Shota Notsu (RIKEN) -7: Complex organic molecules detected in twelve high-mass star-forming regions with Atacama Large Millimeter/submillimeter Array (ALMA) -8: The Cygnus Allscale Survey of Chemistry and Dynamical Environments: CASCADE: Overview and first results toward DR20 from the Max Planck IRAM Observatory program (MIOP) -9: Influence of grain growth on CO ⁄ ice spectroscopic profiles : Modelling for dense cores and disks -10: Effects of the environment and feedback physics on the initial mass function of stars in the STARFORGE simulations -11: Centrifugal Barrier and Super-Keplerian Rotation in Protostellar Disk Formation -12: Ice features of low-luminosity protostars in near-infrared spectra of AKARI/IRC 12. Ice features of low-luminosity protostars in near-infrared spectra of AKARI/IRC Jaeyeong Kim, Jeong-Eun Lee, Woong-Seob Jeong, Il-Seok Kim, Yuri Aikawa, Jeniffer A. Noble, Minho Choi, Ho-Gyu Lee, Michael M. Dunham, Chul-Hwan Kim, Bon-Chul Koo ★ We present near-infrared spectra of three low-luminosity protostars and one background star in the Perseus molecular cloud, acquired using the Infrared Camera (IRC) onboard the AKARI space telescope. For the comparison with different star-forming environments, we also present spectra of the massive protostar AFGL 7009S, where the protostellar envelope is heated significantly, and the low-mass protostar RNO 91, which is suspected to be undergoing an episodic burst. We detected ice absorption features of H2O, CO2, and CO at all spectra around the wavelengths of 3.05, 4.27, and 4.67 μm, respectively. At least two low-luminosity protostars, we also detected the XCN ice feature at 4.62 μm. The presence of the crystalline H2O ice and XCN ice components indicates that the low-luminosity protostars experienced a hot phase via accretion bursts during the past mass accretion process. We compared the ice abundances of low-luminosity protostars with those of the embedded low-mass protostars and the dense molecular clouds and cores, suggesting that their ice abundances reflect the strength of prior bursts and the timescale after the last burst. AKARI (あかり)/IRCで取得された低質量原始星の近赤外スペクトルを解析。近赤外線の氷featureを検出(H₂O, CO₂, CO, HCN) H2OとHCN氷featureより結晶質氷の存在が示唆される事から、過去に降着バーストによる加熱現象が生じた可能性と、過去のバーストからの経過時間を議論。個人的期待：JWST等の原始星の観測との比較も興味深い(cf. CORINOS program) Table 2 Best-fitting Laboratory Data a
pure amorphous: blue or cyan dotted lines crystalline: green dotted–dashed line polar mixture: orange dashed line NH3氷: 2.95  μ m非晶質H₂O氷: 3.05 μ m結晶質H₂O氷: 3.1 μ m原始星：結晶質H₂O氷の成分がdominant Perseus 3:強い結晶質H₂O氷成分→Perseus 1&2と比べ、過去の降着burstが強大だった? CO₂氷: 4.27  μ m HCN: green line CO₂/CO比大→より最近降着バーストが発生。 COがガス中に昇華して戻りきっていない?昇華温度：Tc02>Tc0著者コメント：N₂H+やHCO+輝線観測(スノーラインやガス電離率のトレーサー)との比較も大事
CORINOS I: JWST/MIRI Spectroscopy and Imaging of a Class 0 protostar IRAS 15398-3359
YAO-LUN YANG,¹,² JOEL D. GREEN,³ KLAUS M. PONTOPPIDAN,³ JENNIFER B. BERGNER, 4 L. ILSEDORE CLEEVES,² Neal J. Evans II, 5 Robin T. Garrod,6 Mihwa Jin,7,8 Chul Hwan Kim, 9 Jaeyeong Kim,10 Jeong-Eun Lee,9 NAMI SAKAI,¹ CHRISTOPHER N. SHINGLEDECKER,¹¹ BRIELLE SHOPE,¹² JOHN J. TOBIN,¹³ AND EWINE F. VAN DISHOECK¹⁴,¹³ JWST/MIRI 5-28 μ m, ~0.1” R～3000 Yang et al. (2022) CORINOS program 7.
