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Post Info TOPIC: Supernova remnant


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Posts: 131433
Date:
Tycho's Supernova Remnant
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HH211
Tycho Supernova Remnant
MPIA/NASA

This composite image of the Tycho supernova remnant combines infrared and X-ray observations obtained with NASA's Spitzer and Chandra space observatories, respectively, and the Calar Alto observatory, Spain. It shows the scene more than four centuries after the brilliant star explosion witnessed by Tycho Brahe and other astronomers of that era.

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Posts: 131433
Date:
RE: Supernova remnant
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Title: Newly confirmed and high quality candidate Galactic SNRs uncovered from the AAO/UKST HAlpha survey
Authors: M. Stupar, Q. A. Parker, M. D. Filipovic

We report catalogue of 21 new Galactic supernova remnants (SNRs) which we have uncovered in the optical regime as filamentary emissions and extended nebulosities on images of the Anglo Australian Observatory/United Kingdom Schmidt Telescope (AAO/UKST) HAlpha survey of the southern Galactic plane. Our follow-up spectral observations of about 60 candidate nebulosities confirmed classical optical SNR emission lies for 21 structures, especially via the presence of a very strong [SII] doublet at 6717 and 6731A relative to HAlpha Morphologically, 11 of these new remnants are in the form of a coherent, extended arc or shell of nebulosity, while the remaining objects are more irregular in form but clearly filamentary in nature, typical of optically detected SNRs. In 11 cases there was a clear if not complete match between the optical and radio structures with HAlpha filamentary structures registered inside and along the presumed radio borders. Additionally, ROSAT X-ray sources were detected inside the optical/radio borders of 11 of these new remnants and 3 may have an associated pulsar. When the multi-wavelength data is considered together it presents strong evidence to confirm identification of 21 new, mostly senile Galactic SNRs, including G288.7-6.3, G315.1+2.7 and G332.5-5.6, previously identified as possible remnants from preliminary radio observations. We also confirm existence of radio quite but optically active supernova remnants.

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Posts: 131433
Date:
Supernova remnant G350.1-0.3
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g350_mos1_source1_morph_source2_blue_L.jpg
Credit: ESA XMM-Newton

 Position(2000): RA 17 21 03.4, Dec  -37 26 17

ESAs orbiting X-ray observatory XMM-Newton has re-discovered an ignored celestial gem. The object in question is one of the youngest and brightest supernova remnants in the Milky Way, the corpse of a star that exploded around 1000 years ago.
Its shape, age and chemical composition will allow astronomers to better understand the violent ways in which stars end their lives.
Exploding stars seed the Universe with heavy chemical elements necessary to build planets and create life. The expanding cloud of debris that each explosion leaves behind, known as a supernova remnant (SNR), is a bright source of X-rays and radio waves. Generally, the debris is thought to appear as an expanding bubble or ring.
When astronomers took the first high-resolution radio images of a celestial object known as G350.1-0.3 in the 1980s, they saw an irregular knot of gases that did not seem to meet these expectations. So it was classified as a probable background galaxy and was quietly forgotten.
Now Bryan Gaensler and Anant Tanna, both at the University of Sydney, have used the X-ray capabilities of XMM-Newton with their colleagues to prove that appearances can be deceptive. G350.1-0.3 is indeed the debris of an exploded star despite its misshapen configuration.

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Posts: 131433
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RE: Supernova remnant
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Title: Study of Nonthermal Emission from SNR RX J1713.7-3946 with Suzaku
Authors: Takaaki Tanaka, Yasunobu Uchiyama, Felix A. Aharonian, Tadayuki Takahashi, Aya Bamba, Junko S. Hiraga, Jun Kataoka, Tetsuichi Kishi****a, Motohide Kokubun, Koji Mori, Kazuhiro Nakazawa, Robert Petre, Hiroyasu Tajima, Shin Watanabe

We present results obtained from a series of observations of the supernova remnant RX J1713.7-3946 by the Suzaku satellite. The observations cover about two-thirds of the remnant surface. We successfully detected hard X-rays up to ~ 40 keV from each pointing. The hard X-ray spectra are described by power-law functions with photon indices of ~ 3.0, which are larger than those in the energy region below 10 keV. Connection of the spatially-integrated XIS and HXD spectra clearly reveals a spectral cutoff in the 0.4--40 keV X-ray spectrum. This cutoff is interpreted to correspond to the maximum acceleration energy of electrons emitting synchrotron radiation. The wide-band coverage of Suzaku for the first time allows us to derive the parent electron spectrum in the cutoff region, which shows good agreement with theoretical predictions. The inferred cutoff energy in the spatially-integrated X-ray spectrum indicates that particle acceleration in the remnant is so efficient that it is almost at the theoretical limit, the so-called Bohm limit. Based on the Suzaku data, we present results of multi-wavelength studies from spectral and morphological points of view. The spectral energy distribution favours the hadronic scenario rather than the leptonic scenario. For the morphology studies, we compare the surface brightness maps from the Suzaku XIS and the H.E.S.S. telescope. We confirm the strong correlation between X-ray and TeV gamma-ray emission. In addition to the correlation, we found that in the bright western rim regions the X-ray emission is brighter than expected from the general X-ray to gamma-ray correlation.

