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1.
Gillian Pearce Bruce Patchett Jeremy Allington-Smith Ian Parry 《Astrophysics and Space Science》1988,150(2):267-271
We present the spectrum of the supernova SN1987L in NGC 2336 over the wavelength range 4000–9700 Å as recorded in one 500 s exposure on 20–21 October, 1987. This spectrum was taken using the new Faint Object Spectrograph on the 4.2 m William Herschel Telescope (WHT) at the Observatorio del Roque de los Muchachos.We conclude that SN1987L was a type Ia supernova, and approximately 100 days post maximum at the time of the observation. 相似文献
2.
We present two spectra of the supernova SN1988A in M58 (NGC4579) over the wavelength range 4000–9700 Å, as recorded by the Faint Object Spectrograph on the 4.2 m William Herschel Telescope at the Observatorio del Roque de los Muchachos. We conclude that SN1988A was a type II supernova. 相似文献
3.
A. Pastorello M. Turatto S. Benetti E. Cappellaro I. J. Danziger P. A. Mazzali F. Patat A. V. Filippenko D. J. Schlegel † T. Matheson ‡ 《Monthly notices of the Royal Astronomical Society》2002,333(1):27-38
We present the photometric and spectroscopic evolution of the type IIn SN 1995G in NGC 1643, on the basis of 4 years of optical and infrared observations. This supernova shows very flat optical light curves similar to SN 1988Z, with a slow decline rate at all times. The spectra are characterized by strong Balmer lines with multiple components in emission and with a P Cygni absorption component blueshifted by only 700 km s−1 . This feature indicates the presence of a slowly expanding shell above the SN ejecta as in the case of SNe 1994aj and 1996L. As in other SNe IIn, the slow luminosity decline cannot be explained only with a radioactive energy input, and an additional source of energy is required, most likely that produced by the interaction between supernova ejecta and a pre-existent circumstellar medium (CSM). It was estimated that the shell material has a density n H ≫108 cm-3 , consistent with the absence of forbidden lines in the spectra. About 2 years after the burst the low-velocity shell is largely overtaken by the SN ejecta and the luminosity drops at a faster rate. 相似文献
4.
Zhao Gang Zhao Yong-heng Huang Jia-sheng Feng Long-long Huang Ke-liang Peng Qiu-he Lu Tan 《Chinese Astronomy and Astrophysics》1988,12(4):294-297
We carried out a Monte Carlo simulation calculation on the observed data of neutrino events of the supernova SN1987A. Our results show that the best value for the rest-mass of neutrino is 3–4 eV. We also calculated the light curve of the neutrino bursts and the energy spectrum.Our results impose constraints on the rest-mass of neutrino and the mass of the precursor of SN 1987A. 相似文献
5.
Astronomy Letters - I explore the origin of an asymmetry of the H $$\alpha$$ emission from a circumstellar (CS) shell around type IIP supernova SN 2013fs in the spectrum taken 10.3 h... 相似文献
6.
We investigate the possibility of detecting the circumstellar Na I D1,2 and Ca II H, K absorption lines in the spectra of type IIP supernovae at the photospheric phase. Our modeling shows that the Na I doublet lines will not be seen in the spectra of type IIP supernovae at moderate stellar wind densities, for example, characteristic of SN 1999em, while the rather intense Ca II lines with P Cyg profiles should be detectable. The same model is used to describe the circumstellar Na I and Ca II lines in the spectrum of SN 1998S, a type IIL supernova with a dense wind. We show that the circumstellar line intensities in this supernova are reproduced only if there is an ultraviolet excess that is mainly attributable to the Comptonization of supernova radiation in the shock wave. 相似文献
7.
The most luminous Supernova SN2006gy (more than 100 times brighter than a typical supernova) has been a challenge to explain by standard models. For example, pair-instability supernovae which are luminous enough seem to have too slow a rise, and core-collapse supernovae do not seem to be luminous enough. We present an alternative scenario involving a Quark Nova (an explosive transition of the newly born neutron star to a quark star) in which a second explosion (delayed) occurs inside the ejecta of a normal supernova. The reheated supernova ejecta can radiate at higher levels for longer periods of time primarily due to reduced adiabatic-expansion losses, unlike the standard supernova case. We find an encouraging match between the resulting light curve and that observed in the case of SN2006gy suggesting that we might have at hand the first ever signature of a Quark Nova. Successful application of our model to SN2005gj and SN2005ap is also presented. 相似文献
8.
