scholarly journals The Sax Mission For X-Ray Astronomy

1990 ◽  
Vol 123 ◽  
pp. 141-150 ◽  
Author(s):  
R.C. Butler ◽  
L. Scarsi
Keyword(s):  
Energy Band ◽  
Broad Band ◽  
Energy Spectra ◽  
X Ray ◽  
Joint Development ◽  
Space Agency ◽  
Italian Space Agency ◽  
Galactic Sources ◽  
Bright Source

AbstractThe satellite for X-ray astronomy SAX, to be launched at the end of 1993, is devoted to systematic, integrated and comprehensive, studies of galactic and extra-galactic sources in the energy band 0.1–200 keV, and is under joint development by the Italian Space Agency (ASI) and the Netherlands Agency for Aerospace programs (NIVR), with the participation of SRU/SRON and SSD/ESTEC. The basic scientific objectives can be summarized as follows:– Broad band spectroscopy (E/Δ E=12) from 0.1–10 keV with imaging resolution of 1 arcmin.– Continuum and line spectroscopy (E/Δ E=5–20) in the energy range 3–200 keV.– Variability studies of bright source energy spectra on timescales from milliseconds to days and months.– Systematic long term variability studies over the entire sky down to a source intensity of 1 mCrab.

scholarly journals The X-ray Astronomy Satellite SAX

1990 ◽  
Vol 115 ◽  
pp. 302-306
Author(s):  
R.C. Butler
Keyword(s):  
Energy Range ◽  
Scintillation Counter ◽  
Broad Band ◽  
Wide Energy Range ◽  
Wide Field ◽  
X Ray ◽  
Wide Energy ◽  
Cyclotron Line ◽  
Galactic Sources

AbstractThe SAX satellite is forseen for launch at the end of 1992 to study the X-ray emission from galactic and extra-galactic sources in the energy range 0.1-200 keV. The payload consists of four concentrator/spectrometer systems (3 units 1-10keV, 1 unit 0.1-10keV), a high pressure gas scintillation proportional counter (3-120keV), a phoswich scintillation counter (15-200keV), and two wide field cameras (2-30keV). Together these instruments will perform the following:- - Broad band spectroscopy (E/ΔE=12) in the energy range 0.1-10 keV with imaging resolution of 1 arcmin- Continuum and cyclotron line spectroscopy (E/ΔE=5-20) in the wide energy range 3-200 keV- Variability studies of bright source energy spectra on time scales from milliseconds to days and months- Systematic long term source variability studies in selected regions of the sky down to a source intensity of 1 mCrab.

AGILE Observations of GW Events

2017 ◽  
Vol 13 (S338) ◽  
pp. 84-89
Author(s):  
Francesco Verrecchia ◽  
Marco Tavani ◽  
Immacolata Donnarumma
Keyword(s):  
Space Mission ◽  
Test Case ◽  
X Ray ◽  
Event Time ◽  
Space Agency ◽  
Upper Limits ◽  
Major Player ◽  
Detection Capabilities ◽  
Γ Ray ◽  
Italian Space Agency

AbstractAGILE is a space mission of the Italian Space Agency dedicated to γ-ray astrophysics, launched in 2007. AGILE performed dedicated real-time searches for possible γ-ray counterparts of gravitational wave (GW) events detected by the LIGO-Virgo scientific Collaboration (LVC) during the O2 observation run. We present a review of AGILE observations of GW events, starting with the first, GW150914, which was a test case for future searches. We focus here on the main characteristics of the observations of the most important GW events detected in 2017, i.e. GW170104 and GW170817. In particular, for the former event we published γ-ray upper limits (ULs) in the 50 MeV – 10 GeV energy band together with a detailed analysis of a candidate precursor event in the Mini-Calorimeter data. As for GW170817, we published a set of constraining γ-ray ULs obtained for integrations preceding and following the event time. These results allow us to establish important constraints on the γ-ray emission from a possible magnetar-like remnant in the first ~1000 s following T0. AGILE is a major player in the search of electromagnetic counterparts of GW events, and its enhanced detection capabilities in hard X-ray/MeV/GeV ranges will play a crucial role in the future O3 observing run.

