Molecular line survey of the high-mass star-forming region NGC 6334I with Herschel/HIFI and the SMA

Abstract

We aim at deriving the molecular abundances and temperatures of the hot molecular cores in the high-mass star-forming region NGC 6334I and consequently deriving their physical and astrochemical conditions. In the framework of the Herschel guaranteed time key program CHESS, NGC 6334I is investigated by using HIFI aboard the Herschel Space Observatory. A spectral line survey is carried out in the frequency range 480-1907 GHz, and auxiliary interferometric data from the SMA in the 230 GHz band provide spatial information for disentangling the different physical components contributing to the HIFI spectrum. The spectral lines are identified with the aid of former surveys and spectral line catalogs. The observed spectrum is then compared to a simulated synthetic spectrum with XCLASS, assuming local thermal equilibrium, and best fit parameters are derived using the model optimization package MAGIX. A total of 46 molecules are identified, with 31 isotopologues, resulting in about 4300 emission and absorption lines. High- energy levels of the dominant emitter methanol and vibrationally excited HCN are detected. The number of unidentified lines remains low with 75, or less than 2 percent of the lines detected. The modeling suggests that several spectral features need two or more components to be fitted properly. Other components could be assigned to cold foreground clouds or to outflows, most visible in the SiO emission. A chemical variation between the two embedded hot cores is found, with more N-bearing molecules identified in SMA1 and O-bearing molecules in SMA2. Spectral line surveys give powerful insights into the study of the interstellar medium. Different molecules trace different physical conditions like the inner hot core, the envelope, the outflows or the cold foreground clouds. The derived molecular abundances provide further constraints for astrochemical models.

30 pages including appendix, 49 figures, accepted for publication in Astronomy and Astrophysics

References in corpus (8)

• Complex Chemistry in Star-Forming Regions: An Expanded Gas-Grain Warm-up Chemical Model
• {Millimeter Multiplicity in NGC 6334 I and I(N)
• S-bearing molecules in Massive Dense Cores
• Hot ammonia in NGC6334I & I(N)
• The high velocity outflow in NGC6334I
• Submillimeter spectroscopy of southern hot cores: NGC6334(I) and G327.3-0.6
• A survey of SiO 5-4 emission towards outflows from massive young stellar objects
• Herschel/HIFI observations of spectrally resolved methylidyne signatures toward the high-mass star-forming core NGC6334I

Cited by in corpus (51)

