A Catalog of Diffuse X-ray-Emitting Features within 20 pc of Sgr A*: Twenty Pulsar Wind Nebulae - AstrophysicsReport as inadecuate




A Catalog of Diffuse X-ray-Emitting Features within 20 pc of Sgr A*: Twenty Pulsar Wind Nebulae - Astrophysics - Download this document for free, or read online. Document in PDF available to download.

Abstract: We present a catalog of 34 diffuse features identified in X-ray images of theGalactic center taken with the Chandra X-ray Observatory. Several of thefeatures have been discussed in the literature previously, including 7 that areassociated with a complex of molecular clouds that exhibits fluorescent lineemission, 4 that are superimposed on the supernova remnant Sgr A East, 2 thatare coincident with radio features that are thought to be the shell of anothersupernova remnant, and one that is thought to be a pulsar wind nebula only afew arcseconds in projection from Sgr A*. However, this leaves 20 features thathave not been reported previously. Based on the weakness of iron emission intheir spectra, we propose that most of them are non-thermal. One long, narrowfeature points toward Sgr A*, and so we propose that this feature is a jet ofsynchrotron-emitting particles ejected from the supermassive black hole. Forthe others, we show that their sizes 0.1-2 pc in length for D=8 kpc, X-rayluminosities between 10^32 and 10^34 erg-s, 2-8 keV, and spectra power lawswith Gamma=1-3 are consistent with those of pulsar wind nebulae. Based on thestar formation rate at the Galactic center, we expect that ~20 pulsars haveformed in the last 300 kyr, and could be producing pulsar wind nebulae. Onlyone of the 19 candidate pulsar wind nebulae is securely detected in an archivalradio image of the Galactic center; the remainder have upper limitscorresponding to L R


Author: M. P. Muno Caltech, F. K. Baganoff MIT, W. N. Brandt Penn State, M. R. Morris UCLA, J.-L. Starck CEA Saclay

Source: https://arxiv.org/







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