POLARIZATION OBSERVATIONS OF 100 PULSARS AT 774 MHz BY THE GREEN BANK TELESCOPE

We report on polarimetric observations of 100 pulsars centered on 774 MHz, made using the Green Bank Telescope, presenting their polarization profiles and polarized flux densities and comparing them with previous observations when possible. For 67 pulsars, these are the first such measurements made. Polarization profiles of 8 millisecond-pulsars in our sample show wide profiles and flat position-angle curves. Strong linear polarization, sometimes approaching 100% of the total intensity, has been detected in all or a part of the average pulse profiles of some pulsars. In general, circular polarization is very weak, although it is observed to be extremely strong in the leading component of PSR J1920+2650. Sense reversal of circular polarization as a function of pulse phase has been detected from both core and other components of more than 20 pulsars. Any relationship between the spin-down luminosity and the percentage of linear polarization is not evident in our data at this frequency.

[1]  Bing Zhang,et al.  Reversals of Radio Emission Direction in PSR B1822?09 , 2005 .

[2]  Simon Johnston,et al.  Evidence for alignment of the rotation and velocity vectors in pulsars. II. Further data and emission heights , 2005, astro-ph/0510260.

[3]  R. Rosenfeld Nature , 2009, Otolaryngology--head and neck surgery : official journal of American Academy of Otolaryngology-Head and Neck Surgery.

[4]  J. Rankin Toward an Empirical Theory of Pulsar Emission , 1987 .

[5]  P. McCulloch,et al.  Polarimetric observations of southern pulsars at 800 and 950 MHz , 1997 .

[6]  The Mode-separated Pulse Profiles of Pulsar Radio Emission , 2000 .

[7]  B. Stappers,et al.  Ellipticity and deviations from orthogonality in the polarization modes of PSR B0329+54 , 2004, astro-ph/0404092.

[8]  D. Stinebring,et al.  Pulsar polarization fluctuations. I. 1404 MHz statistical summaries. , 1984 .

[9]  J. Rankin Toward an empirical theory of pulsar emission. IV. Geometry of the core emission region , 1990 .

[10]  Aidan W. Hotan,et al.  Polarimetric profiles of 27 millisecond pulsars , 2004 .

[11]  S. Johnston,et al.  Profile morphology and polarization of young pulsars , 2006, astro-ph/0603037.

[12]  F. Camilo,et al.  Coherently Dedispersed Polarimetry of Millisecond Pulsars , 1998, astro-ph/9810399.

[13]  S. Kulkarni,et al.  Mean Pulse Shape and Polarization of PSR J0437–4715 , 1997 .

[14]  D. Stinebring,et al.  Arecibo 21 centimeter polarimetry of 64 pulsars - A guide to classification , 1989 .

[15]  A. Karastergiou,et al.  An empirical model for the beams of radio pulsars , 2007, 0707.2547.

[16]  Australia.,et al.  The shape of pulsar radio beams , 1988, astro-ph/0010538.

[17]  J. Rankin Toward an empirical theory of pulsar emission. I: Morphological taxonomy , 1983 .

[18]  V. Radhakrishnan,et al.  Toward an empirical theory of pulsar emission. V. On the circular polarization in pulsar radiation , 1990 .

[19]  J. Benson,et al.  Pulsar polarization: weak sources and emission features at 430 MHz. , 1981 .

[20]  D. Stinebring,et al.  Polarimetry of millisecond pulsars , 1990 .

[21]  Beijing,et al.  Circular polarization in pulsar integrated profiles , 1998, astro-ph/9806021.

[22]  R. Manchester,et al.  Polarization observations of 66 southern pulsars , 1998 .

[23]  C. Ho,et al.  Energetic Radiation from Rapidly Spinning Pulsars. 1. Outer Magnetosphere Gaps. 2. Vela and Crab , 1986 .

[24]  V. Kaspi,et al.  Polarization Properties of Nine Southern Radio Pulsars , 2001, astro-ph/0106544.

[25]  A. G. Lyne,et al.  Multifrequency polarimetry of 300 radio pulsars , 1998 .

[26]  India.,et al.  Understanding the Radio Emission Geometry of Multiple-Component Radio Pulsars from Retardation and Aberration Effects , 2002, astro-ph/0210411.

[27]  On the Excess Dispersion in the Polarization Position Angle of Pulsar Radio Emission , 2004, astro-ph/0401598.

[28]  R. Gangadhara,et al.  Understanding the Radio Emission Geometry of PSR B0329+54 , 2001, astro-ph/0103109.

[29]  A. Lyne,et al.  Pulsar Rotation Measures and the Large-Scale Structure of the Galactic Magnetic Field , 2006, astro-ph/0601357.

[30]  F. Crawford,et al.  Flux Densities and Radio Polarization Characteristics of Two Vela-like Pulsars , 2007, 0706.3182.

[31]  R. Manchester,et al.  psrchive and psrfits: An Open Approach to Radio Pulsar Data Storage and Analysis , 2004, Publications of the Astronomical Society of Australia.

[32]  A. Lyne,et al.  Linear Polarization in Pulsating Radio Sources , 1968, Nature.

[33]  Astrophysics,et al.  The Characteristics of Millisecond Pulsar Emission. II. Polarimetry , 1998, astro-ph/9801178.

[34]  M. Walker,et al.  Pulsars : problems and progress : IAU Colloquium 160, proceedings held at the Research Centre for Theoretical Astrophysics University of Sydney, Australia, 8-12 January 1996 , 1996 .

[35]  J. Rankin Toward an Empirical Theory of Pulsar Emission. VI. The Geometry of the Conal Emission Region , 1993 .

[36]  Ruderman,et al.  Theory of pulsars: polar gaps, sparks, and coherent microwave radiation , 1975 .

[37]  R. Manchester,et al.  The Australia Telescope National Facility Pulsar Catalogue , 2005 .

[38]  D. C. Backer,et al.  Arecibo 430 MHz Pulsar Polarimetry: Faraday Rotation Measures and Morphological Classifications , 2003, astro-ph/0310073.

[39]  J. Cordes,et al.  Arecibo 1418 MHz Polarimetry of 98 Pulsars: Full Stokes Profiles and Morphological Classifications , 1999 .

[40]  W. Straten Radio Astronomical Polarimetry and Point-Source Calibration , 2004, astro-ph/0401536.

[41]  J. Cordes,et al.  Orthogonal modes of polarization from pulsar PSR 2020+28 , 1978 .

[42]  D. Stinebring,et al.  Pulsar Polarization Fluctuations - Part One - 1404-MHZ Statistical Summaries , 1984 .

[43]  R. Manchester,et al.  Polarization observations of nine southern millisecond pulsars , 2004, astro-ph/0403199.