what would a neutron star look like? – surface thermal emission from neutron stars chang,...
Post on 20-Dec-2015
222 views
TRANSCRIPT
![Page 1: 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](https://reader036.vdocuments.site/reader036/viewer/2022062313/56649d405503460f94a1ae99/html5/thumbnails/1.jpg)
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
![Page 2: 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](https://reader036.vdocuments.site/reader036/viewer/2022062313/56649d405503460f94a1ae99/html5/thumbnails/2.jpg)
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
![Page 3: 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](https://reader036.vdocuments.site/reader036/viewer/2022062313/56649d405503460f94a1ae99/html5/thumbnails/3.jpg)
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 ?
![Page 4: 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](https://reader036.vdocuments.site/reader036/viewer/2022062313/56649d405503460f94a1ae99/html5/thumbnails/4.jpg)
Neutron star models
a model of neutron stars
![Page 5: 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](https://reader036.vdocuments.site/reader036/viewer/2022062313/56649d405503460f94a1ae99/html5/thumbnails/5.jpg)
(Baym & Pethick, 1979, ARA&A 17, 415)
Neutron star models
huge uncertainty in neutron star models
![Page 6: 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](https://reader036.vdocuments.site/reader036/viewer/2022062313/56649d405503460f94a1ae99/html5/thumbnails/6.jpg)
(Scientific American, Feb. 2003)
Neutron star models
the atmosphere of neutron stars
![Page 7: 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](https://reader036.vdocuments.site/reader036/viewer/2022062313/56649d405503460f94a1ae99/html5/thumbnails/7.jpg)
?
What would a neutron star look like ?
![Page 8: 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](https://reader036.vdocuments.site/reader036/viewer/2022062313/56649d405503460f94a1ae99/html5/thumbnails/8.jpg)
![Page 9: 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](https://reader036.vdocuments.site/reader036/viewer/2022062313/56649d405503460f94a1ae99/html5/thumbnails/9.jpg)
![Page 10: 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](https://reader036.vdocuments.site/reader036/viewer/2022062313/56649d405503460f94a1ae99/html5/thumbnails/10.jpg)
![Page 11: 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](https://reader036.vdocuments.site/reader036/viewer/2022062313/56649d405503460f94a1ae99/html5/thumbnails/11.jpg)
![Page 12: 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](https://reader036.vdocuments.site/reader036/viewer/2022062313/56649d405503460f94a1ae99/html5/thumbnails/12.jpg)
![Page 13: 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](https://reader036.vdocuments.site/reader036/viewer/2022062313/56649d405503460f94a1ae99/html5/thumbnails/13.jpg)
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
![Page 14: 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](https://reader036.vdocuments.site/reader036/viewer/2022062313/56649d405503460f94a1ae99/html5/thumbnails/14.jpg)
Some theoretical works
Current status: modelling and observations
(Ho & Lai 2001, MNRAS 327, 1081)
![Page 15: 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](https://reader036.vdocuments.site/reader036/viewer/2022062313/56649d405503460f94a1ae99/html5/thumbnails/15.jpg)
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)
![Page 16: 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](https://reader036.vdocuments.site/reader036/viewer/2022062313/56649d405503460f94a1ae99/html5/thumbnails/16.jpg)
The Vela pulsar’s Chandra spectrum
Current status: modelling and observations
(Pavlov et al. 2001, ApJ 552, L129)
![Page 17: 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](https://reader036.vdocuments.site/reader036/viewer/2022062313/56649d405503460f94a1ae99/html5/thumbnails/17.jpg)
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)
![Page 18: 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](https://reader036.vdocuments.site/reader036/viewer/2022062313/56649d405503460f94a1ae99/html5/thumbnails/18.jpg)
The case of 1E1207.4-5209
Current status: modelling and observations
PN spectra for different phases(Bignami et al. 2003, Nature 423, 725)
![Page 19: 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](https://reader036.vdocuments.site/reader036/viewer/2022062313/56649d405503460f94a1ae99/html5/thumbnails/19.jpg)
Modelling the observed spectra
Coming next…
Thank You!
Measuring the polarization
Are neutron stars really neutron stars?
![Page 20: 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](https://reader036.vdocuments.site/reader036/viewer/2022062313/56649d405503460f94a1ae99/html5/thumbnails/20.jpg)
![Page 21: 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](https://reader036.vdocuments.site/reader036/viewer/2022062313/56649d405503460f94a1ae99/html5/thumbnails/21.jpg)
![Page 22: 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](https://reader036.vdocuments.site/reader036/viewer/2022062313/56649d405503460f94a1ae99/html5/thumbnails/22.jpg)
![Page 23: 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](https://reader036.vdocuments.site/reader036/viewer/2022062313/56649d405503460f94a1ae99/html5/thumbnails/23.jpg)
Taylor, Manchester & Lyne1993, ApJS 88, 529
![Page 24: 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](https://reader036.vdocuments.site/reader036/viewer/2022062313/56649d405503460f94a1ae99/html5/thumbnails/24.jpg)
![Page 25: 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](https://reader036.vdocuments.site/reader036/viewer/2022062313/56649d405503460f94a1ae99/html5/thumbnails/25.jpg)
![Page 26: 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](https://reader036.vdocuments.site/reader036/viewer/2022062313/56649d405503460f94a1ae99/html5/thumbnails/26.jpg)
![Page 27: 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](https://reader036.vdocuments.site/reader036/viewer/2022062313/56649d405503460f94a1ae99/html5/thumbnails/27.jpg)
![Page 28: 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](https://reader036.vdocuments.site/reader036/viewer/2022062313/56649d405503460f94a1ae99/html5/thumbnails/28.jpg)
![Page 29: 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](https://reader036.vdocuments.site/reader036/viewer/2022062313/56649d405503460f94a1ae99/html5/thumbnails/29.jpg)
![Page 30: 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](https://reader036.vdocuments.site/reader036/viewer/2022062313/56649d405503460f94a1ae99/html5/thumbnails/30.jpg)
The Hubble image of RX J1856.5-3754
![Page 31: 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](https://reader036.vdocuments.site/reader036/viewer/2022062313/56649d405503460f94a1ae99/html5/thumbnails/31.jpg)
![Page 32: 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](https://reader036.vdocuments.site/reader036/viewer/2022062313/56649d405503460f94a1ae99/html5/thumbnails/32.jpg)
![Page 33: 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](https://reader036.vdocuments.site/reader036/viewer/2022062313/56649d405503460f94a1ae99/html5/thumbnails/33.jpg)
Possenti et al. 1996, A&A 313, 565
![Page 34: 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](https://reader036.vdocuments.site/reader036/viewer/2022062313/56649d405503460f94a1ae99/html5/thumbnails/34.jpg)
Greiveldinger et al. 1996,ApJ 465, L35
![Page 35: 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](https://reader036.vdocuments.site/reader036/viewer/2022062313/56649d405503460f94a1ae99/html5/thumbnails/35.jpg)
Finley et al. 1992, ApJ 394, L21