We present a miniaturized and wide field-of-view X-ray and Gamma-ray imager consisting of a segme... more We present a miniaturized and wide field-of-view X-ray and Gamma-ray imager consisting of a segmented 2D optics-collimator coupled to the high-sensitivity semiconductor pixel detector Timepix equipped with a high-Z sensor (CdTe 2000 μm thick). The compact payload has been deployed in low-Earth orbit (LEO) onboard the 3U Cubesat VZLUSAT-2 which was launched on 13 January 2022. The instrument is designed to verify small spacecraft borne observation in open space of hard X-ray and Gamma-ray sources both of celestial and atmospheric origin. High-resolution spectral-sensitive X-ray and Gamma-ray images are provided with enhanced event discrimination and wide field-of-view up to 60°. Description of the instrument together with response evaluation and tests in ground with well-defined sources are presented. The intended observational plan for in-orbit measurements is outlined along with astrophysical goals and issues.
We report on multicolor photometry of long GRB080603B afterglow from BOOTES-1B and BOOTES-2. The ... more We report on multicolor photometry of long GRB080603B afterglow from BOOTES-1B and BOOTES-2. The optical afterglow has already been reported to present a break in the optical lightcurve at 0.12 ± 0.2 days after the trigger. We construct the lightcurve and the spectral energy distribution and discuss the nature of the afterglow.
We present multiwavelength observations of the optically flaring source SWFIT J195509+261406, and... more We present multiwavelength observations of the optically flaring source SWFIT J195509+261406, and discuss its nature considering several possibilities, amongst them a microquasar origin. Finally we suggest a likely magnetar nature implying a missing link to the dim isolated neutron stars.
We discuss the nature and recent observations (optical and gamma-rays) of symbiotics binary/Mira ... more We discuss the nature and recent observations (optical and gamma-rays) of symbiotics binary/Mira variable V407 Cygni. In addition we discuss another object of similar category, namely the variable star FY Aql with possible association with an eruptive gamma-ray source.
We report on an ongoing study based on blink-comparison of more than 5000 Bamberg Observatory Sou... more We report on an ongoing study based on blink-comparison of more than 5000 Bamberg Observatory Southern Sky Patrol Plates performed within a continuation of a student high school project (Jugend Forscht). After a detailed analyses and classification, 6 non-classified objects were identified as emulsion defects, 19 as asteroids, 37 as variable stars, and 6 as real OT-GRB candidates.
Proceedings of VII Microquasar Workshop: Microquasars and Beyond — PoS(MQW7), 2009
We report on the astrophysical aspects-with emphasis on the study of microquasars-of very wide-fi... more We report on the astrophysical aspects-with emphasis on the study of microquasars-of very wide-field X-ray telescopes with high sensitivity. The prototypes are very promising, allowing the proposals for space projects with very wide-field Lobster-eye X-ray optics to be considered. The novel telescopes will monitor the sky with unprecedented sensitivity and angular resolution of the order of 1 arcmin. They are expected to contribute essentially to study of various astrophysical objects such as AGN, SNe, Gamma-ray bursts (GRBs), X-ray flashes (XRFs), galactic binary sources including microquasars, stars, CVs, X-ray novae, various transient sources etc.
Proceedings of VII Microquasar Workshop: Microquasars and Beyond — PoS(MQW7), 2009
We present multiwavelength observations of the optically flaring source SWFIT J195509+261406, and... more We present multiwavelength observations of the optically flaring source SWFIT J195509+261406, and discuss its nature considering several possibilities, amongst them a microquasar origin. Finally we suggest a likely magnetar nature implying a missing link to the dim isolated neutron stars.
