| 1. |
- Feroci, M., et al.
(författare)
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The large observatory for x-ray timing
- 2014
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Ingår i: Proceedings of SPIE - The International Society for Optical Engineering. - : SPIE. - 9780819496126
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Konferensbidrag (refereegranskat)abstract
- The Large Observatory For x-ray Timing (LOFT) was studied within ESA M3 Cosmic Vision framework and participated in the final downselection for a launch slot in 2022-2024. Thanks to the unprecedented combination of effective area and spectral resolution of its main instrument, LOFT will study the behaviour of matter under extreme conditions, such as the strong gravitational field in the innermost regions of accretion flows close to black holes and neutron stars, and the supranuclear densities in the interior of neutron stars. The science payload is based on a Large Area Detector (LAD, 10 m2 effective area, 2-30 keV, 240 eV spectral resolution, 1° collimated field of view) and a Wide Field Monitor (WFM, 2-50 keV, 4 steradian field of view, 1 arcmin source location accuracy, 300 eV spectral resolution). The WFM is equipped with an on-board system for bright events (e.g. GRB) localization. The trigger time and position of these events are broadcast to the ground within 30 s from discovery. In this paper we present the status of the mission at the end of its Phase A study.
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| 2. |
- Amati, L., et al.
(författare)
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The THESEUS space mission concept : science case, design and expected performances
- 2018
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Ingår i: Advances in Space Research. - : ELSEVIER SCI LTD. - 0273-1177 .- 1879-1948. ; 62:1, s. 191-244
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Tidskriftsartikel (refereegranskat)abstract
- THESEUS is a space mission concept aimed at exploiting Gamma-Ray Bursts for investigating the early Universe and at providing a substantial advancement of multi-messenger and time-domain astrophysics. These goals will be achieved through a unique combination of instruments allowing GRB and X-ray transient detection over a broad field of view (more than 1 sr) with 0.5-1 arcmin localization, an energy band extending from several MeV down to 0.3 keV and high sensitivity to transient sources in the soft X-ray domain, as well as on-board prompt (few minutes) follow-up with a 0.7 m class IR telescope with both imaging and spectroscopic capabilities. THESEUS will be perfectly suited for addressing the main open issues in cosmology such as, e.g., star formation rate and metallicity evolution of the inter-stellar and intra-galactic medium up to redshift similar to 10, signatures of Pop III stars, sources and physics of re-ionization, and the faint end of the galaxy luminosity function. In addition, it will provide unprecedented capability to monitor the X-ray variable sky, thus detecting, localizing, and identifying the electromagnetic counterparts to sources of gravitational radiation, which may be routinely detected in the late '20s/early '30s by next generation facilities like aLIGO/ aVirgo, eLISA, KAGRA, and Einstein Telescope. THESEUS will also provide powerful synergies with the next generation of multi-wavelength observatories (e.g., LSST, ELT, SKA, CTA, ATHENA).
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| 3. |
- Marinucci, A., et al.
(författare)
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Polarization constraints on the X-ray corona in Seyfert Galaxies : MCG-05-23-16
- 2022
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Ingår i: Monthly notices of the Royal Astronomical Society. - : Oxford University Press (OUP). - 0035-8711 .- 1365-2966. ; 516:4, s. 5907-5913
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Tidskriftsartikel (refereegranskat)abstract
- We report on the first observation of a radio-quiet active galactic nucleus (AGN) in polarized X-rays: the Seyfert 1.9 galaxy MCG-05-23-16. This source was pointed at with the Imaging X-ray Polarimetry Explorer (IXPE) starting on 2022 May 14 for a net observing time of 486 ks, simultaneously with XMM-Newton (58 ks) and NuSTAR (83 ks). A polarization degree Π smaller than 4.7 per cent (at the 99 per cent confidence level) is derived in the 2–8 keV energy range, where emission is dominated by the primary component ascribed to the hot corona. The broad-band spectrum, inferred from a simultaneous fit to the IXPE, NuSTAR, and XMM-Newton data, is well reproduced by a power law with photon index Γ = 1.85 ± 0.01 and a high-energy cutoff EC = 120 ± 15 keV. A comparison with Monte Carlo simulations shows that a lamp-post and a conical geometry of the corona are consistent with the observed upper limit, a slab geometry is allowed only if the inclination angle of the system is less than 50°.
