2007A&A...461..551P


C.D.S. - SIMBAD4 rel 1.7 - 2019.10.19CEST07:42:11

2007A&A...461..551P - Astronomy and Astrophysics, volume 461, 551-564 (2007/1-2)

Simulations of polarized dust emission.

PELKONEN V.-M., JUVELA M. and PADOAN P.

Abstract (from CDS):

The aim is to study the polarization of thermal dust emission to see if the alignment of the grain by radiative torques could explain the observed relation between the degree of polarization and intensity. Predictions are made for polarimetry observations with the Planck satellite. Our results are based on model clouds derived from MHD simulations of magnetized turbulent flows. The continuum radiative transfer problem is solved with Monte Carlo methods to estimate the three-dimensional distribution of dust emission and the radiation field strength affecting the grain alignment. The minimum grain size aligned by the radiative torques is calculated, and the Rayleigh polarization reduction factor, R, is derived for different grain size distributions. We show maps of polarized thermal dust emission that are predicted by the models. The relation between the intensity and polarization degree is examined in self-gravitating cores. Furthermore, we study the effects of wavelength, resolution, and observational noise. We are able to reproduce the P/I-relation with the grain alignment by radiative torques. The decrease in intrinsic polarization and total emission means that sub-mm polarimetry carries only a little information about the magnetic fields in dense cores with high visual extinction. The interpretation of the observations will be further complicated by the unknown magnetic field geometry and the fact that what is observed as cores may, in fact, be a superposition of several density enhancements. According to our calculations, Planck will be able to map dust polarization reliably when AV exceeds ∼2mag at spatial resolution of ∼15'.

Abstract Copyright:

Journal keyword(s): dust, extinction - ISM: clouds - polarization - radiative transfer

Simbad objects: 1

goto Full paper

goto View the reference in ADS

Number of rows : 1

N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2019
#notes
1 NAME Cyg Complex reg 20 32 +45.0           ~ 507 0

    Equat.    Gal    SGal    Ecl

C.D.S. - SIMBAD4 rel 1.7 - 2019.10.19CEST07:42:11

Available data : Basic data  •  Identifiers  •  Plot & images  •  Bibliography  •  Measurements  •  External archives  •  Notes  •  Annotations


Basic data :
NAME Cyg Complex -- Region defined in the sky
Origin of the objects types :

(Ref) Object type as listed in the reference "Ref"
(acronym) Object type linked to the acronym according to the original reference
() Anterior to 2007, before we can link the objet type to a reference, or given by the CDS team in some particular cases

Other object types:
reg ()
Syntax of coordinates is : "ra dec (wtype) [error ellipse] quality bibcode" :
  • ra dec : right ascension and declination (unit and frame defined according to your Output Options)
    Grey values are increasing the original precision due to the computation of frame transformations
  • (wtype) : wavelength class for the origin of the coordinates (Rad, mm, IR, Optical, UV, Xray, Gam)
  • [error ellipse] : coordinates error major axis, minor axis (in mas at defined epoch in the original catalogue),
    position angle (in degrees North celestial pole to East)
  • quality : flag of quality
    • E ≥ 10"
    • D : 1-10" (and some old data)
    • C : 0.1-1"
    • B : 0.01-0.1" + 2MASS, Tyc
    • A : VLBI, Hipparcos
  • bibcode : bibcode of the coordinates reference
ICRS coord. (ep=J2000) :
20 32 00.0 +45 00 00 [ ] E ~
Syntax of coordinates is : "ra dec (wtype) [error ellipse] quality bibcode" :
  • ra dec : right ascension and declination (unit and frame defined according to your Output Options)
    Grey values are increasing the original precision due to the computation of frame transformations
  • (wtype) : wavelength class for the origin of the coordinates (Rad, mm, IR, Optical, UV, Xray, Gam)
  • [error ellipse] : coordinates error major axis, minor axis (in mas at defined epoch in the original catalogue),
    position angle (in degrees North celestial pole to East)
  • quality : flag of quality
    • E ≥ 10"
    • D : 1-10" (and some old data)
    • C : 0.1-1"
    • B : 0.01-0.1" + 2MASS, Tyc
    • A : VLBI, Hipparcos
  • bibcode : bibcode of the coordinates reference
FK4 coord. (ep=B1950 eq=1950) :
20 30 18.9 +44 49 46 [ ]
Syntax of coordinates is : "ra dec (wtype) [error ellipse] quality bibcode" :
  • ra dec : right ascension and declination (unit and frame defined according to your Output Options)
    Grey values are increasing the original precision due to the computation of frame transformations
  • (wtype) : wavelength class for the origin of the coordinates (Rad, mm, IR, Optical, UV, Xray, Gam)
  • [error ellipse] : coordinates error major axis, minor axis (in mas at defined epoch in the original catalogue),
    position angle (in degrees North celestial pole to East)
  • quality : flag of quality
    • E ≥ 10"
    • D : 1-10" (and some old data)
    • C : 0.1-1"
    • B : 0.01-0.1" + 2MASS, Tyc
    • A : VLBI, Hipparcos
  • bibcode : bibcode of the coordinates reference
Gal coord. (ep=J2000) :
083.0584 +03.1569 [ ]
SIMBAD with radius arcmin
Interactive AladinLite view
Back
sedIcon
VizieR photometry viewer    sed-help-icon
within radius arcsec The VizieR photometry tool allows for easy visualization of photometry points extracted around the Simbad position from photometry-enabled catalogues in VizieR.
The search radius has to be specified by the user. It is currently limited to a maximum of 30 arcsec. It depends mostly on the precision or quality of the coordinates (SIMBAD and VizieR catalogs), the resolution of the images from which the sources were extracted, source extent, and source crowding.
Suggestions are: crowded field: 0.5 to 1.5 arcsec, 3 arcsec otherwise; uncertain coordinates (SIMBAD quality E or coordinates without reference): 5 to 30 arsec (risky!).

The link on the acronym of the identifiers give access to the information for this acronym in the dictionary of nomenclature.
Identifiers (3) :
An access of full data is available using the icon Vizier near the identifier of the catalogue

NAME Cyg Complex NAME Cyg Region NAME Cygnus Region

Plots and Images

plot

radius arcmin


CDS portal

CDS Simplay
(requires flash)

Aladin applet

References (507 between 1850 and 2019) (Total 507)
Simbad bibliographic survey began in 1850 for stars (at least bright stars) and in 1983 for all other objects (outside the solar system).
Follow new references on this object
                Reference summaries :

                from: to:

                 or select by : (not exhaustive, explanation here)


Annotations :
Annotations allow a user to add a note or report an error concerning the astronomical object and its data. It requires registration to post a note. See description .
The list of all annotations to SIMBAD objects can be found here .

Currently no annotations available

add an annotation to this object

report an error concerning the data of this object


To bookmark this query, right click on this link: simbad:objects in 2007A&A...461..551P and select 'bookmark this link' or equivalent in the popup menu


2019.10.19-07:42:11

© Université de Strasbourg/CNRS

    • Contact