Electroforming In Space And Ground Telescopes

2020 ◽  
Author(s):  
Valsecchi Giuseppe
Keyword(s):  
Radio Telescope ◽  
Grazing Incidence ◽  
Space Telescopes ◽  
Telescope Array ◽  
X Ray ◽  
Electroforming Process ◽  
Space Agency ◽  
Thin Nickel ◽  
Grazing Incidence Optics ◽  
Italian Space Agency

In the last 25 years, electroforming process has been extensively optimized to produce grazing incidence optics for the X-ray space telescopes, enabling the renown observatories Beppo-SAX for the Italian Space Agency, SWIFT for NASA, XMM Newton for ESA, eROSITA for MPE. These optics are made of thin Nickel mirrors that are grown by electroforming process in an electrolytic bath on a Gold coated mandrel.Electroforming has also been adopted for production of large reflector panels for sub-millimeter radio telescope applications. Between 2006 and 2016, 3000 mirror panels for 25 antennas of the ALMA radio-telescope array of ESO and 1600 mirror panels for the 50-m diameter Large Millimeter Telescope (LMT) “Alfonso Serrano” of INAOE were designed, produced and tested.

Properties of H3+ and CH4 at mid and equatorial latitudes in the Jovian atmosphere, observed with JIRAM on Juno

2021 ◽  
Author(s):  
Alessandra Migliorini ◽  
Bianca M. Dinelli ◽  
Marialuisa Moriconi ◽  
Francesca Altieri ◽  
Chiara Castagnoli ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Vertical Distribution ◽  
Polar Region ◽  
Broad Band ◽  
Mixing Ratio ◽  
Scientific Instruments ◽  
Spectral Measurements ◽  
Space Agency ◽  
Infrared Spectrometer ◽  
Italian Space Agency

<p>The NASA Juno spacecraft is studying Jupiter’s atmosphere in depth since August 2016. The Jupiter Infrared Auroral Mapper (JIRAM) experiment (Adriani et al. 2014), one of the scientific instruments on board Juno, is composed of two broad-band imagers and an infrared spectrometer, dedicated to the observation of the auroral and chemical composition of the Jupiter’s atmosphere. Images and spectral observations in limb view geometry have been acquired since orbit 17 (December 2018) onwards, providing a wealth of details of the atmosphere at mid to equatorial latitudes, with a spatial resolution of the order of hundreds of meters per pixel. CH<sub>4</sub> and H<sub>3</sub><sup>+</sup> emissions around the 3-μm region show two well separated layers at 200 km and at about 500-600 km above the 1-bar level. The CH<sub>4</sub> emission is quite unexpected and shows a maximum of emission close to the equator. In this work we present the distribution of CH<sub>4</sub> and H<sub>3</sub><sup>+</sup> as observed at limb from December 2018 to September 2020 with the imaging subsystem of JIRAM. Their vertical distribution, obtained from simultaneous spectral measurements, is also shown. Temperature and volume mixing ratio (VMR) of the two species, retrieved using the spectral region between 3 and 4 μm (Dinelli et al. 2017, 2019) are discussed and compared with previous measurements.</p><p><strong>Acknowledgments</strong></p><p>The project JIRAM is funded by the Italian Space Agency.</p><p> </p><p><strong>References</strong></p><p>Adriani A. Filacchione G., Di Iorio T., et al. (2014). JIRAM, the Jovian infrared Auroral mapper. Space Sci. Rev. 213, 393, https://doi.org/10.1007/s11214-014-0094-y.</p><p>Dinelli, B.M., et al. (2017), Preliminary Results from the JIRAM Auroral Observations taken during the first Juno orbit: 1 - Methodology and Analysis Applied to the Jovian Northern Polar Region, Geophys. Res. Lett., doi:10.1002/2017GL072929.</p><p>Dinelli B.M., Adriani A., Mura A., Altieri F., Migliorini A., Moriconi M.L., (2019). JUNO/JIRAM’s view of Jupiter’s H<sub>3</sub><sup>+</sup> emissions, Phil. Trans. R. Soc.</p>

scholarly journals AGILE results on relativistic outflows above 100MeV

2018 ◽  
Vol 27 (10) ◽  
pp. 1844015 ◽  
Author(s):  
Carlotta Pittori
Keyword(s):  
Particle Acceleration ◽  
Energy Range ◽  
High Energy ◽  
Extreme Conditions ◽  
X Ray ◽  
Space Agency ◽  
X Ray Imaging ◽  
Agile Satellite ◽  
Radiation Processes ◽  
Italian Space Agency