Nuovo Cimento C Geophysics Space Physics C, Jul 1, 2005
We find that although the absolute magnitude of the optical afterglow (OA) of GRB011121 in the la... more We find that although the absolute magnitude of the optical afterglow (OA) of GRB011121 in the late phase (t − T0 > 10 days) is approximately consistent with that of the SN 1998bw-type supernova SN 2001ke, previously found by Garnavich P. M. et al. (ApJ, 582 (2003) 924), a good match of their colors occurs only for t − T0 = 13-23 days in the observer frame of GRB011121. We are able to constrain the possible SN in the OA of GRB010222 to be of the peculiar SN 1998bw or SN 2002ap type, but not of SNe classified as Type Ic in the database of Poznanski D. et al. (PASP, 114 (2002) 833). Neither colors nor absolute magnitude of the OA of GRB970508 in the late phase are consistent with those of any of the above-mentioned (sub)types of SN. These results imply that the bumps in the late phase of the OAs can be caused by several mechanisms. Color indices thus appear to be a powerful tool in the analysis of these phenomena, even for archival data of OAs.
We show some possibilities of using the method of the color indices for analysis of optical count... more We show some possibilities of using the method of the color indices for analysis of optical counterparts of high energy sources. We focus on the types of objects for which this method is only rarely used (optical afterglows of GRBs (including the discrimination between the synchrotron emission from the jet and thermal emission from supernova), supersoft X-ray sources, microquasars, magnetars). We show that these indices are very helpful in forming the representative ensemble of events. Even variations of strong emission lines with respect to the continuum can be resolved by this method. We emphasize that not only the color indices of the object at a given moment, but also the time evolution of these indices are important for its classification and study. Combination of the color indices with the spectral energy distribution is desirable.
The Burst Observer and Optical Transient Exploring System (BOOTES) is a network of telescopes tha... more The Burst Observer and Optical Transient Exploring System (BOOTES) is a network of telescopes that allows the continuous monitoring of transient astrophysical sources. It was originally devoted to the study of the optical emissions from gamma-raybursts (GRBs) that occur in the Universe. In this paper we show the initial results obtained using the spectrograph COLORES (mounted on BOOTES-2), when observing optical transients (OTs) of a diverse nature.
We present and discuss the recent progress in design of wide field X-ray monitors with Lobster-ey... more We present and discuss the recent progress in design of wide field X-ray monitors with Lobster-eye X-ray optics, with emphasis on astrophysical aspects and justification.
The X--ray sky monitoring represents valuable energy spectral extension to optical sky monitoring... more The X--ray sky monitoring represents valuable energy spectral extension to optical sky monitoring. Lobster--Eye all--sky monitors are able to provide relatively high sensitivity and good time resolution in the soft X--ray energy range up to 10 keV. The fine time resolution can be used to alert optical robotic telescopes for follow--up and multispectral analyzes in the visible light.
A large majority of GRBs exhibit X-ray emission. In addition, a dedicated separate group of GRB, ... more A large majority of GRBs exhibit X-ray emission. In addition, a dedicated separate group of GRB, the XRFs, exists which emission dominates in the X-ray spectral range. And the third group of GRB related objects (yet hypothetical) are the group of off-axis observed GRBs (orphan afterglows). These facts justify the consideration of an independent experiment for monitoring, detection and analyses of GRBs and others fast X-ray transients in X-rays. We will present and discuss such experiment based on wide-field X-ray telescopes of Lobster Eye type. We show that the wide field and fine sensitivity of Lobster Eye X-ray All-Sky Monitor make such instruments important tools in study of GRBs.
A substantial fraction of gamma-ray bursts is related to objects emitting temporarily optical lig... more A substantial fraction of gamma-ray bursts is related to objects emitting temporarily optical light, i.e. optical afterglows and optical transients. So far, these phenomena (optical transients) were detected only after related gamma-ray satellite detection. However, taking into account their optical magnitudes at maximum light, these objects should be detectable in various historical and recent optical surveys, including photographic sky patrol. Here we report on an extended study based on blink-comparison of 5004 Bamberg Observatory Southern Sky Patrol Plates performed within a student project (Jugend Forscht).
The Optical Monitors, despite of lower detection limits, are still valuable for detection of prom... more The Optical Monitors, despite of lower detection limits, are still valuable for detection of prompt real-time and (hypothetical) pre-burst optical emission of gamma-ray bursts. We refer on the ongoing project at the Astronomical Institute in Ondrejov based on digitized data from the photographic EN network.
