SF newsletter 342 #13-18
M. Momose (Ibaraki Univ.)#15, 16 (Yebes 40m/IRAM 30m望遠鏡による30-50GHz & 77-240GHzのラインサーベイの結果）#14 (ちょっとだけ紹介)
その他 (アブストラクトと一言メモ)

already occurred. Finally, we examine the disk mass – host mass relationship and find that BD disks are largely consistent withpreviously-determined relationships for disks around T Tauri stars.

15.

Discovery in space of ethanolamine, the simplest phospholipid head group

Víctor M. Rivilla, Izaskun Jiménez-Serra, Jesús Martín-Pintado, Carlos Briones, Lucas F. Rodríguez-Almeida,
Fernando Rico-Villas, Belén Tercero, Shaoshan Zeng, Laura Colzi, Pablo de Vicente, Sergio Martín, Miguel A.
Requena-Torres F Cell membranes are a key element of life because they keep the genetic material and metabolic machinery
together. All present cell membranes are made of phospholipids, yet the nature of the first membranes and the origin ofphospholipids are still under debate. We report here the first detection in space of ethanolamine, NH2 CH2 CH2 OH, which forms
the hydrophilic head of the simplest and second most abundant phospholipid in membranes. The molecular column density
13
2of ethanolamine in interstellar space is N =(1.51±0.07)⇥10 cm , implying a molecular abundance with respect to H2 of10(0.9-1.4)⇥10. Previous studies reported its presence in meteoritic material but they suggested that it is synthesized in themeteorite itself by decomposition of amino acids. However, we find that the proportion of the molecule with respect to water
6in the interstellar medium is similar to the one found in the meteorite (10 ). These results indicate that ethanolamine forms
eﬃciently in space and, if delivered onto early Earth, it could have contributed to the assembling and early evolution of primitive
membranes.

• Sgr N2領域にあるマイルドなcloud-cloud collision領域G+0.693-0.027に対するDetectionofthecyanomidyl
radical(HNCN):anewinterstellar
species
with
the
NCN
Yebes 40m (31.0-50.4GHz) + IRAM 30m (71.77-116.72GHz)のラインサーベイで，backbone

メタノールアミンの星間空間での初検出
V. M. Rivilla,
I. Jiménez-Serra, J. García de la Concepción, J. Martín-Pintado, L. Colzi, L. F. RodríguezAlmeida, B. Tercero, F. Rico-Villas, S. Zeng, S. Martín, M. A. Requena-Torres, P. de Vicente F We report here
• メタノールアミンは生命体にとって欠かせない，細胞膜やコンパートメントを形作る
the first detection in the interstellar medium of the cyanomidyl radical (HNCN). Using the Yebes 40m and the IRAM 30m
telescopes, wehave targeted the doublets of the N =2 1, 4 3, 5 4, 6 5, and 7 6 transitions of HNCN toward the molecular「リン脂質」の中の親水性頭部として最も多く含まれるものの1つ
cloud G+0.693-0.027. We have detected three unblended lines of HNCN, these are the N =6 5 doublet and one line of the
13 cm-2, H2に対する相対アバンダンスは(0.9-1.4)×10-10。
•
N=
1.5×10N =4 3 transition. Additionally we present one line of the N =5 4 transition partially blended with emission from otherspecies. The Local Thermodynamic Equilibrium best fit to the data gives a molecular abundance of (0.91±0.05)⇥10 10 with
• メタノールアミンはエンスタタイトコンドライト隕石でも見つかっていたが，H2Oにrespect to H2 . The relatively low abundance of this species in G+0.693-0.027, and its high reactivity, suggest that HNCN ispossibly produced
by gas-phase chemistry. Our work shows that this highly reactive molecule is present in interstellar space,
対する存在比はそれと同程度だった。水とともに，地球に運ばれてきたかも！？

生命体の3つの基本サブシステム• Compartment (コンパートメント＝膜で区画された構成。例えば細胞膜）• Metabolic machinery（代謝システム）• Information-bearing molecules （遺伝情報を格納する分子）
後ろの2つは compartmentがあって始めて成り立つものであるので，細胞膜をはじめとするCompartmentは最初の生命体の発現とその後の進化の必須条件と言える

細胞膜の特徴とエタノールアミン
リン脂質(phospholipid)が２重構造を作り脂溶性のものは透過させるのに対して水溶性のものはほとんど透過しない!"#$%"&'()*+,'"&-#+&.(-,/0!12
6,++/.,.9:&-,/
0%"#$%"#+(%()/9(+&*,:292;234564564574/
1'"&-#+&.(-,/01'82"*):#%"(+(;//
",&)

)2

リン脂質は親水性頭部(hydrophilic head)と疎水性尾部(hydrophobic tails)からなる
エタノールアミンは，細胞膜リン脂質の親水性頭部の中で最も簡単な構造を持ち，&2かつ細胞膜で2番目に多いリン脂質(ホスファチジルエタノールアミン)を作る
エタノールアミン(NH2CH2CH2OH)は，

6,++"*):#%"#9(;/"*):#%"#9(;//'&(+$グリシン(NH2CH2COOH)の前駆体としても有望視されている Fig. 1. Structure of cellular membranes. a) Schematic view of a cell; b) Zoom-in view of the cell membrane, formed by a phospholipid bilayer; c) Three-dimensiona

宇宙物質中での観測帯域中にあると計算されていた全遷移 (23,655本!)のうち

16.9 K5(0,5) - 4(0,4)

8(2,7) - 7(2,6)

19.2 K8(1,7) - 7(1,6)

18.6 K

別の可能性：EtAがISMで形成されるショックを伴う分子雲。アイスマントルのerosionによる豊富なガス化学。密度~104cm-3オーダ，Tex = 5-15Kでラインの密度(blending)は控え目→探索には理想的。

29.2 K

CH3NH2

13CH CHCN
29(4,5) - 8(4,4)

HOCS+

HCCCHO

観測対象のG+0.693-0.027: Sgr N2領域にある，マイルドなCCCに伴う低速(<20km)

26.0 K
CH3COCH39(3,7) - 8(3,6)

23.5 K
CH3COOH9(2,8) - 8(2,7)
aGg-(CH2OH)2

19.8 K

CH3OCH3

ラインサーベイで初検出！

8(2,6) - 7(2,5)

c-C3H4

今回，Yebes 40mとIRAM 30mを用いた

7.2 K

CH3C13CH

CH3COCH38(0,8) - 7(0,7)

5.5 K

HNCS +
HCOCN

14.6 K4(1,3) - 3(1,2)

c-CC13CH2

TA*(K)

OCS

7(1,6) - 6(1,5)

6.7 K

CH3OCHO

その起源は不明であった。隕石母天体での特殊環境下でのアミノ酸分解？ それだと原始地球への供給量は限られる

4(2,2) - 3(2,1)

CH2CH13CN

6.7 K

H2CCO

4(2,3) - 3(2,2)

NH2CN

アルマハータ・シッタ隕石はEtAを含むが4.8 K

10(0,10) - 9(0,9) 25.5 K

c-C2H4O

4(0,4) - 3(0,3)

C2H5OH

エタノールアミン(EtA)

CH3OCHO

強いと予想されていた45本中，ブレンドしていない検出が14本

Frequency (GHz)
Fig. 2. Unblended or slightly blended transitions of EtA towards the G+0.693-0.027 molecular cloud. The quantum numbers involved in the transition are indicated in the upper
left of each panel, and the energies of the upper level are indicated in the upper right. The red thick line depicts the best LTE fit to the EtA rotational transitions. The thinblue line shows the expected molecular emission from all the molecular species identified in our spectral survey, overplotted to the observed spectra (gray histograms). The
three-dimensional structure of EtA is shown in the center of the figure: black, red, blue and white balls denote carbon, oxygen, nitrogen and hydrogen atoms, respectively.

