1. Lensed type Ia supernova “Encore” at z=2 : the first instance of two multiply imaged supernovae in the same host galaxyJustin Pierel, A. B. Newman, S. Dhawan, M. Gu, B. A. Joshi, T. Li, S. Schuldt, L. G. Strolger, S. H. Suyu, Tanja Petrushevska, 2024, izvirni znanstveni članek Ključne besede: supernova, James Webb Space Telescope, Hubble constant Objavljeno v RUNG: 31.05.2024; Ogledov: 1088; Prenosov: 9 Celotno besedilo (953,07 KB) Gradivo ima več datotek! Več... |
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3. THE PECULIAR EXTINCTION LAW OF SN 2014J MEASURED WITH THE HUBBLE SPACE TELESCOPERahman Amanullah, Ariel Goobar, Joel Johansson, D.P.K. Banerjee, V. Venkataraman, V. Joshi, N.M. Ashok, Yi Cao, Mansi Kasliwal, S.R. Kulkarni, P.E. Nugent, Tanja Petrushevska, V. Stanishev, 2014, izvirni znanstveni članek Opis: The wavelength dependence of the extinction of Type Ia SN 2014J in the nearby galaxy M82 has been measured
using UV to near-IR photometry obtained with the Hubble Space Telescope, the Nordic Optical Telescope, and
the Mount Abu Infrared Telescope. This is the first time that the reddening of an SN Ia is characterized over the
full wavelength range of 0.2–2μm. A total-to-selective extinction, RV 3.1, is ruled out with high significance.
The best fit at maximum using a Galactic type extinction law yields RV = 1.4 ± 0.1. The observed reddening of
SN 2014J is also compatible with a power-law extinction, Aλ/AV = (λ/λV )
p as expected from multiple scattering
of light, with p = −2.1 ± 0.1. After correcting for differences in reddening, SN 2014J appears to be very similar
to SN 2011fe over the 14 broadband filter light curves used in our study. Ključne besede: dust, extinction – galaxies: individual (Messier 82) – supernovae: individual SN2014J Objavljeno v RUNG: 22.01.2018; Ogledov: 4149; Prenosov: 0 Gradivo ima več datotek! Več... |
4. Very high-energy gamma-ray signature of ultrahigh-energy cosmic-ray acceleration in Centaurus AJagdish Joshi, Marlui Miranda, Lili Yang, Soebur Razzaque, 2017, objavljeni povzetek znanstvenega prispevka na konferenci Opis: The association of at least a dozen ultrahigh-energy cosmic-ray (UHECR) events with energy 54 EeV or higher detected by the Pierre Auger Observatory from the direction of Centaurus-A, the nearest radio galaxy, supports the scenario of UHECR acceleration in the jets of radio galaxies. Multiwavelength observations of Centaurus-A suggest that the inner jet is likely the site for particle acceleration, which emits in X-ray to very high-energy (VHE) gamma-ray. We model broadband spectral energy distribution with emission from shock-accelerated electrons and protons in a combined synchrotron-self-Compton and photo-hadronic scenario. The UHECR flux from Centaurus-A, required to explain Pierre Auger data, successfully explains observed VHE gamma rays as photo-hadronic emission. Ključne besede: Centaurus A, gamma ray, cosmic rays Objavljeno v RUNG: 17.01.2018; Ogledov: 4151; Prenosov: 0 Gradivo ima več datotek! Več... |
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