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Sample records for integral source igr

  1. Swift-XRT follow-up of the unidentified INTEGRAL source: IGR J08282-3736

    NASA Astrophysics Data System (ADS)

    Malizia, A.; Landi, R.; Bassani, L.; Bird, A. Bazzano A. J.; Gehrels, N.; Kennea, J. A.

    2011-04-01

    In this telegram we report the X-ray follow-up observations performed with Swift-XRT of the unidentified INTEGRAL source IGR J08282-3736 listed in Bird et al. 2010 (ApJS, 186, 1). IGR J08282-3736 has already been optically classified as a HMXB by Masetti et al. 2010 (A&A, 519, 96) in the hypothesis that the emitting line star SS188 (also 1RXS J082615.4-373610) was the counterpart of the INTEGRAL source.

  2. Swift/XRT follow-up of the unidentified INTEGRAL source IGR J14043-6148

    NASA Astrophysics Data System (ADS)

    Landi, R.; Malizia, A.; Bazzano, A.; Fiocchi, M.; Bird, A. J.; Gehrels, N.

    2011-02-01

    We report the results of an X-ray follow-up observation performed with Swift/XRT of the unidentified INTEGRAL source IGR J14043-6148 listed in the 4th IBIS Survey Catalogue (Bird et al. 2010, ApJS, 186, 1). Inside the 90% IBIS error circle, we find an X-ray source detected at 6.5 sigma c.l. (0.3-10 keV), which is still observed at 6.1 sigma c.l. above 3 keV. It is positioned at R.A.(J2000) = 14h 04m 29.63s and Dec.(J2000) = -61d 47m 19.7s (4.5 arcsec uncertainty).

  3. CHANDRA OBSERVATIONS OF FIVE INTEGRAL SOURCES: NEW X-RAY POSITIONS FOR IGR J16393-4643 AND IGR J17091-3624

    SciTech Connect

    Bodaghee, A.; Tomsick, J. A.; Rahoui, F.; Rodriguez, J.

    2012-06-01

    The Chandra High Resolution Camera observed the fields of five hard X-ray sources in order to help us obtain X-ray coordinates with subarcsecond precision. These observations provide the most accurate X-ray positions known for IGR J16393-4643 and IGR J17091-3624. The obscured X-ray pulsar IGR J16393-4643 lies at R.A. (J2000) = 16{sup h}39{sup m}05.{sup s}47, and decl. = -46 Degree-Sign 42'13.''0 (error radius of 0.''6 at 90% confidence). This position is incompatible with the previously proposed counterpart 2MASS J16390535-4642137, and it points instead to a new counterpart candidate that is possibly blended with the Two Micron All Sky Survey star. The black hole candidate IGR J17091-3624 was observed during its 2011 outburst providing coordinates of R.A. = 17{sup h}09{sup m}07.{sup s}59, and decl. = -36 Degree-Sign 24'25.''4. This position is compatible with those of the proposed optical/IR and radio counterparts, solidifying the source's status as a microquasar. Three targets, IGR J14043-6148, IGR J16358-4726, and IGR J17597-2201, were not detected. We obtained 3{sigma} upper limits of, respectively, 1.7, 1.8, and 1.5 Multiplication-Sign 10{sup -12} erg cm{sup -2} s{sup -1} on their 2-10 keV fluxes.

  4. Discovery of X-Ray Pulsations from the INTEGRAL Source IGR J11014-6103

    NASA Astrophysics Data System (ADS)

    Halpern, J. P.; Tomsick, J. A.; Gotthelf, E. V.; Camilo, F.; Ng, C.-Y.; Bodaghee, A.; Rodriguez, J.; Chaty, S.; Rahoui, F.

    2014-11-01

    We report the discovery of PSR J1101-6101, a 62.8 ms pulsar in IGR J11014-6103, a hard X-ray source with a jet and a cometary tail that strongly suggests it is moving away from the center of the supernova remnant (SNR) MSH 11-61A at v > 1000 km s-1. Two XMM-Newton observations were obtained with the EPIC pn in small window mode, resulting in the measurement of its spin-down luminosity \\dot{E}=1.36× 1036 erg s-1, characteristic age τ c = 116 kyr, and surface magnetic field strength Bs = 7.4 × 1011 G. In comparison to τ c , the 10-30 kyr age estimated for MSH 11-61A suggests that the pulsar was born in the SNR with initial period in the range 54 <= P 0 <= 60 ms. PSR J1101-6101 is the least energetic of the 15 rotation-powered pulsars detected by INTEGRAL, and has a high efficiency of hard X-ray radiation and jet power. We examine the shape of the cometary nebula in a Chandra image, which is roughly consistent with a bow shock at the velocity inferred from the SNR age and the pulsar's \\dot{E}. However, its structure differs in detail from the classic bow shock, and we explore possible reasons for this.