赤がEtA，青は全分子を考慮した予想スペクトル，
Discussion. We report a clear detection in the ISM of EtA, adetected so far in the ISM (29), and all other species reported
towards G+0.693 in previous works (21–25). The predicted
contribution from all molecular species is shown with a blue
solid line in Fig. 2, confirming that 14 transitions of EtA are
either clean or not significantly contaminated by the emis-

precursor of phospholipids, with a relatively high abundance(10≠10 with respect to molecular hydrogen). This detection
adds to that of precursors of ribonucleotides (23–25) and aminoacids (30, 31) in the ISM. The building blocks of the three

結構よく合っている！

The gray shaded area corresponds to a hydrogenation chain. The chemical reactions indicated with colored arrows have been proposed in previous works: magenta (36), blue(38), orange (41), cyan (39), green (41, 47). In black, we show the formation routes proposed in this work. The solid arrows indicate surface chemistry reactions, and dashedarrows denote gas phase chemistry.

ブレンドしていない遷移の一覧

観測帯域中にあると計算されていた全遷移 (23,655本!)のうち

CH3NH2HCCCHOaGg-(CH2OH)2

c-C3H4

IRAM 30m telescope. We have carried out a spectral survey at 3

CH3OCHOHNCS +
HCOCN

7.2 K

8(1,7) - 7(1,6)

18.6 K

CH3C13CH

CH3COCH3

CH2CH13CN

c-CC13CH2

13CH CHCN
2

CH3COCH3

4.8
6.7
6.7
5.5
7.2
14.6
16.9
19.2
18.6
19.8
23.5
26.0
29.2
25.5

5(0,5) - 4(0,4)

C2H5OH-5.64603-5.74549-5.72208-5.59088-5.35979-4.84093-4.76916-4.73500-4.67140-4.66443-4.57750-4.57780-4.61854-4.48695

CH3COOH4(0,4) - 3(0,3)
4(2,3) - 3(2,2)
4(2,2) - 3(2,1)
4(1,3) - 3(1,2)
5(0,5) - 4(0,4)
7(1,6) - 6(1,5)
8(0,8) - 7(0,7)
8(2,7) - 7(2,6)
8(1,7) - 7(1,6)
8(2,6) - 7(2,5)
9(2,8) - 8(2,7)
9(3,7) - 8(3,6)
9(4,5) - 8(4,4)
10(0,10) - 9(0,9)

CH3OCH3

39.7379429
40.4083769
41.1366268
42.2557255
49.1932727
73.0048603
76.6071016
80.0223886
82.8757878
84.2912932
89.7254251
91.6032870
91.8301065
94.7010488

CH3OCHOEup (K)

NH2CN

logAul (s≠1 )OCS

Transition

H2CCO

of 1.7 km s at 45 GHz. We covered a total spectral range- 3(0,3) GHz- 3(2,2) GHz.
4.8 K to 4(2,3)
6.7 K
4(2,2)position- 3(2,1)
6.7 K switching4(1,3) - 3(1,2)
5.5 K
from4(0,4)
31.07550.424The
mode
was used, with the reference position located at (-885”,+290”)with respect to G+0.693 (24, 27). The telescope pointing andfocus were checked every one or two hours through pseudocontinuum observations towards VX Sgr, a red hypergiant star
near the target source.
The
spectraweremeasured
in
units
of
8(0,8) - 7(0,7) 16.9 K
14.6 K7(1,6) - 6(1,5)
8(2,7) - 7(2,6) 19.2 Kúantenna temperature, TA , since the molecular emission toward
G+0.693 is extended over the beams (55). The noise of the*TA (K) spectra depends on the frequency range, reaching values as low
as 1.0 mK, while in some some intervals it increases up to 4.0
mK. The half power beam width (HP BW ) of the telescope is48” atGHz.
8(2,6)36- 7(2,5)19.8 K9(2,8) - 8(2,7) 23.5 K9(3,7) - 8(3,6) 26.0 K
9(4,5) - 8(4,4) 29.2 K

Table 1. Spectroscopic information (rest frequency, Einstein coefficients (Aul ), and energy of the upper levels (Eup ) of the 14 unblended
or slightly blended rotational transitions of EtA detected towards theG+0.693 molecular cloud (shown in Fig. 2).
Frequency (GHz)

強いと予想されていた45本中，ブレンドしていない検出が14本≠1

10(0,10) - 9(0,9) 25.5 K

c-C2H4O

HOCS+

mm using the IRAM 30m telescope. The observations were
performed in two observing runs during 2019: April 10-16
and August 13-19, from projects numbers 172-18 (PI MartínPintado), 018-19 (PI Rivilla). We Frequency
used the broad-band
Eight
(GHz)
MIxer Receiver (EMIR) and the fast Fourier transform specFig. 2. Unblended or slightly blended transitions of EtA towards the G+0.693-0.027 molecular cloud. The quantum numbers involved in the transition are indicated in the upper
left of each panel,and the energies ofupper level are indicatedupper right.
The red thick line
the best LTE
fit to the EtA rotational transitions. The thintrometers
intheFTS200
mode,in thewhich
provided
adepicts
channelwidth
blue line shows the expected molecular emission from all the molecular species identified in our spectral survey, overplotted to the observed spectra (gray histograms). The
≥200
The
final
were
a oxygen,609 nitrogen
KHz,and hydrogen atoms, respectively.
of EtAkHz.
is shown inthe centerof the spectra
figure: black, red,
blue andsmoothedwhite balls denote tocarbon,tions not only for theories of the origin of life on Earth,three-dimensional
but ofstructure
≠1
i.e.
a
velocity
resolution
of
1.8
km
s
at 100 GHz. The
also on other habitable planets and satellites anywhere in thedetected so far
in the
ISM (29),coverage
and all otherisspecies
reported Discussion.
reporttelescopea clear detection in the ISM of EtA, afull
spectral
71.770-116.720
GHz.WeThe
Universe.
towards G+0.693 in previous works (21–25). The predicted precursor of phospholipids, with a relatively high abundance
pointing and focus were checked every 1.5 h towards brightcontribution from all molecular species is shown with a blue (10≠10 with respect to molecular hydrogen). This detection
The that
spectrawere ofalso
of antenna
solid line in sources.
Fig. 2, confirming
14 transitions
EtAmeasured
are adds to in
thatunitsof precursorsof ribonucleotides (23–25) and amino

赤がEtA，青は全分子を考慮した予想スペクトル

Materials and Methods(SLIMによる)，結構よく合っている！

ú
either clean or not significantly contaminatedby the emis-ú ISM. The building blocks of the three
acids (30, 31) in the3(1,2) - 2(1,1)

ブレンド
している
遷移が
31本

3.5 K

4(1,4) - 3(1,3)

5.1 K

5(1,5) - 4(1,4)

