1. Dust continuum map at 336 GHz (890 !m) for the disk of
めることに…(すいません)

HD 142527. The color scale shows the brightness temperature on
a logarithmic scale. The black contours denote Tb = 5, 10, 15, and20 K, while the white one denotes the 5 " level. The size of the synthesized beam is shown at the left corner of the image with a white ellipseof 0:00 39 ! 0:00 34 (= 55 au ! 48 au) with a major-axis PA of 57ı .
深川さん(当時阪大) 武藤さん(工学院) 芝井さん(当時阪大)

Cycle 0. The maximum and minimum baselines were 380

Akimasa Kataoka (NAOJ)

超新星爆発における偏光
田中雅臣氏ら、すばる望遠鏡のプレスリリース(2012年)•

2012-2014年博士課程、国立天文台理論研究部••

同じ部屋に田中雅臣さん（当時天文台助教）

輻射場の異方性と偏光について田中さんに大変よく議論してもらった。
•

当時、キロノバのオパシティを計算していて忙しhttps://subarutelescope.org/jp/results/2012/08/02/952.html

かったはず…

The Astrophysical Journal, 754:63 (10pp), 2012 July 20

(b)
(a)

•

CMBのE-mode偏光も似たような物理(c)

田中雅臣さん
Figure 1. Schematic illustration of polarization in the SN ejecta (see also
Kasen et al. 2003; Leonard & Filippenko 2005; Wang & Wheeler 2008).
(a) When the photosphere is spherical, polarization is canceled out, and nopolarization is expected. At the wavelength of a line, polarization producedby the electron scattering is depolarized by the line transition. (b) When theion distribution is spherical, the remaining polarization is canceled, and no

The properties of linear p
the Stokes parameters. Thr
Stokes parameters as a fract
U ≡ Û /I , where Q̂ and Û c
Û = I45 − I135 , respectively
through the ideal polarizatio
Stokes parameters Q and U,
obtained by2θ =The position angle is measu
Figure 2 shows the expect
model (top) and a 3D clump
spectra are calculated by theline optical depth distributi
those in Kasen et al. (2003)of the simulations will be gleft panels show the distribu
model, the opacity is enhan
region, while in the 3D modein the randomly distributed c

Tanaka et al. 2012

Akimasa Kataoka (NAOJ)

01
0.1
mum grain size [cm]

0.8

0.6

0.6

1

振り返って見ると…
0.8
0.6

0.4

0.4

0.4

0.2

0.2

0.2

0

0

0

-0.2

-0.2
0.001

-0.2

1

0.01
0.1
Maximum grain size [cm]

ω

0.8

P

1

ω

protoplanetary disk.

1

1

at the scattering angle of 90 and the albedo ! = sca /(abs + sca ) as a function of maximum grain size.
ed to have power law of n(a) / a 3.5 . The wavelengths are assumed to be 1.3 mm for the left panel andhe arrows indicate the maximum grain size which has the most efficient polarization by 90 scattering.

BLE 1
ain size for observed
lengths

1.2
1

disk. The object is optically thin everywhere.
sensitive grain size amax

0.8•

理論研究中心だったが、たまたま観測研
究のモデリングに誘ってもらった•

たまたま観測の（ごく初歩の）知識と興
味はあった

•

偶然偏光モデリングの知識があった

Prediction of polarization fraction
3.1 mm0.87 mm (Band 3)(Band 7)7 mm
(Band 1)0.34 mm(Band 10)Pω

1 mm
This 500
corresponds
to point B in Figure 6.0.6
Byµm•
vectors150
areµmin the radial direction in the inner
0.4
ng. This70isµm
due to the net ﬂux from the azimuthal
g. larger than the net ﬂux in the radial direction.
0.2•
nds to point A in Figure 6. This double-ringniquefeaturethe polarization due to dust
0size foreach ofwavelengthd thus this will be a clue to distinguish the
hat the polarization due to 90
0.001
0.01
0.1
1
echanism.
Maximum grain size [cm]an be significant only when the
Kataoka et al., 2015
e to have a large albedo (§2.2)
zationfrom Lopsided
ProtoplanetaryDiskswisotropic
scattering(§2.3).
(grain size) ~ λ/2π
grain
to be detected.
culate size
the expected
polarization from a Fig.
lopsided
4.— The polarization times the albedo P ! against the maxpendenceof polarizationeffi- observed
imum withgrain size. This figure represents the sensitive grain size
ic the lopsided
disk structure

研究のアイディアはもとは他の人からメカニズム自体も他の天文分野で枯れた
物理

0.
空隙率もわかりそう
0
=
φ
(
0
)
3
00

Initial
(b=0)

