Herschel observations of EXtraordinary Sources: Analysis of the full Herschel/HIFI molecular line survey of Sagittarius B2(N)

Abstract

A sensitive broadband molecular line survey of the Sagittarius B2(N) star-forming region has been obtained with the HIFI instrument on the Herschel Space Observatory, offering the first high-spectral resolution look at this well-studied source in a wavelength region largely inaccessible from the ground (625-157 um). From the roughly 8,000 spectral features in the survey, a total of 72 isotopologues arising from 44 different molecules have been identified, ranging from light hydrides to complex organics, and arising from a variety of environments from cold and diffuse to hot and dense gas. We present an LTE model to the spectral signatures of each molecule, constraining the source sizes for hot core species with complementary SMA interferometric observations, and assuming that molecules with related functional group composition are cospatial. For each molecule, a single model is given to fit all of the emission and absorption features of that species across the entire 480-1910 GHz spectral range, accounting for multiple temperature and velocity components when needed to describe the spectrum. As with other HIFI surveys toward massive star forming regions, methanol is found to contribute more integrated line intensity to the spectrum than any other species. We discuss the molecular abundances derived for the hot core, where the local thermodynamic equilibrium approximation is generally found to describe the spectrum well, in comparison to abundances derived for the same molecules in the Orion KL region from a similar HIFI survey.

Accepted to ApJ. 64 pages, 14 figures. Truncated abstract

References in corpus (11)

• Complex Chemistry in Star-Forming Regions: An Expanded Gas-Grain Warm-up Chemical Model
• Formation of methyl formate and other organic species in the warm-up phase of hot molecular cores
• The largest oxigen bearing organic molecule repository
• Low sulfur depletion in the Horsehead PDR
• Herschel observations of EXtra-Ordinary Sources: Analysis of the HIFI 1.2 THz Wide Spectral Survey Toward Orion KL I. Methods
• Detection of E-cyanomethanimine towards Sagittarius B2(N) in the Green Bank Telescope PRIMOS Survey
• Organic Molecules in the Galactic Center. Hot Core Chemistry without Hot Cores
• APEX mapping of H3O+ in the Sgr B2 region
• The ISO LWS high resolution spectral survey towards Sagittarius B2
• Non-Thermal Continuum toward SGRB2(N-LMH)
• Gas-phase CO2 emission toward Cepheus A East: the result of shock activity?

Cited by in corpus (27)

• 2021 Census of Interstellar, Circumstellar, Extragalactic, Protoplanetary Disk, and Exoplanetary Molecules
• Constraining the abundances of complex organics in the inner regions of solar-type protostars
• Complex organic molecules in low-mass protostars on solar system scales -- I. Oxygen-bearing species
• Interstellar formamide (NH${}_2$CHO), a key prebiotic precursor
• Investigating the Minimum Energy Principle in Searches for New Molecular Species - the Case of H${}_2$C${}_3$O Isomers
• Methylamine and other simple N-bearing species in the hot cores NGC 6334I MM1-3
• N-bearing complex organics toward high-mass protostars: Constant ratios pointing to formation in similar pre-stellar conditions across a large mass range
• Detection of Interstellar HC${}_5$O in TMC-1 with the Green Bank Telescope
• 13C-methyl formate: observations of a sample of high mass star-forming regions including Orion-KL and spectroscopic characterization
• 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
• First detection of 13CH in the interstellar medium
• SMA Observations of W3(OH) Complex: Physical and Chemical Differentiation between W3(H${}_2$O) and W3(OH)
• Evolution of complex organic molecules in hot molecular cores: Synthetic spectra at (sub-)mm wavebands
• Terahertz spectroscopy of N${}^{18}$O and isotopic invariant fit of several nitric oxide isotopologs
• Submillimeter imaging of the Galactic Center starburst Sgr B2. Warm molecular, atomic, and ionized gas far from massive star-forming cores
• Small-scale physical and chemical structure of diffuse and translucent molecular clouds along the line of sight to Sgr B2
• Formation of the simplest amide in molecular clouds: formamide (NH${}_2$CHO) and its derivatives in H${}_2$O-rich and CO-rich interstellar ice analogs upon VUV irradiation
• Search for methylamine in high mass hot cores
• Evidence for ubiquitous carbon grain destruction in hot protostellar envelopes
• Sulfur-bearing species in molecular clouds
• Herschel observations of extraordinary sources: Full Herschel/HIFI molecular line survey of Sagittarius B2(M)
• The CH radical at radio wavelengths: Revisiting emission in the 3.3GHz ground state lines
• The Opaque Heart of the Galaxy IC 860: Analogous Protostellar, Kinematics, Morphology, and Chemistry
• The physical and chemical structure of Sagittarius B2 VIIIa. Dust and ionized gas contributions to the full molecular line survey of 47 hot cores
• The physical and chemical structure of Sagittarius B2, VIII. Full molecular line survey of hot cores
• An ALCHEMI inspection of sulphur-bearing species towards the central molecular zone of NGC 253
• Investigation of the rotational spectrum of CH${}_3$${}^{17}$OH and its tentative detection toward Sagittarius B2(N)