Article
Astronomy & Astrophysics
Shota Notsu, Ewine F. van Dishoeck, Catherine Walsh, Arthur D. Bosman, Hideko Nomura
Summary: X-ray strongly affects the abundances of water and related oxygen-bearing species in low-mass protostellar envelopes, mainly through ion-molecule reactions and X-ray-induced photodissociation of gas-phase water molecules within the water snowline.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
P. Nazari, B. Tabone, G. P. Rosotti, M. L. van Gelder, R. Meshaka, E. F. van Dishoeck
Summary: This study investigates the abundance and presence of methanol in protostellar systems. The results suggest that dust optical depth and the presence of a disk can reduce methanol emission. Therefore, the absence of gas-phase methanol emission does not imply its absence in either gas or ice.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
M. L. van Gelder, P. Nazari, B. Tabone, A. Ahmadi, E. F. van Dishoeck, M. T. Beltran, G. A. Fuller, N. Sakai, A. Sanchez-Monge, P. Schilke, Y-L Yang, Y. Zhang
Summary: This study investigates the presence of methanol, a complex organic molecule, in protostellar systems. The results suggest that methanol emission can be obscured by dust optical depth and may primarily exist in the ice. The presence of a disk and high mm opacity dust grains can significantly reduce methanol emission. Therefore, both the effects of the disk and dust optical depth should be considered when analyzing observations. It is important to consider the physical structure of low-mass protostars in future chemical studies as the absence of gas-phase methanol emission does not imply the absence of methanol molecules in either gas or ice.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
P. Freeman, S. Bottinelli, R. Plume, E. Caux, C. Monaghan, B. Mookerjea
Summary: By investigating the prevalence of carbon chain species and their environment in high-mass star-forming regions, this study conducted targeted spectral surveys of two sources in the direction of Cygnus X - AFGL 2591 and IRAS 20126+4104. The observed molecular spectra were used to construct a local thermodynamic equilibrium (LTE) model to determine the physical environment in which these molecules originate.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
Tanya Kushwahaa, Maria N. Drozdovskaya, Lukasz Tychoniec, Benoit Tabone
Summary: This study investigates the gas-phase H2S/OCS ratio in low-mass protostars to gain insights into the physical and chemical conditions in the birth cloud of Sun-like stars. The results show that the H2S/OCS ratio is closely related to the stellar cloud environment, with BHR71-IRS1 having a H2S/OCS ratio that matches that of comet 67P/Churyumov-Gerasimenko.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
Zainab Awad, Audrey Coutens, Serena Viti, Jonathan Holdship
Summary: The study investigated the formation mechanism of interstellar methyl formate and its deuterated isotopologues using a gas-grain chemical model. It was found that radical-radical association on grains and H-D substitution reactions play crucial roles in the formation of these molecules in low-mass star-forming regions. Additional experimental and theoretical studies are needed for a better understanding of the interstellar formation of these species.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
L. Gehrig, E. I. Vorobyov
Summary: Our study shows that additional heat added into the stellar interior, accretion history, and stellar winds have the strongest influence on the spin evolution of low-mass stars during their first million years. Based on these results, we are motivated to combine our model with a hydrodynamic disk evolution code to include important aspects such as episodic accretion events, magnetic disk winds, and photoevaporation.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
P. Nazari, M. L. van Gelder, E. F. van Dishoeck, B. Tabone, M. L. R. van't Hoff, N. F. W. Ligterink, H. Beuther, A. C. A. Boogert, A. Caratti O Garatti, P. D. Klaassen, H. Linnartz, V. Taquet, L. Tychoniec
Summary: The study found similarities in the abundances of nitrogen-bearing complex organic molecules compared to oxygen-bearing species in two deeply embedded protostars, suggesting a shared chemical history but with some variations due to local conditions like temperature sensitivity. Future data will enable a direct comparison between ice and gas abundances of smaller and larger nitrogen-bearing species.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
V Wakelam, A. Coutens, P. Gratier, T. H. G. Vidal, N. Vaytet
Summary: The emission of several molecules from the L1451-mm FHSC candidate was observed, and a low-velocity and compact outflow was detected, supporting the hypothesis that L1451-mm is at an early protostellar stage.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
L. Gehrig, E. Gaidos, M. Guedel
Summary: The rotation periods of young low-mass stars after disks have dissipated but before magnetized winds have removed significant angular momentum is an important starting point for gyrochronology and models of stellar rotational evolution. A recent analysis suggests that the distribution of specific angular momentum (SAM) in these stars is mass-independent, but the underlying physics of this observation is unclear.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
