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Abstract:

In 1969, Donald Lynden-Bell became the first astrophysicist to suggest that supermassive black holes in the cores of galaxies might generate the profuse energy put out by quasars — the astonishingly luminous distant bodies identified by astronomer Maarten Schmidt earlier that decade. Lynden-Bell proposed that quasars are powered by the release of gravitational energy as material falls into the deep potential well of the black hole, a process that is much more efficient than thermonuclear fusion

Abstract:

Abstract We present optical photometric (up to ∼410 d since Bmax) and spectroscopic (up to ∼157 d since Bmax) observations of a Type Iax supernova (SN) 2014dt located in M61. SN 2014dt is one of the brightest and closest (D ∼ 20 Mpc) discovered Type Iax SN. It best matches the light-curve evolution of SN 2005hk and reaches a peak magnitude of MB ∼ −18.13 ± 0.04 mag with Δm15 ∼ 1.35 ± 0.06 mag. The early spectra of SN 2014dt are similar to other Type Iax SNe, whereas the nebular spectrum at 157 d is dominated by narrow emission features with less blending as compared to SNe 2008ge and 2012Z. The ejecta velocities are between 5000 and 1000 km s−1, which also confirms the low-energy budget of Type Iax SN 2014dt compared to normal Type Ia SNe. Using the peak bolometric luminosity of SN 2005hk, we estimate the 56Ni mass of ∼0.14 M⊙. The striking similarity between SN 2014dt and SN 2005hk implies that a comparable amount of 56Ni would have been synthesized in the explosion of SN 2014dt.