Search NASA⌕ Search

SEARCH · Search NASA

Results for “supernova (SN)”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 37 records · Page 2
All sourcesNASA NTRSDOE OSTI
NASA NTRS1978

Optical emission from a fast shock wave - The remnants of Tycho's supernova and SN 1006

The faint optical filaments in Tycho's supernova remnant appear to be emission from a shock front moving at 5600 km/s. The intensity of the hydrogen lines, the absence of forbidden lines of heavy elements in the spectrum, and the width of the filaments are explained by a model in which a collisionless shock wave is moving into partially neutral gas. The presence of the neutral gas can be used to set an upper limit of approximately 5 x 10 to the 47th power ergs to the energy in ionizing radiation emitted by a Type I supernova. The patchy neutral gas is probably part of the warm neutral component of the interstellar medium. The existing information on the remnant of SN 1006 indicates that its emission is similar in nature to that from Tycho's remnant.

Chevalier, R. A.↗
NASA NTRS2009

Five Years in the Mid-Infrared Development of the SN 1987A Supernova Remnant

Spitzer has been used to monitor the mid-IR evolution of SN 1987A over a 5 year period as it develops into a supernova remnant through interaction with its surrounding environment. This interaction is dominated by the collision of the ejecta with the pre-existing equatorial ring. The mid-IR continuum indicates an increasing mass of shock-heated silicate dust, but without any significant change in temperature of the dust grains. Comparison of the IR and X-ray evolution of the remnant can be used to infer plasma conditions and the processing of the dust in the shock-heated X-ray emitting gas.

Dwek, Eliahu↗
NASA NTRS1974

Spectrophotometry of supernovae

Studies were made of a type II supernova (SN 1970g in M 101) and a type I supernova (SN 1972e in NGC 5253) covering the wavelength range from 3200 to 10,000 A. The absolute spectral energy distributions show that both types have a continuum that varies slowly and uniformly with time and carries the bulk of the radiated flux at early epochs. Some lines in both types have P Cygni profiles: broad emissions with broad absorptions at their violet edges. Some lines are common to both types and persist throughout the evolution of the spectrum.

Kirshner, R. P.↗
NASA NTRS2012

Radio and X-Ray Observations of SN 2006jd: Another Strongly Interacting Type IIn Supernova

We report four years of radio and X-ray monitoring of the Type IIn supernova SN 2006jd at radio wavelengths with the Very Large Array, Giant Metrewave Radio Telescope and Expanded Very Large Array at X-ray wavelengths with Chandra, XMM-Newton and Swift-XRT. We assume that the radio and X-ray emitting particles are produced by shock interaction with a dense circumstellar medium. The radio emission shows an initial rise that can be attributed to free-free absorption by cool gas mixed into the nonthermal emitting region external free-free absorption is disfavored because of the shape of the rising light curves and the low gas column density inferred along the line of sight to the emission region. The X-ray luminosity implies a preshock circumstellar density approximately 10(exp 6) per cubic meter at a radius r approximately 2 x 10(exp 16) centimeter, but the column density inferred from the photoabsorption of X-rays along the line of sight suggests a significantly lower density. The implication may be an asymmetry in the interaction. The X-ray spectrum shows Fe line emission at 6.9 keV that is stronger than is expected for the conditions in the X-ray emitting gas. We suggest that cool gas mixed into the hot gas plays a role in the line emission. Our radio and X-ray data both suggest the density profile is flatter than r2 because of the slow evolution of the unabsorbed emission.

Chandra, Poonam↗
NASA NTRS1991

SN 1991T - Gamma-Ray Observatory's first supernova?

Consideration is given to the explosion of the Type Ia supernova SN 1991T in the nearby galaxy NGC 4527 detected in gamma-ray lines by the recently launched GRO. The dominant gamma-line and continuum features of the new 'delayed detonation' model FDEFA1 are calculated and compared to those for standard deflagration models W7 and cdtg7. It is shown that there are many useful hard photon discriminants of the Type Ia explosion mechanism that can, in principle, be detected by the OSSE and COMPTEL instruments on the GRO. Either SN 1991T, if bright enough, or one of the several Type Ia supernovae expected to be within the GRO's range during its active life, may make it possible to settle the detonation/deflagration debate, verify the generic thermonuclear white dwarf model of Type Ia explosions, and calibrate the Type Ia B(max)/847 keV line flux ratio.

