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7 results on '"Boggs, S.E."'

1. The Nature of the Torus in the Heavily Obscured AGN Markarian 3: an X-Ray Study

Author

Guainazzi, M, Risaliti, G, Awaki, H, Arevalo, P, Bauer, F. E, Bianchi, S, Boggs, S.E, Brandt, W. N, Brightman, M, Christensen, F. E, Craig, W. W, Forster, K, Hailey, C. J, Harrison, F, Koss, M, Longinotti, A, Markwardt, C. B, Marinucci, A, Matt, G, Reynolds, C. S, Ricci, C, Stern, D, Svoboda, J, Walton, D, and Zhang, W

Subjects
Astrophysics
Abstract

In this paper, we report the results of an X-ray monitoring campaign on the heavily obscured Seyfert galaxy, Markarian 3, carried out between the fall of 2014 and the spring of 2015 with NuSTAR, Suzaku and XMMNewton. The hard X-ray spectrum of Markarian 3 is variable on all the time-scales probed by our campaign, down to a few days. The observed continuum variability is due to an intrinsically variable primary continuum seen in transmission through a large, but still Compton-thin column density (N(sub H) approx. 0.8-1.1 x 10(exp 24)/sq cm). If arranged in a spherical-toroidal geometry, the Compton scattering matter has an opening angle approx. 66deg, and is seen at a grazing angle through its upper rim (inclination angle approx. 70deg). We report a possible occultation event during the 2014 campaign. If the torus is constituted by a system of clouds sharing the same column density, this event allows us to constrain their number (17 +/- 5) and individual column density, [approx. (4.9 +/- 1.5) x 10(exp 22)/ sq cm]. The comparison of IR and X-ray spectroscopic results with state-of-the art torus models suggests that at least two-thirds of the X-ray obscuring gas volume might be located within the dust sublimation radius. We report also the discovery of an ionized absorber, characterized by variable resonant absorption lines due to He- and H-like iron. This discovery lends support to the idea that moderate column density absorbers could be due to clouds evaporated at the outer surface of the torus, possibly accelerated by the radiation pressure due to the central AGN emission leaking through the patchy absorber.

Published
2016
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2. Antideuteron based dark matter search with GAPS: Current progress and future prospects

Author

Hailey, C.J., Aramaki, T., Boggs, S.E., Doetinchem, P.v., Fuke, H., Gahbauer, F., Koglin, J.E., Madden, N., Mognet, S.A.I., Ong, R., Yoshida, T., Zhang, T., and Zweerink, J.A.

Subjects
*DARK matter, *SPECTROMETERS, *GALACTIC halos, *ASTROPHYSICS, *STANDARD model (Nuclear physics), *COSMIC rays, *ASTROPHYSICAL collisions
Abstract

Abstract: The General Antiparticle Spectrometer (GAPS) is a new approach to the indirect detection of dark matter. It relies on searching for primary antideuterons produced in the annihilation of dark matter in the galactic halo. Low energy antideuterons produced through Standard Model processes, such as collisions of cosmic-rays with interstellar baryons, are greatly suppressed compared to primary antideuterons. Thus a low energy antideuteron search provides a clean signature of dark matter. In GAPS antiparticles are slowed down and captured in target atoms. The resultant exotic atom deexcites with the emission of X-rays and annihilation pions, protons and other particles. A tracking geometry allows for the detection of the X-rays and particles, providing a unique signature to identify the mass of the antiparticle. A prototype detector was successfully tested at the KEK accelerator in 2005, and a prototype GAPS balloon flight is scheduled for 2011. This will be followed by a full scale experiment on a long duration balloon from Antarctica in 2014. We discuss the status and future plans for GAPS. [Copyright &y& Elsevier]

Published
2013
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3. Construction, characterization, and environmental testing of a Laue lens prototype using Fe and Al crystals.

Author

Wade, C., Barrière, N.M., Tomsick, J.A., Hanlon, L., Boggs, S.E., Lowell, A., von Ballmoos, P., and Massahi, S.

