Radio Spectrum and Distance of the SNR HB9

New images are presented of the supernova remnant (SNR) HB9 based on 408 MHz and 1420 MHz continuum emission and HI-line emission data of the Canadian Galactic Plane Survey (CGPS) by the Dominion Radio Astrophysical Observatory (DRAO). Two methods of spectral index analysis for HB9 are presented and compared: one removes compact sources at both frequencies but is limited to the resolution of the 408 MHz image; the other removes compact sources only in the 1420 MHz image so is effective at higher spatial resolution. The second allows more detailed spectral index variation studies than the first. The two T-T plot methods and new integrated flux densities give spectral index (S_{\nu}\propto\nu^{-alpha}) for the whole of HB9 of 0.48+-0.03; and 0.47+-0.06, respectively. These are lower than previous spectral index for HB9 (alpha=0.61). Spatial variations of spectral index are derived using the second method and yield a steeper spectral index for interior regions than for the rim. This can be explained by a standard curved interstellar electron energy spectrum combined with lower interior magnetic field compared to that near the outer shock, which results in a larger proportion of steep spectrum emission for lines-of-sight through the central body of the SNR. HI observations show structures probably associated with the SNR in the radial velocity range -3 to -9 km/s and suggest a distance of 0.8+-0.4 kpc for the SNR. This is consistent with the distance to the radio pulsar 0458+46, offset from the center of HB9 by 23'. However the pulsar spindown and kinematic ages are significantly greater than estimates of the SNR age: the Sedov age for HB9 is 6600 yr and the evaporative cloud model yields ages of 4000-7,000 yr.Comment: 8 pages, 6 figures, 1 table, accepted by A&

The HI absorption distance of HESS J1943+213 favours its extragalactic nature

The H.E.S.S. collaboration (Abramowski et al. 2011) dicovered a new TeV point-like source HESS J1943+213 in the Galactic plane and suggested three possible low-energy-band counterparts: a $\gamma$-ray binary, a pulsar wind nebula (PWN), or a BL Lacertae object. We measure the distance to the radio counterpart G57.76-1.29 of HESS J1943+213. We analyze Very Large Array observations to obtain a reliable HI absorption spectrum.The resulting distance limit is $\ge$ 16 kpc. This distance strongly supports that HESS J1943+213 is an extragalactic source, consistent with the preferred counterpart of the HESS collaboration.Comment: 3 figures, 2 pages, A&A accepte

Women's clubs: Dispersing Shakespeare across America

This is the author's accepted manuscript. The final published article is available from the link below. Copyright @ 2011 Symbiosis - A Transatlantic Journal.This article explains the importance of women's clubs in America and their role in the dissemination of Shakespeare in the 19th and 20th centuries

The Distances of SNRs Kes 69 and G21.5-0.9 from HI and 13CO Spectra

We obtain new HI and $^{13}$CO images around Supernova Remnants (SNR) Kes 69 and G21.5-0.9. By comparing HI spectra with $^{13}$CO emission spectra, we significantly revise the kinematic distance for Kes 69 to $\sim$ 5.5 kpc, which was 11.2 kpc, and refine the kinematic distance for G21.5-0.9 to ~4.8 kpc. For Kes 69, the highest velocity of absorption is ~86 km/s and a prominent HI emission feature at ~ 112 km/s has no respective absorption. These new results suggest that Kes 69 is associated with a newly detected extended 1720 MHz OH maser at velocity of ~85 km/s that originates from within the bright southern radio shell of Kes 69. For G21.5-0.9, the highest velocity of absorption is ~67 km/s. The HI absorption spectra of the nearby bright source PMN J1832-1035 and of Kes 69 show a common absorption feature at velocity of ~69 km/s, which is not seen for G21.5-0.9. The resulting velocity of ~68 km/s gives the best distance estimate of ~4.8 kpc for G21.5-0.9 and associated young pulsar J1833-1034.Comment: 5 page, 2 figs. Monthly Notices of the Royal Astronomical Society: Letters. in pres

Discovery of A New Faint Radio SNR G108.2-0.6

A new faint and large shell-type radio Supernova Remnant (SNR) G108.2-0.6 has been discovered in the Canadian Galactic Plane Survey (CGPS). The SNR shows an elliptical shell-type structure at 1420 MHz, and has a 408-1420 MHz TT-plot spectral index of $\alpha$=-0.5$\pm$0.1 (S$_{\nu}$$\propto$$\nu$$^{\alpha}$), typical of a shell-type SNR. The remnant's flux density at 1420 MHz is 6.6$\pm$0.7 Jy, and at 408 MHz is 11.5$\pm$1.2 Jy. Both of these are corrected for compact sources. An integrated spectral index of $-0.45\pm$0.13 is determined. This new SNR has among the lowest surface brightness of any known remnant ($\Sigma$$_{1 GHz}$=2.4$\times10^{-22}$ W m$^{-2}$ Hz$^{-1}$ sr$^{-1}$). 21 cm Stokes Q and U CGPS data (plus preliminary Effelsberg Q and U maps) show some suggestive features that correlate with total power. \ion{H}{i} observations show structures associated with G108.2$-$0.6 in the radial velocity range $-$53 to $-$58 km s$^{-1}$, and indicate it is located in the Perseus arm shock at a distance of 3.2$\pm$0.6 kpc. At this distance the diameter of G108.2$-$0.6 is 58 pc. IRAS maps (12, 25, 60 and 100\mu m) of the new SNR show rich infrared emission surrounding G108.2$-$0.6.Comment: 10 pages, 6 figs, accepted by A&