  5. INTEGRAL source IGR J16562-3301 --- a new BL Lac object

    NASA Astrophysics Data System (ADS)

    Burenin, R.; Revnivtsev, M.; Mescheryakov, A.; Bikmaev, I.; Pavlinsky, M.; Sunyaev, R.

    2007-11-01

    The accurate position of the hard X-ray source IGR J16562-3301/SWIFT J1656.3-3302 (Okajima et al. 2006, ATel #799, Krivonos et al. 2007, astro-ph/0701836) was determined earlier by Tueller et al. (2006, ATEL #835) using SWIFT/XRT observation of this field. We found that more accurate position of this source can be derived from the same data when the systematics of SWIFT/XRT astrometry is corrected using the other two bright X-ray sources identified with relatively bright optical stars.

  6. DISCOVERY OF X-RAY PULSATIONS FROM THE INTEGRAL SOURCE IGR J11014–6103

    SciTech Connect

    Halpern, J. P.; Gotthelf, E. V.; Camilo, F.; Tomsick, J. A.; Ng, C.-Y.; Bodaghee, A.; Rodriguez, J.; Chaty, S.

    2014-11-10

    We report the discovery of PSR J1101–6101, a 62.8 ms pulsar in IGR J11014–6103, a hard X-ray source with a jet and a cometary tail that strongly suggests it is moving away from the center of the supernova remnant (SNR) MSH 11–61A at v > 1000 km s{sup –1}. Two XMM-Newton observations were obtained with the EPIC pn in small window mode, resulting in the measurement of its spin-down luminosity E-dot =1.36×10{sup 36} erg s{sup –1}, characteristic age τ {sub c} = 116 kyr, and surface magnetic field strength B{sub s} = 7.4 × 10{sup 11} G. In comparison to τ {sub c}, the 10-30 kyr age estimated for MSH 11–61A suggests that the pulsar was born in the SNR with initial period in the range 54 ≤ P {sub 0} ≤ 60 ms. PSR J1101–6101 is the least energetic of the 15 rotation-powered pulsars detected by INTEGRAL, and has a high efficiency of hard X-ray radiation and jet power. We examine the shape of the cometary nebula in a Chandra image, which is roughly consistent with a bow shock at the velocity inferred from the SNR age and the pulsar's E-dot . However, its structure differs in detail from the classic bow shock, and we explore possible reasons for this.

  7. THE INTEGRAL SOURCE IGR J16328-4726: A HIGH-MASS X-RAY BINARY FROM THE BEPPOSAX ERA

    SciTech Connect

    Fiocchi, M.; Bazzano, A.; Natalucci, L.; Persi, P.; Piro, L.; Ubertini, P.; Bird, A. J.; Drave, S. P.

    2013-01-01

    We report on temporal and spectral analysis of the INTEGRAL fast transient candidate IGR J16328-4726 observed with BeppoSAX in 1998 and more recently with INTEGRAL. The MECS X-ray data show a frequent microactivity typical of the intermediate state of supergiant fast X-ray transients and a weak flare with a duration of {approx}4.6 ks. The X-ray emission in the 1.5-10 keV energy range is well described through the different time intervals by an absorbed power-law model. Comparing spectra from the lower emission level up to the peak of the flare, we note that while the power-law photon index was constant ({approx}2), the absorption column density varied by a factor of up to {approx}6-7, reaching a value of {approx}2 Multiplication-Sign 10{sup 23} cm{sup -2} at the peak of the flare. Analysis of the long-term INTEGRAL/IBIS light curve confirms and refines the proposed {approx}10.07 day period, and the derived ephemeris places the BeppoSAX observations away from periastron. Using the near- and the mid-IR available observations, we constructed a spectral infrared distribution for the counterpart of IGR J16328-4726, allowing us to identify its counterpart as a high-mass OB type star and to classify this source as a firm HMXB. Following the standard clumpy wind theory, we estimated the mass and the radius of the clump responsible for the flare. The obtained values of M {sub cl} {approx_equal} 4 Multiplication-Sign 10{sup 22}g and R{sub cl} {approx_equal} 4.4 Multiplication-Sign 10{sup 6} km are in agreement with expected values from theoretical predictions.

