G. Kanbach | University College Dublin (original) (raw)

Papers by G. Kanbach

Research paper thumbnail of Gamma-ray burst investigation via polarimetry and spectroscopy (GRIPS)

Experimental Astronomy, 2008

The primary scientific goal of the GRIPS mission is to revolutionize our understanding of the ear... more The primary scientific goal of the GRIPS mission is to revolutionize our understanding of the early universe using γ-ray bursts. We propose a new generation gamma-ray observatory capable of unprecedented spectroscopy over a wide range of γ-ray energies (200 keV-50 MeV) and of polarimetry (200-1000 keV). The γ-ray sensitivity to nuclear absorption features enables the measurement of column densities as high as 10 28 cm −2. Secondary goals achievable by this mission include direct measurements of all types of supernova interiors through γ-rays from radioactive decays, nuclear astrophysics with massive stars and novae, and studies of particle acceleration near compact stars, interstellar shocks, and clusters of galaxies.

Research paper thumbnail of A position sensitive gamma-ray detector based on silicon drift detectors coupled to scintillators for application in the MEGA compton telescope

IEEE Symposium Conference Record Nuclear Science 2004., 2004

An array of gamma-ray detectors based on silicon drift detectors (SDD) coupled to thallium activa... more An array of gamma-ray detectors based on silicon drift detectors (SDD) coupled to thallium activated cesium iodide (CsI(Tl)) scintillating crystals is presented. Because of SDDs low output capacitance and the possibility to have the first amplifying stage directly integrated on chip, SDDs show better noise performance than traditional p-i-n photodiodes. The array is read out with custom made ASICs built to match with the SDDs electrical properties. Shaped signals are digitally converted by a Digital Front-End Electronic Board which also takes care of ASICs handshaking. The system architecture is based on that of the IBIS/PICsIT instrument onboard the INTEGRAL satellite, at present fully operative. The instrument has been designed as a calorimeter module suitable to work in conjunction with the MEGA Compton telescope prototype, developed at the Max Planck Institut für Extraterrestrische Physik (MPE), Garching, Germany. The calorimeter module will detect photons scattered by the MEGA silicon tracker. The improvements in energy resolution provided by SDD/CsI(Tl) detectors should improve the overall energy and angular resolution of the Compton telescope. The detectors properties and the system performance, from analogue signal conditioning to the digital data handling will be reported and discussed.

Research paper thumbnail of History of the Gamma-Ray Light Curves of the Pulsars PSR0531+21 and PSR0833-45 as Measured by Cos-B

Research paper thumbnail of The EGRET detection of quasar 1633 + 382

The Astrophysical Journal, 1993

Research paper thumbnail of EGRET Observations of the Extragalactic Gamma‐Ray Emission

The Astrophysical Journal, 1998

The all-sky survey in high-energy gamma rays (E [ 30 MeV) carried out by EGRET aboard the Compton... more The all-sky survey in high-energy gamma rays (E [ 30 MeV) carried out by EGRET aboard the Compton Gamma Ray Observatory provides a unique opportunity to examine in detail the di †use gamma-ray emission. The observed di †use emission has a Galactic component arising from cosmic-ray interactions with the local interstellar gas and radiation, as well as an almost uniformly distributed component that is generally believed to originate outside the Galaxy. Through a careful study and removal of the Galactic di †use emission, the Ñux, spectrum, and uniformity of the extragalactic emission are deduced. The analysis indicates that the extragalactic emission is well described by a power-law photon spectrum with an index of [(2.10^0.03) in the 30 MeV to 100 GeV energy range. No large-scale spatial anisotropy or changes in the energy spectrum are observed in the deduced extragalactic emission. The most likely explanation for the origin of this extragalactic high-energy gamma-ray emission is that it arises primarily from unresolved gamma-rayÈemitting blazars.

Research paper thumbnail of Nuclear Resonances: The quest for large column densities and a new tool

Nuclear physics offers us a powerful tool: using nuclear resonance absorption lines to infer the ... more Nuclear physics offers us a powerful tool: using nuclear resonance absorption lines to infer the physical conditions in astrophysical settings which are otherwise difficult to deduce. Present-day technology provides an increase in sensitivity over previous gamma-ray missions large enough to utilize this tool for the first time. The most exciting promise is to measure gamma-ray bursts from the first star(s) at redshifts 20-60, but also active galactic nuclei are promising targets.

