The Presupernova H [CSC]ii[/CSC] Region around SN 1987A

Chevalier, Roger A.; Dwarkadas, Vikram V.

doi:10.1086/309714

Cited by 162 publications

(216 citation statements)

References 19 publications

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“…We also assumed n e ∼ 1.5n H for the ring abundances (e.g., Masai & Nomoto 1994). Considering our simple modeling and the embedded uncertainty in the assumed geometry, the derived range of the electron density is in good agreement with the previously suggested values for the preshock HII region (Chevalier & Dwarkadas 1995;Borkowski et al 1997b;Lundqvist 1999), assuming density enhancement by a factor of 4 at the front of a strong adiabatic shock.…”

Section: Spectrum and Lightcurvesupporting

confidence: 88%

Monitoring the Evolution of the X‐Ray Remnant of SN 1987A

Park

Burrows

Garmire

et al. 2002

ApJ

127

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We report on the results of our monitoring program of the remnant of SN 1987A with the Advanced CCD Imaging Spectrometer (ACIS) on board the Chandra X-ray Observatory. Two new observations have been performed in AO2, bringing the total to four monitoring observations over the past two years. Over this time period, new techniques for correction of "Charge Transfer Inefficiency (CTI)" and for use of charge spreading to provide angular resolution somewhat better than the pixel size of the CCD detector have become available at Penn State. We have processed all four observations using sub-pixel resolution to obtain the highest possible angular resolution, and using our CTI correction software to provide more reliable spectral analysis and flux estimations.The high angular resolution images indicate that the X-ray bright knots are convincingly correlated with the optical spots, primarily at ∼ <1 keV, while higher energy photons are very well correlated with radio images. Our data also provide marginal evidence for radial expansion of the X-ray remnant at a rate of 5200 ± 2100 km s −1 . The X-ray flux appears to linearly increase by ∼60% over the 18 month period of these observations. The spectrum is dominated by broad complexes of atomic emission lines and can be fit with a simple model of a planeparallel shock with electron temperatures of kT ∼ 2 − 4 keV and a postshock electron density of n e ∼ 210 − 420 cm −3 . The implied 0.5 − 10 keV band luminosity in 2001 April is ∼1.3 × 10 35 ergs s −1 ; as of that date, we still observe no direct evidence for the central point source, with an upper limit on the observed luminosity of L X ∼ 5.5 × 10 33 ergs s −1 in the 2 − 10 keV band.

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Section: Spectrum and Lightcurvesupporting

confidence: 88%

Monitoring the Evolution of the X‐Ray Remnant of SN 1987A

Park

Burrows

Garmire

et al. 2002

ApJ

127

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“…In particular, model Ðts to superresolved images of the radio emission suggest that the source of the radio emission was expanding at only D2800 km s~1 in the period 1992È1995, much lower than the average speed of 35,000 km s~1 required between the time of explosion and the Ðrst imaging observations in 1992 (Gaensler et al 1997). While this expansion speed is not a direct measurement of the speed of the supernova shock, it clearly indicates that the shock had undergone a dramatic deceleration from its initial speed of greater than 50,000 km s~1 (Hanuschik & Dachs 1987), as would occur if the shock encountered a signiÐcant jump in the density of circumstellar material (Chevalier & Dwarkadas 1995 ;Borkowski et al 1997) associated with a dense H II region inside the circumstellar ring. The interpretation is also consistent with the observed soft X-ray emission from SN 1987A (Beuermann, Brandt, & Pietsch 1994 ;Gorenstein, Hughes, & Tucker 1994 ;Hasinger, Aschenbach, & 1996), Trumper though the X-ray evolution is relatively poorly sampled.…”

Section: Up To 1995mentioning

confidence: 86%

“…1997) which required a dramatic deceleration of the supernova shock at or prior to the onset of the second phase of radio emission. More detailed models for the radio emission (Du †y, Ball, & Kirk 1995, hereafter DBK95) and for the hydrodynamics of the interaction of the supernova ejecta with the CSM (e.g., Chevalier & Dwarkadas 1995 ;Borkowski, Blondin, & McCray 1997) all attribute the radio emission to the interaction of the SN shock with a density jump in the CSM. The implied radius of the circumstellar density jump responsible for the reappearance of the radio emission is smaller than that of the dense ring surrounding SN 1987A (Jakobsen et al 1991 ;Plait et al 1995 ;Sonneborn et al 1997).…”

Section: Introductionmentioning

confidence: 99%

Radio Supernova 1987A at 843 MHz

Ball

Crawford

Hunstead

et al. 2001

ApJ

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“…This interaction was predicted (Luo & McCray 1991;Luo et al 1994;Chevalier & Dwarkadas 1995;Borkowski et al 1997) shortly after the discovery of the circumstellar ring. It began about a decade after the outburst, with the discovery of the first of many "hot spots" Michael et al 2000;Pun et al 2002).…”

Section: Introductionmentioning

confidence: 91%

The Reverse Shock of SNR 1987A at 18 Years after Outburst

Smith

Zhekov

Heng

et al. 2005

ApJ

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We use low-dispersion spectra obtained at the Magellan Observatory to study the broad Ha emission from the reverse shock of the infant supernova remnant SNR 1987A. These spectra demonstrate that the spatiokinematic structure of the reverse shock can be distinguished from that of the circumstellar ring and hot spots, even at groundbased spatial resolution. We measure a total dereddened Ha flux of ergs s Ϫ1 cm Ϫ2 at an epoch Ϫ13 ‫)22.0ע(99.1‬ # 10 18.00 yr after outburst. At 50 kpc, the total reverse shock luminosity in Ha is roughly 15 , which implies a L , total flux of neutral hydrogen atoms across the reverse shock of s Ϫ1 , or roughly yr Ϫ1 . Ϫ38.9 # 10 2.3 # 10 M , This represents an increase by a factor of ∼4 since 1997. Lyman continuum radiation from gas shocked by the forward blast wave can ionize neutral hydrogen atoms in the supernova debris before they reach the reverse shock. If the inward flux of ionizing photons exceeds the flux of hydrogen atoms approaching the reverse shock, this preionization will shut off the broad Lya and Ha emission. The observed X-ray emission of SNR 1987A implies that the ratio of ionizing flux to hydrogen atom flux across the reverse shock is presently at least 0.04. The X-ray emission is increasing much faster than the flux of atoms, and if these trends continue, we estimate that the broad Lya and Ha emission will vanish in Շ7 yr.

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The Presupernova H [CSC]ii[/CSC] Region around SN 1987A

Cited by 162 publications

References 19 publications

Monitoring the Evolution of the X‐Ray Remnant of SN 1987A

Monitoring the Evolution of the X‐Ray Remnant of SN 1987A

Radio Supernova 1987A at 843 MHz

The Reverse Shock of SNR 1987A at 18 Years after Outburst

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