SN Ib Research Articles

The nature of S Andromedae (SN 1885A)

The spectral data on S Andromedae, or SN 1885A, which indicate that it was a type I supernova, are reexamined, and it is concluded that SN 1885A belongs to a supernova class distinct from types SN Ia and SN Ib. The light curve had a rapid rise to maximum, a rapid postmaximum decline, and a large magnitude difference between maximum and 150 days postmaximum, compared to other type I events. SN 1885A was probably a low-mass explosion, ejecting 0.1-0.3 solar mass of matter mostly in the form of Ni-56. This suggests that it left behind a compact remnant, either a neutron star or a white dwarf.

Classification of supernovae and their remnants

view Abstract Citations (64) References (110) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Classification of Supernovae and Their Remnants van den Bergh, Sidney Abstract Most young supernova remnants can be assigned to one of three distinct types: oxygen-rich remnants (Cas A), plerionic remnants (Crab), and collisionless shocks (Tycho). The presence of a pulsar in the LMC remnant 0540-69.3 suggests that this object is intermediate between oxygen-rich remnants and plerions Some remnants, such as CTB 80, W50/SS 433, G5.3-1.0, and G349.7+0.2 still defy classification. The fact that four out of seven oxygen-rich remnants are located in H II regions suggests that their progenitors were O-type stars. Most oxygen-rich SNRs were probably produced by SN Ib, but the progenitor of Cas A appears to have retained a thin outer shell of nitrogen-enriched hydrogen and would therefore have been classified as a (sub-luminous) SN II at the time of its explosion in 1658. Since the outer shell of the Crab Nebula is hydrogen-rich, SN 1054 must also have been of Type II. If 3C 58 is identified with SN 1181, then the progenitors of plerions have a range of ~30 in optical luminosity. The apparent absence of a fast-moving shell surrounding the Crab Nebula remains puzzling. Most evidence favors SN Ia as the precursors of collisionless shock-type remnants. The high frequency of such remnants in the Magellanic Clouds is, however, a source of concern. Jetlike features in some SNRs remain unexplained. A highly tentative classification scheme for SNRs produced by massive progenitors is given in Table 4 of this paper. The data in this table suggest that SN Ib have O or W-R main-seguence progenitors and leave oxygen-rich remnants, whereas early B-type stars produce SN II and leave plerionic remnants. With the new supernova rates recently determined by van den Bergh, McClure, and Evans the minimum main-sequence masses for SN II progenitors are found to be 5, 8, and 13 M_sun_ for Hubble parameters of 100, 75, and 50 km s^-1^ Mpc^-1^, respectively. Publication: The Astrophysical Journal Pub Date: April 1988 DOI: 10.1086/166178 Bibcode: 1988ApJ...327..156V Keywords: B Stars; Crab Nebula; H Ii Regions; Magellanic Clouds; O Stars; Supernova Remnants; High Frequencies; Hydrogen; Polarization (Waves); Pulsars; Stellar Evolution; Synchrotron Radiation; Astronomy; NEBULAE: SUPERNOVA REMNANTS; STARS: SUPERNOVAE full text sources ADS | data products SIMBAD (27) NED (11)

Taxonomy of Supernovae

AbstractI review the observed properties of supernovae (SNe), concentrating on recent results obtained from high-quality optical spectra. Although most SNe Ia have similar characteristics at comparable phases, there are some notable variations, particularly in the velocities of the ejecta. Moreover, there is very preliminary evidence for significant differences between the spectra of SNe Ia in H II regions and in elliptical galaxies. SNe II exhibit a wide range of spectral properties, as expected if they are produced by massive stars. At late times strong lines of [O I] and [Ca II] appear in most SNe II, including SN 1987A. In some objects, however, these are absent; the spectrum of SN 1987F, for instance, closely resembled that of a Seyfert 1 nucleus, with prominent H I and Fe II emission lines. Type Ib SNe, which lack the 6150Â absorption band typical of SNe la near maximum brightness, develop strong emission lines of [O I] and [Ca II] many months past maximum, but hydrogen is absent. Hα emission with a P-Cygni profile has, on the other hand, been detected in the early-time spectrum of SN 1987K, an object which later became spectroscopically indistinguishable from an old SN Ib. There is evidence for very weak Hα in the early spectra of several additional SNe Ib. Moreover, 7 – 8 months past maximum the [O I]/Hα and [Ca II]/Hα intensity ratios in SN 1987A were higher than in a few other well-observed SNe II at corresponding times. Hence, Type II and Type Ib SNe may form a continuous sequence in which the mass of the hydrogen envelope is the main variable.

