van der Horst 2010 XRF080109/SN2008D and SN2007uy的射电观测

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XRF080109d的射电

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Title:		Detailed Radio View on Two Stellar Explosions and Their Host Galaxy: XRF080109/SN2008D and SN2007uy in NGC2770
Authors:		van der Horst, A. J.; Kamble, A. P.; Paragi, Z.; Sage, L. J.; Pal, S.; Taylor, G. B.; Kouveliotou, C.; Granot, J.; Ramirez-Ruiz, E.; Ishwara-Chandra, C. H.; Oosterloo, T. A.; Wijers, R. A. M. J.; Wiersema, K.; Strom, R. G.; Bhattacharya, D.; Rol, E.; Starling, R. L. C.; Curran, P. A.; Garrett, M. A.
Publication:		eprint arXiv:1011.2521
Publication Date:		11/2010
Origin:		ARXIV
Keywords:		Astrophysics - High Energy Astrophysical Phenomena
Comment:		13 pages, 6 figures, 3 tables; accepted for publication in ApJ
Bibliographic Code:		2010arXiv1011.2521V

Abstract

The galaxy NGC2770 hosted two core-collapse supernova explosions, SN2008D and SN2007uy, within 10 days of each other and 9 years after the first supernova of the same type, SN1999eh, was found in that galaxy. In particular SN2008D attracted a lot of attention due to the detection of an X-ray outburst, which has been hypothesized to be caused by either a (mildly) relativistic jet or the supernova shock breakout. We present an extensive study of the radio emission from SN2008D and SN2007uy: flux measurements with the Westerbork Synthesis Radio Telescope and the Giant Metrewave Radio Telescope, covering ~600 days with observing frequencies ranging from 325 MHz to 8.4 GHz. The results of two epochs of global Very Long Baseline Interferometry observations are also discussed. We have examined the molecular gas in the host galaxy NGC2770 with the Arizona Radio Observatory 12-m telescope, and present the implications of our observations for the star formation and seemingly high SN rate in this galaxy. Furthermore, we discuss the near-future observing possibilities of the two SNe and their host galaxy at low radio frequencies with the Low Frequency Array.

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Moskvitin 2010 XRF 080109 / SN 2008D and GRB 060218 / SN 2006aj包层速度的演化

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得到了两个时间的谱，通过谱可以得到速度。

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两个时间的谱，黑色6.48天，灰色27.62天

6.48天的谱的拟合

27.6天的谱的拟合

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Title:		Study of Envelope Velocity Evolution of Type Ib-c Core-Collapse Supernovae from Observations of XRF 080109 / SN 2008D and GRB 060218 / SN 2006aj with BTA
Authors:		Moskvitin, A. S.; Sonbas, E.; Sokolov, V. V.; Fatkhullin, T. A.; Castro-Tirado, A. J.
Publication:		eprint arXiv:1004.2633
Publication Date:		04/2010
Origin:		ARXIV
Keywords:		Astrophysics - High Energy Astrophysical Phenomena
Comment:		12 pages, 6 figures, accepted for publication in Astrophysical Bulletin.
Bibliographic Code:		2010arXiv1004.2633M

Abstract

Results of modeling the spectra of two supernovae SN 2008D and SN 2006aj related to the X-ray flash XRF 080109 and gamma-ray burst GRB / XRF 060218, respectively, are studied. The spectra were obtained with the 6-meter BTA telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences in 6.48 and 27.61 days after the explosion of SN 2008D, and in 2.55 and 3.55 days after the explosion of SN 2006aj. The spectra were interpreted in the Sobolev approximation with the SYNOW code. An assumption about the presence of envelopes around the progenitor stars is confirmed by an agreement between the velocities of lines interpreted as hydrogen and helium, and the empiric power-law velocity drop with time for the envelopes of classic core-collapse supernovae. Detection of a P Cyg profile of the H-beta line in the spectra of optical afterglows of GRBs can be a determinative argument in favor of this hypothesis.

