Updates from FOTOSS: Highlights and Statistics from the OATo Photographic Plate Archive

This is a progress report of the on-going work related to the FOTOSS project (Valorizzazione scientifica dell’archivio di osservazioni FOTOgrafiche del Secolo Scorso di patrimonio dell’OATo). First, we give an up-to-date account of the status of the FOTOSS project, including preliminary informations on the number and characteristics of the digitized plate images; we then present a detailed explanation of the content and usage of the latest realization of the Master Plate Catalog (MPC), along with some general statistics based on the observations recorded in the MPC

NGP Reference Catalogue for the SPICA FGS

This document describes the properties of the NGP Reference Catalogue used for the WP1400 “Input Star Catalogue for the SPICA mission” study conducted by the OATo Team for Thales Alenia Space Italia (TASI) within the “FGS Feasibility Consolidation for SPICA Mission” project commissioned by ESA.This technical note describes the properties of the NGP Reference Catalogue used for the analysis presented by Spagna et al "Input Star Catalogue for SPICA mission" OATO-SPICA-FGS-TNO-001 (07/2020

The Panchromatic High-Resolution Spectroscopic Survey of Local Group Star Clusters - I. General Data Reduction Procedures for the VLT/X-shooter UVB and VIS arm

Our dataset contains spectroscopic observations of 29 globular clusters in the Magellanic Clouds and the Milky Way performed with VLT/X-shooter. Here we present detailed data reduction procedures for the VLT/X-shooter UVB and VIS arm. These are not restricted to our particular dataset, but are generally applicable to different kinds of X-shooter data without major limitation on the astronomical object of interest. ESO's X-shooter pipeline (v1.5.0) performs well and reliably for the wavelength calibration and the associated rectification procedure, yet we find several weaknesses in the reduction cascade that are addressed with additional calibration steps, such as bad pixel interpolation, flat fielding, and slit illumination corrections. Furthermore, the instrumental PSF is analytically modeled and used to reconstruct flux losses at slit transit and for optimally extracting point sources. Regular observations of spectrophotometric standard stars allow us to detect instrumental variability, which needs to be understood if a reliable absolute flux calibration is desired. A cascade of additional custom calibration steps is presented that allows for an absolute flux calibration uncertainty of less than ten percent under virtually every observational setup provided that the signal-to-noise ratio is sufficiently high. The optimal extraction increases the signal-to-noise ratio typically by a factor of 1.5, while simultaneously correcting for resulting flux losses. The wavelength calibration is found to be accurate to an uncertainty level of approximately 0.02 Angstrom. We find that most of the X-shooter systematics can be reliably modeled and corrected for. This offers the possibility of comparing observations on different nights and with different telescope pointings and instrumental setups, thereby facilitating a robust statistical analysis of large datasets.Comment: 22 pages, 18 figures, Accepted for publication in Astronomy & Astrophysics; V2 contains a minor change in the abstract. We note that we did not test X-shooter pipeline versions 2.0 or later. V3 contains an updated referenc

FOTOSS Phase I: Chronicle of an Achievement

Prodotto della scheda progetto FOTOSS presente nel PT INAF 2021-2023This document is a record of the key tasks and dedicated activities that ushered the start of FOTOSS, a project of the Torino Astrophysical Observatory (OATo) carried out in cooperation with the Shanghai Astronomical Observatory (SHAO). Its first objective is the high accurate digitization of the entire OATo’s plate archive, with the ultimate goal of preserving century-old astronomical observations for their scientific exploitation

Euclid FGS Input Star Catalogue Verification Test Report

This document is applicable to the FGS Star Catalogue in the frame of the EUCLID Program in the Pre-CD phase and CD phases.The objective of the verification testing is to assess to what degree the delivered third version of the ISC (ISC.R3) satisfy the requirements defined by the Requirement Specifications (EUCL-TAST-RS-2-056). This document presents the results of the executed verification test cases, described in the ISC Verification Test Specifications (VTS), as part of the requirement verification phase described in the DDVP