Complex organic molecules detected in twelve high-mass star-forming regions with At-
acama Large Millimeter/submillimeter Array (ALMA)
Giseon Baek, Jeong-Eun Lee, Tomoya Hirota, Kee-Tae Kim, Mi Kyoung Kim ★ Recent astrochemical models and experiments have explained that complex organic molecules (COMs; molecules composed of six or more atoms) are produced on the dust grain mantles in cold and dense gas in prestellar cores. However, the detailed chemical processes and the roles of physical conditions on chemistry are still far from understood. To address these questions, we investigated twelve high-mass star-forming regions using the ALMA band 6 observations. They are associated with 44/95GHz class I and 6.7 GHz class II CH 3 OH masers, indicative of undergoing active accretion. We found 28 hot cores with COMs emission among 68 continuum peaks at 1.3 mm and specified 10 hot cores associated with 6.7 GHz class II CH3OH masers. Up to 19 COMs are identified including oxygen- and nitrogen-bearing molecules and their isotopologues in cores. The derived abundances show a good agree- ment with those from other low- and high-mass star-forming regions, implying that the COMs chemistry is predominantly set by the ice chemistry in the prestellar core stage. One clear trend is that the COMs detection rate steeply grows with the gas column density, which can be attributed to the efficient formation of COMs in dense cores. In addition, cores associated with a 6.7 GHz class II CH3OH maser tend to be enriched with COMs. Finally, our results suggest that the enhanced abundances of several molecules in our hot cores could be originated by the active accretion as well as different physical conditions of cores. CH 3 OHメーザー天体(大質量星原始星, hot core天体)に対してALMA Band 6で有機物(COMs)の輝線観測観測対象：Class I (44/95 GHz)メーザー天体＆ Class II (6.7 GHz)メーザー天体結果： 19種類のCOMs検出(同位体や、酸素・窒素を含む分子など)光度によらず比較的よく似たCOMs組成パターン→prestellar core stageの化学進化が大事Class IIメーザーの方がCOMsに富んでいる19種類のCOMs検出Model_Fast (Garrod+22) Model  Medium Model  Slow WB 89-789 (Shimonishi+21) AFGL 4176 (Bogelund+19) rion MF peak (Tercero+18) Orion EG pea Orion ET peak B2 (N2) (EmoCA: Belloche+ 16293B (PILS; Jorgensen+20) YPSO Group1 (COMs poor, Belloche+20) LYPSO Group2 (O-,N-COMs rich) YPSO Group3 (CHO poor, CN-COMs rich) HH212 (disk atmosphere, Lee+19) V883Ori (disk midplane, Lee+19) PEACHES (Yang+21) BOX:今回の観測のCOMs組成(CH 3 OHとの比)光度によらず比較的よく似たCOMs組成パターン→原始星期の物理構造(温度など)によらず、 prestellar core stageの化学進化が大事
The Cygnus Allscale Survey of Chemistry and Dynamical Environments: CASCADE:
Overview and first results toward DR20 from the Max Planck IRAM Observatory pro-
gram (MIOP)
ai
H. Beuther, F. Wyrowski, K. M. Menten, J. M. Winters, S. Suri, W. -J. Kim, L. Bouscasse, C. Gieser, M. Sawczuck, I. B. Christensen, I. M. Skretas ★ Context: While star formation on large molecular cloud scales and on small core and disk scales has been investigated intensely over the past decades, the connection of the large-scale interstellar material with the densest small-scale cores has been a largely neglected field. Methods: Using NOEMA and the IRAM 30m telescope, we mapped large areas (640 arcmin²) of the archetypical star formation complex Cygnus X at 3.6 mm wavelengths in line and continuum emission.  Results:  The scope and outline of The Cygnus Allscale Survey of Chemistry and Dynamical Environments (CASCADE) is presented.  