João Braga - Academia.edu (original) (raw)

Papers by João Braga

Research paper thumbnail of Division D Commission 44: Space and High-Energy Astrophysics

Proceedings of the International Astronomical Union, 2015

Division XI, the predecessor to Division D until 2012, was formed in 1994 at the IAU General Asse... more Division XI, the predecessor to Division D until 2012, was formed in 1994 at the IAU General Assembly in The Hague by merging Commission 44 Astronomy from Space and Commission 48 High Energy Astrophysics. Historically, space astrophysics started with the high energy wavelengths (far UV, X-ray, and gamma-ray astronomy) which are only accessible from space. However, in modern astronomy, to study high energy astrophysical processes, almost all wavelengths are used (including gamma-ray, X-ray, UV, optical, infrared, submillimeter and radio). In addition other ground-based facilities, including gravitational wave antennas, neutrino detectors and high-energy cosmic ray arrays are joining in this era of multi-messenger astrophysics, as well as space missions with the primary goals to discover and study exoplanets, are under the umbrella of Division XI.

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Research paper thumbnail of The protoMIRAX Hard X-ray Imaging Balloon Experiment

The protoMIRAX hard X-ray imaging telescope is a balloon-borne experiment developed as a pathfind... more The protoMIRAX hard X-ray imaging telescope is a balloon-borne experiment developed as a pathfinder for the MIRAX satellite mission. The experiment consists essentially in a coded-aperture hard X-ray (30-200 keV) imager with a square array (13×13) of 2mm-thick planar CZT detectors with a total area of 169 cm^2. The total, fully-coded field-of-view is 21^∘× 21^∘ and the angular resolution is 1^∘43'. In this paper we describe the protoMIRAX instrument and all the subsystems of its balloon gondola, and we show simulated results of the instrument performance. The main objective of protoMIRAX is to carry out imaging spectroscopy of selected bright sources to demonstrate the performance of a prototype of the MIRAX hard X-ray imager. Detailed background and imaging simulations have been performed for protoMIRAX balloon flights. The 3σ sensitivity for the 30-200 keV range is 1.9 × 10^-5 photons cm^-2 s^-1 for an integration time of 8 hs at an atmospheric depth of 2.7 g cm^-2 and an aver...

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Research paper thumbnail of CRON-1/NANOMIRAX - Uma Parceria Público-Privada

Anais do 2º Congresso Aeroespacial Brasileiro

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Research paper thumbnail of The MIRAX mission: Payload description and background simulation plan

Proceedings of An INTEGRAL view of the high-energy sky (the first 10 years) - 9th INTEGRAL Workshop and celebration of the 10th anniversary of the launch — PoS(INTEGRAL 2012)

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Research paper thumbnail of XMM and INTEGRAL Simultaneous Observations of 1E 1740.7-2942

Proceedings of An INTEGRAL view of the high-energy sky (the first 10 years) - 9th INTEGRAL Workshop and celebration of the 10th anniversary of the launch — PoS(INTEGRAL 2012)

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Research paper thumbnail of Coded Aperture Imaging in High-energy Astrophysics

Publications of the Astronomical Society of the Pacific

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Research paper thumbnail of Observatory science with eXTP

Science China Physics, Mechanics & Astronomy

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Research paper thumbnail of Tandem Swift and INTEGRAL Data to Revisit the Orbital and Superorbital Periods of 1E 1740.7–2942

The Astrophysical Journal

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Research paper thumbnail of Evidence for a 304-day orbital period for GX 1+4

AIP Conference Proceedings, 2000

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Research paper thumbnail of MIRAX Mission Overview and Status

AIP Conference Proceedings, 2006

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Research paper thumbnail of Division XI: Space & High-Energy Astrophysics

Proceedings of the International Astronomical Union, 2010

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Research paper thumbnail of XXth Meeting of the Brazilian Astronomical Society

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Research paper thumbnail of Division XI: Space and High-Energy Astrophysics

Proceedings of the International Astronomical Union, 2011

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Research paper thumbnail of <title>Event preprocessor for the CdZnTe-strip detector on MIRAX</title>

High-Energy Detectors in Astronomy, 2004

We present the Event Pre Processor (EPP) for the Cadmium-Zinc-Telluride-strip detector of the Har... more We present the Event Pre Processor (EPP) for the Cadmium-Zinc-Telluride-strip detector of the Hard X-ray Imager (HXI) onboard of the MIRAX satellite. The purpose of the EPP is to provide an onboard data reduction and event filtering by applying a non linear energy gain correction for each detector strip. This data reduction is necessary because of the limited telemetry capacity

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Research paper thumbnail of <title>The <emph type="1">MIRAX</emph> x-ray astronomy transient mission</title>