  8. Is the INTEGRAL IBIS Source IGR J17204-3554 a Gamma-Ray-emitting Galaxy Hidden behind the Molecular Cloud NGC 6334?

    NASA Astrophysics Data System (ADS)

    Bassani, L.; De Rosa, A.; Bazzano, A.; Bird, A. J.; Dean, A. J.; Gehrels, N.; Kennea, J. A.; Malizia, A.; Molina, M.; Stephen, J. B.; Ubertini, P.; Walter, R.

    2005-11-01

    We report on the identification of a soft gamma-ray source, IGR J17204-3554, detected with IBIS, the Imager on Board the INTEGRAL Satellite. The source has a 20-100 keV flux of ~3×10-11 ergs cm-2 s-1 and is spatially coincident with NGC 6334, a molecular cloud located in the Sagittarius arm of the Milky Way. Diffuse X-ray emission has been reported from this region by ASCA and interpreted as coming from five far-infrared cores located in the cloud. However, the combined ASCA spectrum with a 9 keV temperature was difficult to explain in terms of emission from young pre-main-sequence stars known to be embedded in the star-forming regions. Detection of gamma rays makes this interpretation even more unrealistic and suggests the presence of a high-energy source in or behind the cloud. Follow-up observations with Swift and archival Chandra data allow us to disentangle the NGC 6334 enigma by locating an extragalactic object with the proper spectral characteristics to explain the gamma-ray emission. The combined Chandra-IBIS spectrum is well fitted by an absorbed power law with Γ=1.2+/-0.1, NH=(1.4+/-0.1)×1023 cm-2, and an unabsorbed 2-10 keV flux of 0.5×10-11 ergs cm-2 s-1. This column density is in excess of the Galactic value, implying that we are detecting a background galaxy concealed by the molecular cloud and further hidden by material located either in the galaxy itself or between IGR J17204-3554 and the cloud. Based on observations obtained with INTEGRAL, an ESA project with instruments and science data center funded by ESA member states (especially the PI countries: Denmark, France, Germany, Italy, Switzerland, Spain), the Czech Republic, and Poland and with the participation of Russia and the US.

  9. Swift, INTEGRAL, RXTE, and Spitzer Reveal IGR J16283-4838

    NASA Technical Reports Server (NTRS)

    Beckmann, V.; Gehrels, N.; Markwardt, C.; Barthelmy S.; Soldi, S.; Paizis, A.; Mowlavi, N.; Kennca, J. A.; Burrows, D. N.; Chester, M.

    2005-01-01

    We present the first combined study of the recently discovered source IGR J16283-4838 with Swift, INTEGRAL, and RXTE. The source, discovered by INTEGRAL on April 7, 2005, shows a highly absorbed (variable N(sub H) = 0.4-1.7 x 10(exp 23) /sq cm) and flat (Gamma approx. 1) spectrum in the Swift/XRT and RXTE/PCA data. No optical counterpart is detectable (V > 20 mag), but a possible infrared counterpart within the Swift/XRT error radius is detected in the 2MASS and Spitzer/GLIMPSE survey. The observations suggest that IGR J16283-4838 is a high mass X-ray binary containing a neutron star embedded in Compton thick material. This makes IGR J16283-4838 a member of the class of highly absorbed HMXBs, discovered by INTEGRAL.

  10. Swift/XRT detection of the hard X-ray source IGR J14549-6459

    NASA Astrophysics Data System (ADS)

    Fiocchi, M.; Bazzano, A.; Landi, R.; Bassani, L.; Gehrels, N.; Kennea, J.; Bird, A. J.

    2010-04-01

    We report the result of a short (900 sec) Swift/XRT observation of the field containing IGR J14549-6459, a new INTEGRAL source recently reported in the 4th IBIS catalogue (Bird et al. 2010, ApJS, 186, 1). The XRT data analysis is performed using the standard procedure described in details in Landi et al. 2010 (MNRAS, 403, 945). The XRT observation locates the X-ray counterpart of IGR J14549-6459 at RA(J2000)= 14h 55m 23.9s, Dec(J2000)= -65d 00m 03.2s with an error of 6".

