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Geology of Tolstoj quadrangle (H08), Mercury
Get PDFThe authors thank D.A. Rothery, G. Tognon and M. Murad-al-shaikh who provided detailed and helpful suggestionsthat improved the quality of the manuscript and map. Theauthors acknowledge the use of MESSENGER data pro-cessed by NASA/Johns Hopkins University Applied PhysicsLaboratory/Carnegie Institution of Washington.Tolstoj quadrangle (H08) is located in the equatorial area of Mercury, between 22.5°N and 22.5°S and 144° and 216°E. Using the NASA/MESSENGER data, we compiled a geological map of thequadrangle at a scale of 1:3.000.000. The main basemap we used was the MDIS 166 m/pixelBDR mosaic. In addition, mosaics with high-incidence illumination from west and east, MDISglobal color mosaics, and the MDIS global DEM have been taken into account. In the map,we considered three feature classes: geological units, lineaments, and surface features.Geological units consist of crater material and plains. Lineaments include crater and pit rims,and structures. Finally, surface features are subdivided into crater chains or clusters, hollows,faculae, bright and dark material. The geological map will be integrated into the global 1:3Mgeological map of Mercury, which is being prepared in support to the ESA/JAXABepiColombo mission
The Software Version Control Procedure for the Array Control and Data Acquisition Software of the Cherenkov Telescope Array Observatory
Get PDFThe Cherenkov Telescope Array Observatory (CTAO) is the next-generation ground-based instrument for gamma-ray astronomy. CTAO will be located at two sites, one in the Northern (La Palma, Spain) and the other in the Southern Hemisphere (Paranal, Chile), with telescopes in three different sizes to cover different energy ranges. The commissioning of the first CTAO Large-Sized Telescope (LST-1) is being finalized at the CTAO-North site. The Array Control and Data Acquisition (ACADA) software is a central element of on-site CTAO operations. ACADA comprises subsystems for central control, the short-term scheduler, monitoring systems, and data handling at rates of GB/s. Consequently, it is a very complex software that requires many developers with different expertise, such as control software, data acquisition, data analysis, scheduling, configuration, and human interfaces. To implement such complex software, ACADA has been broken down into subsystems, which CTAO delegates to expert developer teams around the world through in-kind contributions. All the software is under version control exploiting a dedicated installation of GitLab. We have created at least one repository for each subsystem and a final one for the integration. We have defined the software development and integration procedures so that all phases of the Software Development Life Cycle (SDLC) are supported. Particular attention has been paid to the critical time when a software version is in operation on site and, bug-fixing and new features need to be kept under version control in parallel. The goal is to manage bug fixes without adding new features out of the scope of the release, but at the same time to guarantee the distribution of bug fixes for future releases. This contribution presents our strategy to manage multiple software versions according to the CTAO development plan
La stagione 2023/24 della serie di dirette “Il Cielo in salotto”
Get PDFQuesto report presenta la stagione 2023/2024 della serie di dirette osservative “Il Cielo in salotto” organizzata dalla redazione di EduINAF, il magazine di didattica e divulgazione dell’INAF. Contrariamente agli anni precedenti, questa stagione ha visto una programmazione ridotta, con solo due appuntamenti, dedicati rispettivamente all’osservazione del Sole in orario mattutino (dedicata alle scuole) e a un’eclissi di Sole verificatasi al di fuori del territorio italiano (in Nord America). Si presentano le criticità che hanno portato a questa scelta di programmazione e i risultati delle due dirette, che hanno riscosso grande successo di pubblico, corredati da una serie di raccomandazioni per le stagioni future
The ALPINE-ALMA [CII] survey: Dust emission effective radius up to 3 kpc in the early Universe