Space Telescopes and Instrumentation II: Ultraviolet to Gamma Ray, 2006

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Research paper thumbnail of GAME: GRB and All-sky Monitor Experiment

International Journal of Modern Physics D, 2014

We describe the GRB and all-sky monitor experiment (GAME) mission submitted by a large internatio... more We describe the GRB and all-sky monitor experiment (GAME) mission submitted by a large international collaboration (Italy, Germany, Czech Republic, Slovenia, Brazil) in response to the 2012 ESA call for a small mission opportunity for a launch in 2017 and presently under further investigation for subsequent opportunities. The general scientific objective is to perform measurements of key importance for GRB science and to provide the wide astrophysical community of an advanced X-ray all-sky monitoring system. The proposed payload was based on silicon drift detectors (~1–50 keV), CdZnTe (CZT) detectors (~15–200 keV) and crystal scintillators in phoswich (NaI/CsI) configuration (~20 keV–20 MeV), three well established technologies, for a total weight of ~250 kg and a required power of ~240 W. Such instrumentation allows a unique, unprecedented and very powerful combination of large field of view (3–4 sr), a broad energy band extending from ~1 keV up to ~20 MeV, an energy resolution as ...

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Research paper thumbnail of Discovery of Optical Pulsations in V2116 Ophiuchi ≡ GX 1+4

The Astrophysical Journal, 1997

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Research paper thumbnail of The Orbital Period of the Accreting Pulsar GX 1+4

The Astrophysical Journal, 1999

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Research paper thumbnail of Spectral-Lag Relations in GRB Pulses Detected with HETE-2

Publications of the Astronomical Society of Japan, 2010

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Research paper thumbnail of Development of large volume organic scintillators for use in the MASCO telescope

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 1999

... dos Astronautos 1758, 12227-010 SJ dos Campos, Brazil. b, Instituto de Pesquisas Energéticas ... more ... dos Astronautos 1758, 12227-010 SJ dos Campos, Brazil. b, Instituto de Pesquisas Energéticas e Nucleares, IPEN, Brazil. c, Instituto do Coração do HCFMUSP, Brazil. ... 4 F. D&amp;amp;amp;#x27;Amico, Ph.D. Thesis, Instituto Nacional de Pesquisas Espaciais, Brazil, 1997.. 5 J. Braga, et al. Nucl. Instr ...

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Research paper thumbnail of Division D Commission 44: Space and High-Energy Astrophysics

Proceedings of the International Astronomical Union, 2015

Division XI, the predecessor to Division D until 2012, was formed in 1994 at the IAU General Asse... more Division XI, the predecessor to Division D until 2012, was formed in 1994 at the IAU General Assembly in The Hague by merging Commission 44 Astronomy from Space and Commission 48 High Energy Astrophysics. Historically, space astrophysics started with the high energy wavelengths (far UV, X-ray, and gamma-ray astronomy) which are only accessible from space. However, in modern astronomy, to study high energy astrophysical processes, almost all wavelengths are used (including gamma-ray, X-ray, UV, optical, infrared, submillimeter and radio). In addition other ground-based facilities, including gravitational wave antennas, neutrino detectors and high-energy cosmic ray arrays are joining in this era of multi-messenger astrophysics, as well as space missions with the primary goals to discover and study exoplanets, are under the umbrella of Division XI.

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Research paper thumbnail of The protoMIRAX Hard X-ray Imaging Balloon Experiment

The protoMIRAX hard X-ray imaging telescope is a balloon-borne experiment developed as a pathfind... more The protoMIRAX hard X-ray imaging telescope is a balloon-borne experiment developed as a pathfinder for the MIRAX satellite mission. The experiment consists essentially in a coded-aperture hard X-ray (30-200 keV) imager with a square array (13×13) of 2mm-thick planar CZT detectors with a total area of 169 cm^2. The total, fully-coded field-of-view is 21^∘× 21^∘ and the angular resolution is 1^∘43'. In this paper we describe the protoMIRAX instrument and all the subsystems of its balloon gondola, and we show simulated results of the instrument performance. The main objective of protoMIRAX is to carry out imaging spectroscopy of selected bright sources to demonstrate the performance of a prototype of the MIRAX hard X-ray imager. Detailed background and imaging simulations have been performed for protoMIRAX balloon flights. The 3σ sensitivity for the 30-200 keV range is 1.9 × 10^-5 photons cm^-2 s^-1 for an integration time of 8 hs at an atmospheric depth of 2.7 g cm^-2 and an aver...