Research paper thumbnail of Pulsed high-energy γ-radiation from Geminga (1E0630+178)

Nature, 1992

... Bertsch * , KTS Brazier † , CE Fichtel * , RC Hartman * , SD Hunter * , G. Kanbach † , DA Kni... more ... Bertsch * , KTS Brazier † , CE Fichtel * , RC Hartman * , SD Hunter * , G. Kanbach † , DA Kniffen ‡ , PW Kwok * , YC Lin § , JR Mattox *¶ , HA Mayer–Hasselwander † , C. v. Montigny † , PF Michelson § , PL Nolan § , K. Pinkau ... 9. Bignami, GF, Caraveo, PA & Lamb, RC Astrophys. ...

Research paper thumbnail of New Large-Scale Properties of the Galactic Gamma Radiation Observed by Cos-B in the Context of the Diffuse Emission Within the Galactic Disc

Research paper thumbnail of EGRET detection of high energy gamma rays from the gamma-ray burst of 3 May 1991

Research paper thumbnail of X-RAY PULSATIONS FROM THE RADIO-QUIET GAMMA-RAY PULSAR IN CTA 1

Prompted by the Fermi LAT discovery of a radio-quiet gamma-ray pulsar inside the CTA 1 supernova ... more Prompted by the Fermi LAT discovery of a radio-quiet gamma-ray pulsar inside the CTA 1 supernova remnant, we obtained a 130 ks XMM-Newton observation to assess the timing behavior of this pulsar.

Research paper thumbnail of Detailed characteristics of the high-energy gamma radiation from PSR 0833-45 measured by COS-B

Astronomy & Astrophysics - ASTRON ASTROPHYS, 1980

A series of COS-B observations of the high-energy gamma-ray emission from PSR 0833-45 has been co... more A series of COS-B observations of the high-energy gamma-ray emission from PSR 0833-45 has been combined to derive detailed temporal and spectral characteristics of this source. The gamma-ray period of the pulsar was determined for the observations spanning the time interval October 1975 to June 1977. The variation of the period with time can be expressed as a second-order polynomial including a second derivative or as an exponential function describing the post-glitch behavior of the pulsar. The spectrum of PSR 0833-45 can be represented by a power law of index 1.89 plus or minus 0.06 in the energy range 50 MeV to 3 GeV, but indications of a spectral flattening at low energies and a steepening above a few hundred MeV exist. The pulsed components emitted at different pulsar phases show marked spectral differences. No evidence of a steady gamma-ray emission from the direction of PSR 0833-45 was found.

Research paper thumbnail of Gamma-ray burst investigation via polarimetry and spectroscopy (GRIPS)

Experimental Astronomy, 2008

The primary scientific goal of the GRIPS mission is to revolutionize our understanding of the ear... more The primary scientific goal of the GRIPS mission is to revolutionize our understanding of the early universe using γ-ray bursts. We propose a new generation gamma-ray observatory capable of unprecedented spectroscopy over a wide range of γ-ray energies (200 keV-50 MeV) and of polarimetry (200-1000 keV). The γ-ray sensitivity to nuclear absorption features enables the measurement of column densities as high as 10 28 cm −2. Secondary goals achievable by this mission include direct measurements of all types of supernova interiors through γ-rays from radioactive decays, nuclear astrophysics with massive stars and novae, and studies of particle acceleration near compact stars, interstellar shocks, and clusters of galaxies.

Research paper thumbnail of A position sensitive gamma-ray detector based on silicon drift detectors coupled to scintillators for application in the MEGA compton telescope

IEEE Symposium Conference Record Nuclear Science 2004., 2004

An array of gamma-ray detectors based on silicon drift detectors (SDD) coupled to thallium activa... more An array of gamma-ray detectors based on silicon drift detectors (SDD) coupled to thallium activated cesium iodide (CsI(Tl)) scintillating crystals is presented. Because of SDDs low output capacitance and the possibility to have the first amplifying stage directly integrated on chip, SDDs show better noise performance than traditional p-i-n photodiodes. The array is read out with custom made ASICs built to match with the SDDs electrical properties. Shaped signals are digitally converted by a Digital Front-End Electronic Board which also takes care of ASICs handshaking. The system architecture is based on that of the IBIS/PICsIT instrument onboard the INTEGRAL satellite, at present fully operative. The instrument has been designed as a calorimeter module suitable to work in conjunction with the MEGA Compton telescope prototype, developed at the Max Planck Institut für Extraterrestrische Physik (MPE), Garching, Germany. The calorimeter module will detect photons scattered by the MEGA silicon tracker. The improvements in energy resolution provided by SDD/CsI(Tl) detectors should improve the overall energy and angular resolution of the Compton telescope. The detectors properties and the system performance, from analogue signal conditioning to the digital data handling will be reported and discussed.