  11. Outburst from the SFXT IGR J17544-2619 detected by INTEGRAL

    NASA Astrophysics Data System (ADS)

    Paizis, A.; Kuulkers, E.; Chenevez, J.; Bazzano, A.; Beckmann, V.; Bird, T.; Bodaghee, A.; Del Santo, M.; Domingo, A.; Jonker, P.; Kretschmar, P.; Pottschmidt, K.; Markwardt, C.; Sanchez-Fernandez, C.; Wijnands, R.

    2015-02-01

    During public INTEGRAL Galactic bulge monitoring observations (ATel #438) performed on 2015 February 20-21 at UT 23:04-02:45, we detected the SFXT IGR J17544-2619 (see ATel #7137 for the recent Swift detection of the source outburst).

  12. INTEGRAL confirms activity in EXO 1722-363 / IGR J17252-3616

    NASA Astrophysics Data System (ADS)

    Kreykenbohm, I.; Kretschmar, P.; Wilms, J.; Grinberg, V.; Kuulkers, E.; Hirsch, M.; Pottschmidt, K.; Rodriguez, J.; Sanchez-Fernandez, C.

    2016-08-01

    INTEGRAL observations taken on 2016 August 23 between MJD 57623.26 and 57623.84 clearly confirm the highly absorbed super-giant high mass X-ray binary pulsar EXO 1722-363 (IGR J17252-3616) to be the source reported as flaring in ATel #9412 by MAXI.

  13. SOURCE IDENTIFICATION IN THE IGR J17448-3232 FIELD: DISCOVERY OF THE SCORPIUS GALAXY CLUSTER

    SciTech Connect

    Barrière, Nicolas M.; Tomsick, John A.; Wik, Daniel R.; Chaty, Sylvain; Rodriguez, Jérome

    2015-01-20

    We use a 43 ks XMM-Newton observation to investigate the nature of sources first distinguished by a follow-up Chandra observation of the field surrounding INTEGRAL source IGR J17448-3232, which includes extended emission and a bright point source previously classified as a blazar. We establish that the extended emission is a heretofore unknown massive galaxy cluster hidden behind the Galactic bulge. The emission-weighted temperature of the cluster within the field of view is 8.8 keV, with parts of the cluster reaching temperatures of up to 12 keV; no cool core is evident. At a redshift of 0.055, the cluster is somewhat under-luminous relative to the X-ray luminosity-temperature relation, which may be attributable to its dynamical state. We present a preliminary analysis of its properties in this paper. We also confirm that the bright point source is a blazar, and we propose that it is either a flat spectrum radio quasar or a low-frequency peaked BL Lac object. We find four other fainter sources in the field, which we study and tentatively identify. Only one, which we propose is a foreground Galactic X-ray binary, is hard enough to contribute to IGR J17448-3232, but it is too faint to be significant. We thus determine that IGR J17448-3232 is in fact the galaxy cluster up to ≈45 keV and the blazar beyond.

  14. IGR J12319-0749: Evidence for Another Extreme Blazar Found with INTEGRAL

    NASA Technical Reports Server (NTRS)

    Bassani, L.; Landi, R.; Marshall, F. E.; Malizia, A.; Bazzano, A.; Bird, A. J.; Gehrels, N.; Ubertini, P.; Masetti, N.

    2012-01-01

    We report on the identification of a new soft gamma-ray source, IGR J12319 C0749, detected with the IBIS imager on board the INTEGRAL satellite. The source, which has an observed 20 C100 keV flux of 8.3 10.12 erg cm.2 s.1, is spatially coincident with an AGN at redshift z = 3.12. The broad-band continuum, obtained by combining XRT and IBIS data, is flat ( =1.3) with evidence for a spectral break around 25 keV (100 keV in the source rest frame). X-ray observations indicate flux variability which is further supported by a comparison with a previous ROSAT measurement. IGR J12319 C0749 is also a radio emitting object likely characterized by a flat spectrum and high radio loudness; optically it is a broad-line emitting object with a massive black hole (2.8 109 solar masses) at its center. The source Spectral Energy Distribution is similar to another high redshift blazar, 225155+2217 at z = 3.668: both objects are bright, with a large accretion disk luminosity and a Compton peak located in the hard X-ray/soft gamma-ray band. IGR J12319 C0749 is likely the second most distant blazar detected so far by INTEGRAL.

