Browsing by Author "McNaught, R."

Now showing 1 - 3 of 3
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    A Supernova Candidate from the Siding Spring Survey
    (2010) Drake, A. J.; Djorgovski, S. G.; Mahabal, A. A.; Graham, M. J.; Williams, R.; Prieto, J.; Catelan , Marcio; Christensen, E.; McNaught, R.; Garradd, G.; Beshore, E. C.; Larson, S. M.
    We report the discovery of the first supernova candidate from the Siding Spring Survey (SSS) by the Catalina Real-time Transient Survey (CRTS). The detection has the following details: <table border=1 width=650 align=center> <tr><th>ID</th><th>Disc. Date</th><th>RA</th><th>Dec</th><th>Disc. Mag</th></tr> <tr align=center><td><a href='http://crts.caltech.edu/ATEL/SSS/1005080151534122262.atel.html'> SSS100508:210144-143830</a></td><td> 2010-05-08 </td><td> 21:01:44.10 </td><td> -14:38:30.5 </td><td> 16.4</tr> </table> The host galaxy, 2MFGC 15924 (=PGC 187888), has redshift z=0.0275 (Jones et al....
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    Discovery of Thousands of RR Lyrae by the Catalina Surveys
    (2013) Drake, Andrew J.; Djorgovski, S. G.; Catelan, Márcio; Torrealba, G.; Graham, M.; Mahabal, A. A.; Donalek, C.; Prieto, J.; McNaught, R.; Larson, S. M.; Christensen, E.; Beshore, E. C.
    We have performed an extensive search for RR Lyrae among the 500 million sources observed by the Catalina Surveys. We detect 23,000 type-ab RR Lyrae (of which 18,700 are new discoveries) from a region spanning 3/4 of the sky. By combining calibrated Catalina photometry with RR Lyrae absolute magnitude estimates, we derive accurate distances and investigate the spatial distribution of structures within the Galactic halo. We identify hundreds of new RR Lyrae belonging to the Sagittarius tidal streams system and compare their observed properties with predictions from existing N-body models. We discover significant evidence that firmly establishes the existence of a tidal stream reaching Galactocentric distances beyond 100 kpc. This stream remains to be explained by any Sagittarius model. For 1,500 of the RR Lyrae we find matches with targets observed by past SDSS spectroscopic surveys. Combining the radial velocities and metallicity estimates from the SDSS spectra, with photometric distances, we investigate the kinematics and abundances of halo tidal stream populations....
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    SN 2008jb: A "Lost" Core-collapse Supernova in a Star-forming Dwarf Galaxy at ~10 Mpc
    (2012) Prieto, J. L.; Lee, J. C.; Drake, A. J.; McNaught, R.; Garradd, G.; Beacom, J. F.; Beshore, E.; Catelan, Marcio; Djorgovski, S. G.; Pojmanski, G.; Stanek, K. Z.; Szczygieł, D. M.
    We present the discovery and follow-up observations of SN 2008jb, a core-collapse supernova in the southern dwarf irregular galaxy ESO 302-14 (MB = -15.3 mag) at 9.6 Mpc. This nearby transient was missed by galaxy-targeted surveys and was only found in archival optical images obtained by the Catalina Real-time Transient Survey and the All-Sky Automated Survey. The well-sampled archival photometry shows that SN 2008jb was detected shortly after explosion and reached a bright optical maximum, V max ~= 13.6 mag (M V, max ~= -16.5). The shape of the light curve shows a plateau of ~100 days, followed by a drop of ~1.4 mag in the V band to a slow decline with an approximate 56Co decay slope. The late-time light curve is consistent with 0.04 ± 0.01 M ⊙ of 56Ni synthesized in the explosion. A spectrum of the supernova obtained two years after explosion shows a broad, boxy Hα emission line, which is unusual for normal Type II-Plateau supernovae at late times. We detect the supernova in archival Spitzer and WISE images obtained 8-14 months after explosion, which show clear signs of warm (600-700 K) dust emission. The dwarf irregular host galaxy, ESO 302-14, has a low gas-phase oxygen abundance, 12 + log(O/H) = 8.2 (~1/5 Z ⊙), similar to those of the Small Magellanic Cloud and the hosts of long gamma-ray bursts and luminous core-collapse supernovae. This metallicity is one of the lowest among local (lsim 10 Mpc) supernova hosts. We study the host environment using GALEX far-UV, R-band, and Hα images and find that the supernova occurred in a large star formation complex. The morphology of the Hα emission appears as a large shell (R ~= 350 pc) surrounding the FUV and optical emission. Using the Hα-to-FUV ratio and FUV and R-band luminosities, we estimate an age of ~9 Myr and a total mass of ~2 × 105 M ⊙ for the star formation complex, assuming a single-age starburst. These properties are consistent with the expanding Hα supershells observed in many well-studied nearby dwarf galaxies, which are tell-tale signs of feedback from the cumulative effect of massive star winds and supernovae. The age estimated for the star-forming region where SN 2008jb exploded suggests a relatively high-mass progenitor star with an initial mass M ~ 20 M ⊙ and warrants further study. We discuss the implications of these findings in the study of core-collapse supernova progenitors. This paper includes data gathered with the 6.5 m Magellan telescope at Las Campanas Observatory, Chile....