Burrows, Adam↗
NASA NTRS2018

Photometric and Spectroscopic Properties of Type Ia Supernova 2018oh with Early Excess Emission from the Kepler 2 Observations

Supernova (SN) 2018oh (ASASSN-18bt) is the first spectroscopically confirmed Type Ia supernova (SN Ia) observed in the Kepler field. The Kepler data revealed an excess emission in its early light curve, allowing us to place interesting constraints on its progenitor system. Here we present extensive optical, ultraviolet, and nearinfrared photometry, as well as dense sampling of optical spectra, for this object. SN 2018oh is relatively normal in its photometric evolution, with a rise time of 18.3±0.3 days and Δ(m15)(B)=0.96±0.03 mag, but it seems to have bluer B−V colors. We construct the “UVOIR” bolometric light curve having a peak luminosity of 1.49×10(Exp 43) erg/s, from which we derive a nickel mass as 0.55±0.04M(ʘ) by fitting radiation diffusion models powered by centrally located 56Ni. Note that the moment when nickel-powered luminosity starts to emerge is +3.85 days after the first light in the Kepler data, suggesting other origins of the early-time emission, e.g., mixing of 56Ni to outer layers of the ejecta or interaction between the ejecta and nearby circumstellar material or a nondegenerate companion star. The spectral evolution of SN 2018oh is similar to that of a normal SN Ia but is characterized by prominent and persistent carbon absorption features. The CII features can be detected from the early phases to about 3 weeks after the maximum light, representing the latest detection of carbon ever recorded in an SN Ia. This indicates that a considerable amount of unburned carbon exists in the ejecta of SN 2018oh and may mix into deeper layers.

Thomas Barclay↗
NASA NTRS1987

Observations of SN 1986J in NGC 891

Supernova SN 1986J was discovered at radio wavelengths with the VLA. The object is currently strongest at 6 cm wavelength and probably turned on at 6 cm wavelength in early 1984 and at 20 cm wavelength one or two years later. H I absorption-line observations show that the SN is about 7.7 kpc from the center and within 170 pc of the plane of NGC 891. SN 1986J is, in the radio, both the brightest and most luminous supernova yet found.The supernova has been identified optically with a 20th-magnitude (September, 1986) point source in NGC 891, and was approximately 1 mag brighter in January, 1984. The spectrum is dominated by emission lines; H I, He I, forbidden O I, and probably Fe I and Fe II are seen. The Balmer decrement is very large, with an H-alpha/H-beta flux ratio of about 60. The He I line spectrum and the current optical brightness both suggest that only a small amount of this decrement can be attributed to extinction. The spectrum is similar to those seen in the late phases of type II supernovae; however, the small linewidth (FWHM of about 1000 km/s) suggests that SN 1986J is actually type V.

Rupen, M. P.↗
NASA NTRS2014

Constraints on the Progenitor System of the Type Ia Supernova 2014J from Pre-Explosion Hubble Space Telescope Imaging

We constrain the properties of the progenitor system of the highly reddened Type Ia supernova (SN Ia) 2014J in Messier 82 (M82; d (is) approx. 3.5 Mpc). We determine the supernova (SN) location using Keck-II K-band adaptive optics images, and we find no evidence for flux from a progenitor system in pre-explosion near-ultraviolet through near-infrared Hubble Space Telescope (HST) images. Our upper limits exclude systems having a bright red giant companion, including symbiotic novae with luminosities comparable to that of RS Ophiuchi. While the flux constraints are also inconsistent with predictions for comparatively cool He-donor systems (T (is) approximately 35,000 K), we cannot preclude a system similar to V445 Puppis. The progenitor constraints are robust across a wide range of RV and AV values, but significantly greater values than those inferred from the SN light curve and spectrum would yield proportionally brighter luminosity limits. The comparatively faint flux expected from a binary progenitor system consisting of white dwarf stars would not have been detected in the pre-explosion HST imaging. Infrared HST exposures yield more stringent constraints on the luminosities of very cool (T (is) less than 3000 K) companion stars than was possible in the case of SN Ia 2011fe.

RS Ophiuchi↗
NASA NTRS1979

Soft X-ray emission from the Lupus Loop and Sn 1006 supernova remnants

X-ray maps of the Lupus region have been obtained in a raster scan observation from SAS 3. These show the Lupus Loop to be a faint extended source of soft X-rays with a temperature about 2.5 million K. The most prominent feature of the region is the A.D. 1006 supernova remnant, which is unexpectedly bright at 0.2-1.0 keV. One speculative interpretation of the low-energy flux from SN 1006 is as blackbody radiation from a hot neutron star.

