3 results
Simulating infrared spectro-photometric surveys with a Spritz
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- L. Bisigello, C. Gruppioni, F. Calura, A. Feltre, F. Pozzi, C. Vignali, L. Barchiesi, G. Rodighiero, M. Negrello, F. J. Carrera, K. M. Dasyra, J. A. Fernández-Ontiveros, M. Giard, E. Hatziminaoglou, H. Kaneda, E. Lusso, M. Pereira-Santaella, P. G. Pérez González, C. Ricci, D. Schaerer, L. Spinoglio, L. Wang
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- Journal:
- Publications of the Astronomical Society of Australia / Volume 38 / 2021
- Published online by Cambridge University Press:
- 17 December 2021, e064
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Mid- and far-infrared (IR) photometric and spectroscopic observations are fundamental to a full understanding of the dust-obscured Universe and the evolution of both star formation and black hole accretion in galaxies. In this work, using the specifications of the SPace Infrared telescope for Cosmology and Astrophysics (SPICA) as a baseline, we investigate the capability to study the dust-obscured Universe of mid- and far-IR photometry at 34 and $70\, {\rm{\mu }}\mathrm{m}$ and low-resolution spectroscopy at $17{-}36\, {\rm{\mu }}\mathrm{m}$ using the state-of-the-art Spectro-Photometric Realisations of Infrared-selected Targets at all-z (Spritz) simulation. This investigation is also compared to the expected performance of the Origins Space Telescope and the Galaxy Evolution Probe. The photometric view of the Universe of a SPICA-like mission could cover not only bright objects (e.g. $L_{IR}>10^{12}\,{\rm L}_{\odot}$ ) up to ${z}=10$ , but also normal galaxies ( $L_{IR}<10^{11}\,{\rm L}_{\odot}$ ) up to $\textit{z}\sim4$ . At the same time, the spectroscopic observations of such mission could also allow us to estimate the redshifts and study the physical properties for thousands of star-forming galaxies and active galactic nuclei by observing the polycyclic aromatic hydrocarbons and a large set of IR nebular emission lines. In this way, a cold, 2.5-m size space telescope with spectro-photometric capability analogous to SPICA, could provide us with a complete three-dimensional (i.e. images and integrated spectra) view of the dust-obscured Universe and the physics governing galaxy evolution up to $\textit{z}\sim4$ .
The role of SPICA-like missions and the Origins Space Telescope in the quest for heavily obscured AGN and synergies with Athena
- Part of
- L. Barchiesi, F. Pozzi, C. Vignali, F. J. Carrera, F. Vito, F. Calura, L. Bisigello, G. Lanzuisi, C. Gruppioni, E. Lusso, I. Delvecchio, M. Negrello, A. Cooray, A. Feltre, J. A. Fernández-Ontiveros, S. Gallerani, H. Kaneda, S. Oyabu, M. Pereira-Santaella, E. Piconcelli, C. Ricci, G. Rodighiero, L. Spinoglio, F. Tombesi
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- Journal:
- Publications of the Astronomical Society of Australia / Volume 38 / 2021
- Published online by Cambridge University Press:
- 23 July 2021, e033
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In the black hole (BH)–galaxy co-evolution framework, most of the star formation (SF) and the BH accretion are expected to take place in highly obscured conditions. The large amount of gas and dust absorbs most of the UV-to-soft-X radiation and re-emits it at longer wavelengths, mostly in the IR. Thus, obscured active galactic nuclei (AGN) are very difficult to identify in optical or X-ray bands but shine bright in the IR. Moreover, X-ray background (XRB) synthesis models predict that a large fraction of the yet-unresolved XRB is due to the most obscured (Compton thick, CT: N $_{\text{H}}\ge 10^{24} \,\mathrm{cm}^{-2}$ ) of these AGN. In this work, we investigate the synergies between putative IR missions [using SPace Infrared telescope for Cosmology and Astrophysics (SPICA), proposed for European Space Agency (ESA)/M5 but withdrawn in 2020 October, and Origins Space Telescope, OST, as ‘templates’] and the X-ray mission Athena (Advanced Telescope for High ENergy Astrophysics), which should fly in early 2030s, in detecting and characterising AGN, with a particular focus on the most obscured ones. Using an XRB synthesis model, we estimated the number of AGN and the number of those which will be detected in the X-rays by Athena. For each AGN, we associated an optical-to-Far InfraRed (FIR) spectral energy distribution (SED) from observed AGN with both X-ray data and SED decomposition and used these SEDs to check if the AGN will be detected by SPICA-like or OST at IR wavelengths. We expect that, with the deepest Athena and SPICA-like (or OST) surveys, we will be able to photometrically detect in the IR more than 90% of all the AGN (down to $L_{2-10\text{keV}} \sim 10^{42}\,\mathrm{erg\ s}^{-1}$ and up to $z \sim 10$ ) predicted by XRB synthesis modeling, and we will detect at least half of them in the X-rays. The spectroscopic capabilities of the OST can provide ${\approx}51\,000$ and ${\approx}3\,400$ AGN spectra with $R= 300$ at 25–588 $\unicode[Times]{x03BC}$ m in the wide and deep surveys, respectively, the last one up to $z\approx 4$ . Athena will be extremely powerful in detecting and discerning moderate- and high-luminosity AGN, allowing us to properly select AGN even when the mid-IR torus emission is ‘hidden’ by the host galaxy contribution. We will constrain the intrinsic luminosity and the amount of obscuration for $\sim\!20\%$ of all the AGN (and $\sim\!50\%$ of those with $L_{2-10\text{keV}} > 3.2 \times 10^{43}\,\mathrm{erg\ s}^{-1}$ ) using the X-ray spectra provided by Athena WFI. We find that the most obscured and elusive CT-AGN will be exquisitely sampled by SPICA-like mission or OST and that Athena will allow a fine characterisation of the most luminous ones. This will provide a significant step forward in the process of placing stronger constraints on the yet-unresolved XRB and investigating the BH accretion rate evolution up to very high redshift ( $z \ge 4$ ).
Social stress and atherosclerosis in normocholesterolemic monkeys
- from Section 2 - Psychophysiological processes in disease
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- By J. R. Kaplan, University of Pittsburg, S. B. Manuck, University of Pittsburg, T. B. Clarkson, University of Pittsburg, F. M. Lusso, University of Pittsburg, D. M. Taub, University of Pittsburg, E. W. Miller, University of Pittsburg
- Edited by Andrew Steptoe, St George's Hospital Medical School, University of London, Jane Wardle, Imperial Cancer Research Fund, London
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- Book:
- Psychosocial Processes and Health
- Published online:
- 05 August 2016
- Print publication:
- 24 November 1994, pp 141-146
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Summary
Abstract
Socially stressed adult male cynomolgus monkeys (Macaca fasdcularis) fed a low fat, low cholesterol diet developed more extensive coronary artery atherosclerosis than unstressed controls. Groups did not differ in serum lipids, blood pressure, serum glucose, or ponderosity. These results suggest that psychosocial factors may influence atherogenesis in the absence of elevated serum lipids. Psychosocial factors thus may help explain the presence of coronary artery disease (occasionally severe) in people with low or normal serum lipids and normal values for the other “traditional” risk factors.
The initiation and progression of coronary artery atherosclerosis is often associated with increased concentrations of lipids in the serum (1). Despite this association, many individuals develop severe atherosclerotic lesions while having low serum lipid concentrations, and others develop far more atherosclerosis than would be expected on the basis of a modest evaluation of serum lipids (2). Work with animal models suggests that some of this variability may be explained by the influence of hypertension and immunologic injury to arteries, (3, 4). Yet, much additional variability in atherosclerosis lesion extent remains unexplained, suggesting the existence of other pathogenic mechanisms among normocholesterolemic individuals. In recent years, psychosocial variables have been linked increasingly to ischemic heart disease in human beings (5) and psychosocial manipulations have been shown to exacerbate atherosclerosis in cholesterol-fed cynomolgus monkeys, rabbits, and swine (6-8). At present, though, it is unclear whether psychosocial manipulations are capable of promoting atherogenesis in normocholesterolemic animals and, by implication, in human beings with low or normal serum cholesterol concentrations. The purpose of the present investigation was to provide an initial test of this hypothesis. Our results demonstrate that socially stressed monkeys fed a low fat, low cholesterol diet developed more extensive intimal lesions in the coronary arteries than control animals living under unstressed conditions. Moreover, the differences in lesion extent observed here were not associated with elevations or group differences in serum lipids, blood pressure, serum glucose, or ponderosity.
The experimental animals were 30 male, cynomolgus monkeys (Macaca fascicularis), imported as adults from Malaysia and the Philippine Islands. They were assigned to two experimental conditions (designated the “stressed” and “unstressed” conditions), and within each condition (N = 15), the monkeys were divided randomly into three, five-member groups. During the study, all groups were housed separately in identical pens measuring 2.0 by 3.2 by 2.5 m.