Il Cispio e le sue adiacenze in età antica. Storia urbana e analisi topografica di un settore dell'Esquilino

La ricerca è stata avviata col fine di analizzare la topografia storica di uno dei settori della città antica meno conosciuti: il Cispio. Ci si è così proposti di restituire la storia urbana di una delle aree di Roma che, a causa di una marginalità evidente all’interno delle fonti letterarie risulta tra le più neglette negli studi contemporanei. A livello metodologico si è operato distinguendo tre differenti livelli: analitico, sintetico e interpretativo. Nella struttura della ricerca si è imposta una qualche ridondanza nella organizzazione e nell’analisi delle fonti disponibili, interrogandole sulle diverse tematiche affrontate e riarticolandole secondo prospettive interpretative differenti. La natura stessa del dossier non ha consentito, infatti, una narrazione continua e cronologicamente ordinata, a cui si è così rinunciato. La raccolta dei dati ha mirato a ricostruire ogni ritrovamento occorso lungo la superficie del Cispio, confluito poi nella carta archeologica, che costituisce la parte catalogica di questo lavoro. Ad un livello successivo, quello di sintesi, si è scelto di esaminare ogni tematica topografica sotto una duplice prospettiva quella delle fonti archeologiche e quella delle fonti scritte, cercando in questo modo sia di distinguere il più possibile la lettura dall’interpretazione, sia di valorizzare un dossier di sua natura poco “parlante”. Sono state così affrontate problematiche quali la toponomastica e la topografia, le suddivisioni dello spazio urbano, la viabilità e gli spazi pubblici e i luoghi di culto nell’ambito delle fonti scritte. Per quelle archeologiche, invece, si sono esaminate le dinamiche dello sviluppo pre-urbano, il tessuto insediativo, la viabilità e, seppur brevemente, l’analisi dei reperti mobili. Un apposito spazio, inoltre, è stato dedicato alla complessa problematica della localizzazione del tempio di Giunone Lucina sul Cispio, di fatto il solo edificio che le fonti antiche situano con certezza sul mons. La proposta di localizzazione, ottenuta tramite l’analisi integrata del dossier archeologico con quello letterario ed epigrafico, si è giovata in gran parte della ricerca archivistica sopramenzionata. Si è tentato comunque, per quanto possibile, di restituire un quadro e un areale accettabile per la localizzazione del luogo di culto, e successivamente indagare le distinte possibilità, avanzando una proposta specifica. Infine, ad un ultimo livello più interpretativo si sono analizzate le problematiche di storia urbana dell’area. In questo senso, proprio a causa della limitatezza delle fonti letterarie disponibili il lavoro si è giovato del dossier epigrafico per approfondire il paesaggio religioso e la storia sociale del quartiere. Sulla prima tematica, sostanzialmente limitata alla festività dei Matronalia ci si è proposti di chiarire la ritualità connessa alla celebrazione delle feste in onore della dea, al suo contesto storico ed alle vicende connesse alla fondazione del tempio, tra le più dibattute nella storia degli studi. Sulla storia sociale del quartiere è stata indagata e verificata la presenza di specifiche forme di sociabilità connessa alla eventuale caratterizzazione “professionale” di alcune aree del Cispio. Contestualmente si è cercato di comprendere e ricostruire la presenza di memorie di famiglie nella toponomastica, ed infine, di tracciare un quadro degli abitanti del quartiere, provando a riconoscerne le abitazioni e analizzando i caratteri specifici del popolamento. L’obiettivo finale è stato quello di colmare un vuoto nella storia urbana della città antica, cercando di comprendere l’area nella sua integrità e il complesso sistema di fonti ad essa associate

La Velia da Massenzio a Mussolini. Ideologia, politica e paesaggio urbano

The contribution intends to analyse, investigating the ideological meanings in terms of urban policy, the long-term events that since the age of Maxentius have followed one another in the urban history of the southern slope of the Velia, one of the most representative and historically qualified areas of the centre of Ancient and modern Rome. The hill has been the object of successive transformations that have changed the image and value of this important public space up to the contemporary age. After the late ancient and medieval phases, the functional alterations of the area were followed by the loss of identity of the basilica of Maxentius, recognized as such only in the early 19th century by Antonio Nibby. The views, engravings and drawings from the 17th-19th centuries witness the evolution of the urban image of this part of the city, replaced in the role of symbolic centre by the new focal points of papal Rome. A renewed chapter in the history of the southern slope of the Velia opened up with the French government’s urban policy projects (1809-1814), followed by the 19th-century excavations and then by the idea of the “passeggiata archeologica” which has polarised the archaeological debate and urban planning of the post-unitary period. Finally, the opening of via dell’Impero was the last act of semantization of this sector of the Velia, according to an ideological and propagandist urban policy process that has directly involved the basilica of Maxentius, reinterpreting it in its functions

