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SRT Dynamic Scheduling - Observation Control Tool - first deployment and general overview
No full textIn this report we present a first look at the OCT, that is a foundational software component of the new SRT Dynamic Scheduling system, currently under development. We give a brief description of the overall architecture of the SRT-DS, which is designed to exploit the new high-frequency capabilities of SRT. We therefore provide a description of the technologies used to implement the
software layer on which OCT is based. The OCT is designed to be compatible with the most popular browsers. In the current configuration, the web access is restricted to a VPN protected
server, however we intend to expose the service as a portal with public access. We give a detailed description of the OCT layout, to provide the user with the basic knowledge to interact with the
tool’s features. The general overview provided here will allow you to access OCT and use the web tool to prepare your observations
Svelare i segreti delle stelle (intervista a Mario Giuseppe Guarcello)
Full text linkIl progetto Ewocs dell'Inaf sta indagando super ammassi di giovani stelle nella nostra galassia, per rivoluzionare il modo di studiare la formazione stellare: Mario Giuseppe Guarcello ci mostra i primi risultat
Measurement Campaign of Radio Frequency Interference in a Portion of the C-Band (4–5.8 GHz) for the Sardinia Radio Telescope
Full text linkThe authors thank the administration of the Cagliari Astronomical Observatory and Sergio Poppi, technologist and head of operations of the Sardinia Radio Telescope, for the administrative and logistical support that contributed to the success of this measurement campaign.Radio frequency interference (RFI) analysis is crucial for ensuring the proper functioning of a radio telescope and the quality of astronomical observations, as human-generated interference can compromise scientific data collection. The aim of this study is to present the results of an RFI measurement campaign in the frequency range of 4–5.8 GHz, a portion of the well-known C-band, for the Sardinia Radio Telescope (SRT), conducted in October–November 2023. In fact, this Italian telescope, managed by the Astronomical Observatory of Cagliari (OAC), a branch of the Italian National Institute for Astrophysics (INAF), was recently equipped with a new C-band receiver that operates from 4.2 GHz to 5.6 GHz. The measurements were carried out at three strategically chosen locations around the telescope using the INAF mobile laboratory, providing comprehensive coverage of all possible antenna pointing directions. The results revealed several sources of RFI, including emissions from radar, terrestrial and satellite communications, and wireless transmissions. Characterizing these sources and assessing their frequency band occupation are essential for understanding the impact of RFI on scientific observations. This work provides a significant contribution to astronomers who will use the SRT for scientific observations, offering a suggestion for the development of mitigation strategies and safeguarding the radio astronomical environment for future observational campaigns
The GAPS Programme at TNG: LVIII. Two multi-planet systems with long-period substellar companions around metal-rich stars
Full text linkContext. Due to observational biases, a large fraction of known exoplanets are short-period objects. However, the search for planets began more than 20 yr ago, and so it is already possible – with the use of a suitable dataset – to begin exploring a wider range of the parameter space, such as that encompassing long-period planets. Aims. The aim of this paper is to investigate the presence of long-period giant companions in two systems where one or more planets are already known and for which a long-term trend in the radial velocities (RVs) was noted in previous works. Methods. Over the last 11 yr, we have collected 122 spectra of HD 75898 and 72 spectra of HD 11506 with the High Accuracy Radial velocity Planet Searcher for the Northern hemisphere (HARPS-N) in the framework of the Global Architecture of Planetary Systems (GAPS) project, from which we derived precise RV and activity indicator measurements. Additional RV data from the High-Resolution Echelle Spectrometer (HIRES) are also used here to increase the total time span. For our RV analysis, we used PyORBIT, an advanced Python tool for the simultaneous Bayesian analysis of RVs and stellar activity indicators. In addition, we used astrometric (Gaia DR3) and imaging archive data to complete our analysis. In particular, we combined RVs and astrometry to better constrain the mass and period of the new long-period companions. Results. We find evidence for one additional long-period companion (gas giant planet or brown dwarf) in both systems considered. The new candidate for HD 75898 has a period of roughly 18 yr and a true mass of around 8.5 Mj. For HD 11506, we confirm the new object (planet d) recently announced using HIRES data but we find that the period and true mass are both almost double the values based on HIRES results (Pd ~ 72 yr, Md ~ 13 Mj). In addition, for HD 75898, we also find evidence of an activity cycle affecting RVs with a period of one order of magnitude lower than found in the literature