Chinese Journal of Astronomy and Astrophysics, 2006
We report on astrophysical aspects of fully innovative very wide-field X-ray telescopes with high... more We report on astrophysical aspects of fully innovative very wide-field X-ray telescopes with high sensitivity. The prototypes are very promising, allowing the proposals for space projects with very wide-field Lobster-eye X-ray optics to be considered. The novel telescopes will monitor the sky with unprecedented sensitivity and angular resolution of order of 1 arcmin. They are expected to contribute essentially to study of various astrophysical objects such as AGN, SNe, Gamma-ray bursts (GRBs), X-ray flashes (XRFs), galactic binary sources, stars, CVs, X-ray novae, various transient sources, etc.
There are nearly 3 millions astronomical plates in worlds plate collections (Hudec, 1999). They c... more There are nearly 3 millions astronomical plates in worlds plate collections (Hudec, 1999). They can cover more than 100 year in time and hence represent unique database for analyses of variable objects including variable stars. The use of scanners, powerful computers and innovative software allows the effective data evaluation for the first time.
We find that the color indices (B - V)0, (V - R)0, (R - I)0, (I - J)0 in the observer frame of th... more We find that the color indices (B - V)0, (V - R)0, (R - I)0, (I - J)0 in the observer frame of the optical afterglow (OA) of GRB030329 during t - T 0 < 10 days are consistent with those of a uniform group of 25 OAs of GRBs (Simon V. et al. A&A 377 (2001) 450; AIP Conf. Proc., 727 (2004) 487). Large color variations of this OA for t - T 0 > 12 days are plausibly matched only by those of SN 1998bw although SN 2003dh develops an excess light in the red/IR spectral region. We also emphasize the discordance with other Type-Ic SNe which are not known to be associated with GRBs. The colors thus can help us to resolve the synchrotron component from the contribution of SN and to discriminate between various types of SN (especially important for faint OAs). We also note that the strong concentration of color indices of the ensemble of 26 OAs (including GRB030329) suggests that the local reddening inside their host galaxies is quite similar and relatively small for these events.
We present a miniaturized and wide field-of-view X-ray and Gamma-ray imager consisting of a segme... more We present a miniaturized and wide field-of-view X-ray and Gamma-ray imager consisting of a segmented 2D optics-collimator coupled to the high-sensitivity semiconductor pixel detector Timepix equipped with a high-Z sensor (CdTe 2000 μm thick). The compact payload has been deployed in low-Earth orbit (LEO) onboard the 3U Cubesat VZLUSAT-2 which was launched on 13 January 2022. The instrument is designed to verify small spacecraft borne observation in open space of hard X-ray and Gamma-ray sources both of celestial and atmospheric origin. High-resolution spectral-sensitive X-ray and Gamma-ray images are provided with enhanced event discrimination and wide field-of-view up to 60°. Description of the instrument together with response evaluation and tests in ground with well-defined sources are presented. The intended observational plan for in-orbit measurements is outlined along with astrophysical goals and issues.
We report on multicolor photometry of long GRB080603B afterglow from BOOTES-1B and BOOTES-2. The ... more We report on multicolor photometry of long GRB080603B afterglow from BOOTES-1B and BOOTES-2. The optical afterglow has already been reported to present a break in the optical lightcurve at 0.12 ± 0.2 days after the trigger. We construct the lightcurve and the spectral energy distribution and discuss the nature of the afterglow.
We present multiwavelength observations of the optically flaring source SWFIT J195509+261406, and... more We present multiwavelength observations of the optically flaring source SWFIT J195509+261406, and discuss its nature considering several possibilities, amongst them a microquasar origin. Finally we suggest a likely magnetar nature implying a missing link to the dim isolated neutron stars.
We discuss the nature and recent observations (optical and gamma-rays) of symbiotics binary/Mira ... more We discuss the nature and recent observations (optical and gamma-rays) of symbiotics binary/Mira variable V407 Cygni. In addition we discuss another object of similar category, namely the variable star FY Aql with possible association with an eruptive gamma-ray source.