Subjects
*BRAGG gratings, *ASTROPHYSICS, *ALUMINUM, *NUCLEAR medicine, *CRYSTALS
Abstract

Laue lenses use Bragg diffraction to concentrate soft γ -rays onto a detector. This decoupling of the collecting area from the detector volume can generate a significant increase in sensitivity for applications in astrophysics and nuclear medicine. A demonstrator lens was constructed at the UC Berkeley’s Space Sciences Laboratory in 2014 by gluing 48 Fe and Al diffracting crystals to an aluminium substrate. The goal was to demonstrate a fast and accurate assembly technique that is compatible with the large number of crystals required to fabricate a Laue lens telescope for astronomical observations. We present here the lens design, the assembly technique we used, and the results of measurements of the angular misalignments before and after curing of the glue and during environmental testing (thermal, vacuum, and vibration). We conclude that our alignment technique is fast enough to assemble a full lens made of several thousand crystals. The achieved alignment accuracy had an average of 32.7 ′ ′ and a standard deviation of 44.1 ′ ′ . The accuracy could be improved by using an alternative glue or by having better control over the asymmetry angle resulting from the crystal cut. [ABSTRACT FROM AUTHOR]

Published
2018
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4. NuSTAR reveals the extreme properties of the super-Eddington accreting supermassive black hole in PG 1247+267

Author

Duncan Farrah, Franz E. Bauer, M. Cappi, W. N. Brandt, W. W. Zhang, Giorgio Lanzuisi, M. Dadina, Enrico Piconcelli, Fausto Vagnetti, Andrea Comastri, C. J. Hailey, William W. Craig, S. E. Boggs, Fiona A. Harrison, Giorgio Matt, Claudio Ricci, A. C. Fabian, Dom Walton, Andrea Marinucci, F. E. Christensen, Michele Perna, S. Puccetti, David R. Ballantyne, Alberto Masini, D. Stern, C. Vignali, Cristian Saez, B. Luo, Marcella Brusa, Lanzuisi, G., Perna, M., Comastri, A., Cappi, M., Dadina, M., Marinucci, Andrea, Masini, A., Matt, Giorgio, Vagnetti, F., Vignali, C., Ballantyne, D. R., Bauer, F. E., Boggs, S. E., Brandt, W. N., Brusa, M., Christensen, F. E., Craig, W. W., Fabian, A. C., Farrah, D., Hailey, C. J., Harrison, F. A., Luo, B., Piconcelli, E., Puccetti, S., Ricci, C., Saez, C., Stern, D., Walton, D. J., Zhang, W. W., Marinucci, A., Matt, G., Ballantyne, D.R., Bauer, F.E., Boggs, S.E., Brandt, W.N., Christensen, F.E., Craig, W.W., Fabian, A.C., Hailey, C.J., Harrison, F.A., Walton, D.J., and Zhang, W.W.

Subjects
Accretion, active [Galaxies], Astrophysics::High Energy Astrophysical Phenomena, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Power law, Relativistic disk, Quasars: individual: PG 1247+267, Accretion, accretion disk, Settore FIS/05 - Astronomia e Astrofisica, individual: PG 1247+267 [Quasars], Ionization, 0103 physical sciences, Cutoff, Emission spectrum, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, Galaxies: nuclei, Physics, 010308 nuclear & particles physics, Astronomy and Astrophysics, Quasar, Plasma, Galaxies: active, Astronomy and Astrophysic, Redshift, Space and Planetary Science, nuclei [Galaxies], Accretion disks
Abstract

PG1247+267 is one of the most luminous known quasars at z similar to 2 and is a strongly super-Eddington accreting supermassive black hole (SMBH) candidate. We obtained NuSTAR data of this intriguing source in December 2014 with the aim of studying its high-energy emission, leveraging the broad band covered by the new NuSTAR and the archival XMM-Newton data. Several measurements are in agreement with the super-Eddington scenario for PG1247+267: the soft power law (Gamma = 2.3 +/- 0.1); the weak ionized Fe emission line; and a hint of the presence of outflowing ionized gas surrounding the SMBH. The presence of an extreme reflection component is instead at odds with the high accretion rate proposed for this quasar. This can be explained with three different scenarios; all of them are in good agreement with the existing data, but imply very different conclusions: i) a variable primary power law observed in a low state, superimposed on a reflection component echoing a past, higher flux state; ii) a power law continuum obscured by an ionized, Compton thick, partial covering absorber; and iii) a relativistic disk reflector in a lamp-post geometry, with low coronal height and high BH spin. The first model is able to explain the high reflection component in terms of variability. The second does not require any reflection to reproduce the hard emission, while a rather low high-energy cutoff of similar to 100 keV is detected for the first time in such a high redshift source. The third model require a face-on geometry, which may affect the SMBH mass and Eddington ratio measurements. Deeper X-ray broad-band data are required in order to distinguish between these possibilities.

