What would a neutron star look like? – surface thermal emission from neutron stars Chang, Hsiang-Kuang ( 張祥光 ) Department of Physics & Institute of Astronomy.
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What would a neutron star look like? – surface thermal emission from neutron stars
Chang, Hsiang-Kuang (張祥光 )Department of Physics & Institute of AstronomyNational Tsing Hua University
Where are neutron stars ?
Neutron star models
What would a neutron star look like ?
Surface thermal emission from neutron stars
Current status: observations and modelling
The proposal of neutron stars 1932 Landau 1934 Baade & Zwicky 1939 Oppenheimer & Volkoff
The discovery of radio pulsars 1967 Bell & Hewish
Other neutron star sources : X-ray pulsars, X-ray bursters Soft Gamma Repeaters (SGRs) Anomalous X-ray Pulsars (AXPs) radio-quiet isolated neutron stars
Where are neutron stars ?
Neutron star models
a model of neutron stars
(Baym & Pethick, 1979, ARA&A 17, 415)
Neutron star models
huge uncertainty in neutron star models
(Scientific American, Feb. 2003)
Neutron star models
the atmosphere of neutron stars
?
What would a neutron star look like ?
Better observed in X-rays Physical properties at the surface of
neutron stars (B, g, T, C)
Earlier results Modelling the emergent spectra and
surface structure of neutron stars
Surface thermal emission from neutron stars
Some theoretical works
Current status: modelling and observations
(Ho & Lai 2001, MNRAS 327, 1081)
Some theoretical works
Current status: modelling and observations
log B = 13 (long-dashed)log B = 14 (solid)log B = 15 (short-dashed)
(Oezel 2001, ApJ 563, 276)
The Vela pulsar’s Chandra spectrum
Current status: modelling and observations
(Pavlov et al. 2001, ApJ 552, L129)
The case of 1E1207.4-5209
Current status: modelling and observations
PN (top) & MOS (bottom) spectra fitted with two blackbodies(kT = 0.211 keV, 0.40 keV)
(Bignami et al. 2003, Nature 423, 725)
The case of 1E1207.4-5209
Current status: modelling and observations
PN spectra for different phases(Bignami et al. 2003, Nature 423, 725)
Modelling the observed spectra
Coming next…
Thank You!
Measuring the polarization
Are neutron stars really neutron stars?
Taylor, Manchester & Lyne1993, ApJS 88, 529
The Hubble image of RX J1856.5-3754
Possenti et al. 1996, A&A 313, 565
Greiveldinger et al. 1996,ApJ 465, L35
Finley et al. 1992, ApJ 394, L21
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