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J/A+AS/147/195 Pulsar spectra of radio emission (Maron+, 2000)
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Pulsar spectra of radio emission.
Maron O., Kijak J., Kramer M., Wielebinski R.
<Astron. Astrophys. Suppl. Ser. 147, 195 (2000)>
=2000A&AS..147..195M (SIMBAD/NED BibCode)
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ADC_Keywords: Pulsars ; Radio sources
Keywords: pulsars: general - radiation mechanisms: non-thermal
Abstract:
We have collected pulsar flux density observations and compiled
spectra of 281 objects. The database of Lorimer et al. (1995,
Cat. <J/MNRAS/273/411>) has been extended to frequencies higher than
1.4GHz and lower than 300MHz. Our results show that above 100 MHz the
spectra of the majority of pulsars can be described by a simple power
law with average value of spectral index <{alpha}>=-1.8+/-0.2. A
rigorous analysis of spectral fitting revealed only about 10% of
spectra which can be modelled by the two power law. Thus, it seems
that single power law is a rule and the two power law spectrum is a
rather rare exception, of an unknown origin, to this rule. We have
recognized a small number of pulsars with almost flat spectrum
({alpha}>=-1.0) in the wide frequency range (from 300MHz to 20GHz) as
well as few pulsars with a turn-over at unusually high frequency
(~1GHz).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 68 264 Spectral indices for 266 pulsars with simple
power-law spectrum S~nu^alpha^
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See also:
VII/156 : Catalog of 558 Pulsars (Taylor+ 1993)
J/MNRAS/273/411 : Multifrequency fluxes of 280 pulsars (Lorimer+ 1995)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 2 I2 h RAh Right Ascension J2000 (hours) (3)
4- 5 I2 min RAm Right Ascension J2000 (minutes) (3)
7- 11 F5.2 s RAs Right Ascension J2000 (seconds) (3)
13 A1 --- DE- Declination J2000 (sign) (3)
14- 15 I2 deg DEd Declination J2000 (degrees) (3)
17- 18 I2 arcmin DEm Declination J2000 (minutes) (3)
20- 23 F4.1 arcsec DEs Declination J2000 (seconds) (3)
25- 35 A11 --- PSR Pulsar designation
37- 39 F3.1 GHz Freq1 Frequency range lower limit
41 A1 --- --- [-]
43- 46 F4.1 GHz Freq2 Frequency range upper limit
49- 52 F4.1 --- Sp+Index Spectral index for the frequency range (1)
54- 57 F4.2 --- e_Sp+Index ? rms uncertainty on SI
59- 65 F7.3 --- Q ? Probability of the goodness-of-fit (2)
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Note (1): S {prop.to} {nu}^{alpha}
Note (2): Probability of the goodness-of-fit parameter Q:
If Q is very small then the apparent discrepancies are unlikely to be
chance fluctuations. Much more probably either the model is wrong, or
the measurement errors are larger than stated, or measurement errors
might not be normally distributed. Generally, one may accept models
with Q~0.001 .
Note (3): Coordinates from Taylor's catalogue (VII/158) added at CDS.
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History:
From A&A electronic version.
The J2000 positions were added to table2 at CDS
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(End) Patricia Bauer [CDS] 11-Dec-2000