We report on an ongoing study based on blink-comparison of more than 5000 Bamberg Observatory Sou... more We report on an ongoing study based on blink-comparison of more than 5000 Bamberg Observatory Southern Sky Patrol Plates performed within a continuation of a student high school project (Jugend Forscht). After a detailed analyses and classification, 6 non-classified objects were identified as emulsion defects, 19 as asteroids, 37 as variable stars, and 6 as real OT-GRB candidates.
Proceedings of VII Microquasar Workshop: Microquasars and Beyond — PoS(MQW7), 2009
We report on the astrophysical aspects-with emphasis on the study of microquasars-of very wide-fi... more We report on the astrophysical aspects-with emphasis on the study of microquasars-of very wide-field X-ray telescopes with high sensitivity. The prototypes are very promising, allowing the proposals for space projects with very wide-field Lobster-eye X-ray optics to be considered. The novel telescopes will monitor the sky with unprecedented sensitivity and angular resolution of the order of 1 arcmin. They are expected to contribute essentially to study of various astrophysical objects such as AGN, SNe, Gamma-ray bursts (GRBs), X-ray flashes (XRFs), galactic binary sources including microquasars, stars, CVs, X-ray novae, various transient sources etc.
Proceedings of VII Microquasar Workshop: Microquasars and Beyond — PoS(MQW7), 2009
We present multiwavelength observations of the optically flaring source SWFIT J195509+261406, and... more We present multiwavelength observations of the optically flaring source SWFIT J195509+261406, and discuss its nature considering several possibilities, amongst them a microquasar origin. Finally we suggest a likely magnetar nature implying a missing link to the dim isolated neutron stars.
Nuovo Cimento C Geophysics Space Physics C, Jul 1, 2005
We find that although the absolute magnitude of the optical afterglow (OA) of GRB011121 in the la... more We find that although the absolute magnitude of the optical afterglow (OA) of GRB011121 in the late phase (t − T0 > 10 days) is approximately consistent with that of the SN 1998bw-type supernova SN 2001ke, previously found by Garnavich P. M. et al. (ApJ, 582 (2003) 924), a good match of their colors occurs only for t − T0 = 13-23 days in the observer frame of GRB011121. We are able to constrain the possible SN in the OA of GRB010222 to be of the peculiar SN 1998bw or SN 2002ap type, but not of SNe classified as Type Ic in the database of Poznanski D. et al. (PASP, 114 (2002) 833). Neither colors nor absolute magnitude of the OA of GRB970508 in the late phase are consistent with those of any of the above-mentioned (sub)types of SN. These results imply that the bumps in the late phase of the OAs can be caused by several mechanisms. Color indices thus appear to be a powerful tool in the analysis of these phenomena, even for archival data of OAs.
We show some possibilities of using the method of the color indices for analysis of optical count... more We show some possibilities of using the method of the color indices for analysis of optical counterparts of high energy sources. We focus on the types of objects for which this method is only rarely used (optical afterglows of GRBs (including the discrimination between the synchrotron emission from the jet and thermal emission from supernova), supersoft X-ray sources, microquasars, magnetars). We show that these indices are very helpful in forming the representative ensemble of events. Even variations of strong emission lines with respect to the continuum can be resolved by this method. We emphasize that not only the color indices of the object at a given moment, but also the time evolution of these indices are important for its classification and study. Combination of the color indices with the spectral energy distribution is desirable.
The Burst Observer and Optical Transient Exploring System (BOOTES) is a network of telescopes tha... more The Burst Observer and Optical Transient Exploring System (BOOTES) is a network of telescopes that allows the continuous monitoring of transient astrophysical sources. It was originally devoted to the study of the optical emissions from gamma-raybursts (GRBs) that occur in the Universe. In this paper we show the initial results obtained using the spectrograph COLORES (mounted on BOOTES-2), when observing optical transients (OTs) of a diverse nature.
We present and discuss the recent progress in design of wide field X-ray monitors with Lobster-ey... more We present and discuss the recent progress in design of wide field X-ray monitors with Lobster-eye X-ray optics, with emphasis on astrophysical aspects and justification.