We then focus on the first observed subregion in Cygnus X, namely the DR20 star formation site, which comprises sources in a range of evolutionary stages from cold pristine gas clumps to more evolved ultra- compact HII regions. The data covering cloud to cores scales at a linear spatial resolution of < 5000 au reveal several kinematic cloud components that are likely part of several large-scale flows onto the central cores. The temperature structure of the region is investigated by means of the HCN/HNC intensity ratio and compared to dust-derived temperatures.  We find that the deuterated DCO+ emission is almost exclusively located toward regions at low temperatures below 20 K. Investigating the slopes of spatial power spectra of dense gas tracer intensity distributions (HCO+, H ¹³CO+, and N 2 H + ), we find comparatively flat slopes between —2.9 and —2.6, consistent with high Mach numbers and/or active star formation in DR20. NOEMAとIRAM 30m (3.6 mm)で、はくちょう座X領域をmapping (640 arcmin²) HCN/HNC比からガス温度を算出し、ダスト温度と比較(補足解説スライド参照)その他、dense gas tracer (HCO+, H¹³CO+, and N₂H+)の分布なども算出col. T(HCN/HNC) black HCO†@−6km/s, dotted HCO†@2.8km/s,
Notes: The 1σ rms values are for all lines with a resolution of 0.8 km s-' , except of the hydrogen recombination lines, which have a resolution of 3 km s-1 . The continuum rms is for the whole bandpass, excluding the strong spectral lines. 11. Centrifugal Barrier and Super-Keplerian Rotation in Protostellar Disk Formation Dylan C. Jones, Ka Ho Lam, Zhi-Yun Li, Yisheng Tu ★ With the advent of ALMA, it is now possible to ob- servationally constrain how disks form around deeply embedded protostars. In particular, the recent ALMA C3H2 line observations of the nearby protostar L1527 have been interpreted as evidence for the so-called "centrifugal bar- rier," where the protostellar envelope infall is gradually decelerated to a stop by the centrifugal force in a region of super-Keplerian rotation. To test the concept of centrifugal barrier, which was originally based on angular momentum conserving-collapse of a rotating test particle around a fixed point mass, we carry out simple axisymmetric hydrody- namic simulations of protostellar disk formation including a minimum set of ingredients: self-gravity, rotation, and a prescribed viscosity that enables the disk to accrete. We find that a super-Keplerian region can indeed exist when the viscosity is relatively large but, unlike the classic picture of centrifugal barrier, the infalling envelope material is not decelerated solely by the centrifugal force. The region has more specific angular momentum than its surrounding envelope material, which points to an origin in outward angular momentum transport in the disk (subject to the constraint of disk expansion by the infalling envelope), rather than the spin-up of the envelope material envisioned in the classic picture as it falls closer to the center in order to conserve angular momentum. For smaller viscosities, the super-Keplerian rotation is weaker or non-existing. We conclude that, despite the existence of super-Keplerian rotation in some parameter regime, the classic picture of centrifugal barrier is not supported by our simulations. ALMAによる原始星L1527の観測などから、 ”遠心力バリア”=“遠心力によりエンベロープ→円盤への降着が止められる場所”の存在が議論されている本研究：遠心力バリアとsuper-Kepler回転の存在を軸対称な流体計算によりモデル計算。粘性の大きさなども関係。 β =0.03 ∂ρ + ∇ · (ρν) = 0,
∂t and the momentum equation ν = βΩκ (r) R², ρ ∂t +ρ(ν · ∇)ν = −∇Ρ − ρ∇Φg + ∇ · Π, (2) where the gravitational potential is evaluated using the Poisson equa- tion ∇²Φg = 4πGρ. (3) Figure 6. Ratios of rotational speed to the local Keplerian speed for selected viscosity values, showing that the super-Keplerian rotation becomes more prominent with increasing viscosity. β依存性(1)
9.