Get PDFAims. Measurements of the size of dust continuum emission are an important tool for constraining the spatial extent of star formation, and hence the buildup of stellar mass. Compact dust emission has generally been observed at cosmic noon (z ∼ 2 - 3). However, at earlier epochs, toward the end of the reionization (z ∼ 4 - 6), only the sizes of a handful of infrared (IR) bright galaxies have been measured. In this work, we derive the dust emission sizes of main-sequence (MS) galaxies at z ∼ 5 from the ALPINE survey. Methods. We measured the dust effective radius, re, FIR, in the uv-plane in Band 7 of ALMA for seven ALPINE galaxies with resolved emission and we compared it with rest-frame ultraviolet (UV) and [CII]158 μm measurements. We studied the re, FIR - LIR scaling relation by considering our dust size measurements and all the data in the literature at z ∼ 4 - 6. Finally, we compared our size measurements with predictions from simulations. Results. The dust emission in the selected ALPINE galaxies is rather extended (re, FIR ∼ 1.5 - 3 kpc), similar to [CII]158 μm but a factor of ∼2 larger than the rest-frame UV emission. Putting together all the measurements at z ∼ 5, spanning two decades in luminosity from LIR ∼ 1011 L⊙ to LIR ∼ 1013 L⊙, the data highlight a steeply increasing trend of the re, FIR - LIR relation at LIR < 1012 L⊙, followed by a downturn and a decreasing trend at brighter luminosities. Finally, simulations that extend up to the stellar masses of the ALPINE galaxies considered in the present work predict a subset of galaxies (∼25% at 1010 M⊙ < M∗ < 1011 M⊙) with sizes as large as those measured
Production via thermal slumping of large glass monolithic secondary mirrors (1.8 m diameter) for Schwarzschild-Couder air-Cherenkov gamma-ray telescopes
Get PDFThe standard design for 4-meter diameter class Imaging Atmospheric Cherenkov Telescopes (IACTs) used in groundbased gamma-ray astronomy is the dual-mirror Schwarzschild-Couder-like configuration. This design has been adopted for the telescopes in the ASTRI-Horn and ASTRI Mini-Array experiments (1 + 9 telescopes) and the construction of the 37 telescopes in the Small Size Telescope (SST) sub-array of the Cherenkov Telescope Array Observatory (CTAO) in Chile. The design provides an aplanatic optical response across a field of view wider than 10 degrees and is suitable for compact cameras using small pixels such as SiPM sensors. The telescopes feature secondary mirrors with a diameter of 1.8 meters, made of monolithic glass using a hot-slumping replication process. The paper discusses the manufacturing and characterization results of the prototype mirrors...
Thermo-mechanical sizing and stress-induced birefringence analysis for the MezzoCielo assembly
Get PDFMezzoCielo telescope aims to be a revolutionary optical instrument, designed to exhibit a field of view of around 104 square degrees. As such, it will be able to carry out whole-sky patrolling, which could be exploited, for instance, to track space debris or localize transient phenomena. From an optical stand-point, the telescope is a monocentric lens, composed by an outer glass shell enclosing an inner cavity filled with optical fluid (having proper refractive index for light convergence). From a mechanical point of view, instead, given the limitations related to manufacture large glass elements having high performance, the adoption of a segmented structure, presenting, for example, a platonic solid-like shape, is required. In this paper, the main aspects concerning the sizing of such frame (chosen to be a dodecahedral one) and the thermo-mechanical analysis of the lenses support system assembly, both analytical and numerical, will be presented. In particular, it will be shown how the lenses will be able to operate with little temperature difference across their volume independently from the surrounding conditions and the way in which the telescope can withstand external low temperatures without manifesting high thermal stresses, while maintaining, at the same time, constant focal length. Subsequently, a birefringence investigation, carried out to select the more appropriate lens shape, will be described. From our analysis, pentagonal-shape lenses turn out to be the most suitable ones for the MezzoCielo application
Emerging adaptive optics facility at Large Binocular Telescope Observatory
