132 research outputs found
Modeling SNR G1.9+0.3 as a Supernova Inside a Planetary Nebula
Using 3D numerical hydrodynamical simulations we show that a type Ia
supernova (SN Ia) explosion inside a planetary nebula (PN) can explain the
observed shape of the G1.9+0.3 supernova remnant (SNR) and its X-ray
morphology. The SNR G1.9+0.3 morphology can be generally described as a sphere
with two small and incomplete lobes protruding on opposite sides of the SNR,
termed "ears", a structure resembling many elliptical PNe. Observations show
the synchrotron X-ray emission to be much stronger inside the two ears than in
the rest of the SNR. We numerically show that a spherical SN Ia explosion into
a circumstellar matter (CSM) with the structure of an elliptical PN with ears
and clumps embedded in the ears can explain the X-ray properties of SNR
G1.9+0.3. While the ejecta has already collided with the PN shell in most of
the SNR and its forward shock has been slowed down, the ejecta is still
advancing inside the ears. The fast forward shock inside the ears explains the
stronger X-ray emission there. SN Ia inside PNe (SNIPs) seem to comprise a
non-negligible fraction of resolved SN Ia remnants.Comment: Revised version. 19 pages, 8 figures. Accepted to MNRA
Planning the experiment and optimization of the content of nanoadition in polypropylene monothreads
ΠΠ»Π°Π½ΡΠ²Π°Π½Π½Ρ Π΅ΠΊΡΠΏΠ΅ΡΠΈΠΌΠ΅Π½ΡΡ ΡΠ° ΠΎΠΏΡΠΈΠΌΡΠ·Π°ΡΡΡ ΡΠΊΠ»Π°Π΄Ρ ΠΊΠΎΠΌΠΏΠΎΠ·ΠΈΡΡΡ ΠΏΠΎΠ»ΡΠΏΡΠΎΠΏΡΠ»Π΅Π½/Π±ΡΠ½Π°ΡΠ½Π° Π½Π°Π½ΠΎΠ΄ΠΎΠ±Π°Π²ΠΊΠ° ΡΠΎΠ΄ΠΎ ΠΎΠ΄Π΅ΡΠΆΠ°Π½Π½Ρ ΠΏΠΎΠ»ΡΠΏΡΠΎΠΏΡΠ»Π΅Π½ΠΎΠ²ΠΈΡ
ΠΌΠΎΠ½ΠΎΠ½ΠΈΡΠΎΠΊ Π· Π²ΠΈΡΠΎΠΊΠΈΠΌΠΈ ΠΌΠ΅Ρ
Π°Π½ΡΡΠ½ΠΈΠΌΠΈ ΡΠ° Π°Π½ΡΠΈΠΌΡΠΊΡΠΎΠ±Π½ΠΈΠΌΠΈ Π²Π»Π°ΡΡΠΈΠ²ΠΎΡΡΡΠΌΠΈ. ΠΠ»Ρ ΠΏΠ»Π°Π½ΡΠ²Π°Π½Π½Ρ Π΅ΠΊΡΠΏΠ΅ΡΠΈΠΌΠ΅Π½ΡΡ Π·Π°ΡΡΠΎΡΠΎΠ²Π°Π½ΠΎ ΡΠΈΠΌΠΏΠ»Π΅ΠΊΡΠ½ΠΎ-Π³ΡΠ°ΡΠΊΠΎΠ²ΠΈΠΉ ΠΌΠ΅ΡΠΎΠ΄ Ρ ΠΏΡΠ΅Π²Π΄ΠΎΠΊΠΎΠΎΡΠ΄ΠΈΠ½Π°ΡΠ°Ρ
. ΠΠΏΡΠΈΠΌΡΠ·Π°ΡΡΡ Π²ΠΌΡΡΡΡ Π½Π°Π½ΠΎΠ΄ΠΎΠ±Π°Π²ΠΊΠΈ ΠΏΡΠΎΠ²Π΅Π΄Π΅Π½ΠΎ Π· Π²ΠΈΠΊΠΎΡΠΈΡΡΠ°Π½Π½ΡΠΌ ΠΊΡΠΈΡΠ΅ΡΡΡ Π₯Π°ΡΡΠΈΠ½Π³ΡΠΎΠ½Π°. ΠΠ΅ΡΠΎΠ΄ΠΎΠΌ ΠΌΠ°ΡΠ΅ΠΌΠ°ΡΠΈΡΠ½ΠΎΠ³ΠΎ ΠΌΠΎΠ΄Π΅Π»ΡΠ²Π°Π½Π½Ρ Π΄ΠΎΡΠ»ΡΠ΄ΠΆΠ΅Π½ΠΎ Π²ΠΏΠ»ΠΈΠ² Π½Π°Π½ΠΎΠ΄ΠΎΠ±Π°Π²ΠΊΠΈ ΡΡΡΠ±Π»ΠΎ/ΠΊΡΠ΅ΠΌΠ½Π΅Π·Π΅ΠΌ (Ag/SiO2) Π½Π° Π²Π»Π°ΡΡΠΈΠ²ΠΎΡΡΡ ΠΏΠΎΠ»ΡΠΏΡΠΎΠΏΡΠ»Π΅Π½ΠΎΠ²ΠΈΡ
(ΠΠ) ΠΌΠΎΠ½ΠΎΠ½ΠΈΡΠΎΠΊ ΡΠ° ΠΎΠΏΡΠΈΠΌΡΠ·ΠΎΠ²Π°Π½ΠΎ ΡΠΊΠ»Π°Π΄ ΠΊΠΎΠΌΠΏΠΎΠ·ΠΈΡΡΡ Π΄Π»Ρ ΡΡ
ΡΠΎΡΠΌΡΠ²Π°Π½Π½Ρ. Π‘ΡΠ²ΠΎΡΠ΅Π½Π° ΠΌΠ°ΡΠ΅ΠΌΠ°ΡΠΈΡΠ½Π° ΠΌΠΎΠ΄Π΅Π»Ρ, ΡΠΎ Π²ΡΡΠ°Π½ΠΎΠ²Π»ΡΡ Π²Π·Π°ΡΠΌΠΎΠ·Π²βΡΠ·ΠΎΠΊ ΠΌΡΠΆ Π²ΠΌΡΡΡΠΎΠΌ ΠΊΠΎΠΌΠΏΠΎΠ½Π΅Π½ΡΡΠ² ΡΡΠΌΡΡΡ ΡΠ° Π²Π»Π°ΡΡΠΈΠ²ΠΎΡΡΡΠΌΠΈ Π½Π°Π½ΠΎΠ½Π°ΠΏΠΎΠ²Π½Π΅Π½ΠΈΡ
ΠΠ Π½ΠΈΡΠΎΠΊ. ΠΠΎΠ΄ΠΈΡΡΠΊΠΎΠ²Π°Π½Ρ ΠΌΠΎΠ½ΠΎΠ½ΠΈΡΠΊΠΈ, ΡΡΠΎΡΠΌΠΎΠ²Π°Π½Ρ Π· ΠΎΠΏΡΠΈΠΌΠ°Π»ΡΠ½ΠΎΠ³ΠΎ ΡΠΊΠ»Π°Π΄Ρ ΠΊΠΎΠΌΠΏΠΎΠ·ΠΈΡΡΡ ΠΠ/Π½Π°Π½ΠΎΠ΄ΠΎΠ±Π°Π²ΠΊΠ°, ΠΏΠΎΡΠ΄Π½ΡΡΡΡ Π²ΠΈΡΠΎΠΊΡ ΠΌΡΡΠ½ΡΡΡΡ, Π΅Π»Π°ΡΡΠΈΡΠ½ΡΡΡΡ ΡΠ° ΠΏΡΠΎΡΠ²Π»ΡΡΡΡ Π°Π½ΡΠΈΠΌΡΠΊΡΠΎΠ±Π½Ρ Π΄ΡΡ