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Posts: 131433
Date:
Supernova Remnant CTB 37B
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Title: Chandra and H.E.S.S. observations of the Supernova Remnant CTB 37B
Authors: HESS Collaboration: F. Aharonian, et al
(Version v2)

The >100 GeV gamma-ray source, HESS J1713-381, apparently associated with the shell-type supernova remnant (SNR) CTB 37B, was discovered using H.E.S.S. in 2006. X-ray follow-up observations with Chandra were performed in 2007 with the aim of identifying a synchrotron counterpart to the TeV source and/or thermal emission from the SNR shell. These new Chandra data, together with additional TeV data, allow us to investigate the nature of this object in much greater detail than was previously possible. The new X-ray data reveal thermal emission from a ~4' region in close proximity to the radio shell of CTB 37B. The temperature of this emission implies an age for the remnant of ~5000 years and an ambient gas density of ~0.5 cm-3. Both these estimates are considerably uncertain due to the asymmetry of the SNR and possible modifications of the kinematics due to efficient cosmic ray (CR) acceleration. A bright (~7x10-13erg cm-2s-1) and unresolved (<1'') source (CXOU J171405.7-381031) with a soft (\Gamma ~3.3) non-thermal spectrum is also detected in coincidence with the radio shell. Absorption indicates a column density consistent with the thermal emission from the shell suggesting a genuine association rather than a chance alignment. The observed TeV morphology is consistent with an origin in the complete shell of CTB 37B. The lack of diffuse non-thermal X-ray emission suggests an origin of the gamma-ray emission via the decay of neutral pions produced in interactions of protons and nuclei, rather than inverse Compton (IC) emission from relativistic electrons.

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Posts: 131433
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RE: Supernova remnant
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Title: Spitzer Observations of Supernova Remnant IC 443
Authors: A. Noriega-Crespo (Spitzer Science Center), D.C. Hines (Space Science Institute), K. Gordon (Space Telescope Institute), F.R. Marleau (Spitzer Science Center), G.H. Rieke (Steward Observatory), J. Rho (Spitzer Science Center), W.B. Latter (NASA Herschel Science Center)

We present Spitzer observations of IC 443 obtained with MIPS and IRS as part of our GTO program on the astrophysics of ejecta from evolved stars. We find that the overall morphology at mid/far IR wavelengths resembles even more closely a loop or a shell than the ground based optical and/or near IR images. The dust temperature map, based on the 70/160micron ratio, shows a range from 18 to 30 K degrees. The IRS spectra confirm the findings from previous near+mid IR spectroscopic observations of a collisionally excited gas, atomic and molecular, rich in fine structure atomic and pure H2 rotational emission lines, respectively. The spectroscopic shock indicator, [Ne II] 12.8micron, suggests shock velocities ranging from 60-90 km/s, consistent with the values derived from other indicators.

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Posts: 131433
Date:
Supernova Remnant CTB 37B
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Title: Chandra and H.E.S.S. observations of the Supernova Remnant CTB 37B
Authors: HESS Collaboration: F. Aharonian, et al

The >100 GeV gamma-ray source, HESS J1713-381, apparently associated with the shell-type supernova remnant (SNR) CTB 37B, was discovered using H.E.S.S. in 2006. X-ray follow-up observations with Chandra were performed in 2007 with the aim of identifying a synchrotron counterpart to the TeV source and/or thermal emission from the SNR shell. These new Chandra data, together with additional TeV data, allow us to investigate the nature of this object in much greater detail than was previously possible. The new X-ray data reveal thermal emission from a ~4' region in close proximity to the radio shell of CTB 37B. The temperature of this emission implies an age for the remnant of ~5000 years (assuming a spherical Sedov expansion), disfavouring a suggested association with the supernova of AD 373. A bright (approx 7 x10^-13erg cm^-2 s^-1) and unresolved (<1'') source (CXOU J171405.7-381031) with a soft (Gamma ~ 3.3) non -thermal spectrum is also detected in coincidence with the radio shell. Absorption indicates a column density consistent with the thermal emission from the shell suggesting a genuine association rather than a chance alignment. The observed TeV morphology is consistent with an origin in the complete shell of CTB 37B. The relatively high apparent gas density of the CTB 37B environment (n < 1 cm^-3) and the lack of diffuse non-thermal X-ray emission, are suggestive of an origin of the gamma-ray emission via the decay of neutral pions produced in interactions of protons and nuclei rather than inverse Compton (IC) emission from relativistic electrons.