Euclid FGS Input Star Catalogue - Performance Assessment

This document is applicable to the FGS Star Catalogue in the frame of the EUCLID Program in the Pre-CD phase and CD phases.The objective of this performance assessment is to evaluate the ISC performance with respect to some of the key requirements defined in EUCL-TAST-RS-2-056 that may impact the performance of the FGS. This document presents a broader analysis of the ISC performance, taking into consideration the results of the executed verification test cases described in the VTR

Alone on a wide wide sea. The origin of SECCO 1, an isolated star-forming gas cloud in the Virgo cluster

SECCO 1 is an extremely dark, low-mass (M* ≃ 105 M⊙), star-forming stellar system lying in the low-velocity cloud (LVC) substructure of the Virgo cluster of galaxies, and hosting several HII regions. Here, we review our knowledge of this remarkable system, and present the results of (a) additional analysis of our panoramic spectroscopic observations with MUSE, (b) the combined analysis of Hubble Space Telescope and MUSE data, and (c) new narrowband observations obtained with OSIRIS@GTC to search for additional HII regions in the surroundings of the system. We provide new evidence supporting an age as young as ≲4Myr for the stars that are currently ionizing the gas in SECCO 1. We identify only one new promising candidate HII region possibly associated with SECCO 1, thus confirming the extreme isolation of the system.We also identify three additional candidate pressure-supported dark clouds in Virgo among the targets of the SECCO survey. Various possible hypotheses for the nature and origin of SECCO 1 are considered and discussed, also with the help of dedicated hydrodynamical simulations showing that a hydrogen cloud with the characteristics of SECCO 1 can likely survive for ≳1 Gyr while travelling within the LVC Intra Cluster Medium.GB gratefully acknowledges the financial support by the Spanish Ministry of Economy and Competitiveness under the Ramon y Cajal Programme (RYC-2012-11537) and the grant AYA2014-56795-P. FC acknowledges funding from the INAF PRIN-SKA 2017 1.05.01.88.04

Far IR photometric propagation analysis

This document presents the first results of Task 2a of the “Far IR photometric propagation analysis” study conducted by the OATo Team for Thales Alenia Space Italia (TASI) within the “Far IR Risk Mitigation” project commissioned by ESA.In order to investigate the feasibility of an all-sky guide star catalogue for an FGS operating in the FIR, we cross-match the sources selected in three test regions from the IRAS PSC and from the Spitzer surveys with both the AllWISE catalogue and Gaia DR3. We find 143 and 318 matched IRAS sources within 20° from the NGP and within 2° from the GC, respectively. In addition, we identify 3607 sources from the Spizer/SEP survey and 5398 sources from the Spitzer/MIPSGAL survey within 1° from the GC. We compare the AllWISE magnitudes W4 (22 um) versus the IRAS [25] and Spitzer/MIPS [24], and we confirm that W4 \simeq [24] \simeq [25] due to the similarity of these three passbands. By means of the color-color plots, G–W1 vs. W2–W3, we are able to identify and classify stars and extragalactic objects (e.g. galaxies and QSO’s) in the fields towards intermediate and high Galactic latitudes. We show evidence that stars without IR excess have null color-indexes, so that W2 \simeq W3 \simeq W4 \simeq [24], as the spectral energy distribution in the MIR and FIR of the stars outside the Galactic plane can be well represented by the Rayleigh–Jeans approximation. Moreover, extragalactic sources show positive color-indexes of about W3–W4 \simeq 2 mag, due to the thermal emission from the dust in the ISM. The Galactic Center is a much more challenging region because of the stellar crowding, as well as the strong optical extinction associated with a high sky IR background. Actually, the distribution [24] vs. W4 in the GC region shows a larger spread and systematic offset with respect to the corresponding distribution in the SEP region. Similar results are found for the other passbands [24] vs. W3 or [24] vs. W2. These effects may be due to the non-negligible IR extinction towards the Galactic Center and/or by an instrumental systematic bias produced by the high sky background that contaminates the photometric aperture of the lower resolution WISE data