The Evolutionary Status of Protostellar Clumps Hosting Class II Methanol Masers

Abstract

The Methanol MultiBeam survey (MMB) provides the most complete sample of Galactic massive young stellar objects (MYSOs) hosting 6.7GHz class II methanol masers. We characterise the properties of these maser sources using dust emission detected by the Herschel Infrared Galactic Plane Survey (Hi-GAL) to assess their evolutionary state. Associating 731 (73%) of MMB sources with compact emission at four Hi-GAL wavelengths, we derive clump properties and define the requirements of a MYSO to host a 6.7GHz maser. The median far-infrared (FIR) mass and luminosity are 630M${}_{\odot }$ and 2500L${}_{\odot }$ for sources on the near side of Galactic centre and 3200M${}_{\odot }$ and 10000L${}_{\odot }$ for more distant sources. The median luminosity-to-mass ratio is similar for both at $\sim$4.2L${}_{\odot }/$M${}_{\odot }$. We identify an apparent minimum 70$\mu$m luminosity required to sustain a methanol maser of a given luminosity (with $L_{70}\propto L_{6.7}^{0.6}$). The maser host clumps have higher mass and higher FIR luminosities than the general Galactic population of protostellar MYSOs. Using principal component analysis, we find 896 protostellar clumps satisfy the requirements to host a methanol maser but lack a detection in the MMB. Finding a 70$\mu$m flux density deficiency in these objects, we favour the scenario in which these objects are evolved beyond the age where a luminous 6.7GHz maser can be sustained. Finally, segregation by association with secondary maser species identifies evolutionary differences within the population of 6.7GHz sources.

arXiv commentAccepted for publication in MNRAS, 30 pages, 28 figures + 2 appendices (2 pages, 3 figures)

References in corpus (73)