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Couch 2010 数值模拟SN 2008D的非对称shock breakout

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初始的密度分布

shock的演化


































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Title:		Aspherical Supernova Shock Breakout and the Observations of Supernova 2008D
Authors:		Couch, Sean M.; Pooley, David; Wheeler, J. Craig; Milosavljevic, Milos
Publication:		eprint arXiv:1007.3693
Publication Date:		07/2010
Origin:		ARXIV
Keywords:		Astrophysics - High Energy Astrophysical Phenomena
Comment:		17 page, 27 figures. Submitted to ApJ
Bibliographic Code:		2010arXiv1007.3693C

Abstract

Shock breakout is the earliest, readily-observable emission from a core-collapse supernova explosion. Observing supernova shock breakout may yield information about the nature of the supernova shock prior to exiting the progenitor and, in turn, about the core-collapse supernova mechanism itself. X-ray Outburst 080109, later associated with SN 2008D, is a very well-observed example of shock breakout from a core-collapse supernova. Despite excellent observational coverage and detailed modeling, fundamental information about the shock breakout, such as the radius of breakout and driver of the light curve time scale, is still uncertain. The models constructed for explaining the shock breakout emission from SN 2008D all assume spherical symmetry. We present a study of the observational characteristics of {\it aspherical} shock breakout from stripped-envelope core-collapse supernovae. We conduct two-dimensional, jet-driven supernova simulations from stripped-envelope progenitors and calculate the resulting shock breakout X-ray spectra and light curves. The X-ray spectra evolve significantly in time as the shocks expand outward and are not well-fit by single-temperature and radius black bodies. The time scale of the X-ray burst light curve of the shock breakout is related to the shock crossing time of the progenitor, not the much shorter light crossing time that sets the light curve time scale in spherical breakouts. This could explain the long shock breakout light curve time scale observed for XRO 080109/SN 2008D.

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Nomoto 2009 第一代星和Ib型超新星的联系

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Title:		First Stars Type Ib Supernovae Connection
Authors:		Nomoto, Ken'ichi; Tanaka, Masaomi; Kamiya, Yasuomi; Tominaga, Nozomu; Maeda, Keiichi
Publication:		Low-Metallicity Star Formation: From the First Stars to Dwarf Galaxies, Proceedings of the International Astronomical Union, IAU Symposium, Volume 255, p. 182-188
Publication Date:		12/2008
Origin:		CUP
Keywords:		Galaxy: halo, gamma rays: bursts, nuclear reactions, nucleosynthesis, abundances, stars: abundances, stars: Population II, supernovae: general
Abstract Copyright:		(c) 2008: Copyright © International Astronomical Union 2008
DOI:		10.1017/S1743921308024794
Bibliographic Code:		2008IAUS..255..182N

Abstract

The very peculiar abundance patterns observed in extremely metal-poor (EMP) stars can not be explained by conventional normal supernova nucleosynthesis but can be well-reproduced by nucleosynthesis in hyper-energetic and hyper-aspherical explosions, i.e., Hypernovae (HNe). Previously, such HNe have been observed only as Type Ic supernovae. Here, we examine the properties of recent Type Ib supernovae (SNe Ib). In particular, SN Ib 2008D associated with the luminous X-ray transient 080109 is found to be a more energetic explosion than normal core-collapse supernovae. We estimate that the progenitor's main sequence mass is M_MS = 20 ‑ 25M_ȯ with an explosion of kinetic energy of E_K ~ 6.0 × 10⁵¹ erg. These properties are intermediate between those of normal SNe and hypernovae associated with gamma-ray bursts. Therefore, such energetic SNe Ib could also make an important contribution to the chemical enrichment in the early Universe.

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Bietenholz 2008 VLBI Observations of SN 2008D

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简单地说就是一正常超新星. 速度的upper limit是0.75 c.
和一般超新星的膨胀速度小于30, 000 km s−1也是一致的.

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Title:		VLBI Observations of SN 2008D
Authors:		Bietenholz, M. F.; Soderberg, A. M.; Bartel, N.
Publication:		eprint arXiv:0811.3173
Publication Date:		11/2008
Origin:		ARXIV
Keywords:		Astrophysics
Bibliographic Code:		2008arXiv0811.3173B

Abstract

We report on two epochs of VLBI observations of the Type Ib/c supernova SN 2008D, which was associated with the X-ray outburst XRF 080109, At our first epoch, at t=30 days after the explosion, we observed at 22 and 8.4 GHz, and at our second, at t=133 days, at 8.4 and 5.0 GHz. The VLBI observations allow us to accurately measure the source's size and position at each epoch, and thus constrain its expansion velocity and proper motion. We find the source at best marginally resolved at both epochs, allowing us to place a 3sigma upper limit of ~0.75c on the expansion velocity of a circular source. For an elongated source, our measurements are compatible with mildly relativistic expansion. However, our 3sigma upper limit on the proper motion is 4 micro-arcsec/day, corresponding to an apparent velocity of <0.6c,>c. Taken together, our measurements argue against the presence of any long-lived relativistic outflow in SN 2008D. On the other hand, our measurements are consistent with the non-relativistic expansion velocities of <30,000> Bibtex entry for this abstract Preferred format for this abstract (see Preferences)