Get PDFThe Large Binocular Telescope (LBT) Observatory pioneered Adaptive Optics (AO) technologies such as Adaptive Secondary Mirror (ASM), Pyramid wavefront sensor, and Ground-layer AO using Rayleigh lasers at 8 to 10m class telescopes. We have initiated an effort to turn LBT AO into a facility-class capability. The effort involves (1) building an AO team with AO development capability, (2) improving the robustness of the AO, (3) developing in-house AO expertise to maintain and troubleshoot the AO systems, (4) automating processes for efficient on-sky operation, (5) tracking performance metrics and cultivating accountability for on-sky AO performance, and (6) minimizing the operational risks for the ASMs. We present the status of these developments. LBTO continues its efforts to develop innovative technology. We explore the next phase of AO developments, including Agile Extreme Adaptive Optics (AgXAO) on the DX side of the LINC-NIRVANA optical bench to overcome the limitation imposed by varying and large atmospheric seeing at Mount Graham. AgXAO implementation includes the development of (1) a high-order, high-sensitivity wavefront sensor, (2) a high-density deformable mirror with 3000 actuators and next-generation ASM with about 950 actuators, (3) active optics integration, (4) vibration and wavefront piston control, (5) atmospheric turbulence measurements and weather forecast integration, and (6) a visible camera and an AO-corrected narrow-field fiber-coupled IFU spectrograph using one of the existing workhorse visible spectrographs. Developing AgXAO on the SX side, too, would enable Fizeau imaging in the visible wavelengths. AgXAO will also serve as a general-purpose high-contrast (and subsequently a Fizeau imaging) Testbed on LBT to test advanced wavefront control algorithms, including astrophotonics experiments, and machine learning algorithms with minimal impact on routine science operations. We propose developing AgXAO through student projects to train the next-generation scientists and engineers for the extremely large telescope (ELT) era. The ultimate goal is to push large aperture ground-based telescopes to their performance limits and make them competitive with space telescopes in terms of PSF stability and performance to enable breakthrough science...
JWST observations of 13CO2 ice. Tracing the chemical environment and thermal history of ices in protostellar envelopes
No full textThe structure and composition of simple ices can be severely modified during stellar evolution by protostellar heating. Key to understanding the involved processes are thermal and chemical tracers that can be used to diagnose the history and environment of the ice. The 15.2 µm bending mode of 12CO2 in particular has proven to be a valuable tracer of ice heating events but suffers from grain shape and size effects. A viable alternative tracer is the weaker 13CO2 isotopologue band at 4.39 µm, which has now become accessible at high S/N with the James Webb Space Telescope (JWST). In this study, we present JWST NIRSpec observations of 13CO2 ice in five deeply embedded Class 0 sources that span a wide range in masses and luminosities (0.2-104 L⊙) taken as part of the Investigating Protostellar Accretion Across the Mass Spectrum (IPA) program. The band profiles vary significantly depending on the source, with the most luminous sources showing a distinct narrow peak at 4.38 µm. We first applied a phenomenological approach with which we demonstrate that a minimum of three to four Gaussian profiles are needed to fit the absorption feature of 13CO2. We then combined these findings with laboratory data and show that a 15.2 µm 12CO2 bending-mode-inspired five-component decomposition can be applied to the isotopologue band, with each component representative of CO2 ice in a specific molecular environment. The final solution consists of cold mixtures of CO2 with CH3OH, H2O, and CO as well as segregated heated pure CO2 ice at 80 K. Our results are in agreement with previous studies of the 12CO2 ice band, further confirming that 13CO2 is a useful alternative tracer of protostellar heating and ice composition. We also propose an alternative solution consisting only of heated mixtures of CO2:CH3OH and CO2:H2O ices and warm pure CO2 ice at 80 K (i.e., no cold CO2 ices) for decomposing the ice profiles of HOPS 370 and IRAS 20126, the two most luminous sources in our sample that show strong evidence of ice heating resulting in ice segregation
Discovery of a Collimated Jet from the Low-luminosity Protostar IRAS 16253‑2429 in a Quiescent Accretion Phase with the JWST
