The magnetic field in the Flame nebula

Abstract

Star formation is essential in galaxy evolution and the cycling of matter. The support of interstellar clouds against gravitational collapse by magnetic (B-) fields has been proposed to explain the low observed star formation efficiency in galaxies and the Milky Way. Despite the Planck satellite providing a 5-15' all-sky map of the B-field geometry in the diffuse interstellar medium, higher spatial resolution observations are required to understand the transition from diffuse gas to gravitationally unstable filaments. NGC 2024, the Flame Nebula, in the nearby Orion B molecular cloud, contains a young, expanding HII region and a dense filament that harbors embedded protostellar objects. Therefore, NGC 2024 is an excellent opportunity to study the role of B-fields in the formation, evolution, and collapse of filaments, as well as the dynamics and effects of young HII regions on the surrounding molecular gas. We combine new 154 and 216 micron dust polarization measurements carried out using the HAWC+ instrument aboard SOFIA with molecular line observations of 12CN(1-0) and HCO+(1-0) from the IRAM 30-meter telescope to determine the B-field geometry and to estimate the plane of the sky magnetic field strength across the NGC 2024. The HAWC+ observations show an ordered B-field geometry in NGC 2024 that follows the morphology of the expanding HII region and the direction of the main filament. The derived plane of the sky B-field strength is moderate, ranging from 30 to 80 micro G. The strongest B-field is found at the northern-west edge of the HII region, characterized by the highest gas densities and molecular line widths. In contrast, the weakest field is found toward the filament in NGC 2024. The B-field has a non-negligible influence on the gas stability at the edges of the expanding HII shell (gas impacted by the stellar feedback) and the filament (site of the current star formation).

36 pages, 26 figures Accepted for publication in Astronomy & Astrophysics

References in corpus (107)