A method of forming composite structures using in situ -formed liquid crystal polymer fibers in a thermoplastic matrix
A new high speed and potentially economical method of creating a composite material and structures therefrom is tested. The method consists of spinning composite fibers from a melt blend of a thermoplastic with a liquid crystal polymer (LCP). Discontinuous fibrils of the LCP are formed in situ during the spinning process. These composite fibers are aligned and placed in a mold and heated to melt the thermoplastic matrix, but not the fibrils. A finished composite structure reinforced by the LCP fibrils is obtained when the thermoplastic phase is consequently consolidated. Our experiments show the proposed process is reasonable for an easily processed polystyrene matrix. High modulus fibrils with essentially infinite L/D ratios are readily produced in the extrusion process using 40 wt% of a wholly aromatic poly(ester-co-amide) LCP from Celanese. The integrity and alignment of the LCP fibrils is retained in the molding step. Mechanical tests show that the fibers produced by high shear rate processing have a stiffness approaching 23 GPa and match an axial rule-of-mixtures theory. The use of polystyrene resulted in brittleness. Molded composite plates exhibit slightly lower stiffness and significantly lower strength than individual fibers.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/38419/1/750110103_ftp.pd
Observational Constraints on the Common Envelope Phase
The common envelope phase was first proposed more than forty years ago to
explain the origins of evolved, close binaries like cataclysmic variables. It
is now believed that the phase plays a critical role in the formation of a wide
variety of other phenomena ranging from type Ia supernovae through to binary
black holes, while common envelope mergers are likely responsible for a range
of enigmatic transients and supernova imposters. Yet, despite its clear
importance, the common envelope phase is still rather poorly understood. Here,
we outline some of the basic principles involved, the remaining questions as
well as some of the recent observational hints from common envelope phenomena -
namely planetary nebulae and luminous red novae - which may lead to answering
these open questions.Comment: 29 pages, 8 figures. To appear in the book "Reviews in Frontiers of
Modern Astrophysics: From Space Debris to Cosmology" (eds. Kabath, Jones and
Skarka; publisher Springer Nature) funded by the European Union Erasmus+
Strategic Partnership grant "Per Aspera Ad Astra Simul"
2017-1-CZ01-KA203-03556
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