L. Piscarreta
A5038441933- Gamma-ray bursts and supernovae
- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Particle accelerators and beam dynamics
- Astrophysical Phenomena and Observations
- Magnetic confinement fusion research
- Astro and Planetary Science
- Superconducting Materials and Applications
- Nuclear Physics and Applications
- Combustion and Detonation Processes
- Astrophysics and Cosmic Phenomena
- Nuclear Issues and Defense
- Neutrino Physics Research
Institute of Space Sciences
2023-2024
University of Lisbon
2024
European Southern Observatory
2024
Abstract We present the optical spectroscopic evolution of SN 2023ixf seen in subnight cadence spectra from 1.18 to 15 days after explosion. identify high-ionization emission features, signatures interaction with material surrounding progenitor star, that fade over first 7 days, rapid between observed within same night. compare lines and their relative strength those other supernovae early interaction, finding a close match 2020pni 2017ahn spectrum 2014G at later epochs. To physically...
The first few hours of a supernova contain significant information about the progenitor system. most modern wide-field surveys that scan sky repeatedly every days can discover all kinds transients in those early epochs. At such times, some footprints may be visible, elucidating critical explosion parameters and helping to distinguish between leading models. A dedicated spectroscopic classification programme using optical spectrograph OSIRIS mounted Gran Telescopio de Canarias was set up try...
We present optical and near-infrared photometry spectroscopy of SN 2023aew our findings on its remarkable properties. This event, initially resembling a Type IIb supernova (SN), rebrightened dramatically $\sim$80 d after discovery, at which time spectrum transformed into that Ic. The slowly-evolving specifically resembled post-peak Ic with relatively low line velocities even during the second rise. peak, reached $\sim$107 is both more luminous ($M_r = -18.75\pm0.04$ mag) much broader than...
We aim to provide a detailed characterization of near-infrared spectra for young LT brown dwarfs, including robust spectral typing, calibrating indices, identifying possible binaries, and selecting suitable standards. processed analyzed archival from VLT/X-shooter sample 56 dwarfs with ages between 10 600 Myr types late-M mid-T. re-determine by comparing them set literature templates assess large range calibrated using specifically designed sample. are able identify 15 indices that useful...
Abstract We present photometric and spectroscopic data for SN 2022joj, a nearby peculiar Type Ia supernova (SN Ia) with fast decline rate (Δ m 15,B = 1.4 mag). 2022joj shows exceedingly red colors, value of approximately B − V ≈ 1.1 mag during its initial stages, beginning from 11 days before maximum brightness. As it evolves, the flux shifts toward blue end spectrum, approaching 0 around light. Furthermore, at light beyond, photometry is consistent that typical SNe Ia. This unusual behavior...
We present photometric and spectroscopic data for SN 2022joj, a nearby peculiar Type Ia supernova (SN Ia) with fast decline rate ($\rm{\Delta m_{15,B}=1.4}$ mag). 2022joj shows exceedingly red colors, value of approximately ${B-V \approx 1.1}$ mag during its initial stages, beginning from $11$ days before maximum brightness. As it evolves the flux shifts towards blue end spectrum, approaching 0}$ around light. Furthermore, at light beyond, photometry is consistent that typical SNe Ia. This...
We present high-cadence photometric and spectroscopic observations of SN~2020jfo in ultraviolet optical/near-infrared bands starting from $\sim 3$ to 434$ days after the explosion, including earliest data with 10.4\,m GTC. is a hydrogen-rich Type II SN relatively short plateau duration ($67.0 \pm 0.6$ days). When compared other supernovae (SNe) similar or shorter lengths, exhibits fainter peak absolute $V$-band magnitude ($M_V = -16.90 0.34$ mag). shows significant H$\alpha$ absorption phase...
We present optical and near-infrared photometry spectroscopy of SN 2023aew our findings on its remarkable properties. This event, initially resembling a Type IIb supernova (SN), rebrightens dramatically ∼90 d after the first peak, at which time spectrum transforms into that Ic. The slowly evolving specifically resembles post-peak Ic with relatively low line velocities even during second rise. reached 119 is both more luminous ( M r = −18.75 ± 0.04 mag) much broader than those typical SNe...
We present the optical spectroscopic evolution of SN~2023ixf seen in sub-night cadence spectra from 1.18 to 14 days after explosion. identify high-ionization emission features, signatures interaction with material surrounding progenitor star, that fade over first 7 days, rapid between observed within same night. compare lines and their relative strength those other supernovae early interaction, finding a close match SN~2020pni SN~2017ahn spectrum SN~2014G at later epochs. To physically...
Abstract We present optical, infrared, ultraviolet, and radio observations of SN 2022xkq, an underluminous fast-declining Type Ia supernova (SN Ia) in NGC 1784 ( D ≈ 31 Mpc), from <1 to 180 days after explosion. The high-cadence a photometrically transitional spectroscopically 91bg-like Ia, cover the first weeks following explosion, which are critical distinguishing between explosion scenarios. early light curve 2022xkq has red color exhibits flux excess that is more prominent redder...
Context. JWST and next-generation facilities are expected to uncover populations of free-floating objects below the deuterium-burning limit in a number young clusters star-forming regions. These planetary-mass brown dwarfs have spectral types L T; they shaped by molecular absorption modified their low gravity, which makes them distinct from field objects. Aims. We aim provide detailed characterization near-infrared spectra for LT dwarfs, including robust typing, calibrating indices,...
We present optical, infrared, ultraviolet, and radio observations of SN 2022xkq, an underluminous fast-declining type Ia supernova (SN Ia) in NGC 1784 ($\mathrm{D}\approx31$ Mpc), from $<1$ to 180 days after explosion. The high-cadence a photometrically transitional spectroscopically 91bg-like Ia, cover the first weeks following explosion which are critical distinguishing between scenarios. early light curve 2022xkq has red color exhibits flux excess is more prominent redder bands; this time...
We present high-cadence photometric and spectroscopic observations of SN~2020jfo in ultraviolet optical/near-infrared bands starting from $\sim 3$ to 434$ days after the explosion, including earliest data with 10.4\,m GTC. is a hydrogen-rich Type II SN relatively short plateau duration ($67.0 \pm 0.6$ days). When compared other supernovae (SNe) similar or shorter lengths, exhibits fainter peak absolute $V$-band magnitude ($M_V = -16.90 0.34$ mag). shows significant H$α$ absorption phase that...