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J/ApJ/605/759   Multifrequency obs. of radio pulse broadening      (Bhat+, 2004)

Multifrequency observations of radio pulse broadening and constraints on interstellar electron density microstructure. Bhat N.D.R., Cordes J.M., Camilo F., Nice D.J., Lorimer D.R. <Astrophys. J., 605, 759-783 (2004)> =2004ApJ...605..759B
ADC_Keywords: Pulsars Keywords: ISM: structure - methods: data analysis - pulsars: general - radio continuum: general - scattering Abstract: We have made observations of 98 low Galactic latitude pulsars to measure pulse broadening caused by multipath propagation through the interstellar medium. Data were collected with the 305m Arecibo telescope at four radio frequencies between 430 and 2380MHz. We used a CLEAN-based algorithm to deconvolve interstellar pulse broadening from the measured pulse shapes. We employed two distinct pulse-broadening functions (PBFs): PBF1 is appropriate for a thin screen of scattering material between the Earth and a pulsar, while PBF2 is appropriate for scattering material uniformly distributed along the line of sight from the Earth to a pulsar. We found that some observations were better fitted by PBF1 and some by PBF2. Pulse-broadening times (τd) are derived from fits of PBFs to the data and are compared with the predictions of a smoothed model of the Galactic electron distribution. Several lines of sight show excess broadening, which we model as clumps of high-density scattering material. Description: The observations were made at the Arecibo Observatory. New data for 81 pulsars were obtained in several observing sessions from 2001 May to 2002 November. For the analysis in this paper we also use the data collected by Lorimer, Camilo, & Xilouris (2002AJ....123.1750L) for 17 pulsars, yielding a total of 98 pulsars. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file position.dat 35 98 Pulsar positions (from Simbad) table2.dat 107 179 New measurements of pulse-broadening times and predictions from the electron density models
See also: http://www.atnf.csiro.au/research/pulsar/psrcat : ATNF Pulsar Catalogue Byte-by-byte Description of file: position.dat
Bytes Format Units Label Explanations
1- 10 A10 --- PSR Pulsar identification 16- 17 I2 h RAh Right ascension (J2000.0) 19- 20 I2 min RAm Right ascension (J2000.0) 22- 25 F4.1 s RAs ? Right ascension (J2000.0) 27 A1 --- DE- Declination sign (J2000.0) 28- 29 I2 deg DEd Declination (J2000.0) 31- 32 I2 arcmin DEm Declination (J2000.0) 34- 35 I2 arcsec DEs ? Declination (J2000.0)
Byte-by-byte Description of file: table2.dat
Bytes Format Units Label Explanations
1- 10 A10 --- PSR Pulsar identification 12 A1 --- n_PSR [mi] Type of pulse (1) 14 I1 --- Ref Reference to pulsar parameters (2) 15 A1 --- --- [,] 16- 19 I4 MHz RefFreq Frequency band of the survey that discovered the pulsar 21- 27 F7.2 ms Per ? Pulse period 29- 33 F5.1 pc/cm3 DM ? Dispersion measure 35- 38 F4.1 deg GLON ? Galactic longitude 40- 43 F4.1 deg GLAT ? Galactic latitude 45- 48 I4 MHz Freq ? Observation frequency 50 A1 --- l_PBF1t Limit flag on PBF1t 51- 56 F6.2 ms PBF1t ? PBF1 broadening time 58 A1 --- f_PBF1t [bcde] Flag on PBF1t (3) 60- 63 F4.1 ms e_PBF1t ? Uncertainty in PBF1t 65- 68 F4.2 --- PBF1f ? PBF1 figure of merit 70 A1 --- l_PBF2t Limit flag on PBF2t 71- 76 F6.2 ms PBF2t ? PBF2 broadening time 78 A1 --- f_PBF2t [bcde] Flag on PBF2t (3) 80- 84 F5.2 ms e_PBF2t ? Uncertainty in PBF2t 86- 89 F4.2 --- PBF2f ? PBF2 figure of merit 91 A1 --- l_tc93 Much less than limit flag on tc93 92- 98 F7.3 ms tc93 ? Pulse broadening using the TC93 model 100 A1 --- l_ne2001 Much less than limit flag on ne2001 101-107 F7.3 ms ne2001 ? Pulse broadening using the NE2001 model
Note (1): Flag on PSR as follows: m = Main pulse i = inter pulse See also Fig. 1. Note (2): Reference(s) to pulsar parameters as follows: 1 = ATNF pulsar catalog, available at http://www.atnf.csiro.au/research/pulsar/psrcat 2 = Morris et al. (2002, Cat. J/MNRAS/335/275) 3 = Hobbs et al. (2004), in preparation 4 = Lorimer et al. (2002AJ....123.1750L) 5 = Kramer et al. (2003, Cat. J/MNRAS/342/1299) Note that pulsars in (2), (3), and (5) (Parkes multibeam survey discoveries), as well as in (4), are also available in (1) Note (3): Flags as follows: b = The PBF yields unphysical residuals from the deconvolution for any realistic value of τd (see text). c = Signal-to-noise ratio is too small to allow a meaningful fit to the PBF. d = τd is negligibly small. e = The pulsar is not detected at this frequency.
History: From electronic version of the journal * 01-Dec-2005: Original version * 28-Jul-2008: some positions corrected
(End) Greg Schwarz [AAS], Patricia Vannier [CDS] 07-May-2004
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

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