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Related papers: Magnetic fields and the location of the PDR

200 papers

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…

The relative alignments of mid-infrared traced Galactic bubbles are compared to the orientation of the mean Galactic magnetic field in the disk. The orientations of bubbles in the northern Galactic plane were measured and are consistent…

Astrophysics of Galaxies · Physics 2015-06-11 Michael D. Pavel , Dan P. Clemens

We present high-resolution spectroscopy and images of a photodissociation region (PDR) in M16 obtained during commissioning of NIRSPEC on the Keck II telescope. PDRs play a significant role in regulating star formation, and M16 offers the…

We present linear and circular polarization observations of the water masers in 4 distinct regions spread over 1x2 arcseconds around the HW2 high-mass young stellar object in the Cepheus A star-forming region. We find magnetic fields…

Astrophysics · Physics 2009-11-11 W. H. T. Vlemmings , P. J. Diamond , H. J. van Langevelde , J. M Torrelles

In bright photodissociation regions (PDRs) associated to massive star formation, the presence of dense "clumps" that are immersed in a less dense interclump medium is often proposed to explain the difficulty of models to account for the…

The Galactic HII region G353.2+0.9 is excited by the massive open cluster Pismis-24. By analyzing (sub-)mm molecular-line and -continuum we study the detailed morphology of the gas and dust, as well as their physical parameters and their…

Astrophysics of Galaxies · Physics 2015-06-03 A. Giannetti , J. Brand , F. Massi , A. Tieftrunk , M. T. Beltran

The Orion nebula is a prime example of a massive star-forming region in our galaxy. Observations have shown that gravitational and magnetic energy are comparable in its integral shaped filament (ISF) on a scale of ~1 pc, and that the…

Astrophysics of Galaxies · Physics 2018-01-24 Dominik R. G. Schleicher , Amelia M. Stutz

I compare theoretical models of massive star formation with observations of the Orion Hot Core, which harbors one of the closest massive protostars. Although this region is complicated, many of its features (size, luminosity, accretion…

Astrophysics · Physics 2007-05-23 Jonathan C. Tan

The SCUBA polarized 850 microns thermal emission data of the region OMC-2 in Orion A are added to and homogeneously reduced with data already available in the region OMC-3. The data set shows that OMC-2 is a region generally less polarized…

Astrophysics of Galaxies · Physics 2015-05-18 Frederick Poidevin , Pierre Bastien , Brenda C. Matthews

Photon-dominated regions (PDRs) are expected to show a layered structure in molecular abundances and emerging line emission, which is sensitive to the physical structure of the region as well as the UV radiation illuminating it. We aim to…

We evaluate the role of radiation pressure in the dynamics of HII regions. We first determine under what conditions radiation pressure is significant in comparison to gas pressure and show that, while radiation pressure is generally…

Solar and Stellar Astrophysics · Physics 2009-09-28 Mark R. Krumholz , Christopher D. Matzner

We present the magnetic field in the dense material of the Central Molecular Zone (CMZ) of the Milky Way, traced in 850 $\mu$m polarized dust emission as part of the James Clerk Maxwell Telescope (JCMT) B-fields In STar-forming Region…

The HII regions Sh 217 and Sh 219 are textbook examples of a Stromgren sphere surrounded by an annular photodissociation region (PDR). The annular PDR is observed in both the 21 cm atomic hydrogen emission and the dust (PAH) emission near 8…

Astrophysics · Physics 2009-11-07 L. Deharveng , A. Zavagno , L. Salas , A. Porras , J. Caplan , I. Cruz-Gonzalez

We report the first detection of an hourglass magnetic field aligned with a well-defined outflow-rotation system in a high-mass star-forming region. The observations were performed with Submillimeter Array toward G240.31+0.07, which harbors…

Astrophysics of Galaxies · Physics 2015-06-22 Keping Qiu , Qizhou Zhang , Karl M. Menten , Hauyu B. Liu , Ya-Wen Tang , Josep M. Girart

We report the highest spatial resolution measurement of magnetic fields in M17 using thermal dust polarization taken by SOFIA/HAWC+ centered at 154 $\mu$m wavelength. Using the Davis-Chandrasekhar-Fermi method, we found the presence of…

The physical properties and kinematics of the partially ionized interstellar material near the Sun are typical of warm diffuse clouds in the solar vicinity. The interstellar magnetic field at the heliosphere and the kinematics of nearby…

Astrophysics · Physics 2009-06-23 P. C. Frisch

Many ultracompact HII regions exhibit a cometary morphology in radio continuum emission. In such regions, a young massive star is probably ablating, through its ultraviolet radiation, the molecular cloud clump that spawned it. On one side…

Astrophysics of Galaxies · Physics 2015-06-18 Nathaniel Roth , Steven W. Stahler , Eric Keto

We present an analysis of physical conditions in the Orion Veil, a largely atomic PDR that lies just in front (about 2 pc) of the Trapezium stars. We have obtained 21 cm HI and 18 cm OH VLA Zeeman effect data. These data yield images of the…

Astrophysics of Galaxies · Physics 2016-07-06 T. H. Troland , W. M. Goss , C. L. Brogan , R. M. Crutcher , D. A. Roberts

Regions of massive star formation offer some of the best and most easily-observed examples of radiation hydrodynamics. Boundaries where fully-ionized H II regions transition to neutral/molecular photodissociation regions (PDRs) are of…

Astrophysics of Galaxies · Physics 2015-06-15 P. Hartigan , J. Palmer , L. I. Cleeves