No full textInvestigating Protostellar Accretion (IPA) is a JWST Cycle 1 GO program that uses NIRSpec integral field units and MIRI Medium Resolution Spectrograph to obtain 2.9–28 μm spectral cubes of young, deeply embedded protostars with luminosities of 0.2–10,000 L ⊙ and central masses of 0.15–12 M ⊙. In this Letter, we report the discovery of a highly collimated atomic jet from the Class 0 protostar IRAS 16253‑2429, the lowest-luminosity source (L bol = 0.2 L ⊙) in the IPA program. The collimated jet is detected in multiple [Fe II] lines and [Ne II], [Ni II], and H I lines but not in molecular emission. The atomic jet has a velocity of about 169 ± 15 km s‑1, after correcting for inclination. The width of the jet increases with distance from the central protostar from 23 to 60 au, corresponding to an opening angle of 2.°6 ± 0.°5. By comparing the measured flux ratios of various fine-structure lines to those predicted by simple shock models, we derive a shock speed of 54 km s‑1 and a preshock density of 2.0 × 103 cm‑3 at the base of the jet. From these quantities and using a suite of jet models and extinction laws, we compute a mass-loss rate between 0.4 and 1.1 ×10‑10 M ⊙ yr ‑1. The low mass-loss rate is consistent with simultaneous measurements of low mass accretion rate (2.4 ± 0.8 × 10‑9 M ⊙ yr‑1) for IRAS 16253‑2429 from JWST observations, indicating that the protostar is in a quiescent accretion phase. Our results demonstrate that very low-mass protostars can drive highly collimated, atomic jets, even during the quiescent phase
MINDS: The DR Tau disk. I. Combining JWST-MIRI data with high-resolution CO spectra to characterise the hot gas
No full textContext. The MRS mode of the JWST-MIRI instrument has been shown to be a powerful tool to characterise the molecular gas emission of the inner region of planet-forming disks. Investigating their spectra allows us to infer the composition of the gas in these regions and, subsequently, the potential atmospheric composition of the forming planets. We present the JWST-MIRI observations of the compact T-Tauri disk, DR Tau, which are complemented by ground-based, high spectral resolution (R ~ 60 000-90 000) CO ro-vibrational observations. Aims: The aim of this work is to investigate the power of extending the JWST-MIRI CO observations with complementary, high-resolution, ground-based observations acquired through the SpExoDisks database, as JWST-MIRI's spectral resolution (R ~ 1500- 3500) is not sufficient to resolve complex CO line profiles. In addition, we aim to infer the excitation conditions of other molecular features present in the JWST-MIRI spectrum of DR Tau and link those with CO. Methods: The archival complementary, high-resolution CO ro-vibrational observations were analysed with rotational diagrams. We extended these diagrams to the JWST-MIRI observations by binning and convolution with JWST-MIRI's pseudo-Voigt line profile. In parallel, local thermal equilibrium (LTE) 0D slab models were used to infer the excitation conditions of the detected molecular species. Results: Various molecular species, including CO, CO2, HCN, and C2H2, are detected in the JWST-MIRI spectrum of DR Tau, with H2O being discussed in a subsequent paper. The high-resolution observations show evidence for two 12CO components: a broad component (full width at half maximum of FWHM ~33.5 km s−1) tracing the Keplerian disk and a narrow component (FWHM ~ 11.6 km s−1) tracing a slow disk wind. The rotational diagrams yield CO excitation temperatures of T ≥ 725 K. Consistently lower excitation temperatures are found for the narrow component, suggesting that the slow disk wind is launched from a larger radial distance. In contrast to the ground-based observations, much higher excitation temperatures are found if only the high-J transitions probed by JWST-MIRI are considered in the rotational diagrams. Additional analysis of the 12CO line wings suggests a larger emitting area than inferred from the slab models, hinting at a misalignment between the inner (i ~ 20°) and the outer disk (i ~ 5°). Compared to CO, we retrieved lower excitation temperatures of T ~ 325-900 K for 12CO2, HCN, and C2H2. Conclusions: We show that complementary, high-resolution CO ro-vibrational observations are necessary to properly investigate the excitation conditions of the gas in the inner disk and they are required to interpret the spectrally unresolved JWST-MIRI CO observations. These additional observations, covering the lower-J transitions, are needed to put better constraints on the gas physical conditions and they allow for a proper treatment of the complex line profiles. A comparison with JWST-MIRI requires the use of pseudo-Voigt line profiles in the convolution rather than simple binning. The combined high-resolution CO and JWST-MIRI observations can then be used to characterise the emission, in addition to the physical and chemical conditions of the other molecules with respect to CO. The inferred excitation temperatures suggest that CO originates from the highest atmospheric layers close to the host star, followed by HCN and C2H2 which emit, together with 13CO, from slightly deeper layers, whereas the CO2 emission originates from even deeper inside or further out of the disk