Subluminous Type I supernovae - Their theoretical rate in our Galaxy and in ellipticals

The rate of subluminous Type I SNs (Type Ib) is computed by means of galactic evolutionary models and compared with that of classical Type I SNs (Type Ia) in the Galaxy and in ellipticals. The assumed progenitors for Type Ib SNs are binary systems consisting of a C-O degenerate dwarf plus a nondegenerate He star, whereas those for Type Ia are binary systems made of two C-O degenerate dwarfs. The present time rate of Type Ib SNs in the solar neighborhood is predicted to be almost identical to the present time rate of Type Ia, in agreement with the observational estimates. Furthermore, it is shown that the Type Ib SN rate in ellipticals goes to zero at about 10 to the 9th yr after galaxy formation time, after undergoing a very sharp peak at around 0.05 x 10 to the 9th yr. On the other hand, Type Ia SN explosions continue to occur until the present time, in agreement with the observations. It is concluded that the agreement between the predicted Type Ib SN rate and the observational constraints supports the choice made for the progenitors of such SNs, although other possible progenitors for Type I SNs cannot be excluded.more » 25 references.« less

Type Ib supernovae 1983n and 1985f - Oxygen-rich late time spectra

view Abstract Citations (131) References (23) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Type Ib Supernovae 1983n and 1985f: Oxygen-rich Late Time Spectra Gaskell, C. M. ; Cappellaro, E. ; Dinerstein, H. L. ; Garnett, D. R. ; Harkness, R. P. ; Wheeler, J. C. Abstract Spectroscopic observations of SN 1983n obtained on February 28 and March 1, 1984 (8 mo after maximum light) and of SN 1985f obtained on March 25, 1985 (25 d after discovery), both using the IDS spectrograph on the 2.7-m telescope at McDonald Observatory, are reported and analyzed. The spectra are presented graphically and compared. The spectra of SN 1983n exhibit broad emission lines including the forbidden lines of O I at 6300 and 6364 A and of Ca II at 7291 and 7324 A, the lines of Na I at 5890 and 5896 A, and the semiforbidden line of Mg I at 4562 A. Very similar features are found in the spectrum of SN 1985f, in agreement with the observations of the discoverers (Filippenko and Sargent, 1985), suggesting that both objects are SN of type Ib. From the evidence of H deficiency and the presence of O, circumstellar nebulae, and associated H II regions it is inferred that the progenitors of type Ib SN may be Wolf-Rayet stars. Publication: The Astrophysical Journal Pub Date: July 1986 DOI: 10.1086/184709 Bibcode: 1986ApJ...306L..77G Keywords: Emission Spectra; Line Spectra; Stellar Spectra; Supernovae; Ejecta; H Ii Regions; Oxygen Spectra; Stellar Envelopes; Visible Spectrum; Wolf-Rayet Stars; Astrophysics; STARS: SUPERNOVAE full text sources ADS | data products NED (4) SIMBAD (3)

Temperature dependent isomer shift in Sn119 — Pseudopotential approach

Abstract The theory formulated by Inglesfield based on the pseudopotential method was modified by the thermal lattice vibrations to interpret the explicit temperature dependence of the isomer shift in Sn 119 . A temperature dependent conduction electron charge density at the nucleus was derived by this method and the change of the isomer shift ib Sn 119 with temperature was calculated. We found that the results of Sn 119 in SnMg 2 and SnTe were in good agreement with the experimental results of Lin and Rothberg.