The Asiago-ESO/RASS QSO Survey II. The Southern Sample

This is the second paper of a series describing the Asiago-ESO/RASS QSO survey, a project aimed at the construction of an all-sky statistically well-defined sample of very bright QSOs (B_J 30^{\circ}). The area covered by the survey is 5660 sq. deg. Spectroscopy for the 137 still unidentified objects has been obtained. The total number of AGN turns out to be 111, 63 of which are new identifications. The properties of the selection are discussed. The completeness and the success rate for this survey at the final stage are 63% and 46%, respectively

The Probabilistic Random Forest applied to the selection of quasar candidates in the QUBRICS Survey

The number of known, bright ($i2.5$) QSOs in the Southern Hemisphere is considerably lower than the corresponding number in the Northern Hemisphere due to the lack of multi-wavelength surveys at $\delta<0$. Recent works, such as the QUBRICS survey, successfully identified new, high-redshift QSOs in the South by means of a machine learning approach applied on a large photometric dataset. Building on the success of QUBRICS, we present a new QSO selection method based on the Probabilistic Random Forest (PRF), an improvement of the classic Random Forest algorithm. The PRF takes into account measurement errors, treating input data as probability distribution functions: this allows us to obtain better accuracy and a robust predictive model. We applied the PRF to the same photometric dataset used in QUBRICS, based on the SkyMapper DR1, Gaia DR2, 2MASS, WISE and GALEX databases. The resulting candidate list includes $626$ sources with $i<18$. We estimate for our proposed algorithm a completeness of $\sim84\%$ and a purity of $\sim78\%$ on the test datasets. Preliminary spectroscopic campaigns allowed us to observe 41 candidates, of which 29 turned out to be $z>2.5$ QSOs. The performances of the PRF, currently comparable to those of the CCA, are expected to improve as the number of high-z QSOs available for the training sample grows: results are however already promising, despite this being one of the first applications of this method to an astrophysical context.Comment: Accepted for publication in MNRAS, 12 pages, 11 figures, 4 table

Ultra-deep Large Binocular Camera U-band Imaging of the GOODS-North Field: Depth vs. Resolution

We present a study of the trade-off between depth and resolution using a large number of U-band imaging observations in the GOODS-North field (Giavalisco et al. 2004) from the Large Binocular Camera (LBC) on the Large Binocular Telescope (LBT). Having acquired over 30 hours of data (315 images with 5-6 mins exposures), we generated multiple image mosaics, starting with the best atmospheric seeing images (FWHM $\lesssim$0.8"), which constitute $\sim$10% of the total data set. For subsequent mosaics, we added in data with larger seeing values until the final, deepest mosaic included all images with FWHM $\lesssim$1.8" ($\sim$94% of the total data set). From the mosaics, we made object catalogs to compare the optimal-resolution, yet shallower image to the lower-resolution but deeper image. We show that the number counts for both images are $\sim$90% complete to $U_{AB}$ $\lesssim26$. Fainter than $U_{AB}$$\sim$ 27, the object counts from the optimal-resolution image start to drop-off dramatically (90% between $U_{AB}$ = 27 and 28 mag), while the deepest image with better surface-brightness sensitivity ($\mu^{AB}_{U}$$\lesssim$ 32 mag arcsec$^{-2}$) show a more gradual drop (10% between $U_{AB}$ $\simeq$ 27 and 28 mag). For the brightest galaxies within the GOODS-N field, structure and clumpy features within the galaxies are more prominent in the optimal-resolution image compared to the deeper mosaics. Finally, we find - for 220 brighter galaxies with $U_{AB}$$\lesssim$ 24 mag - only marginal differences in total flux between the optimal-resolution and lower-resolution light-profiles to $\mu^{AB}_{U}$$\lesssim$ 32 mag arcsec$^{-2}$. In only 10% of the cases are the total-flux differences larger than 0.5 mag. This helps constrain how much flux can be missed from galaxy outskirts, which is important for studies of the Extragalactic Background Light.Comment: 24 pages, 14 figures, submitted to PASP, comments welcom

