Ian Stephens
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View article: FIELDMAPS Data Release: Far-infrared Polarization in the “Bones” of the Milky Way
FIELDMAPS Data Release: Far-infrared Polarization in the “Bones” of the Milky Way Open
Polarization observations of the Milky Way and many other spiral galaxies have found a close correspondence between the orientation of spiral arms and magnetic field lines on scales of hundreds of parsecs. This paper presents polarization …
View article: Magnetic Fields in the Bones of the Milky Way
Magnetic Fields in the Bones of the Milky Way Open
Stars primarily form in galactic spiral arms within dense, filamentary molecular clouds. The largest and most elongated of these molecular clouds are referred to as “bones,” which are massive, velocity-coherent filaments (lengths ∼20 to >1…
View article: The Hourglass-shaped Magnetic Fields and Dust Filaments in the HH 211 Protostellar Envelope
The Hourglass-shaped Magnetic Fields and Dust Filaments in the HH 211 Protostellar Envelope Open
Magnetic fields influence the structure and evolution of protostellar systems; thus, understanding their role is essential for probing the earliest stages of star formation. We present Atacama Large Millimeter/submillimeter Array Band 3 an…
View article: First Results from ALPPS: A Sub-Alfvénic Streamer in SVS 13A
First Results from ALPPS: A Sub-Alfvénic Streamer in SVS 13A Open
We present the first results from the Atacama Large Millimeter/submillimeter Array Perseus Polarization Survey, focusing on the magnetic field in the SVS 13A circumbinary disk. The data set includes full Stokes dust continuum observations …
View article: Magnetic Fields in the Bones of the Milky Way
Magnetic Fields in the Bones of the Milky Way Open
Stars primarily form in galactic spiral arms within dense, filamentary molecular clouds. The largest and most elongated of these molecular clouds are referred to as ``bones," which are massive, velocity-coherent filaments (lengths ~20 to >…
View article: Gravitational Binding and Star Formation in Molecular Clouds of the Milky Way
Gravitational Binding and Star Formation in Molecular Clouds of the Milky Way Open
The gravitational binding and star-forming properties of molecular clouds in the Milky Way (MW) are estimated from CO cloud observations and from a model of pressure-bounded virial equilibrium (PVE). Two CO surveys are analyzed with the st…
View article: First results from ALPPS: a sub-Alfvénic streamer in SVS13A
First results from ALPPS: a sub-Alfvénic streamer in SVS13A Open
We present the first results from the ALMA Perseus Polarization Survey (ALPPS), focusing on the magnetic field in the SVS13A circumbinary disk. The dataset includes full-Stokes dust continuum observations at $\sim0\farcs3$ and 870 $μ$m, as…
View article: Gravitational Binding and Star Formation in Molecular Clouds of the Milky Way
Gravitational Binding and Star Formation in Molecular Clouds of the Milky Way Open
The gravitational binding and star-forming properties of molecular clouds (MCs) in the Milky Way (MW) are estimated from CO cloud observations and from a model of pressure-bounded virial equilibrium (PVE). Two CO surveys are analyzed with …
View article: Detailed radial scale height profile of dust grains as probed by dust self-scattering in HL Tau
Detailed radial scale height profile of dust grains as probed by dust self-scattering in HL Tau Open
The vertical settling of dust grains in a circumstellar disk, characterized by their scale height, is a pivotal process in the formation of planets. This study offers in-depth analysis and modeling of the radial scale height profile of dus…
View article: Magnetic Fields in the Pillars of Creation
Magnetic Fields in the Pillars of Creation Open
Due to dust grain alignment with magnetic fields, dust polarization observations of far-infrared emission from cold molecular clouds are often used to trace magnetic fields, allowing a probe of the effects of magnetic fields on the star fo…
View article: Magnetic Fields in the Pillars of Creation
Magnetic Fields in the Pillars of Creation Open
Due to dust grain alignment with magnetic fields, dust polarization observations of far-infrared emission from cold molecular clouds are often used to trace magnetic fields, allowing a probe of the effects of magnetic fields on the star fo…
View article: Massive star cluster seeds form by gravo-turbulent flows rather than magnetized collapse
Massive star cluster seeds form by gravo-turbulent flows rather than magnetized collapse Open
High-mass stars form in protoclusters, where gravo-magnetic processes shape massive star-forming clouds and clumps to be elongated preferentially perpendicular to magnetic fields. Yet it remains unclear whether magnetic fields still govern…
View article: L1448 IRS3B: Dust Polarization Aligned with Spiral Features, Tracing Gas Flows
L1448 IRS3B: Dust Polarization Aligned with Spiral Features, Tracing Gas Flows Open
