* Astronomy

Blobrana · L

RE: PS1-10afx

Blobrana · L

Mystery of dazzling supernova solved

An exceptionally bright supernova that baffled scientists has been explained.
It is so luminous because a galaxy sitting in front amplifies its light - making it appear 100 billion times more dazzling than our Sun.
This cosmic magnifying glass lay hidden between Earth and the supernova - and has now been detected with a telescope in Hawaii.
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Blobrana · L

Super-bright supernova hints at dark lens

Call it the case of the invisible magnifying glass. A bizarrely bright supernova, snapped by the world's largest digital camera, may really have been a normal stellar death intensified by a "dark" gravitational lens.
For more than two years cosmic detectives have been combing over the facts surrounding PS1-10afx. At first glance this exploding star had all the features of a type Ia supernova, which happens when a small, dense white dwarf star steals material from an orbiting companion and then explodes.
But PS1-10afx was 10 to 20 times brighter than any known type Ia.
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Blobrana · L

Title: Extraordinary Magnification of the Ordinary Type Ia Supernova PS1-10afx
Authors: Robert M. Quimby, Marcus C. Werner, Masamune Oguri, Surhud More, Anupreeta More, Masayuki Tanaka, Ken'ichi Nomoto, Takashi J. Moriya, Gaston Folatelli, Keiichi Maeda, Melina Bersten

Recently, Chornock and co-workers announced the Pan-STARRS discovery of a transient source reaching an apparent peak luminosity of ~4x10^44 erg/s. We show that the spectra of this transient source are well fit by normal Type Ia supernova (SNIa) templates. The multi-band colours and light curve shapes are also consistent with a normal SNIa at the spectroscopically determined redshift of z=1.3883; however, the observed flux is a constant factor of 20 times too bright in each band over time as compared to the templates. At a minimum, this shows that the peak luminosities inferred from the light curve widths of some SNeIa will deviate significantly from the established, empirical relation used by cosmologists. We argue on physical grounds that the observed fluxes do not reflect an intrinsically luminous SNIa, but rather PS1-10afx is a normal SNIa whose flux has been amplified by an external source. The only known astrophysical source capable of such magnification is a gravitational lens. Given the lack of obvious lens candidates, such as galaxy clusters, in the vicinity, we further argue that the lens is a supermassive black hole or a comparatively low-mass dark matter halo. In this case, the lens continues to amplify the underlying host galaxy light, and similar lensing may be observable in other quiescent galaxies. If confirmed, this discovery could impact a broad range of topics, from the selection of gamma-ray bursts, to measuring cosmology, to constraints on the nature and distribution of dark matter halos.

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