7.4 K

5(2,4) - 4(2,3)

9.1 K

7(2,5) - 6(2,4)

15.7 K

ブレンドしてない遷移に対する8(1,8) - 7(1,7)

17.0 K8(3,6) - 7(3,5)
8(4,5) - 7(4,4)

21.6 K
24.8 K8(4,4) - 7(4,3)

24.8 K8(3,5) - 7(3,4)

21.7 K9(1,9) - 8(1,8)

21.0 K9(0,9) - 8(0,8)

21.0 K9(4,6) - 8(4,5)

29.2 K9(1,8) - 8(1,7)

23.0 K9(3,6) - 8(3,5) 26.2 K

10(1,10) - 9(1,9) 25.6 K

9(2,7) - 8(2,6)

24.3 K10(2, 9) - 9(2,8)

28.3 K10(3,8) - 9(3,7) 30.9 K

10(1,9) - 9(1,8) 27.9 K

10(4,7) - 9(4,6) 34.1 K

10(4,6)- 9(4,5)

34.1 K

11(1,11) - 10(1,10) 30.5 K

11(0,11)-10(0,10)10(3,7) - 9(3,6)

10(2,8) - 9(2,7)

Rotation Diagram

TA*(K)

全species
を含めて計
算した
モデルと
大きな
矛盾なし
↓
確かにEtA

30.5 K

31.2 K

29.4 K

Fig. 4. Rotational diagram of EtA. The analysis procedure is described in the Materials
and Methods section. The red dots correspond to the 14 EtA transitions shown in
Fig. 2 and Table 1. The black line is the best linear fit to the data points. The derived
values for the molecular column density (N ) and the excitation temperature (Tex ),along with their uncertainties, are indicated in blue in the upper right corner.
11(2,10) -10(2,9) 33.5 K

11(1,10) -10(1,9) 33.2 K

11(3,9) -10(3,8) 36.3 K

12(1,12) -11(1,11) 35.9 K

12(0,12) - 11(0,11) 35.9 K

18Oから求めたH2柱密度との比較
Cand
consequently also in the gas phase, due to shock-induced
sputtering desorption. Alternatively, the amount of HCCO
detected towards G+0.693 might -10
have been produced directlyin the gas phase through the reaction CCH + OH æ HCCO
+ H proposed by (36), since CCH is highly abundant in this2
cloud (37).
HNCCO could also be formed on dust grains from ketene(H2 CCO), after two hydrogen abstractions, and reaction with
the imine radical NH (Fig. 5). G+0.693 presents a variety of

X(EtA) (0.9-1.4)x10

起源
Frequency (GHz)
Fig. 3. Transitions of ethanolamine that appear blended in the observed spectra of G+0.693. All of them have line intensities > 5 mK, according to the best LTE fit described in
the text. The quantum numbers involved in the transition are indicated in the upper left of each panel, and the energies of the upper level are indicated in the upper right. The
red thick line depicts the best LTE fit obtained fitting the EtA rotational transitions shown in Fig. 2. The thin blue line shows the predicted molecular emission from all themolecular species identified in our spectral survey, overplotted to the observed spectra (gray histograms).

：結構高い。

H Oに対する存在比は隕石と同レベル，星間空間に豊富に存在？

CH2 OH on
radical rea
other compected tois an interand methy
abundantMoreov(41), to for
EtA (Fig.
troscopy a
we cannot
in the G+
The pesults into
rotational
cally by (4cies (≥0.2
fication in
makes NH
searches, a
its microw
The dedance of ≥with the cmaterial (ISM is ofratio meas
hata Sitta
classified
other mat星間空間でのEtA形成反応の候補(メチレンイミン)

CCH
HCCO
+H

H2CCO

NH2CH

HNC

+ OH
+N
-2H
+NH

+CO

HNCCO

+H

+ CO
+ 2H

+H

NH2CH2CH3NH2 (メチルアミン)+H+ CH2OH (メタノールと関連)+ CO

NH2CHCO
+C

CH2NH

+H

NH2CH2CO+H

NH2CH2CHO+ 2H

NH2CH2CH2OH+ CO

NH3 (3体反応. Cがabundantでない限り有効でない)

Fig. 5. Summary of the chemical routes proposed for the formation of EtA in the ISM. The molecular species in red have been detected towards the G+0.693 molecular cloud.
The gray shaded area corresponds to a hydrogenation chain. The chemical reactions indicated with colored arrows have been proposed in previous works: magenta (36), blue(38), orange (41), cyan (39), green (41, 47). In black, we show the formation routes proposed in this work. The solid arrows indicate surface chemistry reactions, and dashedarrows denote gas phase chemistry.

! （先行研究）HNCCOのダスト表面上でのH付加がほぼ唯一の提案（グレー部分）。
≠1
Table 1. Spectroscopic information (rest frequency, Einstein coeffi-of 1.7 km s at 45 GHz. We covered a total spectral range
cients (Aul ), and energy of the upper levels (Eup ) of the 14 unblended
from 31.075 GHz to 50.424 GHz. The position switching mode
! HNCCOは，(i)or slightly blendedHCCOにNが付加する反応か，(ii)Hrotational transitions of EtA detected towards the 2CCOのダスト表面反応のいずれかで作る。
was used, with the reference position located at (-885”,+290”)
G+0.693 molecular cloud (shown in Fig. 2).
27).cloudsで検出報告あり。
The telescope pointing andwith respect to G+0.693 (24,
HCCOはG+0.693でもtentativeに検出されている(次頁)他，他にcolddarkfocus were checked every one or two hours through pseudoFrequency (GHz)Transition
logAul (s≠1 )
Eup (K)
continuum observations towards VX Sgr, a red hypergiant star
! （新たな提案）NH
CH-23(0,3)にCH2OHを付加して作るのもありうるのでは？
24(0,4)39.7379429-5.64603
4.8
near the target source. The spectra were measured in units of
40.4083769
4(2,3) - 3(2,2)-5.74549
6.7
ú! グレーの経路中にある分子の大部分は検出できそうな回転遷移は知られていないが，EtA直前のT
antennatemperature,
41.1366268
4(2,2) - 3(2,1)-5.72208
6.7
A , since the molecular emission toward
42.2557255
4(1,3) - 3(1,2)-5.59088
5.5
G+0.693 is extended over the beams (55). The noise of theNH2CH249.1932727
CHOは理論計算による回転遷移周波数の値あり(観測には実験室分光による精密化が必要)。
5(0,5) - 4(0,4)-5.35979
7.2
spectra depends on the frequency range, reaching values as low
73.0048603
7(1,6) - 6(1,5)-4.84093
14.6
as 1.0 mK, while in some some intervals it increases up to 4.0反応経路を決定するために，今後有望な探索対象になるかも。
76.6071016
8(0,8) - 7(0,7)-4.76916
16.9
mK. The half power beam width (HP BW ) of the telescope ismolecular emission from all the molecular species identified in our spectral survey, overplotted to the observed spectra (gray histograms).

