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Radio observations of low-mass star formation in molecular spectral lines have rapidly progressed since the advent of Atacama Large Millimeter/submillimeter Array (ALMA). A gas distribution and its kinematics within a few 100s au scale…

Instrumentation and Methods for Astrophysics · Physics 2022-09-28 Yoko Oya , Hirofumi Kibukawa , Shota Miyake , Satoshi Yamamoto

(Abridged) The physical structure of deeply-embedded low-mass protostars (Class 0) on scales of less than 300 AU is still poorly constrained. Determining this is crucial for understanding the physical and chemical evolution from cores to…

Solar and Stellar Astrophysics · Physics 2016-05-04 M. V. Persson , D. Harsono , J. J. Tobin , E. F. van Dishoeck , J. K. Jørgensen , N. Murillo , S. -P. Lai

During the embedded stage of star formation, bipolar molecular outflows and UV radiation from the protostar are important feedback processes. Our aim is to quantify the feedback, mechanical and radiative, for a large sample of low-mass…

We examine emission from a young protostellar object (YPO) with three-dimensional ideal MHD simulations and three-dimensional non-local thermodynamic equilibrium (non-LTE) line transfer calculations, and show the first results. To calculate…

Solar and Stellar Astrophysics · Physics 2015-05-13 M. Yamada , M. N. Machida , S. Inutsuka , K. Tomisaka

[Abridged] We present spectroscopic observations in H$_{2}$O, CO and related species with \textit{Herschel} HIFI and PACS, as well as ground-based follow-up with the JCMT and APEX in CO, HCO$^{+}$ and isotopologues, of a sample of 49 nearby…

Recent high-resolution observations have enabled detailed investigations of the circumstellar environments around Class 0/I protostars. Several studies have reported that the infall velocity of the envelope is a few times smaller than the…

Solar and Stellar Astrophysics · Physics 2025-02-25 Shingo Hirano , Yuri Aikawa , Masahiro N. Machida

Aims: Revealing the fragmentation, infall, and outflow processes in the immediate environment around massive young stellar objects is crucial for understanding the formation of the most massive stars. Methods: With this goal in mind we…

Solar and Stellar Astrophysics · Physics 2015-06-17 H. Beuther , H. Linz , Th. Henning

We present the highest-resolution three-dimensional simulation to date of the collapse of an atomic cooling halo in the early Universe. We use the moving-mesh code arepo with the primordial chemistry module introduced in Greif (2014), which…

Astrophysics of Galaxies · Physics 2014-12-08 Fernando Becerra , Thomas H. Greif , Volker Springel , Lars Hernquist

While molecular outflows have been studied in details with radio interferometry, observations of the hotter gas in protostellar outflows at a comparable physical scale is often challenging. Combined with ALMA, JWST allows us to investigate…

Prestellar cores, the birthplace of Sun-like stars, form from the fragmentation of the filamentary structure that composes molecular clouds, from which they must inherit at least partially the kinematics. Furthermore, when they are on the…

Astrophysics of Galaxies · Physics 2022-12-28 E. Redaelli , A. Chacón-Tanarro , P. Caselli , M. Tafalla , J. E. Pineda , S. Spezzano , O. Sipilä

Young protostellar binary systems, with expected ages less than $\sim$10$^5$ years, are little modified since birth, providing key clues to binary formation and evolution. We present a first look at the young, Class 0 binary protostellar…

As part of our effort to search for circumstellar disks around high-mass stellar objects, we observed the well-known core G31.41+0.31 with ALMA at 1.4 mm with an angular resolution of~0.22" (~1700 au). The dust continuum emission has been…

We discuss recent models of chemical evolution in the developing and collapsing protostellar envelopes associated with low-mass star formation. In particular, the effects of depletion of gas-phase molecules onto grain surfaces is…

Astrophysics · Physics 2007-05-23 Edwin A. Bergin

We present ALMA $^{12}$CO (2-1), $^{13}$CO (2-1), C$^{18}$O (2-1) molecular line observations of a very young proto-brown dwarf system, ISO-OPH 200. We have conducted physical+chemical modelling of the complex internal structure for this…

Solar and Stellar Astrophysics · Physics 2021-03-17 B. Riaz , M. N. Machida

We present observations of continuum emission in the MIR to mm wavelength range, complemented with ammonia observations, of the dense core ahead of the radio Herbig Haro object HH 80N, found in the GGD 27 region. The continuum emission in…

CONTEXT: The chemistry in the inner few thousand AU of accreting envelopes around young stellar objects is predicted to vary greatly with far-UV and X-ray irradiation by the central star. Aim We search for molecular tracers of high-energy…

We present ALMA 1.3 mm continuum, 12CO, C18O, and SO data for the Class 0 protostars, Lupus 3 MMS, IRAS 15398-3559, and IRAS 16253-2429 at resolutions of ~100 AU. By measuring a rotational profile in C18O, a 100 AU Keplerian disk around a…

Solar and Stellar Astrophysics · Physics 2017-01-18 Hsi-Wei Yen , Patrick M. Koch , Shigehisa Takakuwa , Ruben Krasnopolsky , Nagayoshi Ohashi , Yusuke Aso

We present a near-infrared extinction study of the dark globule B335, a protostellar collapse candidate, using data from HST/NICMOS and the W.M. Keck Observatory. These data allow a new quantitative test of the "inside-out" collapse model…

The high abundances of Complex Organic Molecules (COMs) with respect to methanol, the most abundant COM, detected towards low-mass protostars, tend to be underpredicted by astrochemical models. This discrepancy might come from the large…

Solar and Stellar Astrophysics · Physics 2015-05-20 Vianney Taquet , Ana López-Sepulcre , Cecilia Ceccarelli , Roberto Neri , Claudine Kahane , Steven B. Charnley
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