Circumstellar disk dust polarization in the (sub)millimeter is, for the most part, not from dust grain alignment with magnetic fields but rather indicative of a combination of dust self-scattering with a yet unknown alignment mechanism tha…
View article: Characterizing Magnetic Properties of Young Protostars in Orion
Characterizing Magnetic Properties of Young Protostars in Orion Open
The B -field Orion Protostellar Survey (BOPS) recently obtained polarimetric observations at 870 μ m toward 61 protostars in the Orion molecular clouds with ∼1″ spatial resolution using the Atacama Large Millimeter/submillimeter Array. Fro…
View article: Characterizing Magnetic Properties of Young Protostars in Orion
Characterizing Magnetic Properties of Young Protostars in Orion Open
The {\em B}-field Orion Protostellar Survey (BOPS) recently obtained polarimetric observations at 870 ${\rm μm}$ towards 61 protostars in the Orion molecular clouds with $\sim 1^{\prime\prime}$ spatial resolution using the Atacama Large Mi…
View article: L1448 IRS3B: Dust Polarization Aligned with Spiral Features, Tracing Gas Flows
L1448 IRS3B: Dust Polarization Aligned with Spiral Features, Tracing Gas Flows Open
Circumstellar disk dust polarization in the (sub)millimeter is, for the most part, not from dust grain alignment with magnetic fields but rather indicative of a combination of dust self-scattering with a yet unknown alignment mechanism tha…
View article: The Protostars in Orion: Characterizing the Properties of Their Magnetized Envelopes
The Protostars in Orion: Characterizing the Properties of Their Magnetized Envelopes Open
We present a study connecting the physical properties of protostellar envelopes to the morphology of the envelope-scale magnetic field. We used the Atacama Large Millimeter/submillimeter Array (ALMA) polarization observations of 61 young p…
View article: Magnetic Fields in Massive Star-forming Regions (MagMaR). V. The Magnetic Field at the Onset of High-mass Star Formation
Magnetic Fields in Massive Star-forming Regions (MagMaR). V. The Magnetic Field at the Onset of High-mass Star Formation Open
A complete understanding of the initial conditions of high-mass star formation and what processes determine multiplicity requires the study of the magnetic field in young massive cores. Using Atacama Large Millimeter/submillimeter Array (A…
View article: Magnetic Fields in Massive Star-forming Regions (MagMaR). V. The Magnetic Field at the Onset of High-mass Star Formation
Magnetic Fields in Massive Star-forming Regions (MagMaR). V. The Magnetic Field at the Onset of High-mass Star Formation Open
A complete understanding of the initial conditions of high-mass star formation and what processes determine multiplicity require the study of the magnetic field (B-field) in young, massive cores. Using ALMA 250 GHz polarization (0.3" = 100…
View article: Applying the Velocity Gradient Technique in NGC 1333: Comparison with Dust Polarization Observations
Applying the Velocity Gradient Technique in NGC 1333: Comparison with Dust Polarization Observations Open
Magnetic fields ( B -fields) are ubiquitous in the interstellar medium (ISM), and they play an essential role in the formation of molecular clouds and subsequent star formation. However, B -fields in interstellar environments remain challe…
View article: Applying the Velocity Gradient Technique in NGC 1333: Comparison with Dust Polarization Observations
Applying the Velocity Gradient Technique in NGC 1333: Comparison with Dust Polarization Observations Open
Magnetic fields (B-fields) are ubiquitous in the interstellar medium (ISM), and they play an essential role in the formation of molecular clouds and subsequent star formation. However, B-fields in interstellar environments remain challengi…
View article: Magnetic Fields in Massive Star-forming Regions (MagMaR). IV. Tracing the Magnetic Fields in the O-type Protostellar System IRAS 16547–4247
Magnetic Fields in Massive Star-forming Regions (MagMaR). IV. Tracing the Magnetic Fields in the O-type Protostellar System IRAS 16547–4247 Open
The formation of the massive stars, and in particular, the role that the magnetic fields play in their early evolutionary phase is still far from being completely understood. Here, we present the Atacama Large Millimeter/submillimeter Arra…
View article: Badminton birdie-like aerodynamic alignment of drifting dust grains by subsonic gaseous flows in protoplanetary discs
Badminton birdie-like aerodynamic alignment of drifting dust grains by subsonic gaseous flows in protoplanetary discs Open
Recent (sub)millimetre polarization observations of protoplanetary discs reveal toroidally aligned, effectively prolate dust grains large enough (at least $\sim 100$$\mu$m) to efficiently scatter millimetre light. The alignment mechanism f…
View article: MagMaR III—Resisting the Pressure, Is the Magnetic Field Overwhelmed in NGC6334I?
