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Post Info TOPIC: MOA 2012 BLG-320
Blobrana


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Posts: 131433
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V1324 Scorpii
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Title: A Comprehensive Observational Analysis of V1324 Sco, the Most Gamma-Ray Luminous Classical Nova to Date
Author: Thomas Finzell, Laura Chomiuk, Brian D. Metzger, Frederick M. Walter, Justin D. Linford, Koji Mukai, Thomas Nelson, Jennifer H. S. Weston, Yong Zheng, Jennifer L. Sokoloski, Amy Mioduszewski, Michael P. Rupen, Subo Dong, Terry Bohlsen, Christian Buil, Jose Prieto, R. Mark Wagner, Thomas Bensby, I.A. Bond, T. Sumi, D.P. Bennett, F. Abe, N. Koshimoto, D. Suzuki, P., J. Tristram, Grant W. Christie, Tim Natusch, Jennie McCormick, Jennifer Yee, Andy Gould

It has recently been discovered that some, if not all, classical novae emit GeV gamma-rays during outburst, but the mechanics of this gamma-ray emission are still not well understood. We present here a comprehensive, multi-wavelength dataset---from radio to X-rays---for the most gamma-ray luminous classical nova to-date, V1324 Sco. Using this dataset, we show that V1324 Sco is a canonical dusty Fe-II type nova, with a bulk ejecta velocity of 1150±40 km s^-1 and an ejecta mass of 2.0±0.4 x 10^-5 solar masses. However, despite it's seeming normalcy, there is also evidence for complex shock interactions, including the aforementioned gamma-rays and early time high-brightness temperature radio emission. To explain how a nova can be simultaneously ordinary and have the highest gamma-ray luminosity to date we present a simplified model of the ejecta in which the strength of gamma-ray emission is set by properties the fast ejecta component that collides with a slower component to produce shocks. We conclude by detailing how this model can be tested using future gamma-ray detected novae.

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Blobrana


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Posts: 131433
Date:
Nova V1324 Scorpii
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Title: Distance and Reddening of the Enigmatic Gamma-ray-Detected Nova V1324 Sco
Author: Thomas Finzell, Laura Chomiuk, Ulisse Munari, Frederick M. Walter

It has recently been discovered that some, if not all, classical novae emit GeV gamma-rays during outburst. Despite using an unreliable method to determine its distance, previous work showed that nova V1324 Sco was the most gamma-ray luminous of all gamma-ray-detected novae. We present here a different, more robust, method to determine the reddening and distance to V1324 Sco using high-resolution optical spectroscopy. Using two independent methods we derived a reddening of E(B-V) = 1.16 ± 0.12 and a distance rD > 6.5 kpc. This distance is >40% greater than previously estimated, meaning that V1324 Sco has an even higher gamma-ray luminosity than previously calculated. We also use periodic modulations in the brightness, interpreted as the orbital period, in conjunction with pre-outburst photometric limits to show that a main-sequence companion is strongly favoured.

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Blobrana


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Posts: 131433
Date:
Nova Sco 2012
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Title: The discovery of gamma-ray emission from Nova Sco 2012: An analysis using reprocessed Pass7 data
Authors: A. B. Hill, on behalf of the Fermi-LAT collaboration

In March 2010 the Large Area Telescope (LAT) on-board the Fermi Gamma-ray Space Telescope discovered for the first time >100 MeV gamma-ray emission from a nova within our galaxy, V407 Cyg. The high-energy spectrum and light curve was explained as a consequence of shock acceleration in the nova shell as it interacts with the local ambient medium. It was suspected that the necessary conditions for high-energy emission from novae would be rare. In June 2012 the LAT detected a new flaring source, Fermi J1750-3243, that is spatially coincident and contemporaneous with a new nova, Nova Sco 2012. We report on the exciting discovery of this new 'gamma-ray' nova and present a detailed analysis of its high-energy properties.

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Blobrana


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Posts: 131433
Date:
Nova Scorpii 2012
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A magnitude 11.6 V nova (7th June)  in the constellation Scorpius. 

Position (2000):     RA 17 50 53.90 |  Dec -32° 37' 20.5''



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Blobrana


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Posts: 131433
Date:
MOA 2012 BLG-320
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 NOVA SCORPII 2012

R. M. Wagner, Ohio State University (OSU) and Large Binocular Telescope Observatory; S. Dong, Institute for Advanced Study, Princeton; T. Bensby, Lund Observatory; J. Prieto, Princeton University; I. Bond, Massey University; P. Tristram, Mt. John University Observatory; D. Bennett, University of Notre Dame; K. Wada and T. Sumi, Osaka University, and the Microlensing Observations in Astrophysics (MOA) collaboration; A. Gould, OSU, and the Microlensing Follow-Up Network (microFUN) collaboration; and S. Starrfield, Arizona State University, report the discovery and initial photometry and spectroscopy of a bright transient in the direction of the Galactic bulge. The MOA collaboration detected a candidate microlensing event, designated MOA 2012 BLG-320, on 2012 May 22.80 UT at magnitude I = 18.5, located at R.A. = 17h50m53s.90, Decl. = -32d37'20".5 (equinox 2000.0). No significant source appears at this position on either the R or N survey plates of the Digitized Sky Survey.

CBET3136  



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