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12 result(s) for "A Di Cianno"
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The Enhanced Resolution Imager and Spectrograph for the VLT
ERIS, the Enhanced Resolution Imager and Spectrograph, is an instrument that both extends and enhances the fundamental diffraction limited imaging and spectroscopy capability for the VLT. It replaces two instruments that were being maintained beyond their operational lifetimes, combines their functionality on a single focus, provides a new wavefront sensing module for natural and laser guide stars that makes use of the Adaptive Optics Facility, and considerably improves on their performance. The observational modes ERIS provides are integral field spectroscopy at 1-2.5 {\\mu}m, imaging at 1-5 {\\mu}m with several options for high contrast imaging, and longslit spectroscopy at 3-4 {\\mu}m, The instrument is installed at the Cassegrain focus of UT4 at the VLT and, following its commissioning during 2022, has been made available to the community.
Underluminous Type II Plateau Supernovae: II. Pointing towards moderate mass precursors
We present new data for five under-luminous type II-plateau supernovae (SNe IIP), namely SN 1999gn, SN 2002gd, SN 2003Z, SN 2004eg and SN 2006ov. This new sample of low-luminosity SNe IIP (LL SNe IIP) is analyzed together with similar objects studied in the past. All of them show a flat light curve plateau lasting about 100 days, an under luminous late-time exponential tail, intrinsic colours that are unusually red, and spectra showing prominent and narrow P-Cygni lines. A velocity of the ejected material below 10^3 km/s is inferred from measurements at the end of the plateau. The 56Ni masses ejected in the explosion are very small (less than 10^-2 solar masses). We investigate the correlations among 56Ni mass, expansion velocity of the ejecta and absolute magnitude in the middle of the plateau, confirming the main findings of Hamuy (2003), according to which events showing brighter plateau and larger expansion velocities are expected to produce more 56Ni. We propose that these faint objects represent the low luminosity tail of a continuous distribution in parameters space of SNe IIP. The physical properties of the progenitors at the explosion are estimated through the hydrodynamical modeling of the observables for two representative events of this class, namely SN 2005cs and SN 2008in. We find that the majority of LL SNe IIP, and quite possibly all, originate in the core-collapse of intermediate mass stars, in the mass range 10-15 solar masses.
The gas streamer G1-2-3 in the Galactic Center
The black hole in the Galactic Center, Sgr A*, is prototypical for ultra-low-fed galactic nuclei. The discovery of a hand-full of gas clumps in the realm of a few Earth masses in its immediate vicinity provides a gas reservoir sufficient to power Sgr A*. In particular, the gas cloud G2 is of interest due to its extreme orbit, on which it passed at a pericenter distance of around 100 AU and notably lost kinetic energy during the fly-by due to the interaction with the black hole accretion flow. 13 years prior to G2, a resembling gas cloud called G1, passed Sgr A* on a similar orbit. The origin of G2 remained a topic of discussion, with models including a central (stellar) source still proposed as alternatives to pure gaseous clouds. Here, we report the orbit of a third gas clump moving again along (almost) the same orbital trace. Since the probability of finding three stars on close orbits is very small, this strongly argues against stellar-based source models. Instead, we show that the gas streamer G1-2-3 plausibly originates from the stellar wind of the massive binary star IRS16SW. This claim is substantiated by the fact that the small differences between the three orbits - the orientations of the orbital ellipses in their common plane as a function of time - are consistent with the orbital motion of IRS 16SW.
Detailed study of a rare hyperluminous rotating disk in an Einstein ring 10 billion years ago
Hyperluminous infrared galaxies (HyLIRGs) are the rarest and most extreme starbursts and found only in the distant Universe ( z  ≳ 1). They have intrinsic infrared (IR) luminosities L IR  ≥ 10 13   L ⊙ and are commonly found to be major mergers. Recently, the Planck All-Sky Survey to Analyze Gravitationally-lensed Extreme Starbursts project (PASSAGES) searched ~10 4 deg 2 of the sky and found ~20 HyLIRGs. We describe a detailed study of PJ0116-24, the brightest ( μL IR  ≈ 2.6 × 10 14   L ⊙ , magnified with μ  ≈ 17) Einstein-ring HyLIRG in the southern sky, at z  = 2.125, with observations from the near-IR integral-field spectrograph VLT/ERIS and the submillimetre interferometer ALMA. We detected Hα, Hβ, [N ii ] and [S ii ] lines and obtained an extreme Balmer decrement (Hα/Hβ ≈ 8.73 ± 1.14). We modelled the molecular-gas and ionized-gas kinematics with CO(3–2) and Hα data at ~100–300 pc and (sub)kiloparsec delensed scales, respectively, finding consistent regular rotation. We found PJ0116-24 to be highly rotationally supported ( v rot / σ 0, mol. gas  ≈ 9.4) with a richer gaseous substructure than other known HyLIRGs. Our results imply that PJ0116-24 is an intrinsically massive ( M baryon  ≈ 10 11.3   M ⊙ ) and rare starbursty disk (star-formation rate, SFR = 1,490  M ⊙  yr −1 ) probably undergoing secular evolution. This indicates that the maximal SFR (≳1,000  M ⊙  yr −1 ) predicted by simulations could occur during a galaxy’s secular evolution, away from major mergers. An extreme Einstein ring ~10,000 times as bright as the Milky Way in the infrared is studied with VLT/ERIS and ALMA, and the authors find that the lensed galaxy is a starburst with a fast-rotating disk, rather than being driven by a major merger.