The GAPS programme at TNG LX. Atmospheric characterisation of KELT-9 b via single-line analysis: Detection of six H i Balmer lines, Na I, Ca I, Ca II, Fe I, Fe II, Mg I, Ti II, Sc II, and Cr II
Full text linkAims. We analysed six primary transits of the ultra-hot Jupiter KELT-9 b obtained with the HARPS-N high-resolution spectrograph in the context of the Global Architecture of Planetary Systems (GAPS2) project, to characterise the atmosphere via single-line analysis. Methods. We extracted the transmission spectrum of each individual line by comparing the master out-of-transit spectrum with the in-transit spectra and computing the weighted average of the tomography in the planet reference frame. We corrected for the centre-to-limb variation and the Rossiter-McLaughlin effect by modelling the region of the star disc obscured by the planet during the transit and subtracting it from the master-out spectrum. Results. We detected all six observable lines of the Balmer series within the HARPS-N wavelength range, from Hα to Hζ, with a significance exceeding 5Ï. We also focussed on metal species, detecting Na I, Ca I, Ca II, Fe I, Fe II, Mg I, Ti II, Sc II, and Cr II lines. This is the first detection in the atmosphere of an exoplanet of HÏμ and Hζ lines, as well as of individual lines of Sc II and Cr II. Our detections are supported by a comparison with published synthetic transmission spectra of KELT-9b obtained accounting for non-local thermodynamic equilibrium effects. The results underline the presence of a systematic blueshift due to night-side to day-side winds. Conclusions. The single-line analysis allowed us not only to assess the presence of atomic species in the atmosphere of KELT-9 b, but also to further characterise the local stratification of the atmosphere. Coupling the height distribution of the detected species with the velocity shift retrieved, we acknowledged the height distribution of night-side to day-side winds. Moreover, the study of the rotational broadening of the different species supports the prediction of a tidally locked planet rotating as a rigid body
Deciphering the hidden structures of HH 216 and Pillar IV in M16: results from JWST and HST
Full text linkTo probe the star formation process, we present an observational investigation of the Pillar IV and an ionized knot HH 216 in the Eagle Nebula (M16). Pillar IV is known to host a Class I protostar that drives a bipolar outflow. The outflow has produced the bow shock, HH 216, which is associated with the red-shifted outflow lobe. The JWST near- and mid-infrared images (resolution ~0′′.07-0′′.7) reveal the protostar as a single, isolated object (below 1000 au). The outer boundary of Pillar IV is depicted with the 3.3 μm Polycyclic aromatic hydrocarbon (PAH) emission. HH 216 is traced with the 4.05 μm Brα and the radio continuum emission; however, it is undetected with 4.693 μm H2 emission. HH 216 seems to be associated with both thermal and non-thermal radio emissions. High-resolution images reveal entangled ionized structures (below 3000 au) of HH 216, which appear to be located towards termination shocks. New knots in 4.693 μm H2 emission are detected and are mainly found on Pillar IV's northern side. This particular result supports the previously proposed episodic accretion in the powering source of HH 216. One part of the ionized jet (extent ~0.16 pc) is discovered on the southern side of the driving source. Using the 12CO(J = 1-0), 12CO(J = 3-2), and 13CO(J = 1-0) emission, observational signposts of cloud-cloud collision (or interacting clouds) towards Pillar IV are investigated. Overall, our results suggest that the interaction of molecular cloud components around 23 and 26 km s-1 might have influenced star formation activity in Pillar IV
The GAPS programme at TNG. L. TOI-4515 b: An eccentric warm Jupiter orbiting a 1.2 Gyr-old G-star
Full text linkContext. Different theories have been developed to explain the origins and properties of close-in giant planets, but none of them alone can explain all of the properties of the warm Jupiters (WJs, Porb = 10–200 days). One of the most intriguing characteristics of WJs is that they have a wide range of orbital eccentricities, challenging our understanding of their formation and evolution.
Aims. The investigation of these systems is crucial in order to put constraints on formation and evolution theories. TESS is providing a significant sample of transiting WJs around stars bright enough to allow spectroscopic follow-up studies.
