In this poster we present sonification (the use of sound to convey information) techniques with a... more In this poster we present sonification (the use of sound to convey information) techniques with an example applied to X-ray astronomy. We also present preliminary results of perception experiments. Using sonification we have identified frequencies in the Chandra X-Ray observations of EX Hya, a cataclysmic variable of the intermediate polar type. The frequencies corresponding to 2.44 and 28.3 mHz may be quasi-periodic oscillations characteristic of the source while those identified at 126, 258 and 386 mHz appear to be ...
Proceedings of the International Astronomical Union, 2011
This document presentsJava-based software calledxSonifythat uses a sonification technique (the ad... more This document presentsJava-based software calledxSonifythat uses a sonification technique (the adaptation of sound to convey information) to promote discovery in astronomical data. The prototype is designed to analyze two-dimensional data, such as time-series data. We demonstrate the utility of the sonification technique with examples applied to X-ray astronomy and solar data. We have identified frequencies in theChandraX-Ray observations of EX Hya, a cataclysmic variable of the intermediate polar type. In another example we study the impact of a major solar flare, with its associated coronal mass ejection (CME), on the solar wind plasma (in particular the solar wind between the Sun and the Earth), and the Earth's magnetosphere.
In this poster we present sonification (the use of sound to convey information) techniques with a... more In this poster we present sonification (the use of sound to convey information) techniques with an example applied to X-ray astronomy. We also present preliminary results of perception experiments. Using sonification we have identified frequencies in the Chandra X-Ray observations of EX Hya, a cataclysmic variable of the intermediate polar type. The frequencies corresponding to 2.44 and 28.3 mHz may be quasi-periodic oscillations characteristic of the source while those identified at 126, 258 and 386 mHz appear to be ...
AGN have highly ionized winds seen in UV and X-ray absorption spectra. Analysis of Chandra and XM... more AGN have highly ionized winds seen in UV and X-ray absorption spectra. Analysis of Chandra and XMM-Newton spectra surprisingly shows that the gas in these winds clumps into a few, 2-3, phases with well separated temperatures, and that these lie in pressure balance with one another on the thermal equilibrium in (T, U/T) space. The shape of the hard X-ray continuum determines where this `S' curve of thermal equilibrium lies. We investigate the range of high energy spectral energy distributions for which a multi-phase wind can exist and compare these with observational constraints. We also comment on the contribution to the Compton Hump from scattering in these winds.
Bulletin of the American Astronomical Society, Oct 1, 2000
The intermediate polar EX Hydrae was the subject of an extensive multiwavelength campaign in May-... more The intermediate polar EX Hydrae was the subject of an extensive multiwavelength campaign in May-June 2000 built around a million second EUVE observation of the source. We present results of the EUV to hard X-ray component of the campaign derived from quasi-simultaneous EUVE, Chandra, and RXTE photometric and spectroscopic observations. Emphasis is given to the Chandra HETG spectrum, which shows strong emission lines of H-like O, H- and He-like Ne, Mg, Si, S, Ar, and Fe, and L-shell Fe. Line strengths are used to constrain the temperature and density of the emitting plasma, thereby constraining models of the accretion column.
ATOMDB (http://www.atomdb.org) is a collection of uniformly-formatted atomic data for use in X-ra... more ATOMDB (http://www.atomdb.org) is a collection of uniformly-formatted atomic data for use in X-ray astrophysical spectroscopy that is used by laboratory astrophysicists, observers, and modellers. The current database (v1.3.2) includes both raw atomic rates along with the calculated X-ray spectrum from a collisional plasma over a range of temperatures and densities. Significant improvements have been implemented in the newly released ATOMDB v2.0 of the database. In this release we have: (1) updated the ATOMDB to include many new calculations and laboratory measurements, expanding the range of ions covered and improving the quality of existing holdings; (2) enlarged ATOMDB to incorporate new types of atomic data, such as photoionization rates, absorption cross sections, and fluorescence yields; (3) enhanced existing web tools and created new tools and code libraries that can be used by the entire community to access the ATOMDB. We demonstrate the effect of the improvements to the database by showing x-ray spectra, highlighting the changes which will improve analysis of observations.