G. C. Anupama D. K. Sahu U. K. Gurugubelli T. P. Prabhu N. Tominaga M. Tanaka K. Nomoto 《Monthly notices of the Royal Astronomical Society》2009,392(2):894-903
We present optical UBVRI photometric and spectroscopic data of the Type Ibn supernova SN 2006jc, until the onset of the dust-forming phase. The optical spectrum shows a blue continuum and is dominated by the presence of moderately narrow (velocity ∼2500 km s−1 ) He i emission lines superimposed over a relatively weak supernova spectrum. The helium lines are produced in a pre-existing He-rich circumstellar shell. The observed helium line fluxes indicate the circumstellar shell is dense, with a density of ∼109 –1010 cm−3 . The helium mass in this shell is estimated to be ≲0.07 M⊙ . The optical light curves show a clear signature of dust formation, indicated by a sharp decrease in the magnitudes around day 50, accompanied by a reddening of the colours. The evolution of the optical light curves during the early phase and that of the uvoir bolometric light curve at all phases is reasonably similar to normal Ib/c supernovae. 相似文献
9.
We present the X-ray light curve in the 0.2–2.4 keV band based on fiveROSAT observations of SN1978K in NGC 1313. The X-ray emission is believed to arise from the interaction of the reverse shock and the expanding debris from the supernova. The reverse shock becomes established after the outgoing shock runs into circumstellar matter. 相似文献
10.
V. P. Goranskij E. A. Barsukova A. F. Valeev D. Yu. Tsvetkov I. M. Volkov V. G. Metlov A. V. Zharova 《Astrophysical Bulletin》2016,71(4):422-435
We present spectroscopy and multicolor photometry for the optical transient PSN J09093496+3307204 in the galaxy NGC2770, which has afterwards been transferred into the supernova phase and got the name SN2015bh. Medium-resolution spectral observations were carried out between February 2015 to May 2016 using the focal reducer SCORPIO at the 6-m Russian telescope BTA. They were followed by by photometric observations at the BTA and six other telescopes with 0.5–1m apertures. Both at the phase of the SN impostor (2015a) and at the supernova phase (2015b), besides Balmer emissions, the strong Fe II emissions are seen in the spectrum; so, these spectra resemble those of Williams Fe II type classical novae. Taking into account circumstellar, interstellar and galactic absorption, AV = 1.m 14 ±0.m 15), we determined maximum absolute magnitudes of the object to be MV =–15.m 0 ±0.m 3 at the 2015a phase and of MV =–18.m 14 ±0.m 30 at the 2015b phase. The light curve at the 2015b phase is similar to those of SN IIL. The supernova progenitor is a luminous blue variable (LBV) star with the powerful Hα emission. We consider several hypotheses of supernovae explosions following optical transients related with LBV. The hypothesis of core collapse of an evolved massive star interrupting the process of its merging with massive companion in a binary system (a failed luminous red nova) was chosen as the preferable one for this event. 相似文献
11.
Photographic image-tube spectra (150 Å mm–1, 4500 Å-7000 Å) of the type I supernova (1974g) in the Sc galaxy NGC 4414 obtained at phases+ 14 days and + 40 days past maximum light have been reduced to absolute flux. The positions of various spectral features and the overall appearance of the spectra of SN 1974g closely match previously observed type I SN spectra at similar phases. An electronographic isophotal map of NGC 4414 is presented, and an accurate position of SN 1974g given. A distance to NGC 4414 of 15 Mpc was determined from the recessional velocities and the diameters of Hii regions; while the absolute magnitude at maximum light of SN 1974g was found to beM
B(max)=–19.0. Estimates of the radius of the expanding photosphere of SN 1974g, cetermined by two independent methods, giveR1015 cm in the early post-maximum phases. The time of outburst,t=–25 days, has been estimated for SN 1974g. By assuming the broad emission feature observed at 6480 Å to be H, very rough estimates of the electron density and the mass of ionized hydrogen in the expanding supernova envelope are given. The total (observed) luminous energy of SN 1974g was 1051 erg. 相似文献
12.
A. Pastorello E. Baron D. Branch L. Zampieri M. Turatto M. Ramina S. Benetti E. Cappellaro M. Salvo F. Patat A. Piemonte J. Sollerman B. Leibundgut G. Altavilla 《Monthly notices of the Royal Astronomical Society》2005,360(3):950-962
We present spectroscopic and photometric observations of the peculiar Type II supernova (SN) 1998A. The light curves and spectra closely resemble those of SN 1987A, suggesting that the SN 1998A progenitor exploded when it was a compact blue supergiant. However, the comparison with SN 1987A also highlights some important differences: SN 1998A is more luminous and the spectra show bluer continua and larger expansion velocities at all epochs. These observational properties indicate that the explosion of SN 1998A is more energetic than SN 1987A and more typical of Type II supernovae. Comparing the observational data with simulations, we deduce that the progenitor of SN 1998A was a massive star (∼25 M⊙ ) with a small pre-supernova radius (≲6 × 1012 cm) . The Ba ii lines, unusually strong in SN 1987A and some faint II-P events, are almost normal in the case of SN 1998A, indicating that the temperature plays a key role in determining their strength. 相似文献
13.