Research paper thumbnail of History of the Gamma-Ray Light Curves of the Pulsars PSR0531+21 and PSR0833-45 as Measured by Cos-B

Research paper thumbnail of The EGRET detection of quasar 1633 + 382

The Astrophysical Journal, 1993

Research paper thumbnail of EGRET Observations of the Extragalactic Gamma‐Ray Emission

The Astrophysical Journal, 1998

The all-sky survey in high-energy gamma rays (E [ 30 MeV) carried out by EGRET aboard the Compton... more The all-sky survey in high-energy gamma rays (E [ 30 MeV) carried out by EGRET aboard the Compton Gamma Ray Observatory provides a unique opportunity to examine in detail the di †use gamma-ray emission. The observed di †use emission has a Galactic component arising from cosmic-ray interactions with the local interstellar gas and radiation, as well as an almost uniformly distributed component that is generally believed to originate outside the Galaxy. Through a careful study and removal of the Galactic di †use emission, the Ñux, spectrum, and uniformity of the extragalactic emission are deduced. The analysis indicates that the extragalactic emission is well described by a power-law photon spectrum with an index of [(2.10^0.03) in the 30 MeV to 100 GeV energy range. No large-scale spatial anisotropy or changes in the energy spectrum are observed in the deduced extragalactic emission. The most likely explanation for the origin of this extragalactic high-energy gamma-ray emission is that it arises primarily from unresolved gamma-rayÈemitting blazars.

Research paper thumbnail of Nuclear Resonances: The quest for large column densities and a new tool

Nuclear physics offers us a powerful tool: using nuclear resonance absorption lines to infer the ... more Nuclear physics offers us a powerful tool: using nuclear resonance absorption lines to infer the physical conditions in astrophysical settings which are otherwise difficult to deduce. Present-day technology provides an increase in sensitivity over previous gamma-ray missions large enough to utilize this tool for the first time. The most exciting promise is to measure gamma-ray bursts from the first star(s) at redshifts 20-60, but also active galactic nuclei are promising targets.

Research paper thumbnail of Pulsed high-energy γ-radiation from Geminga (1E0630+178)

Nature, 1992

... Bertsch * , KTS Brazier † , CE Fichtel * , RC Hartman * , SD Hunter * , G. Kanbach † , DA Kni... more ... Bertsch * , KTS Brazier † , CE Fichtel * , RC Hartman * , SD Hunter * , G. Kanbach † , DA Kniffen ‡ , PW Kwok * , YC Lin § , JR Mattox *¶ , HA Mayer–Hasselwander † , C. v. Montigny † , PF Michelson § , PL Nolan § , K. Pinkau ... 9. Bignami, GF, Caraveo, PA & Lamb, RC Astrophys. ...

Research paper thumbnail of New Large-Scale Properties of the Galactic Gamma Radiation Observed by Cos-B in the Context of the Diffuse Emission Within the Galactic Disc

Research paper thumbnail of EGRET detection of high energy gamma rays from the gamma-ray burst of 3 May 1991

Research paper thumbnail of X-RAY PULSATIONS FROM THE RADIO-QUIET GAMMA-RAY PULSAR IN CTA 1

Prompted by the Fermi LAT discovery of a radio-quiet gamma-ray pulsar inside the CTA 1 supernova ... more Prompted by the Fermi LAT discovery of a radio-quiet gamma-ray pulsar inside the CTA 1 supernova remnant, we obtained a 130 ks XMM-Newton observation to assess the timing behavior of this pulsar.

Research paper thumbnail of Detailed characteristics of the high-energy gamma radiation from PSR 0833-45 measured by COS-B

Astronomy & Astrophysics - ASTRON ASTROPHYS, 1980

A series of COS-B observations of the high-energy gamma-ray emission from PSR 0833-45 has been co... more A series of COS-B observations of the high-energy gamma-ray emission from PSR 0833-45 has been combined to derive detailed temporal and spectral characteristics of this source. The gamma-ray period of the pulsar was determined for the observations spanning the time interval October 1975 to June 1977. The variation of the period with time can be expressed as a second-order polynomial including a second derivative or as an exponential function describing the post-glitch behavior of the pulsar. The spectrum of PSR 0833-45 can be represented by a power law of index 1.89 plus or minus 0.06 in the energy range 50 MeV to 3 GeV, but indications of a spectral flattening at low energies and a steepening above a few hundred MeV exist. The pulsed components emitted at different pulsar phases show marked spectral differences. No evidence of a steady gamma-ray emission from the direction of PSR 0833-45 was found.