Per Bjerkeli, Jon P. Ramsey, Daniel Harsono, Adele Plunkett, Zhi-Yun Li, Matthijs H. D. van der Wiel, Hannah Calcutt, Jes K. Jorgensen, Lars E. Kristensen
Summary: Using ALMA data, it was discovered that a forming disk is present in the vicinity of the B335 protostar, with gas falling towards the disk. Further observations are needed to confirm the presence of a rotationally supported disk.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
C. Zhang, Y. Wu, X-C Liu, Mengyao Tang, Di Li, Jarken Esimbek, S-L Qin
Summary: In this study, a survey of carbon-chain molecules (CCMs) was conducted towards four low-mass outflow sources, revealing significant variations in the abundance and types of CCMs among different sources, reflecting differences in the evolutionary stages of star-forming cores. Furthermore, sources rich in carbon chains may exhibit warm carbon-chain chemistry characteristics.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
Maria N. Drozdovskaya, Laurent H. Coudert, Laurent Margules, Audrey Coutens, Jes K. Jorgensen, Sebastien Manigand
Summary: In this study, the column density of di-deuterated methanol in the deeply embedded low-mass protostellar system and astrochemical template source IRAS 16293-2422 is accurately quantified. The results show that di-deuterated molecules consistently have higher D/H ratios than their mono-deuterated counterparts in low-mass protostars. The findings provide insights into the physicochemical provenance of star-forming systems.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
L. Gehrig, D. Steiner, E. Vorobyov, M. Guedel
Summary: The study aims to investigate the influence of hydrodynamic disk evolution on stellar rotational period and vice versa during the accretion phase. By combining the TAPIR disk code with a stellar spin evolution model, the research can reproduce the observed fast and slow rotating stars in young stellar clusters within a defined parameter space.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
W. R. M. Rocha, G. Perotti, L. E. Kristensen, J. K. Jorgensen
Summary: The ENIIGMA fitting tool, based on evolutionary algorithms, successfully identifies ice samples and their fractions with known ice samples. It can decompose the broad spectral range of Elias 29 spectrum, allowing the identification of different molecules in the ice mantle. ENIIGMA is a timely toolbox for spectroscopy analysis of infrared spectra, enabling correct interpretation of astronomical observations in different chemical environments and irradiation fields.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
J. A. Sturm, M. K. McClure, D. Harsono, S. Facchini, F. Long, M. Kama, E. A. Bergin, E. F. van Dishoeck
Summary: This study investigates the measurements of the carbon-to-hydrogen ratio in protoplanetary disks and explores the mechanisms and evolutionary trends of gaseous carbon depletion. By using models and analyzing observational data, the study determines the magnitude of carbon depletion and the effects of disk material drift and dust structure.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
Merel L. R. van 't Hoff, Daniel Harsono, Martijn L. van Gelder, Tien-Hao Hsieh, John J. Tobin, Sigurd S. Jensen, Naomi Hirano, Jes K. Jorgensen, Edwin A. Bergin, Ewine F. van Dishoeck
Summary: The location of the water snowline in protostellar envelopes is crucial in understanding the thermal structure and mass accretion process. In this study, using observations from the ALMA, five protostellar envelopes in Perseus were analyzed to determine the water snowline location. It was found that (H2O)-O-18 and HDO are effective tracers of the snowline, while HCO+ is not suitable. A more detailed analysis is required to derive the snowline location from (HCO+)-C-13 or HC18 O(+ )emission.
ASTROPHYSICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
A. A. Rota, C. F. Manara, A. Miotello, G. Lodato, S. Facchini, M. Koutoulaki, G. Herczeg, F. Long, M. Tazzari, S. Cabrit, D. Harsono, F. Menard, P. Pinilla, G. van der Plas, E. Ragusa, H. -W. Yen
Summary: In this study, ALMA observations of multiple stellar systems reveal that the gas disc size is on average 4.2 times larger than the dust disc size, and that the outer dusty disc in multiple stellar systems is sharply truncated. These findings are consistent with tidal truncation models in multiple stellar systems.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
Feng Long, Sean M. Andrews, Giovanni Rosotti, Daniel Harsono, Paola Pinilla, David J. Wilner, Karin Oberg, Richard Teague, Leon Trapman, Benoit Tabone
Summary: The size of a disk encodes important information about its evolution. By analyzing data from a sample of 44 protoplanetary disks, we found that the size range can be explained by different models of viscous evolution or spread of initial conditions. Most disks' sizes are consistent with MHD wind models, but larger initial disk sizes are needed to explain the CO disks in the sample.
ASTROPHYSICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
Jane Huang, Christian Ginski, Myriam Benisty, Bin Ren, Alexander J. Bohn, Elodie Choquet, Karin Oberg, Alvaro Ribas, Jaehan Bae, Edwin A. Bergin, Til Birnstiel, Yann Boehler, Stefano Facchini, Daniel Harsono, Michiel Hogerheijde, Feng Long, Carlo F. Manara, Francois Menard, Paola Pinilla, Christophe Pinte, Christian Rab, Jonathan P. Williams, Alice Zurlo
Summary: The panchromatic observations of DO Tau highlight the connection of the circumstellar disk to arms extending out to several hundred astronomical units, as well as the presence of stream-like structures that are not gravitationally bound to DO Tau. These observations provide significant insights into the evolution of Class II disks.
ASTROPHYSICAL JOURNAL
(2022)
Article
Multidisciplinary Sciences
Jes K. Jorgensen, Rajika L. Kuruwita, Daniel Harsono, Troels Haugbolle, Lars E. Kristensen, Edwin A. Bergin
Summary: Nearly half of stars similar to our Sun are found in binary or multiple systems, which have a significant impact on their evolution and the protoplanetary disks. A study on a young protostellar system, NGC1333-IRAS2A, reveals that episodic bursts of inhomogeneous accretion occur, generating a wobbling jet. This finding suggests that binarity and multiplicity strongly influence the properties of emerging stars and the structures of protoplanetary disks.
Article
Astronomy & Astrophysics
Merel L. R. van't Hoff, Margot Leemker, John J. Tobin, Daniel Harsono, Jes K. Jorgensen, Edwin A. Bergin
Summary: Direct observational constraints on the water snowline in circumstellar disks are sparse, but chemical imaging provides an alternative way to locate the snowline. ALMA observations of HCO+ and (HCO+)-C-13 emissions allow for some constraints on the snowline's location. Further detailed observations are needed to eliminate other contributions and obtain more accurate results.
ASTROPHYSICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
A. Taillard, V. Wakelam, P. Gratier, E. Dartois, M. Chabot, J. A. Noble, J. V. Keane, A. C. A. Boogert, D. Harsono
Summary: We observed the cold core LDN 429-C to obtain the gas-phase abundances of key species, including CO and CH3OH. Comparing the data for methanol to the methanol ice abundance previously observed allows us to put quantitative constraints on the efficiency of the non-thermal desorption of this species.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
M. K. McClure, W. R. M. Rocha, K. M. Pontoppidan, N. Crouzet, L. E. U. Chu, E. Dartois, T. Lamberts, J. A. Noble, Y. J. Pendleton, G. Perotti, D. Qasim, M. G. Rachid, Z. L. Smith, Fengwu Sun, Tracy L. Beck, A. C. A. Boogert, W. A. Brown, P. Caselli, S. B. Charnley, Herma M. Cuppen, H. Dickinson, M. N. Drozdovskaya, E. Egami, J. Erkal, H. Fraser, R. T. Garrod, D. Harsono, S. Ioppolo, I. Jimenez-Serra, M. Jin, J. K. Jorgensen, L. E. Kristensen, D. C. Lis, M. R. S. McCoustra, Brett A. McGuire, G. J. Melnick, Karin I. Oberg, M. E. Palumbo, T. Shimonishi, J. A. Sturm, E. F. van Dishoeck, H. Linnartz
Summary: Icy grain mantles in interstellar clouds are important reservoirs of volatile elements that connect chemical processes with planet formation and atmospheric composition. Results from the Ice Age program using the James Webb Space Telescope reveal the rich composition of these dense cloud ices, showing the detection of weak ice features and complex organic molecules. The study suggests that simple and complex molecules can form early in ice-rich environments and JWST can trace the molecules seen in planetary atmospheres back to their origins in interstellar clouds.
