Exploring molecular complexity with ALMA (EMoCA): Alkanethiols and alkanols in Sagittarius B2(N2)

Abstract

Over the past five decades, radio astronomy has shown that molecular complexity is a natural outcome of interstellar chemistry, in particular in star forming regions. However, the pathways that lead to the formation of complex molecules are not completely understood and the depth of chemical complexity has not been entirely revealed. In addition, the sulfur chemistry in the dense interstellar medium is not well understood. We want to know the relative abundances of alkanethiols and alkanols in the Galactic Center source Sagittarius B2(N2), the northern hot molecular core in Sgr B2(N), whose relatively small line widths are favorable for studying the molecular complexity in space. We investigated spectroscopic parameter sets that were able to reproduce published laboratory rotational spectra of ethanethiol and studied effects that modify intensities in the predicted rotational spectrum of ethanol. We used the Atacama Large Millimeter Array (ALMA) in its Cycles~0 and 1 for a spectral line survey of Sagittarius B2(N) between 84 and 114.4 GHz. These data were analyzed by assuming local thermodynamic equilibrium (LTE) for each molecule. Our observations are supplemented by astrochemical modeling; a new network is used for the first time that includes reaction pathways for alkanethiols. The column density ratios involving methanol, ethanol, and methanethiol in Sgr B2(N2) are similar to values reported for Orion KL, but those involving ethanethiol are significantly different and suggest that the detection of ethanethiol reported toward Orion KL is uncertain. Our chemical model presently does not permit the prediction of sufficiently accurate column densities of alkanethiols or their ratios among alkanethiols and alkanols. Therefore, additional observational results are required to establish the level of C2H5SH in the dense and warm interstellar medium with certainty.

Astron. Astrophys., accepted; 14 pages of manuscript with figure and tables plus 23 pages of additional online figures. Abstract here shortened considerably

References in corpus (26)

• Complex Chemistry in Star-Forming Regions: An Expanded Gas-Grain Warm-up Chemical Model
• A three-phase chemical model of hot cores: the formation of glycine
• Complex organic molecules in the interstellar medium: IRAM 30 m line survey of Sagittarius B2(N) and (M)
• Testing grain-surface chemistry in massive hot-core regions
• Detection of amino acetonitrile in Sgr B2(N)
• Detection of the simplest sugar, glycolaldehyde, in a solar-type protostar with ALMA
• Increased complexity in interstellar chemistry: Detection and chemical modeling of ethyl formate and n-propyl cyanide in Sgr B2(N)
• Detection of a branched alkyl molecule in the interstellar medium: iso-propyl cyanide
• The largest oxigen bearing organic molecule repository
• Exploring Molecular Complexity with ALMA (EMoCA): Deuterated complex organic molecules in Sagittarius B2(N2)
• 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
• Spectroscopic characterization and detection of Ethyl Mercaptan in Orion
• Detection of E-cyanomethanimine towards Sagittarius B2(N) in the Green Bank Telescope PRIMOS Survey
• The Detection of Interstellar Ethanimine (CH3CHNH) from Observations taken during the GBT PRIMOS Survey
• Discovery of Methyl Acetate and Gauche Ethyl Formate in Orion
• Accurate rest frequencies of methanol maser and dark cloud lines
• First results from the CALYPSO IRAM-PdBI survey. II. Resolving the hot corino in the Class 0 protostar NGC 1333-IRAS2A
• Herschel observations of EXtraordinary Sources: Analysis of the full Herschel/HIFI molecular line survey of Sagittarius B2(N)
• Rotational spectroscopy of isotopic vinyl cyanide, H${}_2$C=CH$-$C$\equiv$N, in the laboratory and in space
• Searching for Trans Ethyl Methyl Ether in Orion KL
• Submillimeter continuum observations of Sagittarius B2 at subarcsecond spatial resolution
• Deuterated molecules in Orion KL from Herschel/HIFI
• Herschel observations of Extra-Ordinary Sources: Methanol as a probe of physical conditions in Orion KL
• Spectroscopic parameters of phosphine, PH3, in its ground vibrational state
• Millimeter Wave and Terahertz Spectra and Global Fit of Torsion-Rotation Transitions in the Ground, First and Second Excited Torsional States of 13CH3OH Methanol

Cited by in corpus (85)

