F. Poidevin

Cosmology with supernova Encore in the strong lensing cluster MACS J0138-2155: Time delays & Hubble constant measurement

Justin Pierel, Erin E. Hayes, Martin Millon, C. Larison et autres

Multiply-imaged supernovae (SNe) provide a novel means of constraining the Hubble constant ($H_0$). Such measurements require a combination of precise models of the lensing mass distribution and an accurate estimate of the relative time delays between arrival of the multiple images. Only …

The ambiguous AT2022rze: Changing-look AGN mimicking a supernova in a merging galaxy system

P. J. Pessi, R. Lunnan, J. Sollerman, L. Yan et autres

AT2022rze is a luminous, ambiguous transient located South-East of the geometric center of its host galaxy at redshift z = 0.08. The host appears to be formed by a merging galaxy system. The observed characteristics of AT2022rze are reminiscent of active galactic …

An extremely soft and weak fast X-ray transient associated with a luminous supernova

W. -X. Li, Z. -P. Zhu, Xingzhu Zou, Jin-Jun Geng et autres

Long gamma-ray bursts (LGRBs), including their subclasses of low-luminosity GRBs (LL-GRBs) and X-ray flashes (XRFs) characterized by low spectral peak energies, are known to be associated with broad-lined Type Ic supernovae (SNe Ic-BL), which result from the core collapse of massive stars …

Eruptive mass loss less than a year before the explosion of superluminous supernovae

A. Gkini, Claes Fransson, R. Lunnan, S. Schulze et autres

We present photometric and spectroscopic observations of SN 2020xga and SN 2022xgc, two hydrogen-poor superluminous supernovae (SLSNe-I) at z = 0.4296 and z = 0.3103, respectively, which show an additional set of broad Mg II absorption lines, blueshifted by a few thousands …

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Spectroscopic analysis of the strongly lensed SN~Encore: Constraints on cosmic evolution of Type Ia supernovae

S. Dhawan, Justin Pierel, Meng Gu, Andrew B. Newman et autres

Strong gravitational lensing magnifies the light from a background source, allowing us to study these sources in detail. Here, we study the spectra of a $z = 1.95$ lensed Type Ia supernova SN~Encore for its brightest Image A, taken 39 days apart. …

JWST Photometric Time-delay and Magnification Measurements for the Triply Imaged Type Ia “SN H0pe” at z = 1.78

Justin Pierel, Brenda Frye, Massimo Pascale, G. B. Caminha et autres

Abstract Supernova (SN) SN H0pe is a gravitationally lensed, triply imaged, Type Ia SN (SN Ia) discovered in James Webb Space Telescope imaging of the PLCK G165.7+67.0 cluster of galaxies. Well-observed multiply imaged SNe provide a rare opportunity to constrain the Hubble …

us, de, gb, se, si, au, dk, it, ca, tw, il, cn, es (code pays fourni par la source)

Lensed Type Ia Supernova "Encore" at z=2: The First Instance of Two Multiply-Imaged Supernovae in the Same Host Galaxy

Justin Pierel, Andrew B. Newman, Suhail Dhawan, Minfeng Gu et autres

A bright ($m_{\rm F150W,AB}$=24 mag), $z=1.95$ supernova (SN) candidate was discovered in JWST/NIRCam imaging acquired on 2023 November 17. The SN is quintuply-imaged as a result of strong gravitational lensing by a foreground galaxy cluster, detected in three locations, and remarkably is …

Optical polarization and spectral properties of the H-poor superluminous supernovae SN 2021bnw and SN 2021fpl

F. Poidevin, Conor M. B. Omand, Réka Könyves-Tóth, I. Pérez-Fournon et autres

New optical photometric, spectrocopic and imaging polarimetry data are combined with publicly available data to study some of the physical properties of the two H-poor superluminous supernovae (SLSN) SN 2021bnw and SN 2021fpl. For each SLSN, the best-fit parameters obtained from the …

SALT3-NIR: Taking the Open-Source Type Ia Supernova Model to Longer Wavelengths for Next-Generation Cosmological Measurements

Justin Pierel, D. O. Jones, W. D. Kenworthy, Mi Dai et autres

A large fraction of Type Ia supernova (SN Ia) observations over the next decade will be in the near-infrared (NIR), at wavelengths beyond the reach of the current standard light-curve model for SN Ia cosmology, SALT3 ($\sim 2800$--8700$A$ central filter wavelength). To …