Published
2016

5. The Phoenix galaxy as seen by NuSTAR

Author

Stephanie M. LaMassa, Matteo Guainazzi, Fiona A. Harrison, Dominic J. Walton, Walter Craig, C. J. Hailey, Michael Koss, S. E. Boggs, Daniel Stern, Andrea Comastri, Franz E. Bauer, Finn Erland Christensen, Claudio Ricci, M. Brightman, Mislav Baloković, Duncan Farrah, Simonetta Puccetti, P. G. Boorman, William W. Zhang, Poshak Gandhi, Alberto Masini, Masini, A., Comastri, A., Puccetti, S., Baloković, M., Gandhi, P., Guainazzi, M., Bauer, F.E., Boggs, S.E., Boorman, P.G., Brightman, M., Christensen, F.E., Craig, W.W., Farrah, D., Hailey, C.J., Harrison, F.A., Koss, M.J., Lamassa, S.M., Ricci, C., Stern, D., Walton, D.J., and Zhang, W.W.

Subjects
Physics, High Energy Astrophysical Phenomena (astro-ph.HE), Seyfert [Galaxies], active [Galaxies], biology, 010308 nuclear & particles physics, galaxies: active, Flux, FOS: Physical sciences, Astronomy and Astrophysics, Context (language use), Astrophysics, Astronomy and Astrophysic, biology.organism_classification, 01 natural sciences, Galaxy, galaxies: Seyfert, galaxies [X-rays], X-rays: galaxies, Space and Planetary Science, 0103 physical sciences, Astrophysics - High Energy Astrophysical Phenomena, Phoenix, 010303 astronomy & astrophysics, X-rays: galaxie
Abstract

著者人数: 21名, Accepted: 2016-09-01, 資料番号: SA1160316000

Published
2016
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6. NuSTAR reveals extreme absorption in z < 0.5 Type 2 quasars

Author

Finn Erland Christensen, Fiona A. Harrison, C. J. Hailey, Franz E. Bauer, A. Del Moro, Francesca Civano, James Aird, Roberto J. Assef, Birong Luo, Brian W. Grefenstette, Daniel Stern, Michael Koss, David M. Alexander, L. Zappacosta, Stephanie M. LaMassa, A. Annuar, Simonetta Puccetti, Ryan C. Hickox, M. Brightman, Andrea Comastri, S. E. Boggs, George B. Lansbury, William W. Craig, Poshak Gandhi, William W. Zhang, Mislav Baloković, W. N. Brandt, Ezequiel Treister, David R. Ballantyne, Cristian Vignali, Lansbury, G.B., Gandhi, P., Alexander, D.M., Assef, R.J., Aird, J., Annuar, A., Ballantyne, D.R., Baloković, M., Bauer, F.E., Boggs, S.E., Brandt, W.N., Brightman, M., Christensen, F.E., Civano, F., Comastri, A., Craig, W.W., Del Moro, A., Grefenstette, B.W., Hailey, C.J., Harrison, F.A., Hickox, R.C., Koss, M., Lamassa, S.M., Luo, B., Puccetti, S., Stern, D., Treister, E., Vignali, C., Zappacosta, L., Zhang, W.W., ITA, and USA

Subjects
Physics, education.field_of_study, active [Galaxies], 010308 nuclear & particles physics, Astrophysics::High Energy Astrophysical Phenomena, Population, galaxies: active, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy and Astrophysics, Quasar, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Type (model theory), 01 natural sciences, Astrophysics - Astrophysics of Galaxies, Redshift, galaxies [X-rays], X-rays: galaxies, Space and Planetary Science, 0103 physical sciences, Source counts, Absorption (electromagnetic radiation), education, Astrophysics - High Energy Astrophysical Phenomena, 010303 astronomy & astrophysics
Abstract

The intrinsic column density (NH) distribution of quasars is poorly known. At the high obscuration end of the quasar population and for redshifts z 1.5e24 cm^-2) type 2 quasars (CTQSO2s); five new NuSTAR observations are reported herein, and four have been previously published. The candidate CTQSO2s lie at z~ 90 net source counts at 8-24 keV). For these NuSTAR-detected sources direct (i.e., X-ray spectral) constraints on the intrinsic AGN properties are feasible, and we measure column densities ~2.5-1600 times higher and intrinsic (unabsorbed) X-ray luminosities ~10-70 times higher than pre-NuSTAR constraints from Chandra and XMM-Newton. Assuming the NuSTAR-detected type 2 quasars are representative of other Compton-thick candidates, we make a correction to the NH distribution for optically selected type 2 quasars as measured by Chandra and XMM-Newton for 39 objects. With this approach, we predict a Compton-thick fraction of f_CT = 36^{+14}_{-12} %, although higher fractions (up to 76%) are possible if indirect absorption diagnostics are assumed to be reliable., Comment: 19 pages, 13 figures, 5 tables. Accepted for publication in ApJ

