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The Temperature and Cooling Age of the White-Dwarf Companion to the Millisecond Pulsar PSR B1855+09

Bell, Jon and van Kerkwijk, Marten and Kaspi, Vicky M. and Kulkarni, Shri (2000) The Temperature and Cooling Age of the White-Dwarf Companion to the Millisecond Pulsar PSR B1855+09. In: Pulsar Astronomy - 2000 and Beyond. Astronomical Society of the Pacific Conference Series. No.202. Astronomical Society of the Pacific , San Francisco, CA, pp. 633-634. ISBN 9781583810293.

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We report on Keck and HST observations of the binary millisecond pulsar PSR B1855+09. We detect its white-dwarf companion and measure m_(F555W) = 25.90 ± 0.12 and m_(F814W) = 24.19 ± 0.11 (Vega system). From the reddening-corrected color we infer a temperature T_(eff) = 4800 ± 800 K. The companion mass is known accurately from measurements of the Shapiro delay of the pulsar signal, M_C = 0.258^(+0.028)_(-0.016) M⊙. Given a cooling model, one can use the measured temperature to determine the cooling age. The main uncertainty in the cooling models for such low-mass white dwarfs is the amount of residual nuclear burning, which depends on the thickness of the hydrogen layer surrounding the helium core. For PSR B1855+09, such models lead to a cooling age of ∼10Gyr, which is twice the spin-down age of the pulsar. It may be that the pulsar does not brake (n=3.0) like a dipole rotating in vacuo. For other pulsar companions, however, ages well over lOGyr are inferred, indicating that the problem may lie with the cooling models. There is no age discrepancy for models in which the white dwarfs are formed with thinner hydrogen layers (< 3 × 10^(−4)M⊙). See van Kerkwijk et al. ApJ (submitted) for more details.

Item Type:Book Section
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Kaspi, Vicky M.0000-0001-9345-0307
Kulkarni, Shri0000-0001-5390-8563
Additional Information:© 2000 Astronomical Society of the Pacific.
Series Name:Astronomical Society of the Pacific Conference Series
Issue or Number:202
Record Number:CaltechAUTHORS:20181120-130647476
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Official Citation:Bell, J., Van Kerkwijk, M., Kaspi, V., & Kulkarni, S. (2000). The Temperature and Cooling Age of the White-Dwarf Companion to the Millisecond Pulsar PSR B1855 09. International Astronomical Union Colloquium, 177, 633-634. doi:10.1017/S025292110006084X
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:91073
Deposited By: Tony Diaz
Deposited On:20 Nov 2018 21:37
Last Modified:16 Nov 2021 03:38

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