E. Sonbas A. S. Moskvitin T. A. Fatkhullin V. V. Sokolov A. Castro-Tirado A. De Ugarte Postigo G. Gorosabel S. Guzij M. Jelinec T. N. Sokolova V. N. Chernenkov 《Astrophysical Bulletin》2008,63(3):228-243
The spectra of the supernova SN 2006aj identified with the X-ray flash (XRF) and gammaray burst XRF/GRB 060218/SN 2006aj taken with the 6-m telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences are found to exhibit features, which can be interpreted as hydrogen lines. Such features indicate the existence of a stellar-wind envelope around the massive star—the progenitor of the gamma-ray burst. The results of our modeling of two early spectra taken with the 6-m telescope 2.55 and 3.55 days after the explosion of the type-Ic supernova SN 2006aj (z=0.0331) are reported. The spectra are modeled in the Sobolev approximation using SYNOW code [1, 2]. The spectra of the optical afterglow of the X-ray flash XRF/GRB 060218 are found to exhibit spectral features, which can be interpreted as: (1) the P Cyg-profile of the Hα line for the velocity of 33000 km/s—a broad and small deformation of the continuum in the wavelength interval 5600–6600Å for the first epoch (2.55 days) and (2) a part of the P Cyg-profile of the Hα line in absorption blueshifted by 24000 km/s—a broad spectral feature with a minimum at 6100Å (rest wavelength) for the second epoch (3.55 days). Given earlier observations made with the 6-m telescope and the spectra taken with other telescopes (ESO Lick, ESO VLT and NOT) prior to February 23, 2006, it can be concluded that we are observing the evolution of optical spectra of the type Ic massive supernova SN2006aj during its transition from the short phase with the “shock breakout” into the external layers of the stellar-wind envelope to the spectra of the phase of rising supernova luminosity, which corresponds to radiative heating. We are the first to observe the signs of hydrogen in the spectra of a gamma-ray afterglow. 相似文献
14.
Korzennik SG Brown TM Fischer DA Nisenson P Noyes RW 《The Astrophysical journal》2000,534(2):L147-L150
We present deep Hubble Space Telescope (HST) imaging, as well as ground-based imaging and spectroscopy, of the optical afterglow associated with the long-duration gamma-ray burst GRB 990712 and its host galaxy. The data were obtained 48-123 days after the burst occurred. The magnitudes of the host (R=21.9, V=22.5) and optical afterglow (R=25.4, V=25.8, 47.7 days after the burst) favor a scenario in which the optical light follows a pure power-law decay with an index of alpha approximately -1.0. We find no evidence for a contribution from a supernova like SN 1998bw. This suggests that either there are multiple classes of long-duration gamma-ray bursts or that the peak luminosity of the supernova was more than 1.5 mag fainter than SN 1998bw. The HST images and EFOSC2 spectra indicate that the gamma-ray burst was located in a bright, extended feature (possibly a star-forming region) 1.4 kpc from the nucleus of a 0.2L*B galaxy at z=0.434, possibly a Seyfert 2 galaxy. The late-time afterglow and host galaxy of GRB 990712 bear some resemblance to those of GRB 970508. 相似文献
15.
Vasilii Gvaramadze 《Astrophysics and Space Science》2000,274(1-2):195-203
A model of the Vela supernova remnant (SNR) based on a cavity explosion of a supernova (SN) star is proposed. It is suggested
that the general structure of the remnant is determined by the interaction of the SN blast wave with a massive shell created
by the SN progenitor (15-20 M⊙) star. A possible origin of the nebula of hard X-ray emission detected around the Velapulsar is discussed.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
16.
Takuji Tsujimoto Toshikazu Shigeyama Yuzuru Yoshii 《Astrophysics and Space Science》2002,281(1-2):221-222
Following our hypothesis that each supernova (SN) event triggers star formation in the swept-up gas, so that newly formed
stars inherit the elemental abundance pattern of individual SNe, we deduce the production sites and yields for r-process elements. We further show that a strong evidence for the origin of r-process nucleosynthesis products was just there in our backyard - supernova SN1987A -, and conclude that 20 M
⊙ SNe are the predominant production sites for r-process elements.
This revised version was published online in September 2006 with corrections to the Cover Date. 相似文献
17.