• The Cologne Database for Molecular Spectroscopy, CDMS, in the Virtual Atomic and Molecular Data Centre, VAMDC
• 2021 Census of Interstellar, Circumstellar, Extragalactic, Protoplanetary Disk, and Exoplanetary Molecules
• 2018 Census of Interstellar, Circumstellar, Extragalactic, Protoplanetary Disk, and Exoplanetary Molecules
• 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
• Astrochemistry During the Formation of Stars
• The ALMA-PILS survey: Isotopic composition of oxygen-containing complex organic molecules toward IRAS 16293-2422B
• Exploring Molecular Complexity with ALMA (EMoCA): Deuterated complex organic molecules in Sagittarius B2(N2)
• Modeling Sulfur Depletion in Interstellar Clouds
• Cometary Chemistry and the Origin of Icy Solar System Bodies, the view after Rosetta
• Formation of complex organic molecules in hot molecular cores through nondiffusive grain-surface and ice-mantle chemistry
• Re-exploring Molecular Complexity with ALMA (ReMoCA): Interstellar detection of urea
• Rotational spectroscopy, tentative interstellar detection, and chemical modelling of N-methylformamide
• The ALMA-PILS survey: Inventory of complex organic molecules towards IRAS 16293-2422 A
• The ALMA-PILS survey: The sulphur connection between protostars and comets: IRAS 16293-2422 B and 67P/Churyumov-Gerasimenko
• Thiols in the ISM: first detection of HC(O)SH and confirmation of C${}_2$H${}_5$SH
• Formation and Atmosphere of Complex Organic Molecules of the HH 212 Protostellar Disk
• Detecting Weak Spectral Lines in Interferometric Data through Matched Filtering
• Complex organic molecules in low-mass protostars on solar system scales -- I. Oxygen-bearing species
• The complex chemistry of hot cores in Sagittarius B2(N): Influence of cosmic-ray ionization and thermal history
• Exploring molecular complexity with ALMA (EMoCA): Detection of three new hot cores in Sagittarius B2(N)
• Exploring molecular complexity with ALMA (EMoCA): Simulations of branched carbon-chain chemistry in Sgr B2(N)
• The physical and chemical structure of Sagittarius B2. II. Continuum millimeter emission of SgrB2(M) and SgrB2(N) with ALMA
• Reactivity of HCO with CH3 and NH2 on Water Ice Surfaces. A Comprehensive Accurate Quantum Chemistry Study
• Aromatics and Cyclic Molecules in Molecular Clouds: A New Dimension of Interstellar Organic Chemistry
• The organic chemistry in the innermost, infalling envelope of the Class 0 protostar L483
• Infrared spectra of complex organic molecules in astronomically relevant ice matrices. I. Acetaldehyde, ethanol, and dimethyl ether
• Precursors of fatty alcohols in the ISM: Discovery of n-propanol
• Sulfur Ice Astrochemistry: A Review of Laboratory Studies
• Search for Interstellar monohydric Thiols
• Prestellar grain-surface origins of deuterated methanol in comet 67P/Churyumov-Gerasimenko
• Formation of interstellar propanal and 1-propanol ice: a pathway involving solid-state CO hydrogenation
• ATOMS: ALMA Three-millimeter Observations of Massive Star-forming regions -- VIII. A search for hot cores by using C${}_2$H${}_5$CN, CH${}_3$OCHO and CH${}_3$OH lines
• Chemical modeling for predicting the abundances of certain aldimines and amines in hot cores
• Molecular ion abundances in the diffuse ISM : CF+, HCO+, HOC+, and C3H+
• Complex organic molecules in diffuse clouds along the line of sight to Sgr B2
• ALMA Survey of Orion Planck Galactic Cold Clumps (ALMASOP): A Hot Corino Survey toward Protostellar Cores in the Orion Cloud
• Interstellar detection and chemical modeling of iso-propanol and its normal isomer
• From interstellar carbon monosulfide to methyl mercaptan: paths of least resistance
• Resolving desorption of complex organic molecules in a hot core: Transition from non-thermal to thermal desorption or two-step thermal desorption?
• The prebiotic molecular inventory of Serpens SMM1 I. An investigation of the isomers CH${}_3$NCO and HOCH${}_2$CN
• Exploring molecular complexity with ALMA (EMoCA): Complex isocyanides in Sgr B2(N)
• Detection of ethanol, acetone, and propanal in TMC-1: New O-bearing complex organics in cold sources
• Importance of source structure on complex organics emission. I. Observations of CH${}_3$OH from low-mass to high-mass protostars
• Methanol deuteration in high-mass protostars
• Sulphur and carbon isotopes towards Galactic centre clouds
• Protostellar Interferometric Line Survey of the Cygnus X region (PILS-Cygnus) -- First results: observations of CygX-N30
