Oxygen-rich Supernova Remnant Research Articles

Spitzer Space Telescope Detection of the Young Supernova Remnant 1E 0102.2-7219

We present infrared observations of the young, oxygen-rich supernova remnant 1E 0102.2-7219 (E0102) in the Small Magellanic Cloud, obtained with the Spitzer Space Telescope. The remnant is detected at 24 μm but not at 8 or 70 μm and has a filled morphology with two prominent filaments. We find evidence for the existence of up to 8 × 10-4 M☉ of hot dust (Td ~ 120 K) associated with the remnant. Most of the hot dust is located in the central region of E0102, which appears significantly enhanced in infrared and radio continuum emission relative to the X-ray emission. Even if all of the hot dust was formed in the explosion of E0102, the estimated mass of dust is at least 100 times lower than what is predicted by some recent theoretical models.

Σ-Drelation for supernova remnants and its dependence on the density of the interstellar medium

During the last couple of decades of work on the � ‐D (radio surface brightness to diameter) relation for supernova remnants (SNRs), it has been generally accepted that no single � ‐D relation can be constructed for all SNRs. However, it may still be possible to construct the relations for some classes of SNRs. In our previous paper we analysed � ‐D relation(s) for remnants in the dense environments of molecular clouds. The aim of this paper is to examine, in the same context, a class of oxygen-rich SNRs, and to extend the analysis to remnants evolving in lower-density interstellar media, namely Balmer-dominated SNRs. We have obtained good relations with certain similarities to our previous findings ‐ similarities that emphasize, again, the role of ambient density in the evolution of SNRs. Ke yw ords: methods: statistical ‐ supernova remnants ‐ radio continuum: ISM.

High resolution X-ray spectroscopy of G292.0+1.8/MSH 11-54

We present a preliminary analysis of XMM-Newton observations of the oxygen-rich supernova remnant G292.0+1.8 (MSH 11-54). Although the spatial extent of the remnant is 8′ the bright central bar is narrow (1-2′) resulting in RGS spectra of a high spectral quality. This allows us to spectroscopically identify a cool, kTe=0.3 keV, and underionized component, resolve details of the Fe-L complex, and resolve the forbidden and resonant lines of the O VII triplet. We are also able to constrain the kinematics of the remnant using Ne IX as observed in the second order spectrum, and O VIII in the first order spectrum. We do not find evidence for O VII line shifts or Doppler broadening (σv<731 km s−1), but line broadening of the Ne X Lyα line seems to be present, corresponding to σv∼1500 km s−1.

Nucleosynthesis in the Oxygen-rich Supernova Remnant G292.0+1.8 from Chandra X-Ray Spectroscopy

We continue our analysis of the Galactic oxygen-rich supernova remnant (SNR) G292.0+1.8, which was observed with the {\it Chandra X-ray Observatory}. The high angular resolution {\it Chandra} data resolve metal-rich ejecta knots as well as the shocked circumstellar medium. X-ray emission from the ejecta material in G292.0+1.8 is dominated by highly ionized O, Ne and Mg. Measured abundance ratios suggest that this material was produced during the hydrostatic evolution of the massive progenitor star. In contrast to Cassiopeia A, there is little evidence for X-ray-emitting ejecta from explosive nucleosynthesis, i.e., material enriched in Si, S, and particularly, Fe. This limits the amount of mixing or overturning of deep ejecta material in G292.0+1.8 and suggests that the ejecta are strongly stratified by composition and that the reverse shock has not propagated to the Si/S or Fe-rich zones. On the other hand, the bright equatorial belt is dominated by X-ray emission with normal chemical composition, which supports shocked dense circumstellar material for its origin. We find that the thermal pressure in the SNR is much higher than the pressure in the pulsar wind nebula (PWN), indicating that the reverse shock has not yet begun to interact with the PWN.

Recent X-ray observations of supernova remnants.