Tentative detection of HCCO (ketenyl)
Table 2. Spectroscopic information (rest frequency, Einstein coefficients (Aul ), and energy of the upper levels (Eup ) of the transitionsof EtA that appear blended in the observed spectra of G+0.693 (seeFig. 3). All of them have line intensities > 5 mK, according to thebest LTE fit described in the text.
Frequency (GHz)Transition

logAul (s≠1 )

Eup (K)31.7653500
3(1,2) - 2(1,1)-6.00114
3.5
38.3746402
4(1,4) - 3(1,3)-5.71626
5.1
47.8493375
5(1,5) - 4(1,4)-5.40899
7.4
up
up
up
50.4153833
5(2,4) - 4(2,3)-5.39849
9.1
73.4680803
7(2,5) - 6(2,4)-4.85633
15.7
75.9126193
8(1,8) - 7(1,7)-4.7827017.0
81.4338930
8(3,6) - 7(3,5)-4.74841
21.6
81.4392902
8(4,5) - 7(4,4)-4.80721
24.8
81.4863522
8(4,4) - 7(4,3)-4.8064624.8
82.2698610
8(3,5) - 7(3,4)-4.73500
21.7
85.1653931
9(1,9) - 8(1,8)-4.6287621.0
85.6467486
9(0,9) - 8(0,8)-4.62059
21.0
91.7192567
9(4,6) - 8(4,5)-4.62007
29.2
92.4964225
9(1,8) - 8(1,7)-4.52562
23.0
93.0416052
9(3,6) - 8(3,5)-4.55708
26.2
94.3821793
10(1,10) - 9(1,9)-4.49166
25.6
95.0023981
9(2,7) - 8(2,6)-4.49975
24.3
99.3388437
10(2,9) - 9(2,8)-4.43880
28.3
101.7229298
10(3,8) - 9(3,7)-4.42905
30.9
101.8639901
10(1,9) - 9(1,8)-4.39813
27.9
102.0183898
10(4,7) - 9(4,6)-4.45929
34.1
102.2528632
10(4,6) - 9(4,5)-4.45637
34.1
Fig. 6. Transitions of HCCO tentatively identified in the spectra of G+0.693. The rotational quantum numbers
involved in the transition
are indicatedin the upper leftof each11(1,11)- 10(1,10)-4.36815
panel, and the energies of the upper level are indicated in the upper right. The red thick line depicts the LTE103.5718907
synthetic spectrumof HCCO.
The blue thinline shows the30.5
predicted
103.7762062- 10(0,10)-4.36532
30.5
molecular emission from all the molecular species identified in our spectral survey, overplotted to the observed
spectra (gray11(0,11)
histograms).
103.9759166
10(3,7) - 9(3,6)-4.39964
31.2
105.5481523
10(2,8) - 9(2,7)-4.35654
29.4
108.8642389
11(2,10) - 10(2,9)-4.31491
33.5
111.0166375
11(1,10) - 10(1,9)-4.28448
33.2
111.7757005
11(3,9) - 10(3,8)-4.29721
36.3
Table 2. Spectroscopic information (rest frequency, Einstein coeffi112.7422238
12(1,12) - 11(1,11)-4.25550
35.9
cients (Aul ), and energy of the upper levels (Eup ) of the transitions
112.8698247
12(0,12) - 11(0,11)-4.25393
35.9
of EtA that appear blended in the observed spectra of G+0.693 (see

2-1

4-3

E =3.1 K

E =10.4 K

5-4

E =15.6 K

TA*(K)

Frequency (GHz)

Table 3. Spectroscopic information (rest frequency, Einstein coefficients (Aul ), and energy of the upper levels (Eup ) of the rotational transitions of ketenyl (HCCO) tentatively detected towards theG+0.693 molecular cloud (shown in Fig. 6).
Frequency (GHz)Transition

logAul (s≠1 )

Eup (K)

43.3176674
43.3211451
43.3295421
43.3354627
43.3368615
43.3373040
86.6191857
86.6423419
86.6438483
86.6558306
86.6574849
86.6652791
108.2823800
108.3040553
108.3051187
108.3178903
108.3190248
108.3280559

2(3,3) - 1(2,2)
2(3,2) - 1(2,1)
2(2,2) - 1(1,1)
2(2,1) - 1(1,0)
2(3,2) - 1(2,2)
2(2,1) - 1(2,1)
4(4,3) - 3(3,3)
4(5,5) - 3(4,4)
4(5,4) - 3(4,3)
4(4,4) - 3(3,3)
4(4,3) - 3(3,2)
4(5,4) - 3(4,4)
5(5,4) - 4(4,4)
5(6,6) - 4(5,5)
5(6,5) - 4(5,4)
5(5,5) - 4(4,4)
5(5,4) - 4(4,3)
5(6,5) - 4(5,5)-6.0192-6.1404-6.0343-6.2739-6.6741-6.4207-6.9202-5.0703-5.0942-5.0772-5.1070-6.3845-6.7293-4.7698-4.7840-4.7747-4.7916-6.2997

3.1
3.1
3.1
3.1
3.1
3.1
10.4
10.4
10.4
10.4
10.4
10.4
15.6
15.6
15.6
15.6
15.6
15.6

アルマハータ・シッタ隕石は（ユレイライトに分類されるが）エンスタタイトコンドライトも含む。エンス

タタイトコンドライトは「地球の海」の起源として有望視されており，水と共にEtAが原始地球に供給されFig. 3). All of them have line intensities > 5 mK, according to thebest LTE fit described in the text.

た可能性は十分ある。そうであれば，原始地球を模した実験的研究は，そこからリン脂質が作られうること
Frequency (GHz)Transition
logA (s )E (K)を既に示しているので，原始生物がどう発現したかのシナリオにも大きな影響があるかもしれない。
31.7653500
3(1,2) - 2(1,1)-6.00114
3.5
Table 3. Spectroscopic information (rest frequency, Einstein coul

38.3746402
47.8493375

4(1,4) - 3(1,3)
5(1,5) - 4(1,4)≠1-5.71626-5.40899

up

5.1
7.4

efficients (Aul ), and energy of the upper levels (Eup ) of the rotational transitions of ketenyl (HCCO) tentatively detected towards themeteorite itself by decomposition of amino acids. However, we find that the proportion of the molecule with respect to waterin the interstellar medium is similar to the one found in the meteorite (10 6 ). These results indicate that ethanolamine forms
eﬃciently in space and, if delivered onto early Earth, it could have contributed to the assembling and early evolution of primitive
membranes.

16.

Detection of the cyanomidyl radical (HNCN): a new interstellar species with the NCN
backbone

アデニン（核酸塩基の一つ）

V. M. Rivilla, I. Jiménez-Serra, J. García de la Concepción, J. Martín-Pintado, L. Colzi, L. F. RodríguezAlmeida, B. Tercero, F. Rico-Villas, S. Zeng, S. Martín, M. A. Requena-Torres, P. de Vicente F We report here
the first detection in the interstellar medium of the cyanomidyl radical (HNCN). Using the Yebes 40m and the IRAM 30m
telescopes, we have targeted the doublets of the N =2 1, 4 3, 5 4, 6 5, and 7 6 transitions of HNCN toward the molecular
cloud G+0.693-0.027. We have detected three unblended lines of HNCN, these are the N =6 5 doublet and one line of the
N =4 3 transition. Additionally we present one line of the N =5 4 transition partially blended with emission from otherspecies. The Local Thermodynamic Equilibrium best fit to the data gives a molecular abundance of (0.91±0.05)⇥10 10 withrespect to H2 . The relatively low abundance of this species in G+0.693-0.027, and its high reactivity, suggest that HNCN ispossibly produced by gas-phase chemistry. Our work shows that this highly reactive molecule is present in interstellar space,
and thus it represents a plausible precursor of larger prebiotic molecules with the NCN backbone such as cyanamide (NH2 CN),
carbodiimide (HNCNH) and formamidine (NH2 CHNH).