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| 4. |
- Volpe, Giovanni, 1979, et al.
(författare)
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Roadmap for optical tweezers
- 2023
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Ingår i: Journal of Physics-Photonics. - : IOP Publishing. - 2515-7647. ; 5:2
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Tidskriftsartikel (refereegranskat)abstract
- Optical tweezers are tools made of light that enable contactless pushing, trapping, and manipulation of objects, ranging from atoms to space light sails. Since the pioneering work by Arthur Ashkin in the 1970s, optical tweezers have evolved into sophisticated instruments and have been employed in a broad range of applications in the life sciences, physics, and engineering. These include accurate force and torque measurement at the femtonewton level, microrheology of complex fluids, single micro- and nano-particle spectroscopy, single-cell analysis, and statistical-physics experiments. This roadmap provides insights into current investigations involving optical forces and optical tweezers from their theoretical foundations to designs and setups. It also offers perspectives for applications to a wide range of research fields, from biophysics to space exploration.
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| 5. |
- Caffau, E., et al.
(författare)
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Systematic investigation of chemical abundances derived using IR spectra obtained with GIANO
- 2019
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 622
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Tidskriftsartikel (refereegranskat)abstract
- Context. Detailed chemical abundances of Galactic stars are needed in order to improve our knowledge of the formation and evolution of our galaxy, the Milky Way. Aims. We took advantage of the GIANO archive spectra to select a sample of Galactic disc stars in order to derive their chemical inventory and to compare the abundances we derived from these infrared spectra to the chemical pattern derived from optical spectra. Methods. We analysed high-quality spectra of 40 stars observed with GIANO. We derived the stellar parameters from the photometry and the Gaia data-release 2 (DR2) parallax; the chemical abundances were derived with the code MyGIsFOS. For a subsample of stars we compared the chemical pattern derived from the GIANO spectra with the abundances derived from optical spectra. We derived P abundances for all 40 stars, increasing the number of Galactic stars for which phosphorus abundance is known. Results. We could derive abundances of 14 elements, 8 of which are also derived from optical spectra. The comparison of the abundances derived from infrared and optical spectra is very good. The chemical pattern of these stars is the one expected for Galactic disc stars and is in agreement with the results from the literature. Conclusions. GIANO is providing the astronomical community with an extremely useful instrument, able to produce spectra with high resolution and a wide wavelength range in the infrared.
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| 6. |
- Abu-Ghanem, Yasmin, et al.
(författare)
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Should patients with low-risk renal cell carcinoma be followed differently after nephron-sparing surgery vs radical nephrectomy?
- 2021
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Ingår i: BJU International. - : John Wiley & Sons. - 1464-4096 .- 1464-410X. ; 128:3, s. 386-394
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To investigate whether pT1 renal cell carcinoma (RCC) should be followed differently after partial (PN) or radical nephrectomy (RN) based on a retrospective analysis of a multicentre database (RECUR).Subjects: A retrospective study was conducted in 3380 patients treated for nonmetastatic RCC between January 2006 and December 2011 across 15 centres from 10 countries, as part of the RECUR database project. For patients with pT1 clear-cell RCC, patterns of recurrence were compared between RN and PN according to recurrence site. Univariate and multivariate models were used to evaluate the association between surgical approach and recurrence-free survival (RFS) and cancer-specific mortality (CSM).Results: From the database 1995 patients were identified as low-risk patients (pT1, pN0, pNx), of whom 1055 (52.9%) underwent PN. On multivariate analysis, features associated with worse RFS included tumour size (hazard ratio [HR] 1.32, 95% confidence interval [CI] 1.14–1.39; P < 0.001), nuclear grade (HR 2.31, 95% CI 1.73–3.08; P < 0.001), tumour necrosis (HR 1.5, 95% CI 1.03–2.3; P = 0.037), vascular invasion (HR 2.4, 95% CI 1.3–4.4; P = 0.005) and positive surgical margins (HR 4.4, 95% CI 2.3–8.5; P < 0.001). Kaplan–Meier analysis of CSM revealed that the survival of patients with recurrence after PN was significantly better than those with recurrence after RN (P = 0.02). While the above-mentioned risk factors were associated with prognosis, type of surgery alone was not an independent prognostic variable for RFS nor CSM. Limitations include the retrospective nature of the study.Conclusion: Our results showed that follow-up protocols should not rely solely on stage and type of primary surgery. An optimized regimen should also include validated risk factors rather than type of surgery alone to select the best imaging method and to avoid unnecessary imaging. A follow-up of more than 3 years should be considered in patients with pT1 tumours after RN. A novel follow-up strategy is proposed.