• The Wide-field Infrared Survey Explorer (WISE): Mission Description and Initial On-orbit Performance
• Embedded Clusters in Molecular Clouds
• GLIMPSE: I. A SIRTF Legacy Project to Map the Inner Galaxy
• Toward Understanding Massive Star Formation
• Preliminary Results from NEOWISE: An Enhancement to the Wide-field Infrared Survey Explorer for Solar System Science
• Clouds, filaments and protostars: the Herschel Hi-GAL Milky Way
• Hi-GAL: the Herschel infrared Galactic Plane Survey
• A Catalog of Extended Green Objects (EGOs) in the GLIMPSE Survey: A new sample of massive young stellar object outflow candidates
• ATLASGAL --- properties of a complete sample of Galactic clumps
• A Minimum Column Density of 1 g cm^-2 for Massive Star Formation
• The Big Problems in Star Formation: the Star Formation Rate, Stellar Clustering, and the Initial Mass Function
• Identifying the Low Luminosity Population of Embedded Protostars in the c2d Observations of Clouds and Cores
• Line-driven winds, ionizing fluxes and UV-spectra of hot stars at extremely low metallicity. I. Very massive O-stars
• A Parallax-based Distance Estimator for Spiral Arm Sources
• The 6-GHz methanol multibeam maser catalogue I: Galactic Centre region, longitudes 345 to 6
• Hi-GAL, the Herschel infrared Galactic Plane Survey: photometric maps and compact source catalogues. First data release for Inner Milky Way: +68°> l > -70°
• A Spitzer Space Telescope Infrared Survey of Supernova Remnants in the Inner Galaxy
• A Class I and Class II Methanol Maser Survey of Extended Green Objects (EGOs) from the GLIMPSE Survey
• How Many Infrared Dark Clouds can form Massive Stars and Clusters?
• Properties of Hi-GAL clumps in the inner Galaxy]{The Hi-GAL compact source catalogue. I. The physical properties of the clumps in the inner Galaxy ($-71.0^{\circ }<\ell <67.0^{\circ }$)
• Methanol masers : Reliable tracers of the early stages of high-mass star formation
• The H_2O southern Galactic Plane Survey (HOPS): I. Techniques and H_2O maser data
• Mid-Infrared Extinction Mapping of Infrared Dark Clouds II. The Structure of Massive Starless Cores and Clumps
• The 6-GHz Multibeam Maser Survey I. Techniques
• 12.2-GHz methanol masers associated with 1.2-mm dust clumps: Quantifying high-mass star formation evolutionary schemes
• The 6-GHz methanol multibeam maser catalogue II: Galactic longitudes 6 to 20
• Source extraction and photometry for the far-infrared and sub-millimeter continuum in the presence of complex backgrounds
• The 6-GHz methanol multibeam maser catalogue IV: Galactic longitudes 186 to 330 including the Orion-Monoceros region
• The data reduction pipeline for the Hi-GAL survey
• Confirmation of the exclusive association between 6.7-GHz methanol masers and high-mass star formation regions
• A 24 Micron Point Source Catalog of the Galactic Plane from Spitzer/MIPSGAL
• Far-Infrared Dust Temperatures and Column Densities of the MALT90 Molecular Clump Sample
• The first Hi-GAL observations of the outer Galaxy: a look to star formation in the third Galactic quadrant in the longitude range 216.5 < l < 225.5
• The Herschel view of massive star formation in G035.39--00.33: Dense and cold filament of W48 undergoing a mini-starburst
• The Bolocam Galactic Plane Survey. XIV. Physical Properties of Massive Starless and Star Forming Clumps
• The Mass-Size Relation from Clouds to Cores. I. A new Probe of Structure in Molecular Clouds
• The Arecibo Methanol Maser Galactic Plane Survey--I: Data
• The diversity of methanol maser morphologies from VLBI observations
• Bipolar Molecular Outflows and Hot Cores in GLIMPSE Extended Green Objects (EGOs)
• Massive Star Formation
• Accurate water maser positions from HOPS
• Direct Spectroscopic Identification of the Origin of 'Green Fuzzy' Emission in Star Forming Regions
• Galactic cold cores VI. Dust opacity spectral index
• Calibration of evolutionary diagnostics in high-mass star formation
• H2O Maser Observations of Candidate Post-AGB Stars and Discovery of Three High-velocity Water Sources
• Multi-transition study and new detections of class II methanol masers
• Massive 70 micron quiet clumps II: non-thermal motions driven by gravity in massive star formation?
• The almost ubiquitous association of 6.7 GHz methanol masers with dust
• A GLIMPSE-based search for 6.7-GHz Methanol Masers and the lifetime of their spectral features
• SPLASH: The Southern Parkes Large-Area Survey in Hydroxyl - First Science from the Pilot Region
• The Arecibo Methanol Maser Galactic Plane Survey-IV: Accurate Astrometry and Source Morphologies
• Observations of 6.7 GHz Methanol Masers with EAVN I: VLBI Images of the first Epoch of Observations
• Investigating high-mass star formation through maser surveys
• 12.2-GHz methanol maser MMB follow-up catalogue - I. Longitude range 330 to 10 degrees
• Massive 70 micron quiet clumps I: evidence of embedded low/intermediate-mass star formation activity
• Planar infall of CH3OH gas around Cepheus A HW2
• European VLBI Network imaging of 6.7 GHz methanol masers
• Excited-state hydroxyl maser catalogue from the methanol multibeam survey -- I. Positions and Variability
• Herschel and SCUBA-2 observations of dust emission in a sample of Planck cold clumps
• A search for water masers associated with class II methanol masers - II. Longitude range 341${}^{\circ }$ to 6${}^{\circ }$
• 12.2-GHz methanol maser MMB follow-up catalogue - II. Longitude range 186 to 330 degrees
• A search for water masers associated with class II methanol masers - I. Longitude range 6 to 20 degrees
• Accurate OH maser positions from the SPLASH pilot region
• EVN observations of 6.7 GHz methanol masers in clusters of massive young stellar objects
• 12.2-GHz methanol maser MMB follow-up catalogue - III. Longitude range 10 to 20 degrees
• ATLASGAL -- physical parameters of dust clumps associated with 6.7 GHz methanol masers
• Tightening the belt: Constraining the mass and evolution in SDC335
• Accurate OH maser positions II. the Galactic Center region
• The 6-GHz multibeam maser survey III: comparison between the MMB and HOPS
• Revising the kinematics of 12GHz CH3OH masers in W3(OH)
• The mid-infrared environments of 6.7 GHz Methanol Masers from the Methanol Multi-Beam Survey
• Maser maps and magnetic field of OH 300.969+1.147
• EVLA Observations of OH Masers in ON 1

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• ATLASGAL -- Relationship between dense star forming clumps and interstellar masers
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• WISE Green Objects (WGOs): the massive star candidates in the whole Galactic Plane ($\mid b\mid <2^{\circ }$)
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