• Sulphur-rich cold gas around the hot core precursor G328.2551-0.5321. An APEX unbiased spectral survey of the 2 mm, 1.2 mm, and 0.8 mm atmospheric windows
• Qualitative observation of reversible phase change in astrochemical ethanethiol ices using infrared spectroscopy
• Identification of Methyl Isocyanate and Other Complex Organic Molecules in a Hot Molecular Core, G31.41+0.31
• Complex organic molecules detected in twelve high-mass star-forming regions with Atacama Large Millimeter/submillimeter Array (ALMA)
• Submillimeter spectroscopy and astronomical searches of vinyl mercaptan, C${}_2$H${}_3$SH
• Rotational spectroscopy of methyl mercaptan CH${}_3$${}^{32}$SH at millimeter and submillimeter wavelengths
• A Centimeter-wave Study of Methanol and Ammonia Isotopologues in Sgr B2(N): Physical and chemical differentiation between two hot cores
• Spectroscopic study and astronomical detection of doubly 13C-substituted ethyl cyanide
• Laboratory rotational spectroscopy of isotopic acetone, CH${}_3^{13}$C(O)CH${}_3$ and ${}^{13}$CH${}_3$C(O)CH${}_3$, and astronomical search in Sagittarius B2(N2)
• Interstellar glycolamide: A comprehensive rotational study and an astronomical search in Sgr B2(N)
• Millimeter and Submillimeter Wave Spectroscopy of Propanal
• Laboratory spectroscopic study and astronomical detection of vibrationally excited n-propyl cyanide
• Rotational and rovibrational spectroscopy of CD${}_3$OH with an account of CD${}_3$OH toward IRAS 16293$-$2422
• Millimeter- and submillimeter-wave spectroscopy of thioformamide and interstellar search toward Sgr B2(N)
• Toward a global model of the interactions in low-lying states of methyl cyanide: rotational and rovibrational spectroscopy of the $v_4=1$ state and tentative interstellar detection of the $v_4=v_8=1$ state in Sgr B2(N)
• Rotational spectroscopy of isotopic oxirane, $c$-C${}_2$H${}_4$O
• A deep search for large complex organic species toward IRAS16293-2422 B at 3 mm with ALMA
• Rotational spectra of isotopic species of methyl cyanide, CH${}_3$CN, in their $v_8=1$ excited vibrational states
• Reexploring Molecular Complexity with ALMA: Insights into chemical differentiation from the molecular composition of hot cores in Sgr B2(N2)
• PRODIGE -- Envelope to Disk with NOEMA III. The origin of complex organic molecule emission in SVS13A
• Rotational spectroscopy of isotopic cyclopropenone, $c$-H${}_2$C${}_3$O, and determination of its equilibrium structure
• SO2 and OCS toward high-mass protostars: A comparative study between ice and gas
• Deuterated methyl mercaptan (CH${}_3$SD): Laboratory rotational spectroscopy and search toward IRAS 16293-2422 B
• Formation of carbonyl sulfide (OCS) via SH radicals in interstellar CO-rich ice under dense cloud conditions
• Expanding the submillimeter wave spectroscopy and astronomical search for thioacetamide (CH3CSNH2) in the ISM
• The rotation-tunneling spectrum of 3-hydroxypropenal and confirmation of its detection toward IRAS 16293$-$2422 B
• Rotational spectrum of isotopic methyl mercaptan, (13)CH3SH, in the laboratory and towards Sagittarius B2(N2)
• Laboratory spectroscopic study of the ${}^{15}$N isotopomers of cyanamide, H${}_2$NCN, and a search for them toward IRAS 16293$-$2422 B
• The salty emission of the intermediate-mass AGB star OH 30.1 -0.7
• Rotation-tunneling spectrum and astrochemical modeling of dimethylamine, CH${}_3$NHCH${}_3$, and searches for it in space
• Rotational spectroscopy of isotopic species of methyl mercaptan at millimeter and submillimeter wavelengths: CH${}_3$${}^{34}$SH
• Rotational spectroscopy of singly ${}^{13}$C substituted isotopomers of propyne and determination of a semi-empirical equilibrium structure
• Millimeter-wave spectroscopy of the ${}^{13}$CH${}_3$OD isotopic species of methyl alcohol
• (Sub-)millimeter-wave spectroscopy of gauche-propanal
• The hot corino-like chemistry of four FUor-like protostars
• Investigation of the rotational spectrum of CH${}_3$${}^{17}$OH and its tentative detection toward Sagittarius B2(N)
• Molecular line ratio diagnostics and gas kinematics in the AGN host Seyfert galaxy NGC 5033
• ATOMS: ALMA Three-millimeter Observations of Massive Star-forming regions -- X. Chemical differentiation among the massive cores in G9.62+0.19
• Rotational Spectroscopy as a Tool to Study Vibration-Rotation Interaction: Investigations of ${}^{13}$CH${}_3$CN and CH${}_3$${}^{13}$CN up to $v_8=2$ and a Search for $v_8=2$ Transitions toward Sagittarius B2(N)