A5054502148- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Astrophysical Phenomena and Observations
- Astronomical Observations and Instrumentation
- Astrophysics and Star Formation Studies
- Gamma-ray bursts and supernovae
- Historical Astronomy and Related Studies
- Historical and Architectural Studies
- History and Developments in Astronomy
- Particle Detector Development and Performance
- Astrophysics and Cosmic Phenomena
- Astro and Planetary Science
- X-ray Spectroscopy and Fluorescence Analysis
- Nuclear Physics and Applications
- Pulsars and Gravitational Waves Research
- Advanced X-ray Imaging Techniques
- Ancient Mediterranean Archaeology and History
- High-pressure geophysics and materials
- Calibration and Measurement Techniques
- Medical Imaging Techniques and Applications
- Maritime and Coastal Archaeology
- Mechanics and Biomechanics Studies
- Atomic and Molecular Physics
- Particle Accelerators and Free-Electron Lasers
- Adaptive optics and wavefront sensing
National Institute for Astrophysics
2005-2019
University of Ferrara
2013-2019
Institute for Space Astrophysics and Planetology
2001-2019
Istituto di Astrofisica Spaziale e Fisica Cosmica di Milano
1995-2010
Istituto di Astrofisica Spaziale e Fisica Cosmica di Bologna
2008
Universidad Nacional Autónoma de México
2002
Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Frascati
1994
Sapienza University of Rome
1990-1991
Space (Italy)
1979
National Research Council
1979
FS CMa stars form a group of objects with the B[e] phenomenon that were previously known as unclassified or warm dust (B[e]WD) until recently. They exhibit strong emission-line spectra and IR excesses, most likely due to recently formed circumstellar dust. These properties have been suggested be ongoing recent rapid mass exchange in binary systems hot primaries various types secondaries. The first paper this series reported an analysis available information about Galactic phenomenon, initial...
view Abstract Citations (31) References (43) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Line feature around 73 KEV from the Crab Nebula. Manchanda, R. K. ; Bazzano, A. La Padula, C. D. Polcaro, V. F. Ubertini, P. Observational data for Nebula obtained with a balloon-borne, multiwire high-pressure xenon proportional counter indicate an X-ray spectrum line at approximately keV. Source continuous emission fits power law of 16.5E to -2.3, and intensity 0.005...
We study the long-term, S Dor-type variability and present hot phase of luminous blue variable (LBV) star GR 290 (Romano's Star) in M 33 order to investigate possible links between LBV late, nitrogen sequence Wolf–Rayet Stars (WNL) stages very massive stars. use intermediate-resolution spectra, obtained with William Herschel Telescope (WHT) 2008 December, when was at minimum (V = ∼18.6), as well new low-resolution spectra BVRI photometry Loiano Cima Ekar telescopes during 2007–2010. identify...
ABSTRACT We have investigated the past light history of luminous variable star GR 290 (M33/V532, Romano’s Star) in M33 galaxy, and collected new spectrophotometric observations order to analyze links between this object, LBV category, Wolf–Rayet stars nitrogen sequence. built historical curve back 1901, from old found several archival plates M33. These recordings together with published data on allowed us infer that for at least half a century was low luminosity state, B ≃ 18–19, most likely...
Context. Understanding the origin of instabilities LBVs is important for shedding light on late evolutionary stages massive stars and chemical evolution galaxies.
FS CMa type stars are a group of Galactic objects with the B[e] phenomenon. They exhibit strong emission-line spectra and infrared excesses, which most likely due to recently formed circumstellar dust. The content identification criteria were described in first two papers series. In this paper we report our spectroscopic photometric observations optical counterpart IRAS 00470+6429 obtained 2003–2008. spectrum is dominated by emission lines, have P Cyg profiles. We detected significant...
We report the discovery of optical counterpart 12.3-s transient X-ray pulsar GS 0834-43. reanalysed archival ROSAT PSPC observations 0834-43, obtaining two new refined positions, ∼14 and ∼18 arcsec away from previously published one, a spin period measurement. Based on these results we carried out infrared (IR) follow-up observations. Within error circles, found relatively faint (V = 20.1) early-type reddened star (V-R 2.24). The spectrum shows strong Hα emission line. IR field confirm...
We report on the discovery of optical/IR counterpart 15.8 s transient X–ray pulsar XTE J1946+274. re–analyzed archival Beppo SAX observations J1946+274 obtaining a new refined position (a circle with 22´´ radius at 90% confidence level). Based this we carried out optical and infra–red (IR) follow–up observations. Within error found relatively faint () IR bright early type reddened star (). The spectra show strong Hα Hβ emission lines. photometric field confirm presence an excess for...