Methods. We carried out a radial velocity (RV) follow-up study of the TESS candidate TOI-4515 b with the high-resolution spectrograph HARPS-N in the context of the GAPS project, the aim of which is to characterize young giant planets, and the TRES and FEROS spectrographs. We then performed a joint analysis of the HARPS-N, TRES, FEROS, and TESS data in order to fully characterize this planetary system.
Results. We find that TOI-4515 b orbits a 1.2 Gyr-old G-star, has an orbital period of Pb = 15.266446 ± 0.000013 days, a mass of Mb = 2.01 ± 0.05 MJ, and a radius of Rb = 1.09 ± 0.04 RJ. We also find an eccentricity of e = 0.46 ± 0.01, placing this planet among the WJs with highly eccentric orbits. As no additional companion has been detected, this high eccentricity might be the consequence of past violent scattering events
Polarimetric characterization of a model of the Multi Angle Polarimeter for the CO2M mission
Full text linkThis report describes the polarimetric characterization of a model of the Multi Angle Polarimeter of the CO2M Mission, by means of the Dual Rotating Retarder Mueller Spectro-Polarimeter technique, which provides the elements of the Mueller matrix of a sample, in our case a model of the telescope optical assembly of the polarimeter
Boost recall in quasi-stellar object selection from highly imbalanced photometric datasets. The reverse selection method
Full text linkContext. The identification of bright quasi-stellar objects (QSOs) is of fundamental importance to probe the intergalactic medium and address open questions in cosmology. Several approaches have been adopted to find such sources in the currently available photometric surveys, including machine learning methods. However, the rarity of bright QSOs at high redshifts compared to other contaminating sources (such as stars and galaxies) makes the selection of reliable candidates a difficult task, especially when high completeness is required. Aims: We present a novel technique to boost recall (i.e., completeness within the considered sample) in the selection of QSOs from photometric datasets dominated by stars, galaxies, and low-z QSOs (imbalanced datasets). Methods: Our heuristic method operates by iteratively removing sources whose probability of belonging to a noninteresting class exceeds a user-defined threshold, until the remaining dataset contains mainly high-z QSOs. Any existing machine learning method can be used as the underlying classifier, provided it allows for a classification probability to be estimated. We applied the method to a dataset obtained by cross-matching PanSTARRS1 (DR2), Gaia (DR3), and WISE, and identified the high-z QSO candidates using both our method and its direct multi-label counterpart. Results: We ran several tests by randomly choosing the training and test datasets, and achieved significant improvements in recall which increased from ~50% to ~85% for QSOs with z > 2.5, and from ~70% to ~90% for QSOs with z > 3. Also, we identified a sample of 3098 new QSO candidates on a sample of 2.6 ×106 sources with no known classification. We obtained follow-up spectroscopy for 121 candidates, confirming 107 new QSOs with z > 2.5. Finally, a comparison of our QSO candidates with those selected by an independent method based on Gaia spectroscopy shows that the two samples overlap by more than 90% and that both selection methods are potentially capable of achieving a high level of completeness. Table B.1 is available at the CDS via anonymous ftp to cdsarc.cds.unistra.fr (ftp://130.79.128.5) or via https://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/683/A34</A
The Excess of JWST Bright Galaxies: A Possible Origin in the Ground State of Dynamical Dark Energy in the Light of DESI 2024 Data
Full text linkINAF Theory-grant “AGN-driven outflows in cosmological models of galaxy formation.”Recent observations by JWST yield a large abundance of luminous galaxies at z ≳ 10 compared to that expected in the ΛCDM scenario based on extrapolations of the star formation efficiency measured at lower redshifts. While several astrophysical processes can be responsible for such observations, here we explore to what extent such an effect can be rooted in the assumed dark energy (DE) sector of the current cosmological model. This is motivated by recent results from different cosmological probes combined with the last data release of the Dark Energy Spectroscopic Instrument, which indicate a tension in the DE sector of the concordance ΛCDM model. We have considered the effect of assuming a DE characterized by a negative Λ as the ground state of a quintessence field on the galaxy luminosity function at high redshifts. We find that such models naturally affect the galaxy UV luminosities in the redshift range 10 ≲ z ≲ 15 needed to match the JWST observations, and with the value of ΩΛ = [‑0.6, ‑0.3] remarkably consistent with that required by independent cosmological probes. A sharp prediction of such models is the steep decline of the abundance of bright galaxies in the redshift range 15 ≲ z ≲ 16