I
(

)
m
(µ

t=

cf. Kataoka et al. 2013ab, Wada et al. 2009

ギュッと詰まってはいなさそう…

O
(

)
m
(µ

Outcome(b=0, ucol=52 m/s)

だけどそんなにスカスカじゃなさそう…

)
m
(µ

)
m
(µ

=
N
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a
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まあまあ詰まっている！

でも結構小さい！！(100ミクロン)

今後•

偏光天体のモデリング•

偏光強度はリング・ギャップで違いがある (Ohashi and Kataoka 2019)•

ダスト沈殿の影響 (Ueda, Kataoka, et al. 2021)

The Astrophysical Journal, 886:103 (19pp), 2019 December 1

Figure 9. Proportion of vertical optical depths at = 870 µm (topsize of Fixed model with amax = 1000 µm (top) and amax = 2900 µ
grains above the ⌧ = 1 surface. The radial position is 20 au.

Strong turbulence
8

•
•

•

ダスト空隙率の影響 (Zhang, Ueda, Kataoka, Zhu, in prep.)

別手法によるダストサイズ測定•

散乱による連続波減光 (Ueda, Kataoka, Tsukagoshi 2020)•

リング天体のダスト高さ測定 (Doi and Kataoka 2021)

偏光の整列成分の解析

Ohashi & Kataoka

No-settling limit

Doi and Kataoka

Only large grains
settle to the mid

Figure 1. 0.87 mm dust continuum polarization in HD 163296. The panels show the total intensity (Stokes I), Stokes Q component, Stokes U component, and polarization
fraction, from left to right. The black and white ellipses indicate the position of the 70 au ring. The polarization vectors are overlaid on the polarization fraction. The polarization
vectors and the polarization fraction are shown where the polarized intensity is higher than 3σPI. Note that the lengths of the polarization vectors are set to be the same.