Article
Astronomy & Astrophysics
Feng Long, Bin B. Ren, Nicole L. Wallack, Daniel Harsono, Gregory J. Herczeg, Paola Pinilla, Dimitri Mawet, Michael C. Liu, Sean M. Andrews, Xue-Ning Bai, Sylvie Cabrit, Lucas A. Cieza, Doug Johnstone, Jarron M. Leisenring, Giuseppe Lodato, Yao Liu, Carlo F. Manara, Gijs D. Mulders, Enrico Ragusa, Steph Sallum, Yangfan Shi, Marco Tazzari, Taichi Uyama, Kevin Wagner, David J. Wilner, Jerry W. Xuan
Summary: This paper presents high-resolution observations of dust continuum and CO line emission towards the disk around the M3.5 star 2MASSJ04124068+2438157 using the Atacama Large Millimeter/submillimeter Array. The dust disk consists of two narrow rings with Gaussian sigma widths, and the outer ring suggests dust trapping in a radial pressure bump. The disk's physical structure and accretion properties favor planet-disk interaction as the explanation for the observed morphology.
ASTROPHYSICAL JOURNAL
(2023)
Article
Multidisciplinary Sciences
John J. Tobin, Merel L. R. van 't Hoff, Margot Leemker, Ewine F. van Dishoeck, Teresa Paneque-Carreno, Kenji Furuya, Daniel Harsono, Magnus V. Persson, L. Ilsedore Cleeves, Patrick D. Sheehan, Lucas Cieza
Summary: Water is a crucial molecule in the formation of stars and planets, aiding the growth of solid material and the formation of planetesimals within disks. However, the water snowline and HDO:H2O ratio in proto-planetary disks have not been well understood. This study directly detects gas phase water in the disk of V883 Ori and finds that the midplane water snowline radius is approximately 80AU, similar to the scale of the Kuiper Belt. Additionally, the HDO:H2O ratio in the disk is comparable to that of protostellar envelopes and comets, exceeding that of Earth's oceans.
Article
Astronomy & Astrophysics
Per Bjerkeli, Jon P. Ramsey, Daniel Harsono, Adele Plunkett, Zhi-Yun Li, Matthijs H. D. van der Wiel, Hannah Calcutt, Jes K. Jorgensen, Lars E. Kristensen
Summary: Using ALMA data, it was discovered that a forming disk is present in the vicinity of the B335 protostar, with gas falling towards the disk. Further observations are needed to confirm the presence of a rotationally supported disk.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
J. A. Sturm, M. K. Mcclure, C. J. Law, D. Harsono, J. B. Bergner, E. Dartois, M. N. Drozdovskaya, S. Ioppolo, K. I. Oberg, M. E. Palumbo, Y. J. Pendleton, W. R. M. Rocha, H. Terada, R. G. Urso
Summary: Observations of edge-on disks play an important role in understanding protoplanetary disk properties. However, current models struggle to reproduce both the spectral energy distributions and scattered light observations due to differences in geometry and dust properties at different wavelengths. In this study, the authors successfully constrained the geometry and characteristics of the protoplanetary disk HH 48 NE using a parameterized dust model and a Monte Carlo framework. The findings provide insights into the physical structure and icy chemistry of this disk.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
Jeong-Eun Lee, Tomoaki Matsumoto, Hyun-Jeong Kim, Seokho Lee, Daniel Harsono, Jaehan Bae, Neal J. J. Evans II, Shu-ichiro Inutsuka, Minho Choi, Ken'ichi Tatematsu, Jae-Joon Lee, Daniel Jaffe
Summary: To gain a better understanding of star formation processes, it is crucial to observe the individual components of protostellar systems and their surrounding material at the earliest stages. We present observations of the young multiple protostellar system, IRAS 04239+2436, revealing three well-developed spiral arms and an accretion streamer. Numerical simulations suggest that these large arms are the result of gravitational interactions between triple protostars and the turbulent infalling envelope.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
D. Harsono, P. Bjerkeli, J. P. Ramsey, K. M. Pontoppidan, L. E. Kristensen, J. K. Jorgensen, H. Calcutt, Z-Y. Li, A. Plunkett
Summary: Outflows and winds launched from young stars have significant impacts on the evolution of protostars and the early stages of planet formation. This study presents observations of a collimated atomic jet and corresponding extended H-2 emission from the low-mass protostar TMC1A. Spectrally broad emissions of H i and He i indicate a combination of protostellar accretion and a wide-angle wind. These observations reveal new information about the hot inner regions of protostars and demonstrate the potential of JWST.
ASTROPHYSICAL JOURNAL LETTERS
(2023)