• Herschel Space Observatory - An ESA facility for far-infrared and submillimetre astronomy
• The CO-to-H2 Conversion Factor
• The Star Formation Efficiency in Nearby Galaxies: Measuring Where Gas Forms Stars Effectively
• The Star Formation Law in Nearby Galaxies on Sub-Kpc Scales
• Control of star formation by supersonic turbulence
• The IRAS Revised Bright Galaxy Sample (RBGS)
• A General Theory of Turbulence-Regulated Star Formation, From Spirals to ULIRGs
• Radiation Pressure Supported Starburst Disks and AGN Fueling
• The Star Formation Rate of Turbulent Magnetized Clouds: Comparing Theory, Simulations, and Observations
• Absorption-Line Probes of Gas and Dust in Galactic Superwinds
• Combined CO & Dust Scaling Relations of Depletion Time and Molecular Gas Fractions with Cosmic Time, Specific Star Formation Rate and Stellar Mass
• The CO-to-H2 Conversion Factor and Dust-to-Gas Ratio on Kiloparsec Scales in Nearby Galaxies
• Massive molecular outflows and negative feedback in ULIRGs observed by Herschel-PACS
• A Molecular Star Formation Law in the Atomic Gas Dominated Regime in Nearby Galaxies
• xCOLD GASS: the complete IRAM-30m legacy survey of molecular gas for galaxy evolution studies
• The Critical Density and the Effective Excitation Density of Commonly Observed Molecular Dense Gas Tracers
• HCN Survey of Normal Spiral, IR-luminous and Ultraluminous Galaxies
• The Star Formation Rate of Supersonic MHD Turbulence
• Common-Resolution Convolution Kernels for Space- and Ground-Based Telescopes
• KINGFISH -- Key Insights on Nearby Galaxies: A Far-Infrared Survey with Herschel: Survey Description and Image Atlas
• On the Star Formation Efficiency of Turbulent Magnetized Clouds
• Variations in the Galactic star formation rate and density thresholds for star formation
• Star Formation Rates in Molecular Clouds and the Nature of the Extragalactic Scaling Relations
• What controls star formation in the central 500 pc of the Galaxy?
• A multi-transition HCN and HCO+ study of 12 nearby active galaxies: AGN versus SB environments
• Cloud-Scale Molecular Gas Properties in 15 Nearby Galaxies
• The Properties of Massive, Dense, Clumps: Mapping Surveys of HCN and CS
• Molecular gas kinematics within the central 250 pc of the Milky Way
• Chandra observations of NGC 253. II: On the origin of diffuse X-ray emission in the halos of starburst galaxies
• A 2 mm spectral line survey of the starburst galaxy NGC 253
• ALMA Reveals the Molecular Medium Fueling the Nearest Nuclear Starburst
• Chandra observations of NGC 253: New insights into the nature of starburst-driven superwinds
• A CS J=5-4 Mapping Survey Towards High-mass Star Forming Cores Associated with Water Masers
• The anatomy of the Orion B Giant Molecular Cloud: A local template for studies of nearby galaxies
• Distances to PHANGS Galaxies: New Tip of the Red Giant Branch Measurements and Adopted Distances
• Star formation laws in Luminous Infrared Galaxies. New observational constraints on models
• Star formation rates and efficiencies in the Galactic Centre
• PHANGS-ALMA Data Processing and Pipeline
• Variations in the Star Formation Efficiency of the Dense Molecular Gas across the Disks of Star-Forming Galaxies
• Cloud Scale ISM Structure and Star Formation in M51
• Molecular Gas Properties on Cloud Scales Across the Local Star-forming Galaxy Population
• Stellar structures, molecular gas, and star formation across the PHANGS sample of nearby galaxies
• Effective destruction of CO by cosmic rays: implications for tracing H${}_2$ gas in the Universe
• Calibration of the total infrared luminosity of nearby galaxies from Spitzer and Herschel bands
• EMPIRE: The IRAM 30-m Dense Gas Survey of Nearby Galaxies
• The EMPIRE Survey: Systematic Variations in the Dense Gas Fraction and Star Formation Efficiency from Full-Disk Mapping of M51
• Molecular Line Emission as a Tool for Galaxy Observations (LEGO). I. HCN as a tracer of moderate gas densities in molecular clouds and galaxies
• New Constraints on the ${}^{12}$CO(2-1)/(1-0) Line Ratio Across Nearby Disc Galaxies
• Enhanced Dense Gas Fraction in Ultra-Luminous Infrared Galaxies
• Molecular Cloud Structure in the Magellanic Clouds: Effect of Metallicity
• Gas flow in barred potentials
• ALMA Multi-line Imaging of the Nearby Starburst Galaxy NGC 253
• HCN Observations of Dense Star-Forming Gas in High Redshift Galaxies
• Dense Molecular Gas Tracers in the Outflow of the Starburst Galaxy NGC 253
• Non-universal star formation efficiency in turbulent ISM
• Catalogue of the morphological features in the Spitzer Survey of Stellar Structure in Galaxies (S${}^4$G)
• Low-J CO Line Ratios From Single Dish CO Mapping Surveys and PHANGS-ALMA
• The molecular gas reservoir of 6 low-metallicity galaxies from the Herschel Dwarf Galaxy Survey: A ground-based follow-up survey of CO(1-0), CO(2-1), and CO(3-2)