6! 同様のデータ(124.8-175.5GHz, 223.3-238.3GHzも)から，HNCNの初の明確な検出を議論。
! NCN骨格は，RNAやDNAなどの二重らせん構造を作る核酸塩基(nucleobase)に含まれる基本構造。
! NH2CN（cyanamide），HNCNH（carbodiimide），NH2CONH2（urea, 尿素）はISMで検出例あり。
! HNCNはNCN骨格を持つより簡単な分子であるにもかかわらず，明確な検出例はなかった（実験室分光は
Yamamoto & Saito 1994; 当時の天体観測では検出に至らず)。
! 今回はG+0.693-0.027で検出した。

C1

CH3CHO

HNCO

HNCO

c-C213CH2

HNCO

HNCO

CH3CCHCH2OHCHO

aGg-(CH2OH)2HCCCHO

HNCO

HC5N

NH2CHO

CH313CCH
C18O
CH3CCH

CH313CCH

C18O

NH2CHOTA*(K)C2H5CHO

Unblended
↓
HNCO

HC5N

NH2CHO

N=4-3

NH2CHOaGg-(CH2OH)2

H13CC13CN

CH3CHOCH3NH2T

HNCO

H13CC13CN

N=2-1

NH2CHOaGg-(CH2OH)2V. M. Rivilla et al.
今回の検出

Blendしているのが多いが，CH3CHOHNCO

CH3CHO

N=6-5の二本が孤立していてCH3CCH

CH313CCH

検出は確か！

CH313CCH

CH3NH2C2H5CHO

c-C213CH2

HNCO

赤がHNCN，青は全分子を考慮した予想スペクトル(SLIM)
CH3CCH

HNCO

CH2OHCHO

aGg-(CH2OH)2HCCCHO

C18O

C18O

N=4-3の一本とNH2CHOTA*(K)

2

to a resolution of 251 kHz, corresponding to
1.7 km s 1 at 45 GHz. The position switchi
00 ,+290 00 ) w
theoff
position
locatedat(-885※JはN原子のスピンによる微細構造分裂を
as in previous works (e.g. Rivilla et al. 2020
2 V. M. Rivilla etUnblendedal.
考慮した角運動量x2 ↓and focus were checked every one or two
Table 1. List of observed transitions of HNCN. We provide
theparameters
Table 1. Listof observed
transitions of HNCN. We provide the parameters
continuum
observations
from the CDMS catalog
entry 041507:
frequencies, quantumtowards
numbers, and the red hyp
N=2-1
N=6-5
from the CDMS catalog entry 041507: frequencies, quantum
numbers, andupper state degeneracy (gu ). We also show the values of the base 10 logarithm
spectrawere measured in units of antenn
the Einsteincoefficients(log ul ), and the energy of the upper levels (⇢u ).
base 10logarithm
upper state degeneracy (gu ). We also show the values ofofthe
The last column indicatesthe molecularspeciesthat produces blendingwithcorrectedforatmosphericabsorption
and spof the Einstein coefficients (log ul ), and the energy ofsome
the HNCN
upper
levels (⇢u ).
transitions.
of thewith
spectra depends on the frequency, sp
The last column indicates the molecular species that produces blending
Frequency
Transition
log ul 6u Eu Blending
mK.
The
half
some HNCN transitions.
(GHz)(#K,k,J)(s 1 ) power(K) beam width (HPBW)
441GHz.
43.9225164⇤
2at-5.688 6 3.2 aGg-(CH2 OH)2
0,2,5/2
0,1,3/2
20,2,3/2 10,1,1/2 -5.7663 4 3.2 NH2 CHO
Frequency N=4-3 Transition
log ul 6u Eu 43.9552012
Blending
The
IRAM
were per87.8601563
40,4,9/2
30,3,7/2-4.739 30m
10 10.5observations
HC5 N
30,3,5/2 during-4.7543 8 201910.5 unblended(GHz)(#K,k,J )(s 1 )(K) 87.8927924⇤ 4ing
0,4,7/2 runs
(April 10 16, Augu
109.8281277 50,5,11/2 40,4,9/2 -4.4385 12 15.8 C18 O
109.8607271⇤ 5ber
40,4,7/215),-4.4479
10part15.8 aGg-(CH2 OH)
2 , HCCCHO 172
as
of
the
projects
0,5,9/2 11⇤⇤43.9225164
20,2,5/2 10,1,3/2 -5.688 6 3.2 131.7953263
aGg-(CH620,6,13/2
OH)250,5,11/2 -4.1943 14 22.1 unblended⇤
133
19unblended(PI Rivilla). We use-4.2006
12 22.1
0,6,11/2 519
0,5,9/2and
N=7-6 20,2,3/2 10,1,1/2 -5.7663 4 3.2 131.8278808
43.9552012
NH2 CHO6018
CCH, CH3 CCH
153.7615965 70,7,15/2 60,6,13/2 -3.9886 16 29.5 CH13
3
MIxer
Receiver(EMIR)
87.8601563
40,4,9/2 30,3,7/2 -4.739 10 10.5 153.7940979
HC5 N 70,7,13/2 60,6,11/2 -3.9932 14 29.5 CH3 CCH and the fast F⇤ Transitions usedtrometers
FTS200mode,
to perform the in
fit withthe SLIM-AUTOFIT
tool ofwhich provid
87.8927924⇤
40,4,7/2 30,3,5/2 -4.7543
8
10.5
unblended
N=5-4
MADCUBA (see text).
18⇠200 kHz. The covered spectral ranges w
109.8281277 50,5,11/2 40,4,9/2 -4.4385 12 15.8 C O
109.8607271⇤ 50,5,9/2 40,4,7/2 -4.4479 10 15.8fromaGg-(CH
OH)
175.5
and
238.2931.075 GHz
to 50.424
GHz.
The GHz,
final spectra
were223.307
smoothed
2124.77
2 , HCCCHO
a resolution of 251 kHz, corresponding to a velocity resolution of
131.7953263⇤ 60,6,13/2 50,5,11/2 -4.1943 14 22.1to unblendedsmoothed
to mode609waskHz,
i.e. a velocit
1 at 45were
1.7
km
s
GHz.
The
position
switching
used,
with
1 atat 100
131.8278808⇤ 60,6,11/2 50,5,9/2 -4.2006 12 22.1theunblended
off position s
located(-885 00GHz.
,+290 00 ) withrespect
to G+0.693,
The
telescope
pointing and13
in previous
worksCH(e.g.3Rivilla
et al. 2020). The telescope pointing
CCH,
CCH
153.7615965 70,7,15/2 60,6,13/2 -3.9886 16 29.5as CH
3 were ery
1.5everyh towards
brightsources.
and focus
checkedone or two hours
through
pseudo- The spect
153.7940979 70,7,13/2 60,6,11/2 -3.9932 14 29.5continuum
CH3 CCH⇤ scale.
observations
towardsThethe rednoise
hypergiant
startheVX Sgr.
The
Tofspectradepends
N=6-5⇤ , andA
spectraweremeasured
in
units
of
antennatemperature,
T
A⇤ Transitions used to perform the fit with the SLIM-AUTOFIT tool ofApproximate
valuesare:
1.7
2.8 mK (⇠71
corrected for atmospheric absorption and spillover losses. The noise
Frequency
(GHz)
N=5-4
of the spectra depends on the frequency, spanning in the range 1 4
MADCUBA (see text).
(⇠90 115 GHz), 3.1 6.8 mK (⇠124 175
mK. The half power beam width (HPBW) of the telescope is ⇠39 00
Figure 1. Transitions of HNCN detected in the observed spectra of G+0.693.
at 44 GHz.
(223 238 GHz). The HPBW of the observat
The best LTE fit to the HNCN lines is shown in red, while the total contribuThe IRAM 30m observations
were performed in three observ00
andused13theoff position fo
frommolecular
31.075 GHz
to (labelled)
50.424 GHz.
The infinal
ing runsduringsmoothed2019 21.6(April 10. We
16, August
19, sameand Decemtion, including otherspecies
identified
the spectra
regioniswereber 11 15), as observations
part of the projects as
172in18the(PI Martín-Pintado),
Yebes 40m observatio
toaresolution
of
251
kHz,
correspondingtoavelocity
resolution
ofshown in blue.
018 19 and 133 19 (PI Rivilla). We used the broad-band Eight
N=7-6
1
MIxer was
Receiver(EMIR)and the fast Fourier transform spec1.7 km s at 45 GHz. The position switching mode
used,
with
trometers in FTS200 mode, which provided a channel width of00
00
the off position located at (-885 ,+290 ) with respect
3covered
ANALYSISRESULTS⇠200 kHz. to
TheG+0.693,
spectral rangesAND
were 71.76
116.72 GHz,
124.77175.5 GHz,and 223.307 238.29 GHz. The final spectraasinprevious
works
(e.g.
Rivillaetal.
2020).
The
telescope
pointinghms
Spain). The observations were centered at U(J2000.0)= 17 47 were
22 smoothed,to 609identification
kHz, i.e. a velocity ofresolutionof 1.8 km
The
the molecularlines o