The imaging and spectral capabilities of the Chandra X-ray Observatory and XMM-Newton are extremely well suited for studying the remnants of supernovae. High-resolution imaging over the band 0.1-10 keV maps the detailed structure of the supernova remnant, delineates the forward and reverse shock fronts and facilitates proper motion studies of the expanding material. High-resolution spectroscopy enables detailed diagnostics of the emitting plasma, including temperatures, ionization balance and abundances. Spectroscopy also reveals Doppler velocities along the line of sight. Most powerful is the capability for imaging spectroscopy, which can probe the progressive ionization at the shock fronts, the elemental distribution in the ejecta, and Doppler imaging. Examples are drawn from recent studies of oxygen-rich supernova remnants of various ages.

A Pulsar Wind Nebula in the Oxygen-rich Supernova Remnant G292.0+1.8

Using the Chandra X-Ray Observatory, we have discovered a diffuse, center-filled region of hard X-ray emission within the young, oxygen-rich supernova remnant (SNR) G292.0+1.8. Near the peak of this diffuse emission lies a pointlike source of X-ray emission that is well described by an absorbed power-law spectrum with photon index 1.72 ± 0.09. This source appears to be marginally extended; its extent of 13 (FWHM) is greater than that of a nearby serendipitous X-ray source with FWHM = 11. This is strong evidence for the presence within SNR G292.0+1.8 of a young rapidly rotating pulsar and its associated pulsar wind nebula. Both the X-ray and radio luminosity of the pulsar wind nebula imply a spin-down energy-loss rate of ~ 1037 ergs s-1 for the still undetected pulsar. The pulsar candidate is 09 from the geometric center of the SNR, which implies a transverse velocity of ~770(D/4.8 kpc)(t/1600 yr)-1 km s-1 assuming currently accepted values for the distance and age of G292.0+1.8.

XMM-Newton EPIC observation of SMC SNR 0102-72.3

Results from observations of the young oxygen-rich supernova remnant SNR 0102-72.3 in the Small Magellanic Cloud during the calibration phase of the XMM-Newton Observatory are presented. Both EPIC-PN and MOS observations show a ringlike structure with a radius of ~$15\arcsec$ already known from Einstein, ROSAT and Chandra observations. Spectra of the entire SNR as well as parts in the eastern half were analyzed confirming shocked hot plasma in non-uniform ionization stages as the origin of the X-ray emission. The spectra differ in the northeastern and the southeastern part of the X-ray ring, showing emission line features of different strength. The temperature in the northeastern part is significantly higher than in the southeast, reflected by the lines of higher ionization stages and the harder continuum. Comparison to radio data shows the forward shock of the blast wave dominating in the northern part of the SNR, while the southern emission is most likely produced by the recently formed reverse shock in the ejecta. In the case of the overall spectrum of SNR 0102-72.3, the two-temperature non-equilibrium ionization model is more consistent with the data in comparison to the single plane-parallel shock model. The structure of SNR 0102-72.3 is complex due to variations in shock propagation leading to spatially differing X-ray spectra.

Chandra X-Ray Observatory Arcsecond Imaging of the Young, Oxygen-rich Supernova Remnant 1E 0102.2-7219.

We present observations of the young, oxygen-rich supernova remnant 1E 0102.2-7219 taken by the Chandra X-Ray Observatory during its orbital activation and checkout phase. The boundary of the blast-wave shock is clearly seen for the first time, allowing the diameter of the remnant and the mean blast-wave velocity to be determined accurately. The prominent X-ray bright ring of material may be the result of the reverse shock encountering ejecta; the radial variation of O vii versus O viii emission indicates an ionizing shock propagating inward, possibly through a strong density gradient in the ejecta. We compare the X-ray emission with Australia Telescope Compact Array 6 cm radio observations (Amy & Ball) and with archival Hubble Space Telescope [O iii] observations. The ring of radio emission is predominantly inward of the outer blast wave, which is consistent with an interpretation of synchrotron radiation originating behind the blast wave but outward of the bright X-ray ring of emission. Many (but not all) of the prominent optical filaments are seen to correspond to X-ray bright regions. We obtain an upper limit of approximately 9x1033 ergs s-1 (3 sigma) on any potential pulsar X-ray emission from the central region.