We give an overview of the AGILE [Formula: see text]-ray satellite scientific highlights. AGILE is an Italian Space Agency (ASI) mission devoted to observations in the 30[Formula: see text]MeV–50[Formula: see text]GeV [Formula: see text]-ray energy range, with simultaneous X-ray imaging in the 18–60[Formula: see text]keV band. Launched in April 2007, the AGILE satellite has completed its tenth year of operations in orbit, and it is substantially contributing to improve our knowledge of the high-energy sky. Emission from cosmic sources at energies above 100[Formula: see text]MeV is intrinsically nonthermal, and the study of the wide variety of observed Galactic and extragalactic [Formula: see text]-ray sources provides a unique opportunity to test theories of particle acceleration and radiation processes in extreme conditions.

scholarly journals Detection of a High-Temperature Blackbody Hump in Black Hole Spectra. The strongly redshifted annihilation line

2020 ◽  
Author(s):  
Lev Titarchuk ◽  
Elena Seifina
Keyword(s):  
Black Hole ◽  
High Temperature ◽  
Broad Band ◽  
Spectral Feature ◽  
Line Emission ◽  
Energy Spectra ◽  
Color Temperature ◽  
Iron Line ◽  
Annihilation Line ◽  
X Ray

Abstract We detected a so called high-temperature blackbody (HBB) component, found in the 15 – 40 keV range, in the broad-band X-ray energy spectra of black hole (BH) candidate sources. A detailed study of this spectral feature is presented using data from five of the Galactic BH binaries, Cyg X–1, GX 339–4, GRS 1915+105, SS 433 and V4641 Sgr in the low/hard, intermediate, high/soft and very soft spectral states (LHS, IS, HSS and VSS, respectively) and spectral transitions between them using RXTE, INTEGRAL and BeppoSAX data. In order to fit the broad-band energy spectra of these sources we used an additive XSPEC model, composed of the Comptonization component and the Gaussian line component. In particular, we reveal that the IS spectra have the HBB component which color temperature, kTHBB is in the range of 4.5 – 5.9 keV. This HBB feature has been detected in some spectra of these five sources only in the IS (for the photon index Γ > 1.9) using different X-ray telescopes. We also demonstrate that a timescale of the HBB-feature is of orders of magnitude shorter than the timescale of the iron line and its edge. That leads us to conclude that these spectral features are formed in geometrically different parts of the source and which are not connected to each other. Laurent & Titarchuk (2018) demonstrated a presence of a gravitational redshifted annihilation line emission in a BH using the Monte-Carlo simulations and therefore the observed HBB hump leads us to suggest this feature is a gravitational redshifted annihilation line observed in these black holes.

scholarly journals The long-term enhanced brightness of the magnetar 1E 1547.0–5408

2020 ◽  
Vol 633 ◽  
pp. A31 ◽  
Author(s):  
Francesco Coti Zelati ◽  
Alice Borghese ◽  
Nanda Rea ◽  
Daniele Viganò ◽  
Teruaki Enoto ◽  
...  
Keyword(s):  
Thermal Emission ◽  
Broad Band ◽  
Spectral Shape ◽  
Band Spectrum ◽  
Pulse Profile ◽  
X Ray ◽  
Time Period ◽  
Order Of Magnitude ◽  
Cooling Trend

We present the evolution of the X-ray emission properties of the magnetar 1E 1547.0–5408 since February 2004 over a time period covering three outbursts. We analyzed new and archival observations taken with the Swift, NuSTAR, Chandra, and XMM–Newton X-ray satellites. The source has been observed at a relatively steady soft X-ray flux of ≈10−11 erg cm−2 s−1 (0.3–10 keV) over the last 9 years, which is about an order of magnitude fainter than the flux at the peak of the last outburst in 2009, but a factor of ∼30 larger than the level in 2006. The broad-band spectrum extracted from two recent NuSTAR observations in April 2016 and February 2019 showed a faint hard X-ray emission up to ∼70 keV. Its spectrum is adequately described by a flat power law component, and its flux is ∼7 × 10−12 erg cm−2 s−1 (10–70 keV), that is a factor of ∼20 smaller than at the peak of the 2009 outburst. The hard X-ray spectral shape has flattened significantly in time, which is at variance with the overall cooling trend of the soft X-ray component. The pulse profile extracted from these NuSTAR pointings displays variability in shape and amplitude with energy (up to ≈25 keV). Our analysis shows that the flux of 1E 1547.0–5408 is not yet decaying to the 2006 level and that the source has been lingering in a stable, high-intensity state for several years. This might suggest that magnetars can hop among distinct persistent states that are probably connected to outburst episodes and that their persistent thermal emission can be almost entirely powered by the dissipation of currents in the corona.

scholarly journals AstroSat view of GRS 1915+105 during the soft state: detection of HFQPOs and estimation of mass and spin

