L483: Warm Carbon-chain Chemistry Source Harboring Hot Corino Activity
Yoko Oya,Nami Sakai,Yoshimasa Watanabe,Aya E. Higuchi,Tomoya Hirota,Ana López-Sepulcre,Takeshi Sakai,Yuri Aikawa,Cecilia Ceccarelli,Cecilia Ceccarelli,Bertrand Lefloch,Bertrand Lefloch,Emmanuel Caux,Emmanuel Caux,Charlotte Vastel,Charlotte Vastel,Claudine Kahane,Claudine Kahane,Satoshi Yamamoto +18 more
TLDR
In this article, an infalling-rotating envelope is traced by the CS line, while a very compact component with a broad velocity width is observed for the CS, SO, HNCO, NH$_2$CHO, and HCOOCH$_3$ lines.Abstract:
The Class 0 protostar, L483, has been observed in various molecular lines in the 1.2 mm band at a sub-arcsecond resolution with ALMA. An infalling-rotating envelope is traced by the CS line, while a very compact component with a broad velocity width is observed for the CS, SO, HNCO, NH$_2$CHO, and HCOOCH$_3$ lines. Although this source is regarded as the warm carbon-chain chemistry (WCCC) candidate source at a 1000 au scale, complex organic molecules characteristic of hot corinos such as NH$_2$CHO and HCOOCH$_3$ are detected in the vicinity of the protostar. Thus, both hot corino chemistry and WCCC are seen in L483. Although such a mixed chemical character source has been recognized as an intermediate source in previous single-dish observations, we here report the first spatially-resolved detection. A kinematic structure of the infalling-rotating envelope is roughly explained by a simple ballistic model with the protostellar mass of 0.1--0.2 $M_\odot$ and the radius of the centrifugal barrier (a half of the centrifugal radius) of 30--200 au, assuming the inclination angle of 80\degr\ (0\degr\ for a face-on). The broad line emission observed in the above molecules most likely comes from the disk component inside the centrifugal barrier. Thus, a drastic chemical change is seen around the centrifugal barrier.read more
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The UMIST database for astrochemistry 2012
D. McElroy,Catherine Walsh,A. J. Markwick,Martin A. Cordiner,Martin A. Cordiner,K. W. Smith,Tom J. Millar +6 more
TL;DR: The UMIST Database for Astrochemistry (UDfaa) as discussed by the authors contains 6173 gas-phase reactions involving 467 species, 47 of which are new to this release.
Tracing the mass during low-mass star formation I: submillimeter continuum observations and simple analysis
Abstract: We have obtained 850 and 450 μm continuum maps of 21 low-mass cores with SEDs ranging from pre-protostellar to Class I (18 K < Tbol < 370 K), using SCUBA at the JCMT. In this paper we present the maps, radial intensity profiles, and photometry. Pre-protostellar cores do not have power-law intensity profiles, whereas the intensity profiles of Class 0 and Class I sources can be fitted with power laws over a large range of radii. A substantial number of sources have companion sources within a few arcminutes (two out of five pre-protostellar cores, nine out of 16 Class 0/I sources). The mean separation between sources is 10,800 AU. The median separation is 18,000 AU including sources without companions as a lower limit. The mean value of the spectral index between 450 and 850 μm is 2.8 ± 0.4, with pre-protostellar cores having slightly lower spectral indices (2.5 ± 0.4). The mean mass of the sample, based on the dust emission in a 120'' aperture, is 1.1 ± 0.9 M☉. For the sources fitted by power-law intensity distributions (Iν(b)/Iν(0) = (b/b0)m), the mean value of m is 1.52 ± 0.45 for Class 0 and I sources at 850 μm and 1.44 ± 0.25 at 450 μm. Based on a simple analysis, assuming the emission is in the Rayleigh-Jeans limit and that Td(r) ∝ r-0.4, these values of m translate into power-law density distributions (n ∝ r-p) with p ~ 2.1. However, we show that this result may be changed by more careful consideration of effects such as beam size and shape, finite outer radii, more realistic Td(r), and failure of the Rayleigh-Jeans approximation.
Journal ArticleDOI
Astrochemical evolution along star formation: Overview of the IRAM Large Program ASAI.
Bertrand Lefloch,Bertrand Lefloch,Rafael Bachiller,Cecilia Ceccarelli,José Cernicharo,Claudio Codella,A. Fuente,Claudine Kahane,Ana López-Sepulcre,Mario Tafalla,Charlotte Vastel,Emmanuel Caux,M. González-García,E. Bianchi,E. Bianchi,A. I. Gómez-Ruiz,A. I. Gómez-Ruiz,Jonathan Holdship,E. Mendoza,J. Ospina-Zamudio,Linda Podio,D. Quénard,E. Roueff,Nami Sakai,Serena Viti,Satoshi Yamamoto,Kento Yoshida,Cécile Favre,T. Monfredini,Heidy M Quitián-Lara,Nuria Marcelino,Heloisa M. Boechat-Roberty,Sylvie Cabrit +32 more
TL;DR: An overview of the Large Program "Astrochemical Surveys At IRAM" (ASAI), which aims to carry out unbiased millimeter line surveys of the first stages of the formation process of solar-type stars, from prestellar cores to the late protostellar phase, is presented.
Journal ArticleDOI
The census of interstellar complex organic molecules in the Class I hot corino of SVS13-A
E. Bianchi,E. Bianchi,C. Codella,C. Codella,Cecilia Ceccarelli,Cecilia Ceccarelli,Fanny Vazart,Rafael Bachiller,Nadia Balucani,Nadia Balucani,Nadia Balucani,Mathilde Bouvier,M. De Simone,J. Enrique-Romero,Claudine Kahane,Claudine Kahane,Bertrand Lefloch,Bertrand Lefloch,Ana López-Sepulcre,J. Ospina-Zamudio,Linda Podio,Vianney Taquet +21 more
TL;DR: In this paper, the first census of the interstellar complex organic molecules (iCOMs) in the low-mass Class I protostar SVS13-A, obtained by analysing data from the IRAM-30m Large Project ASAI (Astrochemical Surveys At IRAM).
Journal ArticleDOI
Questioning the spatial origin of complex organic molecules in young protostars with the CALYPSO survey
Arnaud Belloche,Anaëlle Maury,Anaëlle Maury,Sébastien Maret,S. Anderl,Aurore Bacmann,Ph. André,Sylvain Bontemps,S. Cabrit,Claudio Codella,M. Gaudel,Frederic Gueth,Charlène Lefèvre,Bertrand Lefloch,Linda Podio,Leonardo Testi +15 more
TL;DR: In this paper, the column densities of the detected molecules under the local thermodynamic equilibrium approximation were derived and correlations between their abundances and with various source properties were found for the origin of COMs in young protostars.
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The UMIST database for astrochemistry 2012
D. McElroy,Catherine Walsh,A. J. Markwick,Martin A. Cordiner,Martin A. Cordiner,K. W. Smith,Tom J. Millar +6 more
TL;DR: The UMIST Database for Astrochemistry (UDfaa) as mentioned in this paper contains 6173 gas-phase reactions involving 467 species, 47 of which are new to this release.
Journal ArticleDOI
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