Kiloparsec-scale gaseous clumps and star formation at z = 5–7

We investigate the morphology of the [Cii] emission in a sample of “normal” star-forming galaxies at 5 < z < 7:2 in relation to their UV (rest-frame) counterpart. We use new ALMA observations of galaxies at z 6 7, as well as a careful re-analysis of archival ALMA data. In total 29 galaxies were analysed, 21 of which are detected in [Cii]. For several of the latter the [Cii] emission breaks into multiple components. Only a fraction of these [Cii] components, if any, is associated with the primary UV systems, while the bulk of the [Cii] emission is associated either with fainter UV components, or not associated with any UV counterpart at the current limits. By taking into account the presence of all these components, we find that the L[CII]-SFR relation at early epochs is fully consistent with the local relation, but it has a dispersion of 0.48 0.07 dex, which is about two times larger than observed locally. We also find that the deviation from the local L[CII]-SFR relation has a weak anti-correlation with the EW(Ly ). The morphological analysis also reveals that [Cii] emission is generally much more extended than the UV emission. As a consequence, these primordial galaxies are characterised by a [Cii] surface brightness generally much lower than expected from the local [CII] SFR relation. These properties are likely a consequence of a combination of di erent e ects, namely: gas metallicity, [Cii] emission from obscured star-forming regions, strong variations of the ionisation parameter, and circumgalactic gas in accretion or ejected by these primeval galaxies.European Research Council RM acknowledges ERC Advanced Grant 695671 ‘QUENCH’. AF acknowledges support from the ERC Advanced Grant INTERSTELLAR H2020/740120

A mass threshold in the number density of passive galaxies at z∼\sim2

The process that quenched star formation in galaxies at intermediate and high redshift is still the subject of considerable debate. One way to investigate this puzzling issue is to study the number density of quiescent galaxies at z~2, and its dependence on mass. Here we present the results of a new study based on very deep Ks-band imaging (with the HAWK-I instrument on the VLT) of two HST CANDELS fields (the UKIDSS Ultra-deep survey (UDS) field and GOODS-South). The new HAWK-I data (taken as part of the HUGS VLT Large Program) reach detection limits of Ks>26 (AB mag). We select a sample of passively-evolving galaxies in the redshift range 1.4<z<2.5. Thanks to the depth and large area coverage of our imaging, we have been able to extend the selection of quiescent galaxies a magnitude fainter than previous analyses. Through extensive simulations we demonstrate, for the first time, that the observed turn-over in the number of quiescent galaxies at K>22 is real. This has enabled us to establish unambiguously that the number counts of quiescent galaxies at z~2 flatten and slightly decline at magnitudes fainter than Ks~22(AB mag.). We show that this trend corresponds to a stellar mass threshold $M_*10^{10.8}\,{\rm M_{\odot}}$ below which the mechanism that halts the star formation in high-redshift galaxies seems to be inefficient. Finally we compare the observed pBzK number counts with those of quiescent galaxies extracted from four different semi-analytic models. We find that none of the models provides a statistically acceptable description of the number density of quiescent galaxies at these redshifts. We conclude that the mass function of quiescent galaxies as a function of redshift continues to present a key and demanding challenge for proposed models of galaxy formation and evolution.Comment: Accepted for publication on Astronomy and Astrophysic

Spectroscopy of QUBRICS quasar candidates: 1672 new redshifts and a Golden Sample for the Sandage Test of the Redshift Drift

The QUBRICS (QUasars as BRIght beacons for Cosmology in the Southern hemisphere) survey aims at constructing a sample of the brightest quasars with z>~2.5, observable with facilities in the Southern Hemisphere. QUBRICS makes use of the available optical and IR wide-field surveys in the South and of Machine Learning techniques to produce thousands of bright quasar candidates of which only a few hundred have been confirmed with follow-up spectroscopy. Taking advantage of the recent Gaia Data Release 3, which contains 220 million low-resolution spectra, and of a newly developed spectral energy distribution fitting technique, designed to combine the photometric information with the Gaia spectroscopy, it has been possible to measure 1672 new secure redshifts of QUBRICS candidates, with a typical uncertainty $\sigma_z = 0.02$. This significant progress of QUBRICS brings it closer to (one of) its primary goals: providing a sample of bright quasars at redshift 2.5 < z < 5 to perform the Sandage test of the cosmological redshift drift. A Golden Sample of seven quasars is presented that makes it possible to carry out this experiment in about 1500 hours of observation in 25 years, using the ANDES spectrograph at the 39m ELT, a significant improvement with respect to previous estimates.Comment: 11 pages, 10 figures, accepted for publication in MNRA