2020 ◽  
Vol 499 (4) ◽  
pp. 5891-5901
Author(s):  
H Sreehari ◽  
Anuj Nandi ◽  
Santabrata Das ◽  
V K Agrawal ◽  
Samir Mandal ◽  
...  
Keyword(s):  
Broad Band ◽  
Power Spectra ◽  
Periodic Oscillation ◽  
High Energy ◽  
Energy Spectra ◽  
Large Area ◽  
X Ray ◽  
Soft State ◽  
Photon Index ◽  
Area X

ABSTRACT We report the results of AstroSat observations of GRS 1915+105 obtained using 100 ks Guaranteed Time during the soft state. The colour–colour diagram indicates a variability class of δ with the detection of high-frequency quasi-periodic oscillation (HFQPO) in the power density spectra. The HFQPO is seen to vary in the frequency range of 67.96–70.62 Hz with percentage rms ∼0.83–1.90 per cent and significance varying from 1.63 to 7.75. The energy dependent power spectra show that the HFQPO features are dominant only in 6–25 keV energy band. The broad-band energy spectra (0.7–50 keV) of Soft X-ray Telescope and Large Area X-ray Proportional Counter modelled with nthComp and powerlaw imply that the source has an extended corona in addition to a compact ‘Comptonizing corona’ that produces high-energy emission and exhibits HFQPOs. The broad-band spectral modelling indicates that the source spectra are well described by thermal Comptonization with electron temperature (kTe) of 2.07–2.43 keV and photon index (Γnth) between 1.73 and 2.45 with an additional powerlaw component of photon index (ΓPL) between 2.94 and 3.28. The norm of nthComp component is high (∼8) during the presence of strong HFQPO and low (∼3) during the absence of HFQPO. Further, we model the energy spectra with the kerrbb model to estimate the accretion rate, mass, and spin of the source. Our findings indicate that the source accretes at super-Eddington rate of $1.17\!-\!1.31~ \dot{M}_{\rm Edd}$. Moreover, we find the mass and spin of the source as 12.44–13.09 M⊙ and 0.990–0.997 with $90{{\ \rm per\ cent}}$ confidence suggesting that GRS 1915+105 is a maximally rotating stellar mass X-ray binary black hole source.

scholarly journals X-ray Observations of SN 1993J

2005 ◽  
Vol 192 ◽  
pp. 53-58
Author(s):  
H.-U. Zimmermann
Keyword(s):  
Energy Band ◽  
Thermal Emission ◽  
Emission Model ◽  
Ionization Equilibrium ◽  
X Ray ◽  
General Decline ◽  
Shock Models

SummaryIn April 2001 SN1993J was observed with both the PN and MOS cameras of the XMM-Newton observatory. A 2-component thermal emission model assuming ionization equilibrium provides a good fit to the spectrum in the 0.3 to 11 keV energy band, but fits to shock models show also acceptable results. The development of the X-ray temperatures over the first 8 years after the explosion is discussed in the light of the standard SN model. The long term X-ray lightcurve shows a general decline of the luminosity with Lx ∝ t−0.30.

scholarly journals A PROPOSED ITALIAN CONTRIBUTION FOR THE MIRAX SCIENTIFIC PAYLOAD

2012 ◽  
Vol 12 ◽  
pp. 110-119
Author(s):  
Y. EVANGELISTA ◽  
M. FEROCI ◽  
A. ARGAN ◽  
R. CAMPANA ◽  
E. COSTA ◽  
...  
Keyword(s):  
Energy Band ◽  
Broad Band ◽  
High Energy ◽  
Scientific Cooperation ◽  
X Ray ◽  
Scientific Mission ◽  
Energy Spectrometer ◽  
Coded Mask ◽  
Prompt Emission ◽  
Scientific Payload

Recent scientific cooperation between Italy and Brazil has opened the possibility of a significant Italian contribution to the scientific payload of the Brazilian mission MIRAX. MIRAX is a small scientific mission for X-ray astronomy, programmed for launch on 2015 on-board the Lattes satellite. The MIRAX scientific objectives include the broad-band study - inclusive of arcminute localisation - of the GRBs prompt emission, and the All Sky monitoring in the 2–50 keV energy band with a source location accuracy of a few arcmin and a daily sensitivity of 3 mCrab. The proposed configuration is composed of a coded-mask X-ray Monitor, equipped with Silicon Drift Detectors (2–50 keV), and a phoswich High Energy Spectrometer, sensitive in the 15–5000 keV energy band.

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