Three supernova remnants observed by BeppoSAX

We present the results of three observations of shell-type supernova remnants observed by BeppoSAX. Two of the remnants (N132D and Cas A) are oxygen rich supernova remnants. They were observed during the PV phase. SN1006 was observed during A01. For SN1006 we present preliminary results on the abundance measurements based on the emission from the center of the remnant.

Erratum: "Hubble Space Telescope Observations of Oxygen-Rich Supernova Remnants in the Magellanic Clouds. I. Narrowband Imaging of N132D in the LMC" [A. J. 112,2,509(1996)

view Abstract Citations (1) References (1) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Erratum: "Hubble Space Telescope Observations of Oxygen-Rich Supernova Remnants in the Magellanic Clouds. I. Narrowband Imaging of N132D in the LMC" [A. J. 112,2,509(1996)] Morse, Jon A. ; Blair, William P. ; Dopita, Michael A. ; Hughes, John P. ; Kirshner, Robert P. ; Long, Knox S. ; Raymond, John C. ; Sutherland, Ralph S. ; Winkler, P. Frank Abstract The line drawings originally shown in Figs. 11 and 12 of Morse et al. 1996, Volume 112, pp. 509-533, were accidentally reversed. The proper figures with their corresponding captions are shown on the next page. See Journal. Publication: The Astronomical Journal Pub Date: November 1996 DOI: 10.1086/118189 Bibcode: 1996AJ....112.2350M Keywords: ERRATA full text sources ADS | data products NED (1) Related Materials (3) Part 1: 1996AJ....112..509M Part 2: 2000ApJ...537..667B Part 3: 2006ApJ...644..188M

Hubble Space Telescope Observations of Oxygen-Rich Supernova Remnants in the Magellanic Cloud. I. Narrow-Band Imaging of N132D in the LMC

view Abstract Citations (56) References (47) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Hubble Space Telescope Observations of Oxygen-Rich Supernova Remnants in the Magellanic Cloud. I. Narrow-Band Imaging of N132D in the LMC Morse, J. A. ; Blair, W. P. ; Dopita, M. A. ; Hughes, J. P. ; Kirshner, R. P. ; Long, K. S. ; Raymond, J. C. ; Sutherland, R. S. ; Winkler, P. F. Abstract We present Hubble Space Telescope (HST WFPC2 images of the young, oxygen- rich supernova remnant N132D in the Large Magellanic Cloud in the [O III]λ5007, [O II]λ3727 and [S II]λλ6724 emission lines, plus a visible continuum band. The ~0.1" resolution of HST allows us to analyze structure within N132D at scales comparable to ground-based images of nearby remnants such as Cas A. The oxygen-rich filaments (seen in [O III] and [O II] emission) are easily distinguished from shocked circumstellar clouds (seen in all three emission lines). Characteristic knots sizes and filament widths are ~0.2" - 0.5" (~1.5-4 x 10^17^ cm), at least partially resolved in our images. For the first time, we discern ionization structure within the shocked interstellar clouds and filaments, reminiscent of filaments in galactic SNRs that are thought to arise from recent shock/interstellar cloud encounters where the full cooling and recombination zone has not yet formed throughout the structure. Conversely, there appears to be fairly uniform ionization in the O-rich filaments. We also observe highly ionized, diffuse emission extending all the way around the outer edges of the remnant, as previously seen in ground-based studies. We compare our HST optical emission-line images of N132D to the ROSAT HRI soft X-ray image and find that the X-ray emission is closely traced optically by shocked circumstellar clouds; the O-rich filaments do not appear to be emitting X-rays. The limb-brightened X-ray shell aligns remarkably precisely along the inner edge of the diffuse outer rim. The diffuse emission probably represents ambient molecular gas that is being dissociated and photoionized by high-energy photons originating in the fast SNR shocks. We have used the MAPPINGS II code to model the X-ray producing main blast wave as an ~800 km s^-1^ shock moving into a circumstellar medium of density N_0_ ~ 3 cm^-3^. The preshock ISM density of N_0_ ~ 3 cm^-3^ inferred from our shock model agrees with the preshock density estimated from the [O III]λ5007 surface brightness in the diffuse outer rim. We also model the [O III]/[S II] emission-line ratios in the photoionized outer rim as a function of distance ahead of the main blast wave using the radiation field produced by fast shocks in the remnant as the ionizing source. According to our models, the ionizing radiation from the ~800 km s^-1^ main blast wave is not sufficient to generate the observed optical emission from the outer rim precursor. An extra source of EUV photons appears necessary to achieve the observed ionization of the preshock gas. We estimate that EUV photons produced in slower shocks moving into QSF-type clouds around the outer rim can probably contribute enough ionizing photons to achieve the observed ionization. Radiative shocks moving through the O-rich filaments may also be an important source of EUV photons. ======================================================================== 1996AJ....112.2350M Publication: The Astronomical Journal Pub Date: August 1996 DOI: 10.1086/118031 Bibcode: 1996AJ....112..509M Keywords: SUPERNOVA REMNANTS full text sources ADS | data products SIMBAD (8) NED (1) MAST (1) HEASARC (1) ESA (1) Related Materials (2) Part 2: 1996AJ....112.2350M Part 3: 2000ApJ...537..667B