Blendが激しくない遷移とN=2-1を組み合わせたLTE解析

sion of HNCN,
identified in thispear unblended
0
1#=2 1 transitio
Molecule#)exvLSR, " Abundance Ref.
13
2
1
1
10
although blende(⇥10 cm ) (K) (km s ) (km s ) (⇥10 )ature. We fixed t
HNCN
1.2±0.1
8.7±0.7 71±1250.91±0.05 (1)1
to 25 km s , w
HNCNH
<2.5
8
69
25
<1.9
(1) ←61,6 - 70,7@223.8GHzがblendedtransitio
227±2
6.8±0.2 67±1
24±1
23.0
(2) 未検出，Tex=8Kを仮定
NH2 CN
species (see e.g.
23
2column density ((a) We adopted #H2 =(1.4±0.3)⇥10 cm , from Martín et al. (2008). (b)References: (1) This work; (2) Zeng et al. (2018); (c) # , vLSR and
The best fit giv, " of the para species; the abundance corresponds to the sum of thevelocity of E LSR
ortho and para species.
consistent to tho
G+0.693 (Reque

Table 2. Derived physical parameters of HNCN and other molecular species
that might be chemically related.

議論(1)：HNCNのProtonated cyanamide
+e-

形成過程
• G+0.693-0.027はマイルドなショック領域，
アイルマントルのerosionがHNCNの比較的

AmidogenN

C N

Cyanonitrene

CN

高いアバンダンスと関連している可能性大• ダスト表面反応によるHNCN形成は，NCNの水素付加かHNCの窒素付加が提案• Yamamoto & Saito (1994)ではNH2CNH+のe-付加を提案。高い反応効率。
• CNとNH2の気相反応も候補。どちらも10-8オーダーのアバンダンスあり。
• NH2CN（cyanamide）やHNCNH（carbodiimide）の破壊も考えられる。

+CN

N
+N

（広がったSiOも受かっている）

H• 実線が表面反応• 点線が気相反応

C N
+e-

+e-

H

+H3+

H

Cyanomidyl
radical
+H

N

H

+CN

N
H

H

+

N C

Hydrogen
Isocyanide

N

+H
H

H

C N

H

Cyanamide

+H
+H
+H

H

N C

N

H

Carbodiimide+NH

Formamidine
H

N

+3H
H

C

N

H

H

Figure 2. Chemical network for the formation of species with the NCN backbone (highlighted in red) such as the cyanomidyl radical (HNCN), carbodiimide (HNCNH), cyanamide (NH2 CN), protonated cyanamide (NH2 CNH+ )and formamidine (NH2 CHNH). Other chemically related species (the NH2
radical and HNC) are also indicated. The name of the different molecules
are shown in blue. The solid/dashed arrows indicate the surface/gas chemicalroutes discussed in the text.

Protonated cyanamide

議論(2)：HNCN as precursor+e-of prebiotic species

Amidogen• NH2CN（cyanamide）: RNAやDNAのヌク
レオチドのkey precursor ? G+0.693では，
NH2CNはHNCNの20倍以上のアバンダンスN

C N

Cyanonitrene

C

N

H

程は非常に効率的なのかも。
• HNCNH（carbodiimide）:

アミノ酸からペプチド結合を作る際の縮合剤として重要？
• NH2CNからの光異性化はUV fieldが非常に強くないと起こらないので，この天体に関してはunlikely。
• NH2CNの形成よりは非効率？
• NH2CHNH（formamidine）：アミノ酸の主要precursor ? (Kitadai & Maruyama 2018)

+CN

N
+N

（2ページ前のTable 2）なので，この形成過• 実線が表面反応• 点線が気相反応

C N
+e-

+e-

H

+H3+

H

Cyanomidyl
radical
+H

N

H

+CN

N
H

H

+

N C

Hydrogen
Isocyanide

N

+H
H

H

C N

H

Cyanamide

+H
+H
+H

H

N C

N

H

Carbodiimide+NH

Formamidine
H

N

+3H
H

C

N

H

H

Figure 2. Chemical network for the formation of species with the NCN backbone (highlighted in red) such as the cyanomidyl radical (HNCN), carbodiimide (HNCNH), cyanamide (NH2 CN), protonated cyanamide (NH2 CNH+ )and formamidine (NH2 CHNH). Other chemically related species (the NH2
radical and HNC) are also indicated. The name of the different molecules
are shown in blue. The solid/dashed arrows indicate the surface/gas chemicalroutes discussed in the text.

CO

12 CO

CO

0.51
1
2.3
1
we propose has NH2 / I12
for
I
and
N
/
I
for
I
&
90
K
km
. The high-I12 CO side should
12 CO . 70 K km
12
12
H2
CO
CO
CO
be generalizable with known adjustments for metallicity, but the influence of interstellar UV fields on the low-I12 CO side may
be sample specific. We discuss how these results expand upon previous works in the CHaMP series, and help tie together
observational, theoretical, and laboratory studies on CO over the past decade.

14.