The X--ray sky monitoring represents valuable energy spectral extension to optical sky monitoring... more The X--ray sky monitoring represents valuable energy spectral extension to optical sky monitoring. Lobster--Eye all--sky monitors are able to provide relatively high sensitivity and good time resolution in the soft X--ray energy range up to 10 keV. The fine time resolution can be used to alert optical robotic telescopes for follow--up and multispectral analyzes in the visible light.
A large majority of GRBs exhibit X-ray emission. In addition, a dedicated separate group of GRB, ... more A large majority of GRBs exhibit X-ray emission. In addition, a dedicated separate group of GRB, the XRFs, exists which emission dominates in the X-ray spectral range. And the third group of GRB related objects (yet hypothetical) are the group of off-axis observed GRBs (orphan afterglows). These facts justify the consideration of an independent experiment for monitoring, detection and analyses of GRBs and others fast X-ray transients in X-rays. We will present and discuss such experiment based on wide-field X-ray telescopes of Lobster Eye type. We show that the wide field and fine sensitivity of Lobster Eye X-ray All-Sky Monitor make such instruments important tools in study of GRBs.
A substantial fraction of gamma-ray bursts is related to objects emitting temporarily optical lig... more A substantial fraction of gamma-ray bursts is related to objects emitting temporarily optical light, i.e. optical afterglows and optical transients. So far, these phenomena (optical transients) were detected only after related gamma-ray satellite detection. However, taking into account their optical magnitudes at maximum light, these objects should be detectable in various historical and recent optical surveys, including photographic sky patrol. Here we report on an extended study based on blink-comparison of 5004 Bamberg Observatory Southern Sky Patrol Plates performed within a student project (Jugend Forscht).
The Optical Monitors, despite of lower detection limits, are still valuable for detection of prom... more The Optical Monitors, despite of lower detection limits, are still valuable for detection of prompt real-time and (hypothetical) pre-burst optical emission of gamma-ray bursts. We refer on the ongoing project at the Astronomical Institute in Ondrejov based on digitized data from the photographic EN network.
Chinese Journal of Astronomy and Astrophysics, 2006
We report on astrophysical aspects of fully innovative very wide-field X-ray telescopes with high... more We report on astrophysical aspects of fully innovative very wide-field X-ray telescopes with high sensitivity. The prototypes are very promising, allowing the proposals for space projects with very wide-field Lobster-eye X-ray optics to be considered. The novel telescopes will monitor the sky with unprecedented sensitivity and angular resolution of order of 1 arcmin. They are expected to contribute essentially to study of various astrophysical objects such as AGN, SNe, Gamma-ray bursts (GRBs), X-ray flashes (XRFs), galactic binary sources, stars, CVs, X-ray novae, various transient sources, etc.
There are nearly 3 millions astronomical plates in worlds plate collections (Hudec, 1999). They c... more There are nearly 3 millions astronomical plates in worlds plate collections (Hudec, 1999). They can cover more than 100 year in time and hence represent unique database for analyses of variable objects including variable stars. The use of scanners, powerful computers and innovative software allows the effective data evaluation for the first time.
We find that the color indices (B - V)0, (V - R)0, (R - I)0, (I - J)0 in the observer frame of th... more We find that the color indices (B - V)0, (V - R)0, (R - I)0, (I - J)0 in the observer frame of the optical afterglow (OA) of GRB030329 during t - T 0 < 10 days are consistent with those of a uniform group of 25 OAs of GRBs (Simon V. et al. A&A 377 (2001) 450; AIP Conf. Proc., 727 (2004) 487). Large color variations of this OA for t - T 0 > 12 days are plausibly matched only by those of SN 1998bw although SN 2003dh develops an excess light in the red/IR spectral region. We also emphasize the discordance with other Type-Ic SNe which are not known to be associated with GRBs. The colors thus can help us to resolve the synchrotron component from the contribution of SN and to discriminate between various types of SN (especially important for faint OAs). We also note that the strong concentration of color indices of the ensemble of 26 OAs (including GRB030329) suggests that the local reddening inside their host galaxies is quite similar and relatively small for these events.
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Papers by Rene Hudec