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L

Posts: 131433
Date:
RE: Supernova remnant
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Title: Massive-Star Forming Infrared Loop around the Crab-like Supernova Remnant G54.1+0.3: Post Main-Sequence Triggered Star Formation?
Authors: Bon-Chul Koo, Christopher F. McKee, Jae-Joon Lee, Ho-Gyu Lee, Jeong-Eun Lee, Dae-Sik Moon, Seung Soo Hong, Hidehiro Kaneda, Takashi Onaka

We report the discovery of a star-forming loop around the young, Crab-like supernova remnant (SNR) G54.1+0.3 using the AKARI infrared satellite. The loop consists of at least eleven young stellar objects (YSOs) embedded in a ring-like diffuse emission of radius ~1'. The YSOs are bright in the mid-infrared and are also visible in the Spitzer Space Telescope Galactic plane survey images. Their Spitzer colours are similar to those of class II YSOs in [3.6]-[5.8] but significantly redder in [8]-[24], i.e., 0<[3.6]-[5.8]<1.2 and 5<[8]-[24]<9. Most of them have near-infrared counterparts in the 2MASS JHKs images, and some of them have an optical counterpart too. Their JHKs colours and magnitudes indicate that the YSOs are massive (<= 10 Msun) pre-main-sequence stars at the same distance to the SNR, i.e., 8 kpc, which supports the association of the star-forming loop with the SNR. The dereddened spectral energy distributions are similar to eraly Herbig Be stars, which are early B-type pre-main-sequence stars with inner disks that have been destroyed. The confinement to a loop structure indicates that the YSOs are young, i.e., <= 2 Myr. We propose that their formation is triggered by the progenitor star of G54.1+0.3, which has a mass of <= 15 Msun. The triggering must have occurred near the end of the progenitor's life, possibly after it had evolved off the main sequence.

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Posts: 131433
Date:
RCW 86
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Title: H.E.S.S. observations of the supernova remnant RCW 86
Authors: S. Hoppe (1), M. Lemoine-Goumard (2), for the H.E.S.S. Collaboration ((1) Max-Planck-Institut für Kernphysik, Heidelberg, Germany, (2) CENBG/CNRS-IN2P3, Université Bordeaux I, France)

The shell-type supernova remnant (SNR) RCW 86 - possibly associated with the historical supernova SN 185 - was observed during the past three years with the High Energy Stereoscopic System (H.E.S.S.), an array of four atmospheric-Cherenkov telescopes located in Namibia. The multi-wavelength properties of RCW 86, e.g. weak radio emission and North-East X-ray emission almost entirely consisting of synchroton radiation, resemble those of two very-high energy (VHE; > 100 GeV) gamma-ray emitting SNRs RX J1713.7-3946 and RX J0852-4622. The H.E.S.S. observations reveal a new extended source of VHE gamma-ray emission. The morphological and spectral properties of this new source will be presented.

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L

Posts: 131433
Date:
RE: Supernova remnant
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IC 443 (also known as the Jellyfish Nebula) is a Galactic supernova remnant (SNR) in the constellation Gemini. On the plan of the sky, it is located near the star Eta Geminorum. Its distance is roughly 5,000 light years (~5×1016 km) from Earth.
IC 443 is thought to be the remains of a supernova occurred 3,000 - 30,000 years ago.

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CXOU J061705.3+222127
Position(2000): RA 06h 17m 05.20s | Dec +22 21' 26.70"

Beginning with a wide-field view of the supernova remnant IC 443, this sequence moves into a closer look at the neutron star embedded within known as CXOU J061705.3+222127. The images show these objects in X-rays (blue), radio (green), and optical (red). The location and orientation of J0617's wake are mysterious for astronomers who would have expected it to be aligned toward the center of IC 443.


Credit: Chandra X-ray: NASA/CXC/B.Gaensler et al; ROSAT X-ray: NASA/ROSAT/Asaoka & Aschenbach; Radio Wide: NRC/DRAO/D.Leahy; Radio Detail: NRAO/AUI/NSF; Optical: DSS

IC 443.kmz
Google Sky file


-- Edited by Blobrana at 15:26, 2008-01-12

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