• 'The Brick' is not a brick: A comprehensive study of the structure and dynamics of the Central Molecular Zone cloud G0.253+0.016
• Forming Super Star Clusters in the Central Starburst of NGC 253
• Heart of Darkness: the influence of galactic dynamics on quenching star formation in galaxy spheroids
• Spatially resolved optical IFU spectroscopy of the inner superwind of NGC 253
• A Model for the Onset of Self-gravitation and Star Formation in Molecular Gas Governed by Galactic Forces: I. Cloud-scale Gas Motions
• Star Formation Laws and Efficiencies across 80 Nearby Galaxies
• The Survey of Water and Ammonia in the Galactic Center (SWAG): Molecular Cloud Evolution in the Central Molecular Zone
• Dense Gas, Dynamical Equilibrium Pressure, and Star Formation in Nearby Star-Forming Galaxies
• Excitation Mechanisms for HCN (1-0) and HCO+ (1-0) in Galaxies from the Great Observatories All-sky LIRG Survey
• The Atlas3D Project -- XI. Dense molecular gas properties of CO-luminous early-type galaxies
• Millimeter-Wave Line Ratios and Sub-beam Volume Density Distributions
• Warm Molecular Hydrogen in the Galactic Wind of M82
• ALCHEMI: an ALMA Comprehensive High-resolution Extragalactic Molecular Inventory. Survey presentation and first results from the ACA array
• New insights on the dense molecular gas in NGC253 as traced by HCN and HCO+
• Dense gas is not enough: environmental variations in the star formation efficiency of dense molecular gas at 100pc scales in M51
• HCN and HCO+ emission in the disk of M31
• CO Multi-line Imaging of Nearby Galaxies (COMING). IX. ${}^{12}$CO($J$=2-1)/${}^{12}$CO($J$=1-0) line ratio on kiloparsec scales
• CS, HC3N and CH3CCH multi-line analyses towards starburst galaxies. The evolution of cloud structures in the central regions of galaxies
• The MALATANG Survey: the L_gas-L_IR correlation on sub-kiloparsec scale in six nearby star-forming galaxies as traced by HCN J=4-3 and HCO^+ J=4-3
• Linking Dense Gas from the Milky Way to External Galaxies
• Galactic Bar/Spiral Arm Interactions in NGC3627
• The Structure, Kinematics and Physical Properties of the Molecular Gas in the Starburst Nucleus of NGC 253
• Spatially-Resolved Dense Molecular Gas and Star Formation Rate in M51
• Do Spectroscopic Dense Gas Fractions Track Molecular Cloud Surface Densities?
• Molecular Gas in NUclei of GAlaxies (NUGA) XIV. The barred LINER/Seyfert 2 galaxy NGC 3627
• Outflows from Super Star Clusters in the Central Starburst of NGC253
• The headlight cloud in NGC 628: An extreme giant molecular cloud in a typical galaxy disk
• Dense Gas Fraction and Star Formation Efficiency Variations in the Antennae Galaxies
• The Distribution and Origin of C${}_2$H in NGC 253 from ALCHEMI
• Spatially Resoved 12CO(2-1)/12CO(1-0) in the Starburst Galaxy NGC 253: Assessing Optical Depth to Constrain the Molecular Mass Outflow Rate
• Dense molecular gas properties on 100 pc scales across the disc of NGC 3627
• Dense Gas in M33 (HerM33es)
• The Green Bank Telescope Maps the Dense, Star-Forming Gas in the Nearby Starburst Galaxy M82
• The ALMOND Survey: Molecular cloud properties and gas density tracers across 25 nearby spiral galaxies with ALMA
• X-ray Properties of NGC 253's Starburst-Driven Outflow
• Dense gas in low-metallicity galaxies
• Distribution and Kinematics of Molecular Gas in Barred Spiral Galaxies. I. NGC 3504
• A 2-3 mm high-resolution molecular line survey towards the centre of the nearby spiral galaxy NGC 6946
• Microwave Continuum Emission and Dense Gas Tracers in NGC 3627: Combining Jansky VLA and ALMA Observations
• Spatially resolved star-formation relations of dense molecular gas in NGC 1068
• Deep Hα Observations of NGC 253: a Very Extended and Possibly Declining Rotation Curve?
• The NIR structure of the barred galaxy NGC253 from VISTA
• Dense Gas in the Outer Spiral Arm of M51
• Some like it cold: molecular emission and effective dust temperatures of dense cores in the Pipe Nebula
• The turbulent gas structure in the centers of NGC253 and the Milky Way
• The MALATANG Survey: Dense Gas and Star Formation from High Transition HCN and HCO+ maps of NGC253
• Dense molecular gas in a sample of LIRGs and ULIRGs: The low-redshift connection to the huge high-redshift starbursts and AGNs
• A constant N${}_2$H${}^{+}$(1-0)-to-HCN(1-0) ratio on kiloparsec scales
• The Lyman Alpha Reference Sample XI: Efficient Turbulence Driven Lyα Escape and the Analysis of IR, CO and [C II]158 μm

Cited by in corpus (4)

• Dense gas scaling relations at kiloparsec scales across nearby galaxies with the ALMA ALMOND and IRAM 30m EMPIRE surveys
• A 260 pc resolution ALMA map of HCN(1-0) in the galaxy NGC 4321
• Surveying the Whirlpool at Arcseconds with NOEMA (SWAN) II: Survey design and observations
• Estimating the dense gas mass of molecular clouds using spatially unresolved 3 mm line observations