MagMaR III—Resisting the Pressure, Is the Magnetic Field Overwhelmed in NGC6334I? Open
We report on Atacama Large Millimeter/submillimeter Array observations of polarized dust emission at 1.2 mm from NGC6334I, a source known for its significant flux outbursts. Between five months, our data show no substantial change in total…
View article: The Evolution of Protostellar Outflow Opening Angles and the Implications for the Growth of Protostars
The Evolution of Protostellar Outflow Opening Angles and the Implications for the Growth of Protostars Open
We use 1-4" (300-1200 au) resolution 12CO(2-1) data from the MASSES (Mass Assembly of Stellar Systems and their Evolution with the SMA) project to measure the projected opening angles of 46 protostellar outflows in the Perseus Molecular Cl…
View article: The evolution of protostellar outflow opening angles and the implications for the Growth of Protostars
The evolution of protostellar outflow opening angles and the implications for the Growth of Protostars Open
We use $1-4$ arcsec ($300-1200$ au) resolution $^{12}$CO (2 − 1) data from the MASSES (Mass Assembly of Stellar Systems and their Evolution with the Submillimeter Array) project to measure the projected opening angles of 46 protostellar ou…
View article: Magnetic Fields in Massive Star-forming Regions (MagMaR): Unveiling an Hourglass Magnetic Field in G333.46–0.16 Using ALMA
Magnetic Fields in Massive Star-forming Regions (MagMaR): Unveiling an Hourglass Magnetic Field in G333.46–0.16 Using ALMA Open
The contribution of the magnetic field to the formation of high-mass stars is poorly understood. We report the high angular resolution (∼0.″3, 870 au) map of the magnetic field projected on the plane of the sky ( B POS ) toward the high-ma…
View article: Magnetic Fields in Massive Star-forming Regions (MagMaR) IV: Tracing the Magnetic Fields in the O-type protostellar system IRAS 16547$-$4247
Magnetic Fields in Massive Star-forming Regions (MagMaR) IV: Tracing the Magnetic Fields in the O-type protostellar system IRAS 16547$-$4247 Open
The formation of the massive stars, and in particular, the role that the magnetic fields play in their early evolutionary phase is still far from being completely understood. Here, we present Atacama Large Millimeter/Submillimeter Array (A…
View article: Magnetic Fields in Massive Star-forming Regions (MagMaR): Unveiling an Hourglass Magnetic Field in G333.46-0.16 using ALMA
Magnetic Fields in Massive Star-forming Regions (MagMaR): Unveiling an Hourglass Magnetic Field in G333.46-0.16 using ALMA Open
The contribution of the magnetic field to the formation of high-mass stars is poorly understood. We report the high-angular resolution ($\sim0.3^{\prime\prime}$, 870 au) map of the magnetic field projected on the plane of the sky (B$_\math…
View article: Badminton Birdie-Like Aerodynamic Alignment of Drifting Dust Grains by Subsonic Gaseous Flows in Protoplanetary Disks
Badminton Birdie-Like Aerodynamic Alignment of Drifting Dust Grains by Subsonic Gaseous Flows in Protoplanetary Disks Open
Recent (sub)millimeter polarization observations of protoplanetary disks reveal toroidally aligned, effectively prolate dust grains large enough (at least ~100 $μ$m) to efficiently scatter millimeter light. The alignment mechanism for thes…