Gorosabel 2008 SN2008D/XRF080109 polarization

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Title:		Simultaneous polarization monitoring of SN2007uy and the axisymmetric SN2008D/XRF080109: isolating geometry from dust
Authors:		Gorosabel, J.; de Ugarte Postigo, A.; Castro-Tirado, A. J.; Agudo, I.; Jelinek, M.; Leon, S.; Augusteijn, T.; Fynbo, J. P. U.; Hjorth, J.; Michalowski, M. J.; Xu, D.; Ferrero, P.; Kann, D. A.; Klose, S.; Rossi, A.; Madrid, J. P.; LLorente, A.; Bremer, M.; Winters, J. -M.
Publication:		eprint arXiv:0810.4333
Publication Date:		10/2008
Origin:		ARXIV
Keywords:		Astrophysics
Comment:		4 pages, 1 figure, submitted to ApJL. Comments welcome
Bibliographic Code:		2008arXiv0810.4333G

Abstract

We report the results of an optical linear polarization monitoring carried out simultaneously for SN2007uy and SN2008D. The observations span 74.9 days, starting 3.6 days after the X-ray outburst of SN2008D and are distributed in 11 visits. For both SNe the polarization is dominated by the host galaxy interstellar polarization (HGIP), especially for SN2007uy. This fact is supported by 1.2 millimeter (mm) observations of NGC2770, carried out at and around the SN2008D position. The 1.2 mm data are consistent with no intrinsic emission from SN2008D and can be entirely explained by the NGC2770 dust emission. Comparing spectroscopic extinction values reported in the literature with the extinction derived from the 1.2 mm data, we conclude that the NGC2770 extinction distribution is heterogeneous. We report also a 3.3 mm flux detection at the SN2008D position, possibly due to the intrinsic SN emission, and not due to the dust. Despite the dominant HGIP, a statistical analysis of the distribution of the SN2008D Stokes parameters strongly suggests an intrinsic variable polarization component. Moreover we show that the temporal evolution of the intrinsic SN2008D polarization agrees with an aspherical axisymmetric expansion with variable eccentricity, consistent with the Collapsar model. In contrast, the SN2007uy polarization can be described by the HGIP plus a constant eccentricity expansion. We conclude that the geometric evolution of the two SNe is intrinsically different.

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Brown 2008 SN 2008D may be the same as SN 1987A

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Title:		Supernova 2008D: A Repetition of Supernova 1987A In a Binary
Authors:		Brown, Gerald E.; Lee, Chang-Hwan
Publication:		eprint arXiv:0810.0912
Publication Date:		10/2008
Origin:		ARXIV
Keywords:		Astrophysics
Comment:		4 pages, 1 figure
Bibliographic Code:		2008arXiv0810.0912B

Abstract

The Supernova 2008D is similar to that of SN 1987A without the H-envelope. Soderberg et al.(2008) reported the serendipitous discovery of the SN2008D at the time of the explosion, accompanied by an X-ray outburst XRF080109. The central remnant, which we believe to be the black-hole (BH) central engine in the Blandford-Znajek mechanism, is estimated, on the basis of the 7% 56Ni production, to have a mass of 1.6-1.8 M_sun. This is not much larger than the upper limit of 1.56 m_sun for the mass of the compact object in SN1987A found by Bethe & Brown (1995); also, on the basis of the 7.5% 56Ni production, they interpreted it as a low-mass BH. Redoing the light curve so as to take into account the absence of convective carbon burning from zero age main sequence 18-24 M_sun and replacing it by carbon shell burning, we see that the remnant in SN2008D must be less massive than in SN 1987A; there of 18 M_sun. Thus, the maximum neutron star mass is 1.5 M_sun. Note that the metallicity of the host galaxy of SN2008D is similar to that of our Galaxy.

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Wang 2008 超新星shock breakout出来的非热辐射

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Title:		Non-thermal emission from supernova shock breakout and the origin of the X-ray transient associated with SN2008D
Authors:		Wang, Xiang-Yu; Li, Zhuo; Waxman, Eli; Meszaros, Peter
Publication:		eprint arXiv:0808.4006
Publication Date:		08/2008
Origin:		ARXIV
Keywords:		Astrophysics
Comment:		6 pages, 1 figure, based on the talk given by Xiang-Yu Wang at the "2008 Nanjing GRB Conference" (evening focused discussion), To appear in the "2008 Nanjing GRB Conference" conference proceedings
Bibliographic Code:		2008arXiv0808.4006W

Abstract

We suggest that non-thermal emission can be produced by multiple scatterings of the photons between the supernova ejecta and pre-shock material in supernova shock breakout. Such bulk-Comptonization process may significantly change the original thermal photon spectrum, forming a power-law non-thermal component at higher energies. We then show that the luminous X-ray outburst XRO081009 associated with SN2008D is likely to be such shock breakout emission from an ordinary type Ib/c supernova.