Published
2015

7. NuSTAR J033202-2746.8: direct constraints on the Compton reflection in a heavily obscured quasar at z~2

Author

Piero Ranalli, Simonetta Puccetti, James Aird, Meg Urry, Stephanie M. LaMassa, S. E. Boggs, David M. Alexander, Fiona A. Harrison, C. J. Hailey, George B. Lansbury, William W. Zhang, Francesca Civano, Andrea Comastri, Finn Erland Christensen, James Mullaney, W. N. Brandt, William W. Craig, Mislav Baloković, Daniel Stern, Poshak Gandhi, Ryan C. Hickox, Birong Luo, A. Del Moro, David R. Ballantyne, Cristian Vignali, Ezequiel Treister, Roberto Gilli, Franz E. Bauer, Del Moro A., Mullaney J.R., Alexander D.M., Comastri A., Bauer F.E., Treister E., Stern D., Civano F., Ranalli P., Vignali C., Aird J.A., Ballantyne D., Balokovic M., Boggs S.E., Brandt W.N., Christensen S.E., Craig W.W., Gandhi P., Gilli R., Hailey C.J., Harrison F.A., Hickox R.C., LaMassa S.M., Lansbury G.B., Luo B., Puccetti S., Urry M., and Zhang W.W.

Subjects
Cosmology and Nongalactic Astrophysics (astro-ph.CO), Spectral shape analysis, active [Galaxies], 010504 meteorology & atmospheric sciences, Astrophysics::High Energy Astrophysical Phenomena, Population, galaxies: active, General [quasars], FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Luminosity, Galaxies [infrared], quasars: individual (NuSTAR J033202-2746.8), quasars: general, X-rays, 0103 physical sciences, Spectral slope, individual (NuSTAR J033202-2746.8) [quasars], Spectroscopy, education, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, Physics, education.field_of_study, infrared: galaxie, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy and Astrophysics, Quasar, Astrophysics - Astrophysics of Galaxies, Redshift, X-rays: galaxies, K-edge, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

We report NuSTAR observations of NuSTAR J033202-2746.8, a heavily obscured, radio-loud quasar detected in the Extended Chandra Deep Field-South, the deepest layer of the NuSTAR extragalactic survey (~400 ks, at its deepest). NuSTAR J033202-2746.8 is reliably detected by NuSTAR only at E>8 keV and has a very flat spectral slope in the NuSTAR energy band (Gamma=0.55^{+0.62}_{-0.64}; 3-30 keV). Combining the NuSTAR data with extremely deep observations by Chandra and XMM-Newton (4 Ms and 3 Ms, respectively), we constrain the broad-band X-ray spectrum of NuSTAR J033202-2746.8, indicating that this source is a heavily obscured quasar (N_H=5.6^{+0.9}_{-0.8}x10^23 cm^-2) with luminosity L_{10-40 keV}~6.4x10^44 erg s^-1. Although existing optical and near-infrared (near-IR) data, as well as follow-up spectroscopy with the Keck and VLT telescopes, failed to provide a secure redshift identification for NuSTAR J033202-2746.8, we reliably constrain the redshift z=2.00+/-0.04 from the X-ray spectral features (primarily from the iron K edge). The NuSTAR spectrum shows a significant reflection component (R=0.55^{+0.44}_{-0.37}), which was not constrained by previous analyses of Chandra and XMM-Newton data alone. The measured reflection fraction is higher than the R~0 typically observed in bright radio-loud quasars such as NuSTAR J033202-2746.8, which has L_{1.4 GHz}~10^27 W Hz^-1. Constraining the spectral shape of AGN, including bright quasars, is very important for understanding the AGN population, and can have a strong impact on the modeling of the X-ray background. Our results show the importance of NuSTAR in investigating the broad-band spectral properties of quasars out to high redshift., 13 pages, 5 figures; accepted for publication in ApJ

Published
2014

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