ABSTRACT The new version of the AtomDB atomic database (v2.0) contains ionization and recombinati... more ABSTRACT The new version of the AtomDB atomic database (v2.0) contains ionization and recombination rates enabling modeling of non-equilibrium ionization (NEI) plasmas as well as those in collisional ionization equilibrium (CIE). Here we present a comparison between the new and old (v1.3) versions of AtomDB, demonstrating the importance of the atomic data/processes involved in some typical NEI scenarios of astrophysical interests by various line-ratio diagnostics as well as other measurements such as equivalent widths, cooling curves, and spectra.
To quantitatively investigate the origin of the narrow Fe line by the reverberation mapping metho... more To quantitatively investigate the origin of the narrow Fe line by the reverberation mapping method, we compare the observed light curves of Fe K$\alpha$ line with the predicted ones, which are obtained by convolving the continuum light curve with the transfer functions in a thin shell and an inclined disk. The best-fit result is given by the disk case with $i=30^\circ$ which is better than a fit to a constant flux of the Fe K line at the 92.7% level (F-test). We find that the emitting radius obtained from the light curve is 25-37 light days, which is consistent with the radius derived from the Fe K line width. Combining the results of the line width and variation, the most likely site for the origin of the narrow iron lines is 20-40 light days away from the central engine, though other possibilities are not completely ruled out. (abridged)
... We warmly thank Will Henney for the excellent work with the I macros. Finally, we thank Lic. ... more ... We warmly thank Will Henney for the excellent work with the I macros. Finally, we thank Lic. SañlJuárez Vega and Mtro. Jaime Márquez Diez-Cafledo for the use of the facilities of the CNA, and Drs. ... Michael Dopita 83. Guillermo GarcIa-Segura 84. Robert O'Dell 85. ...
Revista Mexicana De Astronomia Y Astrofisica Conference Series, Apr 1, 2008
We present a spectral analysis of the X-ray Chandraof the Seyfert 1 Galaxy NGC 5548. The warm abs... more We present a spectral analysis of the X-ray Chandraof the Seyfert 1 Galaxy NGC 5548. The warm absorber present in this object was modeled with the code PHASE. We detected two different outflow velocity systems in this source. One of the absorbing systems has outflow velocity of -1091+/-63 km s(-1) and the other of -568+/-49 km s(-1) . Each system required two absorption components with different ionization level to fit the observed features. Each velocity system may consist of a multi-phase medium.
AGN feedback plays a major role in models of galaxy formation, evolution, and black hole growth. ... more AGN feedback plays a major role in models of galaxy formation, evolution, and black hole growth. However, observationally, the amount of feedback from AGN outflows is not well measured and most models assume an ad-hoc parameterization. We have, for the first time, measured accurately the outflow parameters in a Seyfert galaxy NGC 4051 using XMM data. We find that the mass loss in the outflow is only a few percent of the accretion rate and the outflow energy is only a small fraction of the radiative luminosity. If these physical characteristics are representative of AGN outflows, then they significantly fall short of the requirement for a susscessful feedback model. In this talk I will discuss our observational result and elaborate further on how feedback<br can work.
Bulletin of the American Astronomical Society, Apr 1, 1999
Calculating the spectrum of a thermal plasma remains an ongoing challenge involving both atomic a... more Calculating the spectrum of a thermal plasma remains an ongoing challenge involving both atomic and plasma physics, as well as numerical computational issues. The Astrophysical Plasma Emission Code (APEC) is designed to separate these issues so they can be attacked individually. The code contains no atomic data inherently, but calculates the emission from a hot plasma using atomic data stored separately (see Brickhouse et al. poster). Many atomic processes, including radiative recombination, dielectronic recombination and satellite lines, and collisional de-excitation, are included in a self-consistent fashion. This approach has the advantage, for example, of including the density dependence of each transition. We present results from APEC for a selection of ionic sequences and compare with results from SPEX, Chianti, and the Raymond-Smith code.