  15. IGR J12319-0749: Evidence for Another Extreme Blazar Found with INTEGRAL

    NASA Technical Reports Server (NTRS)

    Bassani, L.; Landi, R.; Marshall, F. E.; Malizia, A.; Bazzano, A.; Bird, A. J.; Gehrels, N.; Ubertini, P.; Masetti, N.

    2012-01-01

    We report on the identification of a new soft gamma-ray source, IGR J12319-0749, detected with the IBIS imager on board the INTEGRAL satellite. The source, which has an observed 20-100 keV flux of approx 8.3 × 10(exp -12) erg/sq. cm/ s, is spatially coincident with an active galactic nucleus (AGN) at redshift z = 3.12. The broad-band continuum, obtained by combining XRT and IBIS data, is flat (Gamma = 1.3) with evidence for a spectral break around 25 keV (100 keV in the source restframe). X-ray observations indicate flux variability, which is also supported by a comparison with a previous ROSAT measurement. IGR J12319-0749 is also a radio-emitting object likely characterised by a flat spectrum and high radio loudness; optically it is a broad-line emitting object with a massive black hole (2.8 × 10(exp 9) solar masses) at its centre. The source spectral energy distribution is similar to another high-redshift blazar, 225155+2217 at z = 3.668: both objects are bright, with a high accretion disk luminosity and a Compton peak located in the hard X-ray/soft gamma-ray band. IGR J12319-0749 is likely the second-most distant blazar detected so far by INTEGRAL.

  16. INTEGRAL/JEM-X detection of type-I X-ray bursts from IGR J17488-2018

    NASA Astrophysics Data System (ADS)

    Bozzo, E.; Falanga, M.; Ferrigno, C.

    2015-02-01

    During the on-going INTEGRAL target of opportunity (ToO) observation of the X-ray transient IGR J17488-2018 (Atel #7098, #7106) located in the Globular Cluster NGC 6440, the two JEM-X telescopes detected so far 7 type-I X-ray bursts from the source.

  17. A possible WISE blazar counterpart of the faint INTEGRAL active galactic nucleus IGR J02341+0228

    NASA Astrophysics Data System (ADS)

    Massaro, F.; Paggi, A.; D'Abrusco, R.

    2012-05-01

    Following the Swift-XRT identification of the counterpart for the faint INTEGRAL active galactic nucleus IGR J02341+0228, associated with a new extragalactic source: QSO B0231+022 (ATEL #4102), we searched in the Wide-field Infrared Survey Explorer (WISE; Wright et al. 2010 AJ, 140, 1868) catalog at the position of the QSO B0231+022 source for an infrared counterpart.

  18. Optical and X-ray Observations of IGR J20187+4041 in the Error Circle of the Variable AGILE Source in Cygnus

    NASA Astrophysics Data System (ADS)

    Halpern, J. P.

    2008-04-01

    With regard to the galaxy 2MASX J20183871+4041003 that was mentioned by Longo et al. (ATel #1492) in connection with a variable AGILE source, I note that this galaxy was first identified with the INTEGRAL source IGR J2018+4043 (=IGR J20187+4041) by Kennea et al. (ATel #788) and Bykov et al. (2006, ApJ, 649, L21) using the Swift XRT. (See also Ajello et al., ATel #1497). While these authors noted the proximity of the unidentified EGRET source 3EG J2020+4017, the galaxy is actually outside the EGRET error box.

  19. INTEGRAL caught a new outburst from IGR J17464-3213

    NASA Astrophysics Data System (ADS)

    Ducci, L.; Rodriguez, J.; Grinberg, V.; Kuulkers, E.; Bozzo, E.

    2014-09-01

    During the observation of the Galactic Center performed from 2014 September 13 at 03:25 to September 15 at 04:18 (UTC), the IBIS/ISGRI and JEM-X instruments on board INTEGRAL detected renewed activity from the black-hole candidate IGR J17464-3213 (H 1743-322).

  20. The Nature of the X-Ray Binary IGR J19294+1816 from INTEGRAL, RXTE, and Swift Observations

    NASA Technical Reports Server (NTRS)

    Rodriquez, J.; Tomsick, J. A.; Bodaghee, A.; ZuritaHeras, J.-A.; Chaty, S.; Paizis, A.; Corbel, S.