Disk Masses and Dust Evolution of Protoplanetary Disks Around Brown Dwarfs

Anneliese M. Rilinger, Catherine C. Espaillat F We present the largest sample of brown dwarf (BD) protoplanetary disk
spectral energy distributions modeled to date. We compile 46 objects with ALMA observations from four star-forming regions: ⇢Ophiuchus, Taurus, Lupus, and Upper Scorpius. Studying multiple regions with various ages enables us to probe disk evolution
over time. Specifically, from our models we obtain values for dust grain sizes, dust settling, and disk mass; we compare how eachof these parameters vary between the regions. We find that disk mass generally decreases with age, though the youngest region,
Ophiuchus, has the lowest disk masses. We find evidence of disk evolution (i.e., grain growth and significant dust settling) in
all four regions, indicating that planet formation and disk evolution may begin to occur at earlier stages. We generally findthese disks contain too little mass to form planetary companions, though we cannot rule out that planet formation may havealready occurred. Finally, we examine the disk mass – host mass relationship and find that BD disks are largely consistent withpreviously-determined relationships for disks around T Tauri stars.

Discovery in space of ethanolamine, the simplest phospholipid head group
Víctor M. Rivilla,
IzaskunJiménez-Serra, Jesús Martín-Pintado, Carlos Briones, Lucas F. Rodríguez-Almeida,• D’Alessoによるdiskmodel(*)を使い，ミリ波・サブミリ波の測光データもあるBrown
Dwarfs周
Fernando Rico-Villas, Belén Tercero, Shaoshan Zeng, Laura Colzi, Pablo de Vicente, Sergio Martín, Miguel A.
りの原始惑星系円盤（46個）に対してSED
fitting，円盤の物理量を推定して進化を議論。
Requena-Torres F Cell membranes are a key element oflife because they keep the genetic material and metabolic machinery
together. All present cell membranes are made of phospholipids, yet the nature of the first membranes and the origin of•phospholipids* 弱い質量降着率を持つ円盤構造をセルフコンシステントに扱えるモデル。
are still under debate. We report here the first detection in space of ethanolamine, NH2 CH2 CH2 OH, which forms
the hydrophilic head of the simplest and second most abundant phospholipid in membranes. The molecular column density• ダストの成長や赤道面へのダスト沈殿が年齢に応じて進行する傾向を見つけた（というが，ダスof ethanolamine in interstellar space is N =(1.51±0.07)⇥1013 cm 2 , implying a molecular abundance with respect to H2 of10(0.9-1.4)⇥10. Previous studies reported its presence in meteoritic material but they suggested that it is synthesized in the
ト成長については，私にはその妥当性はわからなかった）。
meteorite itself by decomposition of amino acids. However, we find that the proportion of the molecule with respect to water• 円盤質量は惑星を作るほど大きいように見えないが，惑星は既にできているのかも。
in the interstellar medium is similar to the one found in the meteorite (10 6 ). These results indicate that ethanolamine forms
eﬃciently in space and, if delivered onto early Earth, it could have contributed to the assembling and early evolution of primitive• 普通のTタウリ円盤に付随する円盤との質的な違いは見られなかった。
membranes.

SEDフィットのパラメータ依存性8· −1" Σ ∝ Mα : #が小さいほ·ど同じMにするには高い$が必要" %：ダスト沈殿度合いを表
すパラメータ，小さいほどより沈殿，ダストが成長" ミリ波と遠赤外線の測光が両方無いと，縮退が解けない
Figure 1. Effect of different parameters in the DIAD SED models. In each panel, all but one parameter is held
constant. See text for the values of the fixed parameters.

RegionTable 5. Outer wall parameters
Object
J04442713
CFHT Tau 9
ISO-Oph 164

zwall,out

Twall,out

Rwall,out

Gap width

au

K

au

au

0.08270.02750.2134

400
300
200

0.27
0.36
1.65

0.20
0.34
1.55

↵

Without our BD sample
Taurus1.31 ± 0.24 1.13 ± 0.11
Lupus
1.10 ± 0.30 1.34 ± 0.18
Upper Sco 1.73 ± 0.39 0.77 ± 0.23
With our BD sample
Taurus0.99 ± 0.14 0.98 ± 0.10
Lupus
1.13 ± 0.24 1.35 ± 0.16
Upper Sco 1.10 ± 0.31 0.53 ± 0.20

主要な結果

円盤質量分布M* vs. Mdisk

16

Figure 2. Histogram of the calculated disk masses for the BDs in this sample. Only a few outliers have masses greaterthan 1 MJ , indicating that most of the BD disks are not currently massive enough to form planetary companions
according to simulations by Payne & Lodato (2007).

領域ごとの違い

(a)

(b)

(c)

(Cohen & Witteborn 1985; Gürtler et al. 1999; Natta et al. 2000). The presence of an emission line indicatesthat a (super)heated optically thin dust layer exists above the optically thick disk (Calvet et al. 1991). In
other words, the 10 µm emission feature is produced by the disk atmosphere. The shape of theFigure
feature 11. Mdisk versus M⇤ relationships for disks in (a) Taurus, (b) Lupus, and (c) Upper Sco. Open circles represent
corresponds to the size of grains in this atmosphere. Submicron-sized grains show a more narrow,thepeakedsample reported in Pascucci et al. (2016), filled circles represent the BDs studied in this work. The black line andshape; as grains grow to be larger than ⇠ 1 µm, the 10 µm feature broadens and flattens.
greyinshaded region represent the best linear fit and uncertainties for the Pascucci et al. (2016) sample; the red line
The maximum size of dust grains in the disk atmosphere, amax,atm , is one of the parameters varied
our SED models. Furthermore, the wavelength coverage of IRS spectra encompasses the 10 µm andspectral
red shaded region represent the best linear fit and uncertainties for the Pascucci et al. (2016) sample plus the BDsfeature. Therefore, for the 34 objects in our sample with IRS spectra, we can use the model fit to the 10 µm

studied in this work. Note that some BDs have very similar host and disk masses, so their points overlap completely.

star-forming regions to each other to assess how disk mass, grain growth, and dust settling vary with age.
Our results are summarized as follows:13.
Census of High- and Medium-mass Protostars V. CO Abundance and the Galactic XCO
FactorRebecca L. Pitts, Peter J. Barnes F We present the second dust continuum data release in the Census of High- andMedium-mass Protostars (CHaMP), expanding the methodology trialed in Pitts et al. 2019 to the entire CHaMP survey area
(280 < l < 300 , 4 < b < +2 ). This release includes maps of dust temperature (Td ), H2 column density (NH2 ), gasphase CO abundance, and temperature-density plots for every prestellar clump with Herschel coverage, showing no evidence ofinternal heating for most clumps in our sample. We show that CO abundance is a strong function of Td , and can be fit with asecond-order polynomial in log-space, with a typical dispersion of a factor of 2–3. The CO abundance peaks at 20.0+0.4
1.0 K with5
a value of 7.4+0.2⇥
10
per H2 ; the low Td at which this maximal abundance occurs relative to laboratory results is likely due
0.3
to interstellar UV bombardment in the largest survey fields. Finally, we show that, as predicted by theoretical literature andhinted at in previous studies of individual clouds, the conversion factor from integrated 12 CO line intensity (I12 CO ) to NH2 ,the XCO -factor, varies as a broken power-law in I12 CO with a transition zone between 70 and 90 K km 1 . The XCO -function
0.51
1
2.3
1
we propose has NH2 / I12
for
I
and
N
/
I
for
I
&
90
K
km
. The high-I12 CO side should
12 CO . 70 K km
12
12 CO
H2
CO
CO
be generalizable with known adjustments for metallicity, but the influence of interstellar UV fields on the low-I12 CO side may
be sample specific. We discuss how these results expand upon previous works in the CHaMP series, and help tie together
observational, theoretical, and laboratory studies on CO over the past decade.

