Distances to Dark Clouds: Comparing Extinction Distances to Maser Parallax Distances

Abstract

We test two different methods of using near-infrared extinction to estimate distances to dark clouds in the first quadrant of the Galaxy using large near infrared (2MASS and UKIDSS) surveys. VLBI parallax measurements of masers around massive young stars provide the most direct and bias-free measurement of the distance to these dark clouds. We compare the extinction distance estimates to these maser parallax distances. We also compare these distances to kinematic distances, including recent re-calibrations of the Galactic rotation curve. The extinction distance methods agree with the maser parallax distances (within the errors) between 66% and 100% of the time (depending on method and input survey) and between 85% and 100% of the time outside of the crowded Galactic center. Although the sample size is small, extinction distance methods reproduce maser parallax distances better than kinematic distances; furthermore, extinction distance methods do not suffer from the kinematic distance ambiguity. This validation gives us confidence that these extinction methods may be extended to additional dark clouds where maser parallaxes are not available.

Accepted to ApJ. 14 pages and 10 figures plus eight additional pages of figures. Full resolution version is available at http://people.bu.edu/jbfoster/papers/Foster_2012_ExtinctionDistances.pdf

References in corpus (12)

• Trigonometric Parallaxes of Massive Star Forming Regions: VI. Galactic Structure, Fundamental Parameters and Non-Circular Motions
• The Boston University-Five College Radio Astronomy Observatory Galactic Ring Survey
• The UKIDSS Galactic Plane Survey
• Kinematic Distances to Molecular Clouds identified in the Galactic Ring Survey
• The Millimeter Astronomy Legacy Team 90 GHz (MALT90) Pilot Survey
• NICEST, a near-infrared color excess method tailored for small-scale structures
• Trigonometric Parallaxes of Massive Star Forming Regions: V. G23.01-0.41 and G23.44-0.18
• Molecular clouds and clumps in the Boston University-Five College Radio Astronomy Observatory Galactic Ring Survey
• Calculation of the Local Standard of Rest from 20,574 Local Stars in the New Hipparcos Reduction with Known Radial Velocities
• Mass reservoirs surrounding massive infrared dark clouds: A view by near-infrared dust extinction
• The nature of the methanol maser ring G23.657-00.127
• Trigonometric Parallaxes of Massive Star-Forming Regions. IX. The Outer Arm in the First Quadrant

Cited by in corpus (30)

• The Dynamics of Massive Starless Cores with ALMA
• High-dynamic-range extinction mapping of infrared dark clouds: Dependence of density variance with sonic Mach number in molecular clouds
• The Bones of the Milky Way
• The Bolocam Galactic Plane Survey. VIII. A Mid-Infrared Kinematic Distance Discrimination Method
• Magnetic Fields in Massive Star-Forming Regions (MagMaR) I. Linear Polarized Imaging of the UCHII Region G5.89-0.39
• ALMA Observations of the IRDC Clump G34.43+00.24 MM3: Hot Core and Molecular Outflows
• Properties of Star Clusters - I: Automatic Distance and Extinction Estimates
• YSO jets in the Galactic Plane from UWISH2: II - Outflow Luminosity and Length distributions in Serpens and Aquila
• Distances to the Supernova Remnants in the Inner Disk
• The Giant Molecular Cloud Environments of Infrared Dark Clouds
• Asymmetric Line Profiles in Dense Molecular Clumps Observed in MALT90: Evidence for Global Collapse
• Physical Conditions of the Earliest Phases of Massive Star Formation: Single-Dish and Interferometric Observations of Ammonia and CCS in Infrared Dark Clouds
• Gas Kinematics and Star Formation in the Filamentary IRDC G34.43+0.24
• The Massive Star-Forming Regions Omnibus X-Ray Catalog, Second Installment
• Into the Darkness: Classical and Type II Cepheids in the Zona Galactica Incognita
• Molecular cloud distances based on the MWISP CO survey and Gaia DR2
• ALMA Observations of the IRDC Clump G34.43+00.24 MM3: 278 GHz Class I Methanol Masers
• ALMA Observations of the IRDC Clump G34.43+00.24 MM3: Complex Organic and Deuterated Molecules
• Confirming the Explosive Outflow in G5.89 with ALMA
• Similar complex kinematics within two massive, filamentary infrared dark clouds
• Mid-J CO shock tracing observations of infrared dark clouds II Low-J CO constraints on excitation, depletion, and kinematics
• ALMA Observations of the IRDC Clump G34.43+00.24 MM3: DNC/HNC Ratio
• Distances to nearby molecular clouds traced by young stars
• Influence of Wolf-Rayet stars on surrounding star-forming molecular clouds
• Mid-J CO Shock Tracing Observations of Infrared Dark Clouds I
• Physical Properties of Galactic Planck Cold Cores revealed by the Hi-GAL survey
• Molecular Clouds: Internal Properties, Turbulence, Star Formation and Feedback
• New eruptive variable in the massive star-forming region associated with IRAS 18507+0121 source
• G337.342-0.119 (the "Pebble"): A Cold, Dense, High-Mass Molecular Cloud with Unusually Large Linewidths and a Candidate High-Mass Star Cluster Progenitor
• An X-ray View of Two Infrared Dark Clouds G034.43+00.24 and G035.39-00.33