The Distance and Age of the SNR Kes 73 and AXP 1E 1841-045

We provide a new distance estimate to the supernova remnant (SNR) Kes 73 and its associated anomalous X-ray pulsar (AXP) 1E 1841-045. 21 cm HI images and HI absorption/ emission spectra from new VLA observations, and 13CO emission spectra of Kes 73 and two adjacent compact HII regions (G27.276+0.148 and G27.491+0.189) are analyzed. The HI images show prominent absorption features associated with Kes 73 and the HII regions. The absorption appears up to the tangent point velocity giving a lower distance limit to Kes 73 of 7.5 kpc, which has previously been given as the upper limit. Also, G27.276+0.148 and G27.491+0.189 are at the far kinematic distances of their radio recombination line velocities. There is prominent HI emission in the range 80--90 km/s for all three objects. The two HII regions show HI absorption at ~ 84 km/s, but there is no absorption in the Kes 73 absorption spectrum. This implies an upper distance limit of ~ 9.8 kpc to Kes 73. This corrected larger distance to Kes 73/ AXP 1E 1841-045 system leads to a refined age of the SNR of 500 to 1000 yr, and a ~ 50% larger AXP X-ray luminosity.Comment: 10 pages, 2 figures, ApJ, dol:10.1086/"529120

The dreamscape of nostalgia: Shakespearean biography: Too much information (but not about Shakespeare)

Shakespearean biography has a long and colourful history, with a new edition of the life of the world’s greatest ever poet published at least once a year. Yet, the records are hardly full with details of his life and are indeed almost non-existent with regard to his writing life. If this is the case, then what are these various biographies made up of? What are they constituted by given that, it seems, their basic foundations are absent? This essay considers these questions in the context of the most important intervention in the field of Shakespearean biography in recent years, Brian Cummings’ essay ‘Shakespeare, Biography and Anti-Biography’. The conclusion it reaches is that the entire sub-genre can be regarded as ‘the dreamscape of nostalgia’, constituted by works of fictional narcissism

Corporate Payout Policy: The Prevalence of Stock Repurchase Programs and Earnings Per Share

The goal of this research is to determine the nature of stock repurchase programs and their susceptibility to manipulation. Through the analysis of five companies known to implement buybacks (Walmart, Pfizer, Boeing, Wells Fargo, Microsoft) in five different industries, for multiple years, the research will include examination of specific variables to attempt to understand the underlying reasons for repurchase programs; what really is taking place when companies buy back their own shares, especially because the motives can vary drastically. As earnings per share is the most widely followed valuation, there is concern that it is not the most accurate for use to compare two (or more) companies when it is susceptible to internal manipulation

The radio SNR G65.1+0.6 and its associated pulsar J1957+2831

New images of the radio Supernova Remnant (SNR) G65.1+0.6 are presented, based on the 408 MHz and 1420 MHz continuum emission and the HI-line emission data of the Canadian Galactic Plane Survey (CGPS). A large shell-like structure seen in the 2695 MHz Effelsberg map appears to have nonthermal spectral index. HI observations show structures associated with the SNR G65.1+0.6 in the radial velocity range of -20 to -26 km$/$s and suggest a distance of 9.2 kpc for the SNR. The estimated Sedov age for G65.1+0.6 is 4 - 14 x10E4 yr. The pulsar (PSR) J1957+2831 is possibly associated with G65.1+0.6, with consistent distance and kinematic age estimate, but different characteristic age than the SNR. The EGRET source 3EG J1958+2909 and gamma-ray source 2CG 065+00 are also near the eastern edge of the SNR but do not agree in position with the pulsar and are likely not associated with the SNR. The SNR's flux densities at 408 MHz (8.6+-0.8 Jy), 1420 MHz (4.9+-0.5 Jy) and 2695 MHz (3.3+-0.5 Jy) have been corrected for flux densities from compact sources within the SNR. The integrated flux density based spectral index between 1420 MHz and 408 MHz is 0.45+-0.11 and agrees with the T-T plot spectral index of 0.34+-0.20. The nearby SNR DA495 has a T-T plot spectral index of 0.50+-0.01.Comment: 7pages, 5 pictures and tables, will appear in A&