Autonomous Observations in Antarctica with AMICA
The Antarctic Multiband Infrared Camera (AMICA) is a double channel camera operating in the 2–28 μm infrared domain (KLMNQ bands) that will allow to characterize and exploit the exceptional advantages for Astronomy, expected from Dome C in Antarctica. The development of the camera control system is at its final stage. After the investigation of appropriate solutions against the critical environment, a reliable instrumentation has been developed. It is currently being integrated and tested to ensure the correct execution of automatic operations. Once it will be mounted on the International Robotic Antarctic Infrared Telescope (IRAIT), AMICA and its equipment will contribute to the accomplishment of a fully autonomous observatory.
High-contrast spectroscopy with the new VLT/ERIS instrument: Molecular maps and radial velocity of the gas giant AF Lep b
The Enhanced Resolution Imager and Spectrograph (ERIS) is the new Adaptive-Optics (AO) assisted Infrared instrument at the Very Large Telescope (VLT). Its refurbished Integral Field Spectrograph (IFS) SPIFFIER leverages a new AO module, enabling high-contrast imaging applications and giving access to the orbital and atmospheric characterisation of super-Jovian exoplanets. We test the detection limits of ERIS and demonstrate its scientific potential by exploring the atmospheric composition of the young super-Jovian AF Lep b and improving its orbital solution by measuring its radial velocity relative to its host star. We present new spectroscopic observations of AF Lep b in \\(K\\)-band at \\(R 11000\\) obtained with ERIS/SPIFFIER at the VLT. We reduce the data using the standard pipeline together with a custom wavelength calibration routine, and remove the stellar PSF using principal component analysis along the spectral axis. We compute molecular maps by cross-correlating the residuals with molecular spectral templates and measure the radial velocity of the planet relative to the star. Furthermore, we compute contrast grids for molecular mapping by injecting fake planets. We detect a strong signal from H\\(_2\\)O and CO but not from CH\\(_4\\) or CO\\(_2\\). This result corroborates the hypothesis of chemical disequilibrium in the atmosphere of AF Lep b. Our measurement of the RV of the planet yields \\( v_R,P = 7.8 1.7\\) km s\\(^-1\\). This enables us to disentangle the degeneracy of the orbital solution, namely the correct longitude of the ascending node is \\(=248^+0.4_-0.7\\) deg and the argument of periapsis is \\(=109^+13_-21\\) deg. Our results demonstrate the competitiveness of the new ERIS/SPIFFIER instrument for the orbital and atmospheric characterisation of exoplanets at high contrast and small angular separation.
MORFEO enters final design phase
MORFEO (Multi-conjugate adaptive Optics Relay For ELT Observations, formerly MAORY), the MCAO system for the ELT, will provide diffraction-limited optical quality to the large field camera MICADO. MORFEO has officially passed the Preliminary Design Review and it is entering the final design phase. We present the current status of the project, with a focus on the adaptive optics system aspects and expected milestones during the next project phase.
Autonomous Observations in Antarctica with AMICA
The Antarctic Multiband Infrared Camera (AMICA) is a double channel camera operating in the 2–28 μm infrared domain (KLMNQ bands) that will allow to characterize and exploit the exceptional advantages for Astronomy, expected from Dome C in Antarctica. The development of the camera control system is at its final stage. After the investigation of appropriate solutions against the critical environment, a reliable instrumentation has been developed. It is currently being integrated and tested to ensure the correct execution of automatic operations. Once it will be mounted on the International Robotic Antarctic Infrared Telescope (IRAIT), AMICA and its equipment will contribute to the accomplishment of a fully autonomous observatory.
MAORY: A Multi-conjugate Adaptive Optics RelaY for ELT
MAORY is the adaptive optics module for ELT providing two gravity invariant ports with the same optical quality for two different client instruments. It enable high angular resolution observations in the near infrared over a large field of view (~1 arcmin2 ) by real time compensation of the wavefront distortions due to atmospheric turbulence. Wavefront sensing is performed by laser and natural guide stars while the wavefront sensor compensation is performed by an adaptive deformable mirror in MAORY which works together with the telescope's adaptive and tip tilt mirrors M4 and M5 respectively.
AMICA – the infrared eye at Dome C
Amica (Antarctic Multiband Infrared Camera) is a dual-channel Infrared Imager (2-28μm), that will be located at the Nasmyth focus of the IRAIT telescope at Dome C. Dome C base, on Antarctic plateau offers an unique chance for infrared astronomy. It has several advantages like temperature, pressure and site environment. Temperature, around –60°C (mean) allows a good atmospheric stability (good seeing and good windows transparency) a low atmospheric background and the reduction of instrumental background. Pressure (equivalent of 4000 m a.s.l.), implies low content of water vapors; this means higher transmission, broader and new astronomical windows. The site offers the possibility of very long observations (about 6 months winter night).