Access to Astronomical Catalogues

← Click to display the menu
J/ApJ/716/893    Polarisation at 850mu{m} in OMC-2 and OMC-3   (Poidevin+, 2010)

Magnetic field structures and turbulent components in the star-forming molecular clouds OMC-2 and OMC-3. Poidevin F., Bastien P., Matthews B.C. <Astrophys. J., 716, 893-906 (2010)> =2010ApJ...716..893P
ADC_Keywords: Polarization ; Radio lines ; Interstellar medium ; Molecular clouds Keywords: ISM: individual objects (OMC-2, OMC-3) - ISM: jets and outflows - magnetic fields - polarization - turbulence Abstract: The SCUBA polarized 850um thermal emission data of the OMC-2 region in Orion A are added to and homogeneously reduced with data already available in the OMC-3 region. The data set shows that OMC-2 is a region generally less polarized than OMC-3. Where coincident, most of the 850um polarization pattern is similar to that measured in 350um polarization data. Only 850um polarimetry data have been obtained in and around MMS7, FIR1 and FIR2, and in the region south of FIR6. A realignment of the polarization vectors with the filament can be seen near FIR1 in the region south of OMC-3. An analysis shows that the energy injected by CO outflows and H2 jets associated with OMC-2 and OMC-3 does not appear to alter the polarization patterns at a scale of the 14" resolution beam. A second-order structure function analysis of the polarization position angles shows that OMC-2 is a more turbulent region than OMC-3. OMC-3 appears to be a clear case of a magnetically dominated region with respect to the turbulence. However, for OMC-2 it is not clear that this is the case. A more in-depth analysis of five regions displayed along OMC-2/3 indicates a decrease of the mean polarization degree and an increase of the turbulent angular dispersion from north to south. A statistical analysis suggests the presence of two depolarization regimes in our maps: one regime including the effects of the cores, the other one excluding it. Description: The observations were carried out on the summit of Mauna Kea in Hawaii, from 2004 September 14 to 20 and on 2005 January 16 with the SCUPOL polarimeter installed in front of the SCUBA detector mounted on the James Clerk Maxwell Telescope (JCMT). OMC-2 data were combined with SCUBA data of OMC-3 retrieved from the JCMT data archive. Objects: ---------------------------------------------------------- RA (2000) DE Designation(s) ---------------------------------------------------------- 05 35 27 -05 10.1 OMC-2 = GAL 208-19.2 05 45 15 -05 00.3 OMC-3 = OMC 3 ---------------------------------------------------------- File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table2.dat 52 135 850 micron polarization data through OMC-2 table3.dat 52 116 850 micron polarization data through OMC-3
See also: J/ApJS/175/277 : Submillimeter-Continuum SCUBA detections (Di Francesco+, 2008) J/ApJS/182/143 : SCUPOL Legacy polarimetry of SCUBA (Matthews+, 2009) J/ApJ/604/717 : Polarization in OMC 1/4 (Houde+, 2004) J/AJ/125/1537 : QUIRC Chandra sources in OMC 2/3 (Tsujimoto+, 2003) J/ApJ/566/974 : CHANDRA obs. of YSOs in OMC-2 and OMC-3 (Tsujimoto+, 2002) J/A+A/392/239 : IR survey of outflows in Orion A (Stanke+, 2002) Byte-by-byte Description of file: table[23].dat
Bytes Format Units Label Explanations
1- 3 I3 --- Seq Running sequence number (1) 5- 6 I2 h RAh Hour of Right Ascension (J2000) 8- 9 I2 min RAm Minute of Right Ascension (J2000) 11- 15 F5.2 s RAs Second of Right Ascension (J2000) 17 A1 --- DE- Sign of the Declination (J2000) 18- 19 I2 deg DEd Degree of Declination (J2000) 21- 22 I2 arcmin DEm Arcminute of Declination (J2000) 24- 27 F4.1 arcsec DEs Arcsecond of Declination (J2000) 29- 33 F5.2 % p Polarization 35- 38 F4.2 % e_p The 1σ error in p 40- 44 F5.1 deg theta Polarization position angle of E-vector in east from north 46- 48 F3.1 deg e_theta The 1σ error in theta 50- 52 F3.1 Jy Flux Flux density in units of Jy/18.6" beam
Note (1): All the data shown here have a polarization level and uncertainty such that, p/e_p>3.
History: From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 31-May-2012
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

catalogue service