Winkler, P. F., Jr.↗
NASA NTRS2020

The Slow Demise of the Long-Lived Sn 2005ip

The Type IIn supernova (SN IIn) 2005ip is one of the most well-studied and long-lasting examples of an SN interacting with its circumstellar environment. The optical light curve plateaued at a nearly constant level for more than five years, suggesting ongoing shock interaction with an extended and clumpy circumstellar medium (CSM). Here, we present continued observations of the SN from ∼1000 to 5000 d post-explosion at all wavelengths, including X-ray, ultraviolet, near-infrared (NIR), and mid-infrared. The UV spectra probe the pre-explosion mass loss and show evidence for CNO processing. From the bolometric light curve, we find that the total radiated energy is in excess of 10 50 erg, the progenitor star’s pre-explosion mass-loss rate was >~ 1 × 10 −2 Mꙩ yr −1 , and the total mass lost shortly before explosion was >~1Mꙩ, though the mass lost could have been considerably larger depending on the efficiency for the conversion of kinetic energy to radiation. The ultraviolet through NIR spectrum is characterized by two high-density components, one with narrow high-ionization lines, and one with broader low-ionization H I, He I, [OI], Mg II, and Fe II lines. The rich Fe II spectrum is strongly affected by Lyα fluorescence, consistent with spectral modelling. Both the Balmer and He I lines indicate a decreasing CSM density during the late interaction period. We find similarities to SN 1988Z, which shows a comparable change in spectrum at around the same time during its very slow decline. These results suggest that, at long last, the shock interaction in SN 2005ip may finally be on the decline.

stars↗
NASA NTRS1987

High-velocity emission in young supernova remnants: SN 1006 and SN 1572

The paper reports the discovery of broad H-alpha emission from the SN 1006 remnant with a FWHM velocity of 2600 + or - 100 km/s. This emission is similar to that seen in the remnant of SN 1572 which has a FWHM for H-alpha of 1800 km/s. The nonradiative model was used to interpret the line widths and the derived shock velocity was compared with proper motion measurements to derive distances of 1.4-2.1 kpc to SN 1006 and 2.0-2.8 kpc to SN 1572.

Kirshner, Robert↗
NASA NTRS1989

Origin of pulsed emission from the young supernova remnant SN 1987A

To overcome difficulties in understanding the origin of the submillisecond optical pulses from SN 1987A a model similar to that of Kundt and Krotscheck for pulsed synchrotron emission from the Crab was applied. The interaction of the expected ultrarelativistic e(sup + or -) pulsar wind with the pulsar dipole electromagnetic wave reflected from the walls of a pulsar cavity within the SN 1987A nubula can generate pulsed optical emission with efficiency at most eta(sub max) is approximately equal to 10(exp -3). The maximum luminosity of the source is reproduced and other observational constraints can be satisfied for an average wind energy flow is approximately equal to 10(exp 38) erg/(s steradian) and for electron Lorentz factor gamma is approximately equal to 10(exp 5). This model applied to the Crab yields pulsations of much lower luminosity and frequency.

Ruderman, M.↗
NASA NTRS1989

On the origin of pulsed emission from the young supernova remnant SN 1987A

To overcome difficulties in understanding the origin of the sub-msec optical pulses from SN 1987A, a model similar to that of Kundt and Krotscheck (1977) for pulsed synchotron emission from the Crab is applied. The interaction of the expected ultrarelativistic electron-positron pulsar wind with pulsar dipole EM wave or wind-carried toroidal magnetic field reflected from the walls of the expected pulsar cavity within the SN 1987A nebula can generate pulsed optical emission with efficiency at most 0.001. The maximum luminosity of the source is reproduced, and other observational constraints can be satisfied for an average wind energy flow of about 10 to the 38th erg/sec sr and for wind electron Lorentz factor gamma of about 100,000. This model applied to the Crab yields pulsations of much lower luminosity and frequency.

Ruderman, M.↗
NASA NTRS1994

Discovery of Shell-Like Radio-Structure in SN 1993J

The radio-luminous supernova SN 1993J in M81 offers an unprecedented opportunity to study with high linear resolution the details of the growth of a supernova radio structure by means of the VLBI technique.

radio-luminous supernova supernova gas speeds↗
NASA NTRS2012

A Swift Look at SN 2011fe: The Earliest Ultraviolet Observations of a Type Ia Supernova

We present the earliest ultraviolet (UV) observations of the bright Type Ia supernova SN 2011fe/PTF11kly in the nearby galaxy M101 at a distance of only 6.4 Mpc. It was discovered shortly after explosion by the Palomar Transient Factory and first observed by Swift/UVOT about a day after explosion. The early UV light is well-defined, with approx. 20 data points per filter in the 5 days after explosion. With these early UV observations, we extend the near-UV template of SNe Ia to earlier times for comparison with observations at low and high redshift and report fits from semiempirical models of the explosion. We find the early UV count rates to be well fit by the superposition of two parabolic curves. Finally, we use the early UV flux measurements to examine a possible shock interaction with a non-degenerate companion. We find that even a solar mass companion at a distance of a few solar radii is unlikely at more than 95% confidence.