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Hu 2008 XRO 080109/SN 2008D的MHD+shock breakout模型

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We propose to attribute the "non-thermal spectrum" observed to be a superposition of different thermal spectra produced at different layers of the stellar envelope.

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Title:		Rebound Shock Breakouts of Exploding Massive Stars: A MHD Void Model
Authors:		Hu, Ren-Yu; Lou, Yu-Qing
Publication:		eprint arXiv:0808.3905
Publication Date:		08/2008
Origin:		ARXIV
Keywords:		Astrophysics
Comment:		4 pages, 1 figure, to appear in the proceedings of Nanjing 2008 GRB Conference, Nanjing, China, 23-27 June 2008
Bibliographic Code:		2008arXiv0808.3905H

Abstract

With a self-similar magnetohydrodynamic (MHD) model of an exploding progenitor star and an outgoing rebound shock and with the thermal bremsstrahlung as the major radiation mechanism in X-ray bands, we reproduce the early X-ray light curve observed for the recent event of XRO 080109/SN 2008D association. The X-ray light curve consists of a fast rise, as the shock travels into the "visible layer" in the stellar envelope, and a subsequent power-law decay, as the plasma cools in a self-similar evolution. The observed spectral softening is naturally expected in our rebound MHD shock scenario. We propose to attribute the "non-thermal spectrum" observed to be a superposition of different thermal spectra produced at different layers of the stellar envelope.

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Tanaka 2008 SN2008D的大质量氦星模型

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Title:		Supernova 2008D associated with the Luminous X-ray Transient 080109: An Energetic Explosion of a Massive Helium Star
Authors:		Tanaka, Masaomi; Tominaga, Nozomu; Nomoto, Ken'ichi; Valenti, S.; Sahu, D. K.; Minezaki, T.; Yoshii, Y.; Yoshida, M.; Anupama, G. C.; Benetti, S.; Chincarini, G.; Della Valle, M.; Mazzali, P. A.; Pian, E.
Publication:		eprint arXiv:0807.1674
Publication Date:		07/2008
Origin:		ARXIV
Keywords:		Astrophysics
Comment:		8 pages, 8 figures, Submitted to the Astrophysical Journal
Bibliographic Code:		2008arXiv0807.1674T

Abstract

We present a theoretical model for supernova (SN) 2008D associated with the luminous X-ray transient 080109. The optical light curve and spectra of the SN are modeled based on realistic progenitor models and the explosion models are obtained from hydrodynamic/nucleosynthetic calculations. We find that SN 2008D is a more energetic explosion than normal core-collapse supernovae, with an ejecta mass of Mej = 5.3 +- 1.0 Msun and a kinetic energy of KE = 6.0 +- 2.5 x 10^{51} erg. The mass of the progenitor is estimated to be Mms = 20-25 Msun. These properties are intermediate between those of normal SNe and hypernovae associated with gamma-ray bursts. The mass of the central remnant is estimated as 1.6 - 1.8 Msun, which is near the boundary between neutron star and black hole formation.

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Mazzali 2008 SN2008D/XRF080109的观测

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包括谱

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Title:		The metamorphosis of Supernova SN2008D/XRF080109: a link between Supernovae and GRBs/Hypernovae
Authors:		Mazzali, Paolo A.; Valenti, Stefano; Della Valle, Massimo; Chincarini, Guido; Sauer, Daniel N.; Benetti, Stefano; Pian, Elena; Piran, Tsvi; D'Elia, Valerio; Elias-Rosa, Nancy; Margutti, Raffaella; Pasotti, Francesco; Antonelli, L. Angelo; Bufano, Filomena; Campana, Sergio; Cappellaro, Enrico; Covino, Stefano; D'Avanzo, Paolo; Fiore, Fabrizio; Fugazza, Dino; Gilmozzi, Roberto; Hunter, Deborah; Maguire, Kate; Maiorano, Elisabetta; Marziani, Paola; Masetti, Nicola; Mirabel, Felix; Navasardyan, Hripsime; Nomoto, Ken'ichi; Palazzi, Eliana; Pastorello, Andrea; Panagia, Nino; Pellizza, Leonardo J.; Sari, Re'em; Smartt, Stephen; Tagliaferri, Gianpiero; Tanaka, Masaomi; Taubenberger, Stefan; Tominaga, Nozomu; Trundle, Carrie; Turatto, Massimo
Publication:		eprint arXiv:0807.1695
Publication Date:		07/2008
Origin:		ARXIV
Keywords:		Astrophysics
Comment:		22 pages, 7 figures. Accepted for publication in Science
Bibliographic Code:		2008arXiv0807.1695M

