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Post Info TOPIC: G292.0+1.8
Blobrana


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Posts: 131433
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PSR J1124-5916
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Title: The PSR J1124-5916 wind nebula in the near-infrared
Authors: Sergey V. Zharikov, Dmitry A. Zyuzin, Yuri A. Shibanov, Ronald E. Mennickent

The young radio pulsar J1124-5916 is associated with a Cas A like supernova remnant G292.0+1.8. It powers a compact torus-like pulsar wind nebula with a jet first detected in X-rays and then identified in the optical and mid-infrared. We carried out deep near-infrared observations of the pulsar field to identify the pulsar and its nebula in this range. The direct imaging mode of the NACO adaptive optics instrument at the ESO VLT in the H and Ks bands was used. In both bands we detected a faint, H=21.30(10) and Ks=20.45(10), extended elliptical object, whose center position is consistent with the X-ray position of the pulsar. The morphology of the object and the orientation of its major axis are in a good agreement with those observed for the pulsar torus-like nebula in the mid-infrared, optical, and X-rays. This suggests that it is the near-infrared counterpart of the nebula. The measured fluxes compiled with the data in other ranges show a complicated unabsorbed power law spectrum of the torus-like nebula with several steep breaks between the near-infrared and mid-infrared, the optical and X-rays, and possibly in the mid-infrared. This implies a multiple relativistic particle population responsible for the synchrotron emission of the nebula in different spectral ranges. We have not resolved the pulsar counterpart from its nebula and place only upper limits on its brightness, H >= 23.9 and Ks >= 22.7. Based on that, its contribution to the total near-infrared flux of the pulsar+nebula system is <= 10%, which is comparable with the expected contribution in the optical.

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Blobrana


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RE: G292.0+1.8
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Title: Spitzer Imaging and Spectral Mapping of the Oxygen-Rich Supernova Remnant G292.0+1.8
Authors: Parviz Ghavamian, Knox S. Long, William P. Blair, Sangwook Park, Robert Fesen, Bryan M. Gaensler, John P. Hughes, Jeonghee Rho, P. Frank Winkler

We present mid-infrared continuum and emission line images of the Galactic oxygen-rich supernova remnant (SNR) G292.0+1.8, acquired using the MIPS and IRS instruments on the Spitzer Space Telescope. The MIPS 24 micron and 70 micron images of G292.0+1.8 are dominated by continuum emission from a network of filaments encircling the SNR. The morphology of the SNR, as seen in the mid-infrared, resembles that seen in X-rays with the Chandra X-ray Observatory. Most of the mid-infrared emission in the MIPS images is produced by circumstellar dust heated in the non-radiative shocks around G292.0+1.8, confirming the results of earlier mid-IR observations with AKARI. In addition to emission from hot dust, we have also mapped atomic line emission between 14 micron and 36 micron using IRS spectral maps. The line emission is primarily associated with the bright oxygen-rich optical knots, but is also detected from fast-moving knots of ejecta. We confirm our earlier detection of 15-25 micron emission characteristic of magnesium silicate dust in spectra of the radiatively shocked ejecta. We do not detect silicon line emission from any of the radiatively shocked ejecta in the southeast of the SNR, possibly because that the reverse shock has not yet penetrated most of the Si-rich ejecta in that region. This may indicate that G292.0+1.8 is less evolved in the southeast than the rest of the SNR, and may be further evidence in favour of an asymmetric SN explosion as proposed in recent X-ray studies of G292.0+1.8.

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Blobrana


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Posts: 131433
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Title: Expanding Ejecta in the Oxygen-Rich Supernova Remnant G292.0+1.8: Direct Measurement through Proper Motions
Authors: P. Frank Winkler, Karl Twelker, Claudine N. Reith, Knox S. Long

We report here the first study of proper motions of fast filaments in the young, oxygen-rich supernova remnant G292.0+1.8, carried out using a series of [O III] 5007 A emission-line images taken over a period of more than 21 years. Images taken at seven epochs from 1986 to 2008, all from telescopes at the Cerro Tololo Inter-American Observatory, show oxygen-emitting filaments, presumably ejecta fragments, throughout most of the remnant. We have measured the proper motions for 67 discrete filaments through two-dimensional correlations between images from different epochs. While the motions are small, mostly 20 to 100 milli-arcsec, they are nevertheless measurable through a robust technique of averaging measurements from many epoch pairs. The data are qualitatively consistent with a free-expansion model, and clearly show systematic motions outward from a point near the center of the radio/X-ray shell. Global fits using this model indicate an expansion center at R.A.(2000.0) = 11:24:34.4, Dec.(2000.0) = -59:15:51, and a kinematic age of 2990+-60 years. The young pulsar PSR J1124-5916 is located 46 arcsec southeast of the expansion center. Assuming that it was launched by the supernova, we expect the pulsar to be moving southeastward at 16 milli-arcsec, or a transverse velocity of 440 km/s. We find the fastest ejecta along an axis oriented roughly N-S in the plane of the sky, suggesting that a bipolar explosion produced G292.0+1.8, as appears to have been the case for Cas A.

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Blobrana


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A spectacular new image shows how complex a stars afterlife can be. By studying the details of this image made from a long observation by NASAs Chandra X-ray Observatory, astronomers can better understand how some stars die and disperse elements like oxygen into the next generation of stars and planets.
At a distance of about 20,000 light years, G292.0+1.8 is one of only three supernova remnants in the Milky Way known to contain large amounts of oxygen. The image shows a rapidly expanding, intricately structured, debris field that contains, along with oxygen, other elements such as neon and silicon that were forged in the star before it exploded.

G292
Credit: X-ray: NASA/CXC/Penn State/S.Park et al.; Optical: Pal.Obs. DSS
JPEG (437.2 kb) Tiff (68.7 MB) PS (6 MB)

Near the centre of G292.0+1.8 is the so-called pulsar wind nebula, most easily seen in high energy X-rays. This is the magnetized bubble of high-energy particles that surrounds the "pulsar", a rapidly rotating neutron star that remained behind after the original, massive star exploded. The narrow, jet-like feature running from north to south in the image is likely parallel to the spin axis of the pulsar.

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Blobrana


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Posts: 131433
Date:
SNR G292.0+1.8
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Title: A Half-Megasecond Chandra Observation of the Oxygen-Rich Supernova Remnant G292.0+1.8
Authors: Sangwook Park (Penn State), John P. Hughes (Rutgers) Patrick O. Slane (CfA), David N. Burrows (Penn State), B. M. Gaensler (Sydney), Parviz Ghavamian (Johns Hopkins)

We report on our initial analysis of a deep 510 ks observation of the Galactic oxygen-rich supernova remnant (SNR) G292.0+1.8 with the  Chandra X-ray Observatory. Our new Chandra ACIS-I observation has a larger field of view and an order of magnitude deeper exposure than the previous  Chandra observation, which allows us to cover the entire SNR and to detect new metal-rich ejecta features. We find a highly non-uniform distribution of thermodynamic conditions of the X-ray emitting hot gas that correlates well with the optical [O  III] emission, suggesting the possibility that the originating supernova explosion of G292.0+1.8 was itself asymmetric. We also reveal spectacular substructures of a torus, a jet, and an extended central compact nebula all associated with the embedded pulsar J1124-5916.

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