Oates, Samantha↗
NASA NTRS2014

Uncovering the Putative B-Star Binary Companion of the SN 1993J Progenitor

The Type IIb supernova (SN) 1993J is one of only a few stripped-envelope SNe with a progenitor star identified in pre-explosion images. SN IIb models typically invoke H envelope stripping by mass transfer in a binary system. For the case of SN 1993J, the models suggest that the companion grew to 22 solar mass and became a source of ultraviolet (UV) excess. Located in M81, at a distance of only 3.6 Mpc, SN 1993J offers one of the best opportunities to detect the putative companion and test the progenitor model. Previously published near-UV spectra in 2004 showed evidence for absorption lines consistent with a hot (B2 Ia) star, but the field was crowded and dominated by flux from the SN. Here we present Hubble Space Telescope Cosmic Origins Spectrograph and Wide-Field Camera 3 observations of SN 1993J from 2012, at which point the flux from the SN had faded sufficiently to potentially measure the UV continuum properties from the putative companion. The resulting UV spectrum is consistent with contributions from both a hot B star and the SN, although we cannot rule out line-of-sight coincidences.

Hubble Space Telescope Cosmic Origins Spectrograph↗
NASA NTRS2012

Early Radio and X-Ray Observations of the Youngest Nearby Type Ia Supernova PTF 11kly (SN 2011fe)

On August 24 (UT) the Palomar Transient Factory (PTF) discovered PTF11kly (SN 2011fe), the youngest and most nearby type Ia supernova (SN Ia) in decades. We followed this event up in the radio (centimeter and millimeter bands) and X-ray bands, starting about a day after the estimated explosion time. We present our analysis of the radio and X-ray observations, yielding the tightest constraints yet placed on the pre-explosion mass-loss rate from the progenitor system of this supernova. We find a robust limit of M(raised dot) less than or equal to 10(exp -8) (w /100 kilometers per second ) solar mass yr(exp -1) from sensitive X-ray non-detections, as well as a similar limit from radio data, which depends, however, on assumptions about microphysical parameters. We discuss our results in the context of single-degenerate models for SNe Ia and find that our observations modestly disfavor symbiotic progenitor models involving a red giant donor, but cannot constrain systems accreting from main sequence or sub-giant stars, including the popular supersoft channel. In view of the proximity of PTF11kly and the sensitivity of our prompt observations we would have to wait for a long time (decade or longer) in order to more meaningfully probe the circumstellar matter of Ia supernovae.

Horesh, Assaf↗
DOE OSTI2024

Linking transients to their host galaxies – II. A comparison of host galaxy properties and rate dependencies across supernova types

ABSTRACT We use the latest data set of supernova (SN) host galaxies to investigate how the host properties – stellar mass, star formation rate (SFR), metallicity, absolute magnitude, and colour–differ across SN types, with redshift-driven selection effects controlled. SN Ib and Ic host galaxies, on average, are more massive, metal-rich, and redder than SN II hosts. For subtypes, SN Ibn and Ic-BL have bluer hosts than their normal SN Ib and Ic siblings; SN IIb has consistent host properties with SN Ib, while hosts of SN IIn are more metal-rich than those of SN II. Hydrogen-deficient superluminous SNe feature bluer and lower luminosity hosts than most subtypes of core-collapse supernova (CC SN). Assuming simple proportionality of CC SN rates and host SFRs does not recover the observed mean host properties; either a population of long-lived progenitors or a metallicity-dependent SN production efficiency better reproduces the observed host properties. Assuming the latter case, the rates of SN II are insensitive to host metallicity, but the rates of SN Ib and Ic are substantially enhanced in metal-rich hosts by a factor of $\sim 10$ per dex increase in metallicity. Hosts of SN Ia are diverse in their observed properties; subtypes including SN Ia-91T, Ia-02cx, and Ia-CSM prefer star-forming hosts, while subtypes like SN Ia-91bg and Ca-rich prefer quiescent hosts. The rates of SN Ia-91T, Ia-02cx, and Ia-CSM are closely dependent on, or even proportional to, their host SFRs, indicating relatively short-lived progenitors. Conversely, the rates of SN Ia-91bg and Ca-rich transients are proportional to the total stellar mass, favouring long-lived progenitors.

Qin, Yu-Jing (ORCID:0000000336586026)↗