In this poster we present sonification (the use of sound to convey information) techniques with a... more In this poster we present sonification (the use of sound to convey information) techniques with an example applied to X-ray astronomy. We also present preliminary results of perception experiments. Using sonification we have identified frequencies in the Chandra X-Ray observations of EX Hya, a cataclysmic variable of the intermediate polar type. The frequencies corresponding to 2.44 and 28.3 mHz may be quasi-periodic oscillations characteristic of the source while those identified at 126, 258 and 386 mHz appear to be ...
Proceedings of the International Astronomical Union, 2011
This document presentsJava-based software calledxSonifythat uses a sonification technique (the ad... more This document presentsJava-based software calledxSonifythat uses a sonification technique (the adaptation of sound to convey information) to promote discovery in astronomical data. The prototype is designed to analyze two-dimensional data, such as time-series data. We demonstrate the utility of the sonification technique with examples applied to X-ray astronomy and solar data. We have identified frequencies in theChandraX-Ray observations of EX Hya, a cataclysmic variable of the intermediate polar type. In another example we study the impact of a major solar flare, with its associated coronal mass ejection (CME), on the solar wind plasma (in particular the solar wind between the Sun and the Earth), and the Earth's magnetosphere.
In this poster we present sonification (the use of sound to convey information) techniques with a... more In this poster we present sonification (the use of sound to convey information) techniques with an example applied to X-ray astronomy. We also present preliminary results of perception experiments. Using sonification we have identified frequencies in the Chandra X-Ray observations of EX Hya, a cataclysmic variable of the intermediate polar type. The frequencies corresponding to 2.44 and 28.3 mHz may be quasi-periodic oscillations characteristic of the source while those identified at 126, 258 and 386 mHz appear to be ...
AGN have highly ionized winds seen in UV and X-ray absorption spectra. Analysis of Chandra and XM... more AGN have highly ionized winds seen in UV and X-ray absorption spectra. Analysis of Chandra and XMM-Newton spectra surprisingly shows that the gas in these winds clumps into a few, 2-3, phases with well separated temperatures, and that these lie in pressure balance with one another on the thermal equilibrium in (T, U/T) space. The shape of the hard X-ray continuum determines where this `S' curve of thermal equilibrium lies. We investigate the range of high energy spectral energy distributions for which a multi-phase wind can exist and compare these with observational constraints. We also comment on the contribution to the Compton Hump from scattering in these winds.
Bulletin of the American Astronomical Society, Oct 1, 2000
The intermediate polar EX Hydrae was the subject of an extensive multiwavelength campaign in May-... more The intermediate polar EX Hydrae was the subject of an extensive multiwavelength campaign in May-June 2000 built around a million second EUVE observation of the source. We present results of the EUV to hard X-ray component of the campaign derived from quasi-simultaneous EUVE, Chandra, and RXTE photometric and spectroscopic observations. Emphasis is given to the Chandra HETG spectrum, which shows strong emission lines of H-like O, H- and He-like Ne, Mg, Si, S, Ar, and Fe, and L-shell Fe. Line strengths are used to constrain the temperature and density of the emitting plasma, thereby constraining models of the accretion column.
ATOMDB (http://www.atomdb.org) is a collection of uniformly-formatted atomic data for use in X-ra... more ATOMDB (http://www.atomdb.org) is a collection of uniformly-formatted atomic data for use in X-ray astrophysical spectroscopy that is used by laboratory astrophysicists, observers, and modellers. The current database (v1.3.2) includes both raw atomic rates along with the calculated X-ray spectrum from a collisional plasma over a range of temperatures and densities. Significant improvements have been implemented in the newly released ATOMDB v2.0 of the database. In this release we have: (1) updated the ATOMDB to include many new calculations and laboratory measurements, expanding the range of ions covered and improving the quality of existing holdings; (2) enlarged ATOMDB to incorporate new types of atomic data, such as photoionization rates, absorption cross sections, and fluorescence yields; (3) enhanced existing web tools and created new tools and code libraries that can be used by the entire community to access the ATOMDB. We demonstrate the effect of the improvements to the database by showing x-ray spectra, highlighting the changes which will improve analysis of observations.