Photoionising shocks in SNRs and AGN

A high velocity radiative shock, or one moving into high-metallicity gas, provides an efficient means to generate a strong local UV photon field. The optical emission from the shock and precursor region is dominated by the photoionised gas, rather than by the cooling region, and the total optical + UV emission scales as the mechanical energy flux through the shock. In this paper, such models are applied to oxygen-rich supernova remnants and AGN. For AGN, the degree of magnetic support in the post-shock gas is an important parameter. LINER and cooling flow spectra can be understood as resulting from high velocity shocks without precursors, while Seyfert 1.5–2 galaxy emission line ratios result from high velocity shocks with their photoionised precursor HII regions. This model explains the problem of the high electron temperatures observed in both classes of object.

Spatially Resolved Kinematics and Longslit Spectroscopy of the Young, Oxygen-Rich Supernova Remnant N132D in the Large Magellanic Cloud

view Abstract Citations (60) References (52) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Spatially Resolved Kinematics and Longslit Spectroscopy of the Young, Oxygen-Rich Supernova Remnant N132D in the Large Magellanic Cloud Morse, Jon A. ; Winkler, P. Frank ; Kirshner, Robert P. Abstract We present [O III]λ5007 Fabry-Perot observations of the young, oxygen-rich supernova remnant N132D in the Large Magellanic Cloud that show the detailed two-dimensional velocity field of the remnant with seeing-limited angular resolution. We also present low-dispersion, long slit spectrophotometry at three slit positions across the remnant covering the wavelength range from [O II]λ3727 to [S II]λλ6724. Combining the kinematic and spectral characteristics shown by the line-emitting features in N132D with X-ray and radio observations, we construct a model for the structure of N132D. Many of the high-velocity, O-rich knots appear to be distributed along the surface of an expanding shell, although some of the highest velocity knots lie outside this shell. From the shell's size and motion, we derive an expansion age of ~3150 yr for N132D. Our age estimate is 2.5 times larger than that derived by Lasker and 25% larger than the estimate of Sutherland and Dopita. Quasistationary flocculi are observed in N132D which have radial velocities in the range +/-200 km s^-1^, electron densities greater than ~2000 cm^-3^, and spectral line ratios that indicate the presence of radiative shock waves. We have also mapped the of faint, diffuse emission and find it is largely coincident with the X-ray and radio shells. However, the limb-brightened edge of the diffuse optical emission shell is displaced several arcsec outside the X- ray shell, as previously noticed by Blair et al. We interpret this emission as arising from quiescent ambient gas lying just ahead of the main supernova blast wave that is being ionized by energetic photons produced in the postshock region. Using our kinematic age estimate, the main blast wave, marked by the extent of the X-ray shell with a radius of ~12 pc, is expanding at an average rate of ~3700 km s^-1^. Publication: The Astronomical Journal Pub Date: May 1995 DOI: 10.1086/117436 Bibcode: 1995AJ....109.2104M Keywords: SUPERNOVA REMNANTS; ISM: KINEMATICS AND DYNAMICS full text sources ADS | data products SIMBAD (19) NED (1)