Abstract

The only supernovae (SNe) to have shown early gamma-ray or X-ray emission thus far are overenergetic, broad-lined Type Ic SNe (Hypernovae - HNe). Recently, SN 2008D shows several novel features: (i) weak XRF, (ii) an early, narrow optical peak, (iii) disappearance of the broad lines typical of SNIc HNe, (iv) development of He lines as in SNeIb. Detailed analysis shows that SN 2008D was not a normal SN: its explosion energy (KE ~ 6*10^{51} erg) and ejected mass (~7 Msun) are intermediate between normal SNeIbc and HNe. We derive that SN 2008D was originally a ~30Msun star. When it collapsed a black hole formed and a weak, mildly relativistic jet was produced, which caused the XRF. SN 2008D is probably among the weakest explosions that produce relativistic jets. Inner engine activity appears to be present whenever massive stars collapse to black holes.

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Chevalier 2008 XRF 080109/SN 2008D的shock breakout 模型

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arXiv:0806.0371 [ps, pdf, other]

Title: Shock Breakout Emission from a Type Ib/c Supernova: XRF 080109/SN 2008D

Authors: Roger A. Chevalier, Claes Fransson

Comments: 11 pages, 1 figure, submitted to ApJL 4/30/08

Subjects: Astrophysics (astro-ph)

The X-ray flash 080109, associated with SN 2008D, can be attributed to the shock breakout emission from a normal Type Ib/c supernova. If the observed emission is interpreted as blackbody emission, the temperature and radiated energy are close to expectations, considering that scattering dominates absorption processes so that spectrum formation occurs deep within the photosphere. The X-ray emission observed at ~10 days is attributed to inverse Compton scattering of photospheric photons with relativistic electrons produced in the interaction of the supernova with the progenitor wind. A simple model for the optical/ultraviolet emission from shock breakout is developed and applied to SN 1987A, SN 1999ex, SN 2008D, and SN 2006aj, all of which have optical emission observed at t~1 day. The emission from the first three can plausibly be attributed to shock breakout emission. The photospheric temperature is most sensitive to the radius of the progenitor star core and the radii in these cases are in line with expectations from stellar evolution. The early optical/ultraviolet observations of SN 2006aj cannot be accommodated by a shock breakout model in a straightforward way.

Malesani 2008 SN 2008D 的早期谱

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Title:		Early spectroscopic identification of SN 2008D
Authors:		Malesani, D.; Fynbo, J. P. U.; Hjorth, J.; Leloudas, G.; Sollerman, J.; Stritzinger, M. D.; Vreeswijk, P. M.; Watson, D. J.; Gorosabel, J.; Michałowski, M. J.; Thöne, C. C.; Augusteijn, T.; Bersier, D.; Jakobsson, P.; Jaunsen, A. O.; Ledoux, C.; Levan, A. J.; Milvang-Jensen, B.; Rol, E.; Tanvir, N. R.; Wiersema, K.; Xu, D.; Albert, L.; Bayliss, M.; Gall, C.; Grove, L. F.; Koester, B. P.; Leitet, E.; Pursimo, T.; Skillen, I.
Publication:		eprint arXiv:0805.1188
Publication Date:		05/2008
Origin:		ARXIV
Keywords:		Astrophysics
Comment:		6 pages, 5 figures, 4 tables; submitted to ApJ Letters
Bibliographic Code:		2008arXiv0805.1188M

Abstract

SN 2008D was discovered while following up a luminous, unusual X-ray transient in the nearby spiral galaxy NGC 2770. We present early spectra of the optical counterpart (1.77 days after the X-ray transient) which first allowed to identify the object as a supernova at redshift z = 0.007. These spectra were acquired during the initial declining phase of the light curve, likely due to the shock breakout. They show a relatively flat continuum with broad undulations, and a strong, W-shaped feature with minima at 3980 and 4190 AA (rest frame). We also present extensive spectroscopic and photometric monitoring of the supernova covering the photospheric phase. Unlike supernovae associated with gamma-ray bursts, SN 2008D displayed prominent He features and is therefore of Type Ib.

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