    2009-01-01

    We report the results of a high-energy multi-instrumental campaign with INTEGRAL, RXTE, and Swift of the recently discovered INTEGRAL source IGR J19294+ 1816. The Swift/XRT data allow us to refine the position of the source to R.A. (J2000) = 19h 29m 55.9s, Decl. (J2000) = +18 deg 18 feet 38 inches . 4 (+/- 3 inches .5), which in turn permits us to identify a candidate infrared counterpart. The Swift and RXTE spectra are well fitted with absorbed power laws with hard (Gamma approx 1) photon indices. During the longest Swift observation, we obtained evidence of absorption in true excess to the Galactic value, which may indicate some intrinsic absorption in this source. We detected a strong (P = 40%) pulsations at 12.43781 (+/- 0.00003) s that we interpret as the spin period of a pulsar. All these results, coupled with the possible 117 day orbital period, point to IGR J19294+ 1816 being an high-mass X-ray binary (HMXB) with a Be companion star. However, while the long-term INTEGRAL/IBIS/ISGRI 18-40 keV light curve shows that the source spends most of its time in an undetectable state, we detect occurrences of short (2000-3000 s) and intense flares that are more typical of supergiant fast X-ray transients. We therefore cannot make firm conclusions on the type of system, and we discuss the possible implication of IGR J19294+1816 being an Supergiant Fast X-ray Transient (SFXT).

  1. LOCALIZING INTEGRAL SOURCES WITH CHANDRA: X-RAY AND MULTI-WAVELENGTH IDENTIFICATIONS AND ENERGY SPECTRA

    SciTech Connect

    Tomsick, John A.; Bodaghee, Arash; Chaty, Sylvain; Rodriguez, Jerome; Halpern, Jules; Kalemci, Emrah; Oezbey Arabaci, Mehtap

    2012-08-01

    We report on Chandra observations of 18 hard X-ray (>20 keV) sources discovered with the INTEGRAL satellite near the Galactic plane. For 14 of the INTEGRAL sources, we have uncovered one or two potential Chandra counterparts per source. These provide soft X-ray (0.3-10 keV) spectra and subarcsecond localizations, which we use to identify counterparts at other wavelengths, providing information about the nature of each source. Despite the fact that all of the sources are within 5 Degree-Sign of the plane, four of the IGR sources are active galactic nuclei (AGNs; IGR J01545+6437, IGR J15391-5307, IGR J15415-5029, and IGR J21565+5948) and four others are likely AGNs (IGR J03103+5706, IGR J09189-4418, IGR J16413-4046, and IGR J16560-4958) based on each of them having a strong IR excess and/or extended optical or near-IR emission. We compare the X-ray and near-IR fluxes of this group of sources to those of AGNs selected by their 2-10 keV emission in previous studies and find that these IGR AGNs are in the range of typical values. There is evidence in favor of four of the sources being Galactic (IGR J12489-6243, IGR J15293-5609, IGR J16173-5023, and IGR J16206-5253), but only IGR J15293-5609 is confirmed as a Galactic source as it has a unique Chandra counterpart and a parallax measurement from previous optical observations that puts its distance at 1.56 {+-} 0.12 kpc. The 0.3-10 keV luminosity for this source is (1.4{sup +1.0}{sub -0.4}) Multiplication-Sign 10{sup 32} erg s{sup -1}, and its optical/IR spectral energy distribution is well described by a blackbody with a temperature of 4200-7000 K and a radius of 12.0-16.4 R{sub Sun }. These values suggest that IGR J15293-5609 is a symbiotic binary with an early K-type giant and a white dwarf accretor. We also obtained likely Chandra identifications for IGR J13402-6428 and IGR J15368-5102, but follow-up observations are required to constrain their source types.