Young oxygen-rich supernova remnants. 1: Observations of three southern remnants

view Abstract Citations (30) References (45) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Young Oxygen-rich Supernova Remnants. I. Observations of Three Southern Remnants Sutherland, Ralph S. ; Dopita, Michael A. Abstract Narrowband imaging and two-dimensional spectrophotometery are combined in a series of observations of N132D, a young, oxygen-rich supernova remnant in the Large Magellanic Cloud. Comparison spectra of two galactic remnants, Pup A and SNR G292.0+ 1.8 are also examined. The observations permit the determination of some important physical parameters of the N132D remnant in particular. An expansion age of 2350 +/- 520 yr is obtained, significantly greater than the ~1300 yr obtained by Lasker (1980). Estimates of the densities and temperatures in the observed oxygen-rich material are made on the basis of simple homogeneous slab models. The models indicate that such simple models are unlikely to be appropriate; nevertheless they do highlight the difficulties of interpretation when the diagnostic plot trends lie in similar directions to that expected from reddening effects. Line fluxes are given in raw form, and estimates of the reddening that may be applicable are given. This forms the first paper in a short series, in the second paper an excitation mechanism for the oxygen-rich material, based on an R-type ionization front model, is presented. Publication: The Astrophysical Journal Pub Date: January 1995 DOI: 10.1086/175180 Bibcode: 1995ApJ...439..365S Keywords: Chronology; Density Distribution; Magellanic Clouds; Oxygen; Supernova Remnants; Temperature Profiles; Flux Density; Image Analysis; Spectrum Analysis; Stellar Spectrophotometry; Velocity Distribution; Astronomy; GALAXIES: MAGELLANIC CLOUDS; ISM: SUPERNOVA REMNANTS full text sources ADS | data products SIMBAD (3) NED (1) Related Materials (1) Part 2: 1995ApJ...439..381S

Young oxygen-rich supernova remnants. 2: an oxygen-rich emission mechanism

view Abstract Citations (57) References (62) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Young Oxygen-rich Supernova Remnants. II. an Oxygen-rich Emission Mechanism Sutherland, Ralph S. ; Dopita, Michael A. Abstract An emission mechanism is presented for the observed oxygen-rich plasma emission in young, oxygen-rich supernova remnants (OSNRs). The mechanism involves the interaction of a fast moving "blob" of oxygen-rich material with the SNR medium, forming a bow-shock/cloud-shock structure. The shock emission is then determined to drive a weak R-type ionization front through the oxygen-rich material. The combined shock and ionization front emission reproduces the major features of the observed optical and UV spectrum. Dynamical constraints based on the observed motions, lifetimes, and estimated densities of the oxygen-rich knots are used to determine model parameters. The plasma composition, predominantly [Ne/O] ~ -0.34, used is consistent with massive stellar evolution and explosive synthesis models. Significantly, the unusually high [O III] temperature-sensitive ratio is reproduced simultaneously with the low ionization, optical, [O I], and [O II] lines. The UV emission is predicted, and a good comparison is made with the UV spectrum of SNR E102.2 - 7219 from observations of Blair et al. (1989). Specific abundance variations were not used to make detailed fits to the observations, detailed abundance determination will require further observations. This forms the second paper in a short series; in the first paper observations for three southern OSNRs were presented. Those observations are used here along with other observations from the literature. Publication: The Astrophysical Journal Pub Date: January 1995 DOI: 10.1086/175181 Bibcode: 1995ApJ...439..381S Keywords: Oxygen; Shock Waves; Spectral Emission; Stellar Models; Supernova Remnants; Ultraviolet Spectra; Abundance; Cooling Flows (Astrophysics); Thermal Stability; Velocity Distribution; Astronomy; RADIATION MECHANISMS: NONTHERMAL; SHOCK WAVES; ISM: SUPERNOVA REMNANTS full text sources ADS | data products SIMBAD (6) NED (1) Related Materials (1) Part 1: 1995ApJ...439..365S