We report on the discovery and confirmation of optical counterparts two transient X-ray pulsars, RX J0052.1-7319 XTE J0111.2-7317. In narrow (~ radius) error circle we found a () 09.5IIIe (a classification as B0Ve star is also possible, since luminosity class depends uncertainty adopted reddening). Medium resolution spectra for this object show Balmer lines in emission with an equivalent width HÅ. box J0111.2-7317 relatively bright (, ) which has been classified B0.5-B1Ve that was later...
Context.Understanding the nature of instabilities LBVs is important to understand late evolutionary stages very massive stars.
view Abstract Citations (24) References (43) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Evidence of hard X-ray emission from three clusters galaxies. Bazzano, A. ; Fusco-Femiano, R. La Padula, C. Polcaro, V. F. Ubertini, P. Manchanda, K. The results hard-X-ray observations in the energy range 20-100 keV are reported for galaxies Coma, A2142, and 3C 129, previously detected at medium energies. data have been obtained with a balloon-borne telescope flown...
We report the first spectroscopic study of LBV candidate GR 290 in M 33 ("Romano's star") taken February 2003, showing, besides prominent hydrogen and He i emission lines, 4630–60 Å blend weak ii 4686 typical Of stars. Our broad–band photometry shows that star was observed during a phase minimum optical luminosity, with , slightly positive colour index, which we tentatively attribute to an anomalous continuum energy distribution. argue is indeed presently high temperature phase, should be...
A serendipitous sky field in Vulpecula was observed with Johnson BVR photometry and slitless spectroscopy the 5600-8000 Årange, looking for emission line late spectral type stars. We discovered that B2V star LS II +32° 9, most probably a member of Vul OB4 association, is now an Hα emitter. Furthermore, we identified optical counterpart IRAS source 19564+3224 as C star. Photometric study surrounding stellar revealed this object lies inside area previously undetected open cluster intermediate...
The supernova explosion of 1054 AD, which originated the Crab Nebula and Pulsar, is probably astronomical event has been most deeply studied by means historical sources. However, many mysteries inconsistencies, both among different sources between what deduced records present day data, are demanding extraordinary efforts theoretical astrophysicists in order to put all data a meaningful framework. An accurate analysis sources, like one we presenting here, may contribute solve some these problems.
Context. GR 290 (M 33/V532 = Romano’s Star) is a suspected post-luminous blue variable star located in M 33 galaxy that shows rare Wolf–Rayet (WR) spectrum during its minimum light phase. In spite of many studies, atmospheric structure, circumstellar environment, and place the general context massive stars’ evolution poorly known. Aims. We present detailed study this star’s wind mass loss, environment associated to star. Methods. Long-slit spectra were obtained luminosity phase with Gran...
view Abstract Citations (17) References (49) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Hard X-ray variability of three active galactic nuclei. Ubertini, P. ; Bazzano, A. La Padula, C. Polcaro, V. F. Manchanda, R. K. Spectral observations nuclei (AGN) in the hard range between 20 and 100 keV are reported. The data include two Seyfert galaxies (MCG 8-11-11 NGC 4151) BL Lac object Mrk 421. observational results were obtained with a large-area balloon-borne...
view Abstract Citations (10) References (65) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Hard X-Ray Timing Observation of the Crab Pulsar and Cygnus X-1 Ubertini, P. ; Bazzano, A. Cocchi, M. La Padula, C. Polcaro, V. F. Staubert, R. Kendziorra, E. Results a timing analysis are presented. These two strong Galactic sources were observed on 1985 August 5 with POKER experiment in energy range 15-130 keV. The spectral behavior, showing canonical spectrum for...
The evolution of the concept time, from first hunters-gatherers communities Paleolithic to Newtonian physics is shortly reviewed. In particular, attention id paid social needs that contributed change this Prehistory Bronze Age and then Iron Age, classical philosophy, Middle Ages Renaissance, up birth modern science.
An analysis performed on a sample of 191 extragalactic X-ray sources different classes (QSOs, Seyfert Galaxies, BLLac, elliptical and S0, spiral irregular galaxies) appears to show general relationship between log z the logarithm 2 keV equivalent monochromatic luminosity brightest object in given redshift interval (regardless class object). This function is almost constant for |$z\lt0.001$|; it has continuous inflection about two orders magnitude = 0.001 0.01, at |$z\gt0.001$|, where only...