Low-frequency spectral turn-overs in millisecond pulsars studied from imaging observations
Low-frequency spectral turn-overs in millisecond pulsars studied from imaging observations
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通过成像观测研究毫秒脉冲星的低频光谱翻转
DOI：
10.1093/mnras/stv1604
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发表时间：
2015-07
影响因子：
4.8
通讯作者：
Noutsos A.
中科院分区：
文献类型：
--
作者：
Kuniyoshi M.;Verbiest J. P. W.;Lee K. J.;Adebahr B.;Kramer M.;Noutsos A.
脉冲星通量密度的测量对于理解脉冲星的发射机制、预测脉冲星巡天观测结果和脉冲星总体星群具有重要意义。通常，这些通量密度是从相位平均的“脉冲轮廓”确定的，但这种方法在低频的适用性有限，因为观察到的脉冲很容易被星际效应如散射或色散扩散，导致非脉冲连续分量，在这种类型的分析中必须忽略。特别是对于频率低于200 MHz的毫秒级射电望远镜（MSP），这种星际效应可能严重损害可探测性和测量的通量密度。在本文中，我们基于一种补充方法（即通过调查档案连续成像数据）来研究MSP光谱。即使这些图像失去了灵敏度，因为在脉冲发射与关闭脉冲噪声的平均，他们是不敏感的散射的影响，并提供了一个可靠的方式来确定通量密度和光谱指数的MSP的基础上脉冲和非脉冲的组件。使用74 MHz的VLSSr以及325 MHz的WENSS和1.4 GHz的NVSS目录，我们调查的成像通量密度的MSP和评估的可能性，在这个人口的频谱翻转。我们确定了三个新的MSP光谱指数，并确定了六个新的MSP可能的频谱翻转。
Measurements of pulsar flux densities are of great importance for understanding the pulsar emission mechanism and for predictions of pulsar survey yields and the pulsar population at large. Typically these flux densities are determined from phase-averaged `pulse profiles', but this method has limited applicability at low frequencies because the observed pulses can easily be spread out by interstellar effects like scattering or dispersion, leading to a non-pulsed continuum component that is necessarily ignored in this type of analysis. In particular for the class of the millisecond pulsars (MSPs) at frequencies below 200 MHz, such interstellar effects can seriously compromise detectability and measured flux densities. In this paper, we investigate MSP spectra based on a complementary approach, namely through investigation of archival continuum imaging data. Even though these images lose sensitivity to pulsars since the on-pulse emission is averaged with off-pulse noise, they are insensitive to effects from scattering and provide a reliable way to determine the flux density and spectral indices of MSPs based on both pulsed and unpulsed components. Using the 74 MHz VLSSr as well as the 325 MHz WENSS and 1.4 GHz NVSS catalogues, we investigate the imaging flux densities of MSPs and evaluate the likelihood of spectral turn-overs in this population. We determine three new MSP spectral indices and identify six new MSPs with likely spectral turn-overs.
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影响因子：
64.8
作者：
D. Backer;S. Kulkarni;C. Heiles;Michael M. Davis;W. Goss
通讯作者：
D. Backer;S. Kulkarni;C. Heiles;Michael M. Davis;W. Goss
影响因子：
1.6
作者：
W. Lane;W. Cotton;J. Helmboldt;N. Kassim
通讯作者：
W. Lane;W. Cotton;J. Helmboldt;N. Kassim
DOI：
10.1086/313245
发表时间：
1998-10
期刊：
The Astrophysical Journal Supplement Series
影响因子：
--
作者：
I. Stairs;I. Stairs;S. Thorsett;F. Camilo
通讯作者：
I. Stairs;I. Stairs;S. Thorsett;F. Camilo
DOI：
10.1086/305790
发表时间：
1998-01
期刊：
The Astrophysical Journal
影响因子：
--
作者：
M. Kramer;K. Xilouris;D. Lorimer;O. Doroshenko;A. Jessner;R. Wielebinski;A. Wolszczan;F. M. F. Radioastronomie-F.-M.-F.-Radioastronomie-103349564;Bonn;H Germany;Naic;A. Observatory;Puerto Rico.;Usa;D. Astronomy;Astrophysics;P. S. University;Nral;J. Bank;UK.
通讯作者：
M. Kramer;K. Xilouris;D. Lorimer;O. Doroshenko;A. Jessner;R. Wielebinski;A. Wolszczan;F. M. F. Radioastronomie-F.-M.-F.-Radioastronomie-103349564;Bonn;H Germany;Naic;A. Observatory;Puerto Rico.;Usa;D. Astronomy;Astrophysics;P. S. University;Nral;J. Bank;UK.
DOI：
10.1086/187306
发表时间：
1994-04
期刊：
The Astrophysical Journal
影响因子：
--
作者：
M. Bailes;P. A. Harrison;D. Lorimer;S. Johnston;A. Lyne;R. Manchester;N. D'Amico;L. Nicastro;T. Tauris;Clive Robinson
通讯作者：
M. Bailes;P. A. Harrison;D. Lorimer;S. Johnston;A. Lyne;R. Manchester;N. D'Amico;L. Nicastro;T. Tauris;Clive Robinson