Turatto M Suzuki T Mazzali PA Benetti S Cappellaro E Danziger IJ Nomoto K Nakamura T Young TR Patat F 《The Astrophysical journal》2000,534(1):L57-L61
The extraordinary SN 1997cy associated with GRB 970514 has been observed photometrically and spectroscopically for nearly 2 yr. At the time of discovery, SN 1997cy was the brightest supernova (SN) ever observed (MV=-20.1, vhel=19,140 km s-1, H0=65 km s-1 Mpc-1). Up to the last available observations (600 days after the gamma-ray burst), the total time-integrated flux was equal to or larger than that expected from the complete thermalization of the gamma-rays produced by 2.3 M middle dot in circle of 56Co. However, starting already on day 60 the luminosity decline is slower than the 56Co decay rate, indicating that the SN ejecta was interacting with circumstellar material (CSM). The interaction appeared to weaken around day 550. The spectra of SN 1997cy are dominated at all epochs by Halpha emission, which shows at least three components of different widths, as in SN 1988Z. Several other lines with different widths are also visible, especially at early epochs. The entire light curve of SN 1997cy is reproduced by a model of the interaction of the very energetic (E=3x1052 ergs) ejecta of a massive star (25 M middle dot in circle) with the CSM, with some contribution from radioactive decays. The CSM could have been ejected with a mass-loss rate of M&d2; approximately 4x10-4 M middle dot in circle yr-1 as the progenitor star evolved from a blue to a red supergiant about 104 yr before the explosion. The lack of oxygen and magnesium lines in the spectra at nebular phases poses a problem for models requiring high-mass progenitors. The possibility that most of the core material of the progenitor has fallen onto a massive black hole so that the reverse shock dies at the inner edge of the H/He envelope is discussed. 相似文献
18.
D. Yu. Tsvetkov P. V. Balanutsa V. M. Lipunov I. M. Volkov O. A. Tuchin I. P. Kudelina M. V. Pruzhinskaya E. S. Gorbovskoy V. G. Kornilov A. A. Belinskii N. V. Tyurina V. V. Yurkov Yu. P. Sergienko A. G. Tlatov A. V. Parkhomenko D. V. Dormidontov V. A. Senik V. V. Krushinskii 《Astronomy Letters》2011,37(11):775-782
We present the results of our UBVRI CCD photometry for the second brightest supernova of 2009, SN 2009nr, discovered during a sky survey with the telescopes of the MASTER robotic network. Its light and color curves and bolometric light curves have been constructed. The light-curve parameters and the maximum luminosity have been determined. SN 2009nr is shown to be similar in light-curve shape and maximum luminosity to SN 1991T, which is the prototype of the class of supernovae Ia with an enhanced luminosity. SN 2009nr exploded far from the center of the spiral galaxy UGC 8255 and most likely belongs to its old halo population. We hypothesize that this explosion is a consequence of the merger of white dwarfs. 相似文献
19.
We model the interaction of the supernova SN 1995G with a dense circumstellar (CS) gas in a thin-shell approximation. A model fit to the observed bolometric light curve combined with data on the supernova expansion velocity gives estimates for the density, mass (≈1 M⊙), and age (≈8 yr) of the CS envelope. The determined CS-envelope density is shown to be virtually independent of the assumed mass of the supernova envelope because of the high CS-gas density at which the forward shock wave is essentially radiative. The derived CS-envelope density is consistent with the Hα luminosity and with the presence of distinct Thomson scattering in the red wing of this line. The mass of the CS envelope together with its expansion velocity and age indicate that the CS envelope was ejected by the presupernova eight years before the supernova explosion through violent energy release (~6×1048 erg). 相似文献
20.
Kuntal Misra Dave Pooley † Poonam Chandra D. Bhattacharya Alak K. Ray Ram Sagar Walter H. G. Lewin 《Monthly notices of the Royal Astronomical Society》2007,381(1):280-292
We present X-ray, broad-band optical and low-frequency radio observations of the bright type IIP supernova SN 2004et. The Chandra X-ray Observatory observed the supernova at three epochs, and the optical coverage spans a period of ∼470 d since explosion. The X-ray emission softens with time, and we characterize the X-ray luminosity evolution as L X ∝ t −0.4 . We use the observed X-ray luminosity to estimate a mass-loss rate for the progenitor star of ∼2 × 10−6 M⊙ yr−1 . The optical light curve shows a pronounced plateau lasting for about 110 d. Temporal evolution of photospheric radius and colour temperature during the plateau phase is determined by making blackbody fits. We estimate the ejected mass of 56 Ni to be 0.06 ± 0.03 M⊙ . Using the expressions of Litvinova & Nadëzhin we estimate an explosion energy of (0.98 ± 0.25) × 1051 erg . We also present a single epoch radio observation of SN 2004et. We compare this with the predictions of the model proposed by Chevalier, Fransson & Nymark. These multiwavelength studies suggest a main-sequence progenitor mass of ∼20 M⊙ for SN 2004et. 相似文献