grainsd for large
τ =1
The radial
proﬁle of theΣdust is the dust surfacehdensity.
intensity is set using Equations (1)–(3). The unit of intensity is
set to be Jy beam−1 for comparison with the observations.
The calculation of opacity followed that by Kataoka et al.
(2016a). The dust grains were assumed to be spherical and tohave a power-law size distribution with an exponent ofq=−3.5 (Mathis et al. 1977) and maximum grain size amax.
This maximum grain size is considered to be the representative
grain size in the following discussion. The opacity was
3. Disk Modelcalculated using Mie theory. The composition was assumed
small
d for
To perform radiative transfer calculations, we constructed an
to be a mixture of silicateh(50%)
andwater icegrains(50%) (Pollack
axisymmetric dust disk model with several additional rings thatet al. 1994; Kataoka et al. 2014). We used the refractive index
reproduce the continuum image. We discuss the physicalof astronomical silicate (Weingartner & Draine 2001) and
Figure 10. Schematicof the1984)
locationof ⌧ =
surfacerelativeto duparameters of the disk in the following section.
water ice (Warren
and calculated
their1 mixture
basedon
We adopted the following temperature proﬁlewith
a smoothmediumtheory whoseusing the St
Maxwell–Garnett
rule (e.g.,
dust
scale
heightseffectiveof large
grainsis larger than↵t decrease
power-law distribution derived by Isella et al. (2016):
Bohren & Huffman 1983; Miyake & Nakagawa 1993). Note
Figure 5. Comparison of images of HD 163296. The three
images in theleft column
represent observation,and theto
three the mid-plane since even small grains satisfy
mostofgrainssettleimages in the middle and right columns represent
Each
line
0.5simulations with f = 1 (no settling) and f = 8, respectively.
thatadifferent
abundance may lead to a different absolute⎛⎞Rshows the images with di↵erent color ranges. The middle line shows the images that emphasize the azimuthal intensity variation⎜⎟
Tdinnerring,220(1 )of theand theKbottom line shows that of .the outer ring.
value of the degree of polarization, which should be⎝ 1 au ⎠investigatedin future studies.
major axis does not depend on the dust scale height,
is larger than that along the minor axis.
On the otherwhile that along the minor axis depends on the dust
hand, around the outer ring at 100 au, the intensity
We adopted scalea height.
power-lawsurface density
proﬁlewith anThedensity distribution
assumedGaussianthescatteredisverticaldifficultfor the isHL
Tauto bedisk
bedu
Along the minor axis, the higher the dust
along
the major and minor axes islight
almost thesame.
heightis, the wider
the observed dust brightring width regions
Figure 9toshows
the radial intensity profiles along the
exponential tail scale
and
added
exponential
mimic
a dust scale height hd such that Sd  4d ( 2Q hd )is, and the lower the observed intensity at the peak is.
major (top) and minor (bottom) axeswithof the observacause
itstill
a massive envelope which
20
We plot theintensityof bothsimulations
and the obtion toand besimulations
in caseof f = 1embedded
and 8. We canthe observed proﬁle.
We
took
the
intensity
proﬁleonisthe2 h 2 ). Wein(zwell
set an additional dust settling parameter fset
servation along the major and minor axes to check thesee that the simulations reproduces theexp
observationdmajor axis in thenorthwest
direction
to 3.3.avoid along
the theadditional
consistencyof f , which weestimate in section
major axis from the upper panel of Figure
hd  hg fsetthesuch, wherehg surface
is the gas structure
scale height
prevent
usof Figure
frominvestigating
disk
Figure 8 shows the radial intensity profiles of the ob9. The bottom panel
9 shows
thatthe thatradialcrescent-shapedservation
structurereportedin Aroundthe theopposite
direction
along the major
and minor axes.
profile along
the minor axis around the inner ring is wellinner ring at 68 au, the intensity along the major axis
reproduced by f = 1, while that aroundoutercringgthes 8), to mimic grain settling.
(Isella et al. 2018).
The intensity can be expressedas(Beckwithet al.(h1986,
1990).
etWe performed
radiative transfer calculations with RADMC-3D3
IO (R)  (1  eU (R)) BO (Td (R)). The very(2)weak(Dullemondet al. 2012),
taking into accountmultipleturbulence
is consistentwiththescattering,
recent10
as done by Kataoka et al. (2015). The inclination and position
Using this equation, we assume the radial opticaldepth proﬁleMHD
tonon-idealmodelswhereto theseangle
were assumed
be 47°Magneto-Rotationaland 133°. 3, respectively, asbederived by the DSHARP project (Isella et al. 2018).
Instability(MRI)
suppressed
the werediskconvolved
mid-plane
anTheisStokes
I, Q, and Uat
imageswith a⎛ ⎛ R ⎞5 ⎞⎛ R ⎞0.5⎟⎟ ⎟2 toGaussian Bai
beam 2017).
with a full widthat half maximum
U  0.14 ⎜exp ⎜  ⎜(e.g.,
Gammie 1996;
However,even ifof 0MRIis
⎝ 1 au ⎠⎝ ⎝ 35 au ⎠ ⎠produce the ﬁnal model images. Figure 2 shows the intensity
instabilitiesac⎛ 1 ⎛ R  70 au ⎞2is⎞ suppressed, pure
proﬁlehydrodynamic(Stokes I) obtained fromthe continuumwould
data on inthe⎟ ⎟1.1 exp ⎜  ⎜major axis overlaid with the model intensity proﬁle. The ﬁgureth⎝ 2 ⎝ 3.8 au ⎠ ⎠conﬁrms that the model reproduces the continuum image.
⎛ 1 ⎛ R  104 au ⎞2 ⎞The three rings are located at 70, 104, and 160 au, and their⎟ ⎟0.2 exp ⎜  ⎜widths are 3.8, 5.6, and 16 au, respectively. Isella et al. (2018)⎝ 2 ⎝ 5.6 au ⎠ ⎠derived the locations of the two inner rings as 67 au (width: 6.6⎛ 1 ⎛ R  160 au ⎞2 ⎞au) and 101 au (width: 5.8 au), respectively. These values arerecognized in the Stokes Q image because the Stokes Q
emission represents polarization pointing along the disk major
axis in this disk geometry.
In this paper, we perform radiative transfer calculations bytaking into account the polarization due to only self-scattering. This
assumption is consistent with the results reported by Dent et al.
(2019), who indicated that the polarization is produced by the selfscattering without any additional dust alignment mechanism.

set

set

set

set

set

•

ダスト針状の形をしている？(Mori and Kataoka 2021)•

磁場形状はトロイダルだろう (Ohashi, Kataoka et al. 2018)

大橋さん

土井さん

植田さん

Zhangさん

おわりに•

論文にはならない多くの人のご協力でこの研究が成り立っています。ありがとうございました。
•

野辺山電波観測実習（特にTAだった樋口さん）
•

•

•

•

振り返ってみて重要だったこと

すばる実習（今西さん・小宮山さん）•

日本の天文学の裾野の広さ•

学部生/分野外の人向けのプログラム•

近いグループの人からの耳学問

台湾でのセミナーをホストしてくれたShih-Pin Lai氏
ALMAの議論に入れてくれた深川さん・武藤さん・芝井さん•

同じ部屋で学生の議論に散々付き合ってくれた田中雅臣さん•

修士指導教員の野村英子さん•

博士指導教員の富阪幸治さん