• Complex organic molecules in the interstellar medium: IRAM 30 m line survey of Sagittarius B2(N) and (M)
• Herschel Survey of Galactic OH+, H2O+, and H3O+: Probing the Molecular Hydrogen Fraction and Cosmic-Ray Ionization Rate
• Astrochemistry During the Formation of Stars
• Hierarchical fragmentation and differential star formation in the Galactic "Snake": infrared dark cloud G11.11-0.12
• Astrochemistry and compositions of planetary systems
• The ALMA-PILS survey: Isotopic composition of oxygen-containing complex organic molecules toward IRAS 16293-2422B
• An extraordinary outburst in the massive protostellar system NGC6334I-MM1: quadrupling of the millimeter continuum
• Herschel observations of EXtra-Ordinary Sources: Analysis of the HIFI 1.2 THz Wide Spectral Survey Toward Orion KL I. Methods
• eXtended CASA Line Analysis Software Suite (XCLASS)
• Herschel observations of EXtraordinary Sources: Analysis of the full Herschel/HIFI molecular line survey of Sagittarius B2(N)
• A necklace of dense cores in the high-mass star forming region G35.20-0.74N: ALMA observations
• A new study of an old sink of sulfur in hot molecular cores: the sulfur residue
• The Extraordinary Outburst in the Massive Protostellar System NGC6334I-MM1: Emergence of Strong 6.7 GHz Methanol Masers
• ALMA Detection of Interstellar Methoxymethanol (CH${}_3$OCH${}_2$OH)
• A Masing Event in NGC6334I: Contemporaneous Flaring of Hydroxyl, Methanol and Water Masers
• Revealing the dynamics of Class 0 protostellar discs with ALMA
• ALMA reveals sequential high-mass star formation in the G9.62+0.19 complex
• The family of amide molecules toward NGC 6334I
• The Massive Protostellar Cluster NGC6334I at 220 AU Resolution: Discovery of Further Multiplicity, Diversity and a Hot Multi-Core
• Chemistry of massive young stellar objects with a disk-like structure
• The extraordinary outburst in the massive protostellar system NGC6334I-MM1: Flaring of the water masers in a north-south bipolar outflow driven by MM1B
• Methylamine and other simple N-bearing species in the hot cores NGC 6334I MM1-3
• Herschel HIFI observations of O${}_2$ toward Orion: special conditions for shock enhanced emission
• Low levels of methanol deuteration in the high-mass star-forming region NGC 6334I
• 13C-methyl formate: observations of a sample of high mass star-forming regions including Orion-KL and spectroscopic characterization
• The Difference in Abundances between N-bearing and O-bearing Species in High-Mass Star-Forming Regions
• Interstellar Glycolaldehyde, Methyl Formate, and Acetic Acid I: A Bi-modal Abundance Pattern in Star Forming Regions
• First Results of an ALMA Band 10 Spectral Line Survey of NGC 6334I: Detections of Glycolaldehyde (HC(O)CH${}_2$OH) and a New Compact Bipolar Outflow in HDO and CS
• SMA Observations of W3(OH) Complex: Physical and Chemical Differentiation between W3(H${}_2$O) and W3(OH)
• The Herschel/HIFI spectral survey of OMC-2 FIR 4 (CHESS): An overview of the 480 to 1902 GHz range
• Evolution of complex organic molecules in hot molecular cores: Synthetic spectra at (sub-)mm wavebands
• Linking low- to high-mass YSOs with Herschel-HIFI observations of water
• Analysis of the Herschel/HEXOS Spectral Survey Towards Orion South: A massive protostellar envelope with strong external irradiation
• The Detection of Hot Molecular Cores in the Small Magellanic Cloud
• The Role of Terahertz and Far-IR Spectroscopy in Understanding the Formation and Evolution of Interstellar Prebiotic Molecules
• Exploring the Origins of Earth's Nitrogen: Astronomical Observations of Nitrogen-bearing Organics in Protostellar Environments
• Ionization toward the high-mass star-forming region NGC 6334 I
• Complex molecules in W51 North region
• The HIFI spectral survey of AFGL 2591 (CHESS). II. Summary of the survey
• Probing the kinematics and chemistry of the hot core Mon R 2 IRS 3 using ALMA observations
• ALMA Detection of Vibrationally Excited ($v{}_{\mathrm{t}}=1,2$) Acetic Acid toward NGC 6334I
• Interstellar bromine abundance is consistent with cometary ices from Rosetta
• Three-dimensional distribution of hydrogen fluoride gas toward NGC6334 I and I(N)
• Expanding the submillimeter wave spectroscopy and astronomical search for thioacetamide (CH3CSNH2) in the ISM
• MAGellanic Outflow and chemistry Survey (MAGOS): Hot cores in the LMC
• The LMT 2 millimeter receiver system (B4R). II. Science demonstration observations toward Orion-KL/OMC-1
• Organic Acid Chemistry in ISM: Detection of Formic Acid and its Prebiotic Chemistry in Hot Core G358.93$-$0.03 MM1
• Dust Temperature Profiles in Dense Cores Associated With Massive Star-Forming Regions
• ATOMS: ALMA Three-millimeter Observations of Massive Star-forming regions -- X. Chemical differentiation among the massive cores in G9.62+0.19
• MOLLId: software for automatic identification of spectral molecular lines in the sub-millimeter and millimeter bands and its application to the spectra of protostars from the region RCW 120
• Synthesis and Spectroscopic Characterization of Interstellar Candidate Ethynyl Thiocyanate: HCCSCN