Influence of grain growth on CO2 ice spectroscopic profiles : Modelling for dense cores
and disks
Emmanuel Dartois, Jennifer A. Noble, Nathalie Ysard, Karine Demyk, Marin Chabot ★ Interstellar dust grain growth in dense clouds and protoplanetary disks, even moderate, affects the observed interstellar ice profiles as soon as a significant fraction of dust grains is in the size range close to the wave vector at the considered wavelength.  The continuum baseline correction made prior to analysing ice profiles influences the subsequent analysis and hence the estimated ice composi- tion, typically obtained by band fitting using thin film ice mixture spectra. We model the effect of grain growth on ice mantle spectroscopic profiles, focusing on CO2 to see how it can affect interstellar ice mantle spectral analysis and interpretation.  Using the Discrete Dipole Approximation for Scattering and Absorption of Light, the mass absorption coefficients of distributions of grains composed of ellipsoidal silicate cores with water and carbon dioxide ice mantles are calculated. A few other ice mantle compositions are also calculated.  We explore the size distribution evolution from dense clouds to simulate the first steps of grain growth up to three microns in size. The results are injected into RADMC-3D full scattering radiative transfer models of spherical clouds and protoplanetary disk templates to retrieve observable spectral energy distributions. We focus on calculated profile of the CO2 antisymmetric stretching mode ice band profile at 4.27 microns, a meaningful indicator of grain growth. The observed profiles toward dense cores with the Infrared space observatory and Akari satellites already showed profiles possibly indicative of moderate grain growth.The observation of protoplanetary disks at high inclination with the JWST should present distorted profiles that will put constraints on the extent of dust growth. The more evolved the dust size distribution, the more the extraction of the ice mantle composition will require both understanding and taking into account grain growth. 4.27 μ m CO2吸収featureの形状について、ダストサイズ成長度合いに対する依存性を計算ISOやあかり衛星によるdense core天体に対する観測結果とも比較し、ダスト成長度合いなど議論。 JWSTによるedge-on円盤の観測による制限も期待。
10.
Effects of the environment and feedback physics on the initial mass function of stars in
the STARFORGE simulations
Dávid Guszejnov, Michael Y. Grudić, Stella S. R. Offner, Claude-André Faucher-Giguère, Philip F. Hopkins, Anna L. Rosen ★ One of the key mysteries of star formation is the origin of the stellar initial mass function (IMF). The IMF is observed to be nearly universal in the Milky Way and its satellites, and significant variations are only inferred in extreme environments, such as the cores of massive elliptical galaxies. In this work we present simulations from the STARFORGE project that are the first cloud-scale RMHD simulations that follow individual stars and include all relevant physical processes. The simulations include detailed gas thermodynamics, as well as stellar feedback in the form of protostellar jets, stellar ra- diation, winds and supernovae.  In this work we focus on how stellar radiation, winds and supernovae impact star-forming clouds.  Radiative feedback plays a major role in quenching star formation and disrupting the cloud, however the IMF peak is predominantly set by protostellar jet physics. We find the effect of stellar winds is minor, and supernovae occur too lateto affect the IMF or quench star formation. We also investigate the effects of initial conditions on the IMF. The IMF is insensitive to the initial turbulence, cloud mass and cloud surface density, even though these parameters significantly shape the star formation history of the cloud, including the final star formation efficiency.  The characteristic stellar mass depends weakly on metallicity and the interstellar radiation field. Finally, while turbulent driving and the level of magnetization strongly influences the star formation history, they only influence the high-mass slope of the IMF. Cloudスケールの放射磁気流体計算(STARFORGE)により、IMFの周囲物理環境依存性などを探る研究以下、補足解説スライドHCN/HNC比を用いたガス温度測定(Hacar et al. 2020)他の温度決定方法(Tdust, Tk (NH3), Tex (12CO)など)との比較
(3) and
(4)左図のfitting式概ねT κ~15~40 Kで良いfitting式HNC + H → HCN + H and HNC + O → NH + CO (1) (2)