ABSTRACT The new version of the AtomDB atomic database (v2.0) contains ionization and recombinati... more ABSTRACT The new version of the AtomDB atomic database (v2.0) contains ionization and recombination rates enabling modeling of non-equilibrium ionization (NEI) plasmas as well as those in collisional ionization equilibrium (CIE). Here we present a comparison between the new and old (v1.3) versions of AtomDB, demonstrating the importance of the atomic data/processes involved in some typical NEI scenarios of astrophysical interests by various line-ratio diagnostics as well as other measurements such as equivalent widths, cooling curves, and spectra.
To quantitatively investigate the origin of the narrow Fe line by the reverberation mapping metho... more To quantitatively investigate the origin of the narrow Fe line by the reverberation mapping method, we compare the observed light curves of Fe K$\alpha$ line with the predicted ones, which are obtained by convolving the continuum light curve with the transfer functions in a thin shell and an inclined disk. The best-fit result is given by the disk case with $i=30^\circ$ which is better than a fit to a constant flux of the Fe K line at the 92.7% level (F-test). We find that the emitting radius obtained from the light curve is 25-37 light days, which is consistent with the radius derived from the Fe K line width. Combining the results of the line width and variation, the most likely site for the origin of the narrow iron lines is 20-40 light days away from the central engine, though other possibilities are not completely ruled out. (abridged)
... We warmly thank Will Henney for the excellent work with the I macros. Finally, we thank Lic. ... more ... We warmly thank Will Henney for the excellent work with the I macros. Finally, we thank Lic. SañlJuárez Vega and Mtro. Jaime Márquez Diez-Cafledo for the use of the facilities of the CNA, and Drs. ... Michael Dopita 83. Guillermo GarcIa-Segura 84. Robert O&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#x27;Dell 85. ...
Revista Mexicana De Astronomia Y Astrofisica Conference Series, Apr 1, 2008
We present a spectral analysis of the X-ray Chandraof the Seyfert 1 Galaxy NGC 5548. The warm abs... more We present a spectral analysis of the X-ray Chandraof the Seyfert 1 Galaxy NGC 5548. The warm absorber present in this object was modeled with the code PHASE. We detected two different outflow velocity systems in this source. One of the absorbing systems has outflow velocity of -1091+/-63 km s(-1) and the other of -568+/-49 km s(-1) . Each system required two absorption components with different ionization level to fit the observed features. Each velocity system may consist of a multi-phase medium.
AGN feedback plays a major role in models of galaxy formation, evolution, and black hole growth. ... more AGN feedback plays a major role in models of galaxy formation, evolution, and black hole growth. However, observationally, the amount of feedback from AGN outflows is not well measured and most models assume an ad-hoc parameterization. We have, for the first time, measured accurately the outflow parameters in a Seyfert galaxy NGC 4051 using XMM data. We find that the mass loss in the outflow is only a few percent of the accretion rate and the outflow energy is only a small fraction of the radiative luminosity. If these physical characteristics are representative of AGN outflows, then they significantly fall short of the requirement for a susscessful feedback model. In this talk I will discuss our observational result and elaborate further on how feedback<br can work.
Bulletin of the American Astronomical Society, Apr 1, 1999
Calculating the spectrum of a thermal plasma remains an ongoing challenge involving both atomic a... more Calculating the spectrum of a thermal plasma remains an ongoing challenge involving both atomic and plasma physics, as well as numerical computational issues. The Astrophysical Plasma Emission Code (APEC) is designed to separate these issues so they can be attacked individually. The code contains no atomic data inherently, but calculates the emission from a hot plasma using atomic data stored separately (see Brickhouse et al. poster). Many atomic processes, including radiative recombination, dielectronic recombination and satellite lines, and collisional de-excitation, are included in a self-consistent fashion. This approach has the advantage, for example, of including the density dependence of each transition. We present results from APEC for a selection of ionic sequences and compare with results from SPEX, Chianti, and the Raymond-Smith code.
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Papers by Nancy Brickhouse