X-ray surface brightness of Kepler's supernova remnant

Journal Article · Sat Jan 01 04:00:00 EST 1983 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/160586· OSTI ID:6052040

White, R L; Long, K S

We have observed Kepler's supernova remnant (SNR) with the imaging instruments on board the Einstein Observatory. The 0.15-4.5 keV flux incident on the Earth is 1.2 x 10/sup -10/ ergs cm/sup -2/ s/sup -1/; the flux corrected for interstellar absorption is 3.4 x 10/sup -10/ ergs cm/sup -2/ s/sup -1/ (L/sub x/ = 1.0 x 10/sup 36/ ergs s/sup -1/ at D = 5 kpc) if the absorbing column density is N/sub H/ = 2.8 x 10/sup 21/ cm/sup -2/. The remnant is circular and shows a strong shell which is at least 5 times brighter in the north than in the south. The X-ray observations do not unambiguously determine whether the remnant is in the adiabatic or the free expansion phase. If the remnant is in the adiabatic phase, the density of the interstellar medium (ISM) (/sup 1/2/) surrounding Kepler's SNR must be about 5 cm/sup -3/. If the remnant is in the free expansion phase, where most of the emission arises from shock-heated ejecta, the ISM density must still be relatively high, n/sub i/> or approx. =0.1 cm/sup -3/. Even if the ISM is very inhomogeneous, with very many small, dense clouds, we show that the mean density of the ISM must be greater than approx.0.1 cm/sup -3/. In any case, the density of the x-ray emitting gas must be high (/sup 1/2/ > or approx. =10 cm/sup -3/), and the temperature must be fairly low (T/sub e/< or approx. =2 x 10/sup 7/ K). The relatively high ISM density which is required is surprising in view of Kepler's distance above the galactic plane, approx.600 pc. Possibly the ISM around Kepler's SNR and around other type i SNRs is dominated by the mass lost from the presupernova star.

• Research Organization: Columbia Astrophysics Laboratory, Columbia University
• OSTI ID: 6052040
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 264:1; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640103* -- Astrophysics &amp; Cosmology-- Quasi-Stellar
Radio
&amp; X-Ray Sources-- (-1987)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
COSMIC DUST
COSMIC GASES
COSMIC RADIO SOURCES
COSMIC RAY SOURCES
COSMIC X-RAY SOURCES
DUSTS
ELECTROMAGNETIC RADIATION
FLUID MECHANICS
FLUIDS
GASES
HYDRODYNAMICS
IONIZING RADIATIONS
MATHEMATICAL MODELS
MECHANICS
NEBULAE
PLASMA
RADIATION FLUX
RADIATIONS
SHOCK WAVES
SPECTRA
STAR MODELS
SUPERNOVA REMNANTS
X RADIATION
X-RAY SPECTRA