  2. Identifications of Four Integral Sources in the Galactic Plane via CHANDRA Localizations

    NASA Technical Reports Server (NTRS)

    Tomsick, John A.; Chaty, Sylvain; Rodriquez, Jerome; Foschini, Luigi; Walter, Roland; Kaaret, Philip

    2006-01-01

    Hard X-ray imaging of the Galactic plane by the INTEGRAL satellite is uncovering large numbers of 20-100 keV "IGR" sources. We present results from Chandra, INTEGRAL, optical, and IR observations of four IGR sources: three sources in the Norma region of the Galaxy(1GR J16195-4945,IGR J16207-5129, and IGR J16167-4957) and one that is closer to the Galactic center (IGR 5171 95-4100). In all four cases, one relatively bright Chandra source is seen in the INTEGRAL error circle, and these are likely to be the soft X-ray counterparts of the IGR sources. They have hard 0.3-10 keV spectra with power-law photon indices of Gamma = 0.5-1.1. While many previously studied IGR sources show high column densities (NH approx. 10(exp 23)-10(exp 24)/sq cm), only IGR J16195-4945 has a column density that could be as high as 10(exp 23)/sq cm. Using optical and IR sky survey catalogs and our own photometry, we have obtained identifications for all four sources. The J-band magnitudes are in the range 14.9-10.4, and we have used the optical/IR spectral energy distributions (SEDs) to constrain the nature of the sources. Blackbody components with temperature lower limits of >9400 K for IGR J16195-4945 and >18,000 K for IGR J16207-5129 indicate that these are very likely high-mass X-ray binaries (HMXBs). However, for IGR 516167-4957 and IGR J17195-4100, low extinction and the SEDs indicate later spectral types for the putative companions, suggesting that these are not HMXBs.

  3. INTEGRAL detects a new outburst from the millisecond X-ray pulsar IGR J17511-3057

    NASA Astrophysics Data System (ADS)

    Bozzo, E.; Kuulkers, E.; Bazzano, A.; Beckmann, V.; Bird, T.; Bodaghee, A.; Chenevez, J.; Del Santo, M.; Domingo, A.; Jonker, P.; Kretschmar, P.; Markwardt, C.; Paizis, A.; Pottschmidt, K.; Sanchez-Fernandez, C.; Wijnands, R.; Ferrigno, C.; Tuerler, M.

    2015-03-01

    During the observations performed in the direction of the Galactic Bulge on 2015 March 23 from 02:49 to 07:26 (UTC), the instruments on-board INTEGRAL detected a new outburst from the millisecond X-ray pulsar IGR J17511-3057 (ATel #2196, #2197; Papitto et al., 2010, MNRAS, 407, 2575).

  4. INVESTIGATING THE OPTICAL COUNTERPART CANDIDATES OF FOUR INTEGRAL SOURCES LOCALIZED WITH CHANDRA

    SciTech Connect

    Oezbey Arabac Latin-Small-Letter-Dotless-I , Mehtap; Kalemci, Emrah; Tomsick, John A.; Bodaghee, Arash; Halpern, Jules; Chaty, Sylvain; Rodriguez, Jerome

    2012-12-10

    We report on the optical spectroscopic follow-up observations of the candidate counterparts to four INTEGRAL sources: IGR J04069+5042, IGR J06552-1146, IGR J21188+4901, and IGR J22014+6034. The candidate counterparts were determined with Chandra, and the optical observations were performed with 1.5 m RTT-150 telescope (TUeBITAK National Observatory, Antalya, Turkey) and 2.4 m Hiltner Telescope (MDM Observatory, Kitt Peak, Arizona). Our spectroscopic results show that one of the two candidates of IGR J04069+5042 and the one observed for IGR J06552-1146 could be active late-type stars in RS CVn systems. However, according to the likelihood analysis based on Chandra and INTEGRAL, two optically weaker sources in the INTEGRAL error circle of IGR J06552-1146 have higher probabilities to be the actual counterpart. The candidate counterparts of IGR J21188+4901 are classified as an active M-type star and a late-type star. Among the optical spectra of four candidates of IGR J22014+6034, two show H{alpha} emission lines, one is a late-type star, and the other is an M type. The likelihood analysis favors a candidate with no distinguishing features in the optical spectrum. Two of the candidates classified as M-type dwarfs, are similar to some IGR candidates claimed to be symbiotic stars. However, some of the prominent features of symbiotic systems are missing in our spectra, and their NIR colors are not consistent with those expected for giants. We consider the IR colors of all IGR candidates claimed to be symbiotic systems and find that low-resolution optical spectrum may not be enough for conclusive identification.