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| 7. |
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| 8. |
- Capitanio, L., et al.
(författare)
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EREBUS: the EuRopean Extinction BUmp Survey
- 2020
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Ingår i: Experimental astronomy. - : Springer. - 0922-6435 .- 1572-9508. ; 50:1, s. 145-158
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Tidskriftsartikel (refereegranskat)abstract
- Dust in the Interstellar Medium (ISM) is intimately linked to the life cycle of stars. Despite being of such fundamental importance to galaxy evolution, the dynamic behaviour and composition of the ISM are not yet fully understood. Observations of reddened Milky Way OB stars have revealed a strong UV extinction feature around 2175 Å and a precipitous extinction rise to the far UV along the lines of sight. Whilst the carrier(s) for this are at present still being debated, multiple laboratory studies suggest carbonate grains to be the key constituent. EREBUS is a mission concept being developed to study the composition of the ISM in both the Milky Way and Local Group Galaxies, primarily by mapping the spatial distribution of the UV extinction features. As these features are sensitive to the dust composition along the line of sight, EREBUS will provide a wealth of information about the spatial distribution and dynamic behaviour of the carrier(s). The mission proposes to deploy a satellite observatory equipped with a coarse UV spectrograph to map the extinction curve variability in the Milky Way in 3 dimensions and in the Local Group in 2 dimensions. In this paper, we discuss the scientific goals for the project, discuss a proposed observation strategy using an iterative process to develop a hierarchical map, and finally outline the instrument requirements and preliminary spacecraft architecture.
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| 9. |
- Herlin, G, et al.
(författare)
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Quantitative assessment of 99mTc-depreotide uptake in patients with non-small-cell lung cancer: immunohistochemical correlations
- 2009
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Ingår i: Acta radiologica (Stockholm, Sweden : 1987). - : SAGE Publications. - 1600-0455 .- 0284-1851. ; 50:8, s. 902-908
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Tidskriftsartikel (refereegranskat)abstract
- Background: Somatostatin receptor (SSTR) scintigraphy with 99mTc-depreotide is used for differential diagnosis of solitary pulmonary nodules. The method is based on SSTR expression in cancer tissue. Purpose: To estimate the expression of SSTRs in non-small-cell lung cancer (NSCLC) in vitro, and to determine the correlation between 99mTc-depreotide uptake in vivo and different tumor characteristics determined in vitro, such as tumor grade, and presence of SSTR2, MIB-1, and p53. Material and Methods: A total of 127 patients with lung lesions detected on computed tomography (CT) were investigated with SSTR scintigraphy after injection of 740 MBq 99mTc-depreotide. This study includes 19 patients with NSCLC with histologically proven diagnosis. The quantitative evaluation of 99mTc-depreotide was performed using region-of-interest analysis and includes tumor counts/cm3, background counts/cm3, and the ratio between tumor and background counts. Results: 99mTc-depreotide uptake was found in all NSCLC tumors, which expressed SSTR2 defined in vitro by immunochemical methods. SSTR2 expression was negatively correlated to the degree of the tumor's differentiation ( P<0.05). 99mTc-depreotide uptake in tumor cells did not correlate with tumor grade, or SSTR2, MIB-1, or p53 expression. Conclusion: There is an expression of SSTRs in NSCLC. The degree of tumor differentiation correlates negatively with SSTR2 measured in vitro and positively with MIB-1 expression in tumor tissue. No correlation was found between 99mTc-depreotide uptake and possible prognostic factors such as MIB-1 and p53 expression in tumor cells in NSCLC. Lastly, no correlation was found between 99mTc-depreotide uptake and tumor grade or SSTR2 expression.
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