Implications of a hot atmosphere/corino from ALMA observations towards NGC1333 IRAS 4A1

Abstract

We report high angular resolution observations of NGC1333 IRAS4A, a protostellar binary including A1 and A2, at 0.84 mm with the Atacama Large Millimeter/submillimeter Array. From the continuum observations, we suggest that the dust emission from the A1 core is optically thick, and A2 is predominantly optically thin. The A2 core, exhibiting a forest of spectral lines including complex molecules, is a well known hot corino as suggested by previous works. More importantly, we report, for the first time, the solid evidence of complex organic molecules (COMs), including CH3OH, ^13CH3OH, CH2DOH, CH3CHO associated with the A1 core seen in absorption. The absorption features mostly arise from a compact region around the continuum peak position of the A1 core. Rather than originating from a larger common envelope surrounding the protobinary, the COM features are associated with individual cores A1 and A2. Considering the signatures observed in both continuum and spectral lines, we propose two possible scenarios for IRAS 4A1 - the COM absorption lines may arise from a hot-corino-like atmosphere at the surface of an optically-thick circumstellar disk around A1, or the absorption may arise from different layers of a temperature-stratified dense envelope.

20 pages, 7 figues, accepted on 16th Jan, ApJ

References in corpus (22)

• Formation of methyl formate and other organic species in the warm-up phase of hot molecular cores
• The ALMA Protostellar Interferometric Line Survey (PILS): First results from an unbiased submillimeter wavelength line survey of the Class 0 protostellar binary IRAS 16293-2422 with ALMA
• Formation of complex organic molecules in cold objects: the role of gas phase reactions
• The cometary composition of a protoplanetary disk as revealed by complex cyanides
• The origin of complex organic molecules in prestellar cores
• The Spatial Distribution of Complex Organic Molecules in the L1544 Pre-stellar Core
• Constraining the abundances of complex organics in the inner regions of solar-type protostars
• Shedding light on the formation of the pre-biotic molecule formamide with ASAI
• An interferometric study of the low-mass protostar IRAS 16293-2422: small scale organic chemistry
• Herschel observations of EXtra-Ordinary Sources: Analysis of the HIFI 1.2 THz Wide Spectral Survey Toward Orion KL I. Methods
• Formation and Atmosphere of Complex Organic Molecules of the HH 212 Protostellar Disk
• Complex organics in IRAS 4A revisited with ALMA and PdBI: Striking contrast between two neighbouring protostellar cores
• The census of complex organic molecules in the solar type protostar IRAS16293-2422
• Discovery of a Hot Corino in the Bok Globule B335
• Hubble Space Telescope Survey of Interstellar ^12CO/^13CO in the Solar Neighborhood
• The complex chemistry of outflow cavity walls exposed: the case of low-mass protostars
• Deuterated methanol on Solar System scale around the HH212 protostar
• 13C Isotopic Fractionation of HC3N in Star-Forming Regions -Low-Mass Star Forming Region L1527 and High-Mass Star Forming Region G28.28-0.36-
• Complex organic molecules during low-mass star formation: Pilot survey results
• Ammonia Imaging of the Disks in the NGC 1333 IRAS 4A Protobinary System
• Circumbinary Molecular Rings Around Young Stars in Orion
• Observations of Water Masers in the NGC 1333 IRAS 4 Region

Cited by in corpus (12)

• The Perseus ALMA Chemistry Survey (PEACHES). I. The Complex Organic Molecules in Perseus Embedded Protostars
• Hot Corinos Chemical Diversity: Myth or Reality?
• ALMA Survey of Orion Planck Galactic Cold Clumps (ALMASOP): A Hot Corino Survey toward Protostellar Cores in the Orion Cloud
• The Physical Properties of the SVS 13 Protobinary System: Two Circumstellar Disks and a Spiraling Circumbinary Disk in the Making
• Successive deuteration in low-mass star-forming regions: the case of D${}_2$-methanol (CHD${}_2$OH) in IRAS 16293-2422
• ALMA Survey of Orion Planck Galactic Cold Clumps (ALMASOP): I. Detection of New Hot Corinos with ACA
• Detection of Irregular, Sub-mm Opaque Structures in the Orion Molecular Clouds: Protostars within 10000 years of formation?
• The Infall Motion in the Low-Mass Protostellar Binary NGC 1333 IRAS 4A1/4A2
• Feedback of molecular outflows from protostars in NGC 1333, revealed by Herschel and Spitzer spectro-imaging observations
• Probing the Temperature Structure of Optically Thick Disks Using Polarized Emission of Aligned Grains
• Constraints of the formation and abundances of methyl carbamate, a glycine isomer, in hot corinos
• Exploring the 100 au Scale Structure of the Protobinary System NGC 2264 CMM3 with ALMA