Pulsar braking indices, glitches and energy dissipation in neutron stars

Alpar, M. Ali
Baykal, Altan
Almost all pulsars with anomalous positive Omega measurements (corresponding to anomalous braking indices in the range 5 <vertical bar n vertical bar < 100), including all the pulsars with observed large glitches (Delta Omega/Omega > 10(-7)) as well as post-glitch or interglitch Omega measurements, obey the scaling between Omega and glitch parameters originally noted in the Vela pulsar. Negative second derivative values can be understood in terms of glitches that were missed or remained unresolved. We discuss the glitch rates and a priori probabilities of positive and negative braking indices according to the model developed for the Vela pulsar. This behaviour supports the universal occurrence of a non- linear dynamical coupling between the neutron star crust and an interior superfluid component. The implied lower limit to dynamical energy dissipation in a neutron star with spindown rate (Omega) over bar (E) over bar (diss) > 1.7 x 10(-6) (E) over bar (rot). Thermal luminosities and surface temperatures due to dynamical energy dissipation are estimated for old neutron stars which are spinning down as rotating magnetic dipoles beyond the pulsar death line.


RXTE and Swift Observations of SWIFT J0513.4-6547
Sahiner, S.; Serim, Muhammed Miraç; Baykal, Altan; İNAM, SITKI ÇAĞDAŞ (Oxford University Press (OUP), 2016-02-11)
We present timing and spectral analysis of Swift-XRT (X-ray Telescope) and RXTE-PCA (Rossi X-ray Timing Explorer-proportional Counter Array) observations of the transient Be/X-ray pulsar SWIFT J0513.4-6547 during its outburst in 2009 and its rebrightening in 2014. From 2009 observations, short-term spin-up rate of the source after the peak of the outburst is found to have about half of the value measured at the peak of the outburst by Coe et al. When the source is quiescent between 2009 and 2014, average sp...
RXTE-PCA observations of XMMU J054134.7-682550
İNAM, SITKI ÇAĞDAŞ; Townsend, L. J.; McBride, V. A.; Baykal, Altan; Coe, M. J.; Corbet, R. H. D. (Oxford University Press (OUP), 2009-05-21)
We analysed Rossi X-ray Timing Explorer Proportional Counter Array observations of a recent outburst of the X-ray pulsar XMMU J054134.7-682550. We calculated the pulse frequency history of the source. We found no sign of a binary companion. The source spins up when the X-ray flux is higher, with a correlation between the spin-up rate and X-ray flux, which may be interpreted as a sign of an accretion disc. On the other hand, the source was found to have an almost constant spin frequency when the X-ray flux i...
VERITAS discovery of > 200 GeV gamma-ray emission from the intermediate-frequency-peaked BL Lacertae object W Comae
Acciari, V. A.; et. al. (IOP Publishing, 2008-09-10)
We report the detection of very high energy gamma- ray emission from the intermediate- frequency- peaked BL Lacertae object W Comae (z = 0.102) by VERITAS. The source was observed between 2008 January and April. A strong outburst of gamma-ray emission was measured in the middle of March, lasting for only 4 days. The energy spectrum measured during the two highest flare nights is fit by a power law and is found to be very steep, with a differential photon spectral index of Gamma = 3.81 +/- 0.35(stat) +/- 0.3...
Optical imaging and spectroscopic observation of the galactic supernova remnant G85.9-0.6
GÖK, FATMA; Sezer, A.; Aktekin, E.; Guever, T.; Ercan, N. (Springer Science and Business Media LLC, 2009-11-01)
Optical CCD imaging with H alpha and [SII] filters and spectroscopic observations of the galactic supernova remnant G85.9-0.6 have been performed for the first time. The CCD image data are taken with the 1.5 m Russian-Turkish Telescope (RTT150) at TBA degrees TAK National Observatory (TUG) and spectral data are taken with the Bok 2.3 m telescope on Kitt Peak, AZ.
Orbital and spin phase-resolved spectroscopy of the intermediate polar EX Hya using XMM-Newton data
Pekon, Y.; Balman, Şölen (Oxford University Press (OUP), 2011-02-01)
We present the orbital phase-resolved spectra of an intermediate polar, EX Hya, together with the spin phase-resolved spectra during two different epochs using the X-ray Multi-Mirror Mission (XMM-Newton), European Photon Imaging Camera (pn instrument). We find that the source at the two epochs has the same X-ray luminosity of similar to 6.5 x 1031 erg s-1. We detect spectral variations between the 2000 and 2003 observations of the source. We fitted the spectrum using a neutral hydrogen absorption model with...
Citation Formats
M. A. Alpar and A. Baykal, “Pulsar braking indices, glitches and energy dissipation in neutron stars,” MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, pp. 489–496, 2006, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/35068.