Electron energy loss in oxygen plasmas

view Abstract Citations (4) References (38) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Electron Energy Loss in Oxygen Plasmas Victor, G. A. ; Raymond, John C. ; Fox, J. L. Abstract The results of calculations of the energy deposition of energetic electrons in oxygen plasmas are given. In a pure oxygen plasma even with large fractional ionization, much of the electron energy results in the production of additional ionization and excited electronic states. Results are given for separate calculations using theoretical and experimental cross sections for the important O I excitations of S-1 and D-1 because the theoretical and experimental data are not in agreement. These results are useful for understanding the spectra of oxygen-rich supernova remnants. Publication: The Astrophysical Journal Pub Date: November 1994 DOI: 10.1086/174866 Bibcode: 1994ApJ...435..864V Keywords: Electron Energy; Ionization; Oxygen; Plasma Spectra; Plasmas (Physics); Statistical Distributions; Mathematical Models; Novae; Supernova Remnants; Astrophysics; ATOMIC PROCESSES; ISM: SUPERNOVA REMNANTS; PLASMAS full text sources ADS | data products SIMBAD (2)

IUE spectra and optical imaging of the oxygen-rich supernova remnant N132D

We present new optical Charge Coupled Devices (CCD) interference filter imagery and International Ultraviolet Explorer (IUE) spectroscopy for the oxygen-rich supernova remnant N132D in the Large Magellanic Cloud. The optical images show a wealth of structure, and comparison with an archival Einstein High Resolution Imager (HRI) X-ray image shows that a few optical features have X-ray counter-parts, but in general there is little correlation between X-ray and optical features. The IUE spectra at two positions show strong lines of carbon and oxygen, with lines of neon, magnesium, silicon, and helium also present and variable in relative intensities. We use optical data for N132D from Dopita & Tuohy (1984) with our UV observations to compare with shock models (both with and without thermal conduction) and X-ray photoionization model calculations. While none of the model fits is entirely satisfactory, the generally weak UV emission relative to optical disagrees with the general character of shock model predictions and indicates that photoionization is the dominant excitation mechanism for the UV/optical emission. This conclusion is similar to what was found for E0102 - 7219, the oxygen-rich remnant in the Small Magellanic Cloud. We derive rough abundances for the emitting material in N132D, compare to stellar nucleosynthesis models, and discuss the implications for its precursor. A precursor near 20 solar mass is consistent with the data.

New radio observations of supernova remnant 1E 0102.2-7219 in the Small Magellanic Cloud

We present new radio images, including the highest resolution image obtained to date, of the known oxygen-rich supernova remnant 1E 0102.2-7219 in the Small Magellanic Cloud. These images, made with the Molonglo Observatory Synthesis Telescope (44″ resolution) and the Australia Telescope Compact Array (3″ resolution), reveal an almost complete shell of radio emission and a spectral index of ∼−0.7. The images also clearly show a previously unidentified compact component. The radio images are compared with previously published optical emission line and X-ray images, and the identification of the diameter of the supernova blast wave is briefly discussed

The ultraviolet spectrum of an oxygen-rich supernova remnant in the Small Magellanic Cloud

Ultraviolet and optical spectra data are presented for the oxygen-rich supernova remnant 1E 0102-7219 in the SMC. These UV data are the first to seriously constrain the UV emission from an oxygen-rich remnant. Emission lines of O I, forbidden O II, semiforbidden O III, semiforbidden O IV, C IV, forbidden Ne IV, and Mg II have been unambiguously detected in the UV. Shock models for material with abundances appropriate to massive stellar ejecta are calculated, and a number of differences between these models and the observations are found. The UV lines are observed to be weaker relative to optical lines than expected from models. Models of photoionization by the remnant's X-ray emission are calculated, and these provide a better qualitative match to the observed spectra. Approximate abundances in the ejecta are derived and the implications these have for the precursor star are discussed.

The Oxygen-Rich Supernova Remnant in the Small Magellanic Cloud

AbstractWe report ultraviolet and optical spectra of IE 0102-7219, the oxygen-rich supernova remnant in the Small Magellanic Cloud. The UV data contain strong lines of oxygen, carbon, neon, and magnesium. OI recombination lines in the optical and UV permit the relative line intensities to be determined from 1200Å to 1 micron. Models assuming shock excitation and X-ray photoionization have been calculated and compared with the observations.