J/ApJ/702/1230 Rotation measure image of the sky (Taylor+, 2009)
A rotation measure image of the sky.
Taylor A.R., Stil J.M., Sunstrum C.
<Astrophys. J., 702, 1230-1236 (2009)>
=2009ApJ...702.1230T 2009ApJ...702.1230T
ADC_Keywords: Radio sources ; Polarization ; Surveys ; Magnetic fields
Keywords: catalogs - Galaxy: halo - magnetic fields - polarization
Abstract:
We have re-analyzed the NRAO VLA Sky Survey (NVSS) data to derive
rotation measures (RMs) toward 37543 polarized radio sources. The
resulting catalog of RM values covers the sky area north of
declination -40° with an average density of more than one RM per
square degree. We have identified five regions of the sky where the
foreground median RM is consistently less than 1rad/m2 over several
degrees. These holes in the foreground RM will be useful for future
studies of possible small-scale fluctuations in cosmic magnetic field
structures. In addition to allowing measurement of RMs toward
polarized sources, the new analysis of the NVSS data removes the
effects of bandwidth depolarization for |RM|≳100rad/m2 inherent in
the original NVSS source catalog.
Description:
To derive RM values from the NVSS observations, we downloaded the
calibrated NVSS visibility data sets for each snap shot from the
National Radio Astronomy Observatory data server and created mosaic
images in Stokes I, Q, and U in each of the two bands.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
catalog.dat 105 37543 NVSS rotation measure catalog
--------------------------------------------------------------------------------
See also:
VIII/65 : 1.4GHz NRAO VLA Sky Survey (NVSS) (Condon+ 1998)
VII/6 : Polarization of Extragalactic Radio Sources (Eichendorf+ 1980)
J/MNRAS/386/1881 : New pulsar rotation measures (Noutsos+, 2008)
J/ApJ/663/258 : Rotation measures of extragalactic sources in SGPS (Brown+,
2007)
J/ApJ/642/868 : Rotation measures for 223 pulsars (Han+, 2006)
J/ApJS/45/97 : Extragal. Radio Sources Faraday Rotation (Simard-Normandin+
1981)
Byte-by-byte Description of file: catalog.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 I2 h RAh Hour of Right Ascension (J2000)
4- 5 I2 min RAm Minute of Right Ascension (J2000)
7- 11 F5.2 s RAs Second of Right Ascension (J2000)
13- 16 F4.2 s e_RAs 1-σ error in Right Ascension
18 A1 --- DE- Declination sign
19- 20 I2 deg DEd Degree of Declination (J2000)
22- 23 I2 arcmin DEm Arcminute of Declination (J2000)
25- 29 F5.2 arcsec DEs Arcsecond of Declination (J2000)
31- 33 F3.1 arcsec e_DEs 1-σ error in Declination
35- 43 F9.4 deg GLON [-180,180] Galactic longitude
45- 52 F8.4 deg GLAT [-100,180] Galactic latitude
54- 60 F7.1 mJy Si NVSS integrated Stokes I flux density
62- 66 F5.1 mJy e_Si 1-σ error in Stokes I flux density
68- 74 F7.2 mJy Pk Average peak polarized intensity
76- 80 F5.2 mJy e_Pk 1-σ error in polarized intensity
82- 87 F6.2 % m Percent polarization (ratio of peak polarized
intensity to peak Stokes I)
89- 93 F5.2 % e_m 1-σ error in m
95-100 F6.1 rad/m2 RM Rotation measure
102-105 F4.1 rad/m2 e_RM 1-σ error in RM
--------------------------------------------------------------------------------
Nomenclature note:
NVSS radio sources are in Simbad.
History:
Copied at http://www.ucalgary.ca/ras/rmcatalogue
(End) Emmanuelle Perret [CDS] 07-Oct-2011