Disk Masses and Dust Evolution of Protoplanetary Disks Around Brown Dwarfs•Anneliese
Carina-Sagittarius
tothe
core-scale(~1- 0.1 dwarfpc) condensations対象
M. Rilinger, Armに存在する300のclumpCatherine C. Espaillat F We present
largest sampleof brown(BD) protoplanetary disk

spectral energy distributions modeled to date. We compile 46 objects with ALMA observations from four star-forming regions: ⇢にしたMopraによる包括的な分子輝線サーベイ
Ophiuchus, Taurus, Lupus, and Upper Scorpius. Studying multiple regions with various ages enables us to probe disk evolution
time. Specifically, from our models we obtain values for dust grain sizes, dust settling, and disk mass; we compare how each•over
この論文ではCOアバンダンスの変化やXcoを議論
of these parameters vary between the regions. We find that disk mass generally decreases with age, though the youngest region,
Ophiuchus, has the lowest disk masses. We find evidence of disk evolution (i.e., grain growth and significant dust settling) in
all four regions, indicating that planet formation and disk evolution may begin to occur at earlier stages. We generally findthese disks contain too little mass to form planetary companions, though we cannot rule out that planet formation may have

17.
The dipper population of Taurus seen with K2

Noemi Roggero, Jérôme Bouvier, Luisa M. Rebull, Ann Marie Cody F Dippers are typically low-mass, pre-mainsequence stars that display dips in their light curves. These dips have been attributed to dusty warps that form in the innerpart of the disk. Our goal is to derive the properties of dipper stars in Taurus to assess the physical mechanisms that induce
dipper light curves. We used the light curves of K2 C4 and C13 to select a dipper sample among 179 members and possible
members of the Taurus star-forming region based on the light-curve morphology. We studied the periodicities by combining
periodograms with wavelet analysis and derived the stellar parameters from the photometry. We also studied the morphology ofthe photometric dips. We find a dipper occurrence of 30% in disk-bearing stars observed with K2 that were identified visuallyby us. This represents a lower limit to their true occurrence. About half of the dippers are aperiodic, and most of these aredominated by another type of variability. The chosen sample is of late spectral type (K/M), low mass and moderate massaccretion rates and has periods of a few days. We observed a transient dipper over a few rotation cycles and a dipper with achanging period. The structure of the dips can be complex and varies strongly over timescales of down to one stellar rotation.
The corotation radii are located at a few stellar radii, and the temperatures at corotation allow dust survival. Many of thesystems are seen at moderate to high inclination. We find that the angular extension of the dusty structure producing the dips
is correlated with the stellar period. Magnetospheric accretion, which causes an accretion column and its base to occult the star,can explain most of the observed light curves. Although compatible with the model, many of the stellar inclination angles aremoderate and do not exclude mechanisms other than the occultation by an inner disk warp to account for dipper light curves.

• Taurus領域の若いK/M型星179個に対して，K2データを解析，dipper現象を探索。
Impactof the external radiation field on the structure and evolution of supernova remnants• Diskを付随する天体の30%からdipper的な変動を発見した。

Mario Romero, Yago Ascasibar, Jan Palouš, Richard Wünsch, Mercedes Mollá F We carry out 1D hydrodynamical
simulationsof the evolution of a spherically symmetric supernova remnant (SNR) subject to an external radiation field (ERF)• Dipのパターンは複雑で星の自転周期と同等な時間スケールまで変化が見られる。
that influences the cooling and heating rates of the gas. We consider homogeneous media with ambient hydrogen number
densities
nH,0 of 0.1 and 1accretioncm 3 permeatedby an average radiation field including the cosmicで大体説明可能ではないか。
microwave, extragalactic, and• Magnetosphericcolumnとその根元による星のoccultation
Galactic backgrounds, attenuated by an eﬀective column density NH,e↵ from 1018 to 1021 cm 2 . Our results may be classified
into two broad categories: at low NH,e↵ , the ERF presents little absorption in the ultraviolet (ionising) regime, and all thesystems are seen at moderate to high inclination. We find that the angular extension of the dusty structure producing the dips
is correlated with the stellar period. Magnetospheric accretion, which causes an accretion column and its base to occult the star,can explain most of the observed light curves. Although compatible with the model, many of the stellar inclination angles aremoderate and do not exclude mechanisms other than the occultation by an inner disk warp to account for dipper light curves.

18.

Impact of the external radiation field on the structure and evolution of supernova remnants

Mario Romero, Yago Ascasibar, Jan Palouš, Richard Wünsch, Mercedes Mollá F We carry out 1D hydrodynamical
simulations of the evolution of a spherically symmetric supernova remnant (SNR) subject to an external radiation field (ERF)
that influences the cooling and heating rates of the gas. We consider homogeneous media with ambient hydrogen number
densities nH,0 of 0.1 and 1 cm 3 permeated by an average radiation field including the cosmic microwave, extragalactic, andGalactic backgrounds, attenuated by an eﬀective column density NH,e↵ from 1018 to 1021 cm 2 . Our results may be classified
into two broad categories: at low NH,e↵ , the ERF presents little absorption in the ultraviolet (ionising) regime, and all the’unshielded’ cases feature an equilibrium temperature Teq ⇠ 7000 K below which the ambient gas cannot cool further. In this
scenario, the SNR develops a nearly isothermal shock profile whose shell becomes thicker over time. At higher NH,e↵ , the ERF
is heavily absorbed in the UV range, yielding a roughly constant heating function for temperatures . 104 K. These ‘shielded’cases develop a thin, cold and dense shell throughout their evolution. Energy and momentum injection to the medium do
not change significantly between both scenarios, albeit luminosity is higher and more uniformly distributed over the shell forunshielded SNR.

A multi-line study of the filamentary infrared dark cloud G351.78-0.54

O.
L. Ryabukhina, I. I. Zinchenko F We present results of a multi-line study of the filamentary infrared dark cloud• SNR近傍に外部輻射場があったときにそれがSNRの構造と進化にどのような影響があるかを数値
G351.78-0.54 in the 1.3 and 0.8 mm wavelength bands. The lines of the three isotopologues of carbon monoxide CO, N2 H+ ,CHシミュレーションで調べた
3 CCH and HNCO were observed. The aim was to study the general structure of the filamentary cloud, its fragmentationand physical parameters with the emphasis on properties of dense clumps in this cloud. Several dense clumps are identified
from the N2 H+ (3-2) data, their masses and virial parameters are determined using the C18 O (2-1) line. Temperatures of someclumps are estimated from the CH3 CCH and HNCO data. Almost all clumps appear to be gravitationally unstable. The density
estimates obtained from the C18 O (3-2)/(2-1) and N2 H+ (3-2)/(1-0) intensity ratios are in the range n ⇠ (0.3 3) ⇥ 105 cm 2 .
The HNCO emission is detected exclusively toward the first clump which contains the luminous IR source IRAS 17233-3606,