Far-infrared molecular lines from Low- to High-Mass Star Forming Regions observed with Herschel

Abstract

(Abridged) We study the response of the gas to energetic processes associated with high-mass star formation and compare it with studies on low- and intermediate-mass young stellar objects (YSOs) using the same methods. The far-IR line emission and absorption of CO, H${}_2$O, OH, and [OI] reveals the excitation and the relative contribution of different species to the gas cooling budget. Herschel-PACS spectra covering 55-190 um are analyzed for ten high-mass star forming regions of various luminosities and evolutionary stages at spatial scales of ~10^4 AU. Radiative transfer models are used to determine the contribution of the envelope to the far-IR CO emission. The close environments of high-mass YSOs show strong far-IR emission from molecules, atoms, and ions. Water is detected in all 10 objects even up to high excitation lines. CO lines from J=14-13 up to typically 29-28 show a single temperature component, Trot~300 K. Typical H${}_2$O temperatures are Trot~250 K, while OH has Trot~80 K. Far-IR line cooling is dominated by CO (~75 %) and to a smaller extent by OI (~20 %), which increases for the most evolved sources. H${}_2$O is less important as a coolant for high-mass sources because many lines are in absorption. Emission from the envelope is responsible for ~45-85 % of the total CO luminosity in high-mass sources compared with only ~10 % for low-mass YSOs. The highest-J lines originate most likely from shocks, based on the strong correlation of CO and H${}_2$O with physical parameters of the sources from low- to high-masses. Excitation of warm CO is very similar for all mass regimes, whereas H${}_2$O temperatures are ~100 K higher for high-mass sources than the low-mass YSOs. Molecular cooling is ~4 times more important than cooling by [OI]. The total far-IR line luminosity is about 10${}^{-3}$ and 10${}^{-5}$ times lower than the dust luminosity for the low- and high-mass YSOs.

23 pages, 19 figures, 6 Tables. Accepted to Astronomy and Astrophysics

References in corpus (38)

• Herschel Space Observatory - An ESA facility for far-infrared and submillimetre astronomy
• The Photodetector Array Camera and Spectrometer (PACS) on the Herschel Space Observatory
• A computer program for fast non-LTE analysis of interstellar line spectra
• An atomic and molecular database for analysis of submillimetre line observations
• Toward Understanding Massive Star Formation
• Structure and Evolution of the Envelopes of Deeply Embedded Massive Young Stars
• ISO spectroscopy of gas and dust: from molecular clouds to protoplanetary disks
• Tracing the Mass during Low-Mass Star Formation. I. Submillimeter Continuum Observations
• Water in star-forming regions with Herschel (WISH): II. Evolution of 557 GHz 110-101 emission in low-mass protostars
• Water in Star-Forming Regions with the Herschel Space Observatory (WISH): Overview of key program and first results
• HYPERION: An open-source parallelized three-dimensional dust continuum radiative transfer code
• Mid-Infrared line diagnostics of Active Galaxies -- A spectroscopic AGN survey with ISO-SWS
• Embedded Protostars in the Dust, Ice, and Gas In Time (DIGIT) Key Program: Continuum SEDs, and an Inventory of Characteristic Far-Infrared Lines from PACS Spectroscopy
• Modelling Herschel observations of hot molecular gas emission from embedded low-mass protostars
• Models for Dense Molecular Cloud Cores
• Origin of the hot gas in low-mass protostars: Herschel-PACS spectroscopy of HH 46
• APEX-CHAMP+ high-J CO observations of low-mass young stellar objects: III. NGC 1333 IRAS 4A/4B envelope, outflow and UV heating
• Thermal Water Vapor Emission from Shocked Regions in Orion
• Herschel/PACS Spectroscopic Survey of Protostars in Orion: The Origin of Far-Infrared CO Emission
• APEX-CHAMP+ high-J CO observations of low-mass young stellar objects: I. The HH 46 envelope and outflow
• The complete far-infrared and submillimeter spectrum of the Class 0 protostar Serpens SMM1 obtained with Herschel. Characterizing UV-irradiated shocks heating and chemistry
• Water in star-forming regions with Herschel: highly excited molecular emission from the NGC 1333 IRAS 4B outflow
• High-J CO survey of low-mass protostars observed with Herschel-HIFI
• Water in star-forming regions with Herschel (WISH). IV. A survey of low-J H2O line profiles toward high-mass protostars
• Water in massive star-forming regions: HIFI observations of W3 IRS5
• Disks and Outflows in CO Rovibrational Emission from Embedded, Low-Mass Young Stellar Objects
• Collisional excitation of far-infrared line emissions from warm interstellar carbon monoxide (CO)
• Herschel-HIFI observations of high-J CO lines in the NGC 1333 low-mass star-forming region
• OH far-infrared emission from low- and intermediate-mass protostars surveyed with Herschel-PACS
• Herschel-HIFI observations of high-J CO and isotopologues in star-forming regions: from low- to high-mass
• Far-IR Excited OH Lines from Orion KL Outflows
• The Water Vapor Abundance in Orion KL Outflows
• Herschel-PACS spectroscopy of the intermediate mass protostar NGC7129 FIRS 2
• Revealing the environs of the remarkable southern hot core G327.3-0.6
• L1448-MM observations by the Herschel Key program, "Dust, Ice, and Gas In Time" (DIGIT)
• Extended Far-Infrared CO Emission in the Orion OMC-1 Core
• The HIFI spectral survey of AFGL2591 (CHESS). I. Highly excited linear rotor molecules in the high-mass protostellar envelope
• The distribution of warm gas in the G327.3--0.6 massive star-forming region

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