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Research paper thumbnail of CRON-1/NANOMIRAX - Uma Parceria Público-Privada

Anais do 2º Congresso Aeroespacial Brasileiro

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Research paper thumbnail of The MIRAX mission: Payload description and background simulation plan

Proceedings of An INTEGRAL view of the high-energy sky (the first 10 years) - 9th INTEGRAL Workshop and celebration of the 10th anniversary of the launch — PoS(INTEGRAL 2012)

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Research paper thumbnail of XMM and INTEGRAL Simultaneous Observations of 1E 1740.7-2942

Proceedings of An INTEGRAL view of the high-energy sky (the first 10 years) - 9th INTEGRAL Workshop and celebration of the 10th anniversary of the launch — PoS(INTEGRAL 2012)

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Research paper thumbnail of Coded Aperture Imaging in High-energy Astrophysics

Publications of the Astronomical Society of the Pacific

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Research paper thumbnail of Observatory science with eXTP

Science China Physics, Mechanics & Astronomy

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Research paper thumbnail of Tandem Swift and INTEGRAL Data to Revisit the Orbital and Superorbital Periods of 1E 1740.7–2942

The Astrophysical Journal

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Research paper thumbnail of Evidence for a 304-day orbital period for GX 1+4

AIP Conference Proceedings, 2000

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Research paper thumbnail of MIRAX Mission Overview and Status

AIP Conference Proceedings, 2006

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Research paper thumbnail of Division XI: Space & High-Energy Astrophysics

Proceedings of the International Astronomical Union, 2010

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Research paper thumbnail of XXth Meeting of the Brazilian Astronomical Society

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Research paper thumbnail of Division XI: Space and High-Energy Astrophysics

Proceedings of the International Astronomical Union, 2011

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Research paper thumbnail of <title>Event preprocessor for the CdZnTe-strip detector on MIRAX</title>

High-Energy Detectors in Astronomy, 2004

We present the Event Pre Processor (EPP) for the Cadmium-Zinc-Telluride-strip detector of the Har... more We present the Event Pre Processor (EPP) for the Cadmium-Zinc-Telluride-strip detector of the Hard X-ray Imager (HXI) onboard of the MIRAX satellite. The purpose of the EPP is to provide an onboard data reduction and event filtering by applying a non linear energy gain correction for each detector strip. This data reduction is necessary because of the limited telemetry capacity

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Research paper thumbnail of <title>The <emph type="1">MIRAX</emph> x-ray astronomy transient mission</title>

Space Telescopes and Instrumentation II: Ultraviolet to Gamma Ray, 2006

Bookmarks Related papers MentionsView impact

Research paper thumbnail of GAME: GRB and All-sky Monitor Experiment

International Journal of Modern Physics D, 2014

We describe the GRB and all-sky monitor experiment (GAME) mission submitted by a large internatio... more We describe the GRB and all-sky monitor experiment (GAME) mission submitted by a large international collaboration (Italy, Germany, Czech Republic, Slovenia, Brazil) in response to the 2012 ESA call for a small mission opportunity for a launch in 2017 and presently under further investigation for subsequent opportunities. The general scientific objective is to perform measurements of key importance for GRB science and to provide the wide astrophysical community of an advanced X-ray all-sky monitoring system. The proposed payload was based on silicon drift detectors (~1–50 keV), CdZnTe (CZT) detectors (~15–200 keV) and crystal scintillators in phoswich (NaI/CsI) configuration (~20 keV–20 MeV), three well established technologies, for a total weight of ~250 kg and a required power of ~240 W. Such instrumentation allows a unique, unprecedented and very powerful combination of large field of view (3–4 sr), a broad energy band extending from ~1 keV up to ~20 MeV, an energy resolution as ...

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Research paper thumbnail of Discovery of Optical Pulsations in V2116 Ophiuchi ≡ GX 1+4

The Astrophysical Journal, 1997

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Research paper thumbnail of The Orbital Period of the Accreting Pulsar GX 1+4

The Astrophysical Journal, 1999

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Research paper thumbnail of Spectral-Lag Relations in GRB Pulses Detected with HETE-2

Publications of the Astronomical Society of Japan, 2010

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Research paper thumbnail of Development of large volume organic scintillators for use in the MASCO telescope

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 1999

... dos Astronautos 1758, 12227-010 SJ dos Campos, Brazil. b, Instituto de Pesquisas Energéticas ... more ... dos Astronautos 1758, 12227-010 SJ dos Campos, Brazil. b, Instituto de Pesquisas Energéticas e Nucleares, IPEN, Brazil. c, Instituto do Coração do HCFMUSP, Brazil. ... 4 F. D&amp;amp;amp;#x27;Amico, Ph.D. Thesis, Instituto Nacional de Pesquisas Espaciais, Brazil, 1997.. 5 J. Braga, et al. Nucl. Instr ...

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