  5. Identifying IGR J18293-1213 and IGR J14091-6108 as magnetic CVs

    NASA Astrophysics Data System (ADS)

    Clavel, Maïca; Tomsick, John; Rahoui, Farid; Krivonos, Roman

    2016-07-01

    The 'Unidentified INTEGRAL sources' legacy program conducted by NuSTAR aims at conclusively identifying 18 persistent hard X-ray sources detected by INTEGRAL in the Galactic plane. These individual identifications will help to characterize the corresponding population of faint hard X-ray sources in the Galaxy by improving the completeness of the current sample. IGR J18293-1213 and IGR J14091-6108 were observed in 2015 with NuSTAR & Swift/XRT and with NuSTAR, XMM-Newton, VLT & SOAR, respectively. The spectral and variability analyses we performed led to the successful identification of these two sources as magnetic Cataclysmic Variables and provided strong constraints on the corresponding systems. In particular, IGR J18293-1213 is an Intermediate Polar with a white dwarf mass of about 0.8 solar mass. The eclipse detected in the NuSTAR light curve provided sufficient information to fully characterize the orbital parameters of this first binary system. The X-ray spectrum of IGR J14091-6108 is much harder, suggesting that the white dwarf is more massive than those currently known and it reveals to be close to the Chandrasekhar limit, based on fits using the IP Mass model of Suleimanov et al. (2005). The optical spectrum and the timing analysis also provided an estimation of a distance and a spin period for this second source. I will present our analyses and the detailed parameters we obtained.

  6. FIVE NEW INTEGRAL UNIDENTIFIED HARD X-RAY SOURCES UNCOVERED BY CHANDRA

    SciTech Connect

    Fiocchi, M.; Bazzano, A.; Ubertini, P.; Capitanio, F.

    2010-09-10

    The IBIS imager on board INTEGRAL, with a sensitivity better than a milliCrab in deep observations and a point-source location accuracy on the order of few arcminutes, has thus far localized 723 hard X-ray sources in the 17-100 keV energy band, of which about 1/3 are still unclassified. The aim of this paper is to provide subarcsecond localizations of the unidentified sources, necessary to pinpoint the optical and/or infrared (IR) counterpart of those objects whose nature is so far unknown. Cross-correlation between the new IBIS sources published in the fourth INTEGRAL/IBIS Survey catalog and the Chandra/ACIS data archive resulted in a sample of five previously unidentified objects. We present here the results of Chandra X-ray Observatory observations of these five hard X-ray sources discovered by the INTEGRAL satellite. We associated IGR J10447-6027 with IR source 2MASS J10445192-6025115, IGR J16377-6423 with the cluster CIZA J1638.2-6420, IGR J14193-6048 with the pulsar with nebula PSR J1420-6048, and IGR J12562+2554 with the quasar SDSS J125610.42+260103.5. We suggest that the counterpart of IGR J12288+0052 may be an active galactic nucleus/quasi-stellar object type 2 at a confidence level of 90%.

  7. DISCOVERY OF AN ENERGETIC 38.5 ms PULSAR POWERING THE GAMMA-RAY SOURCE IGR J18490-0000/HESS J1849-000

    SciTech Connect

    Gotthelf, E. V.; Halpern, J. P.; Terrier, R.; Mattana, F.

    2011-03-10

    We report the discovery of a 38.5 ms X-ray pulsar in observations of the soft {gamma}-ray source IGR J18490-0000 with the Rossi X-ray Timing Explorer (RXTE). PSR J1849-0001 is spinning down rapidly with period derivative 1.42 x 10{sup -14} s s{sup -1}, yielding a spin-down luminosity E-dot = 9.8 x 10{sup 36} erg s{sup -1}, characteristic age {tau}{sub c}{identical_to}P/2 P-dot = 42.9 kyr, and surface dipole magnetic field strength B{sub s} = 7.5 x 10{sup 11} G. Within the INTEGRAL/IBIS error circle lies a point-like XMM-Newton and Chandra X-ray source that shows evidence of faint extended emission consistent with a pulsar wind nebula (PWN). The XMM-Newton spectrum of the point source is well fitted by an absorbed power-law model with photon index {Gamma}{sub PSR} = 1.1 {+-} 0.2, N{sub H} = (4.3 {+-} 0.6) x 10{sup 22} cm{sup -2}, and F{sub PSR}(2-10 keV) = (3.8 {+-} 0.3) x 10{sup -12} erg cm{sup -2} s{sup -1}, while the spectral parameters of the extended emission are roughly {Gamma}{sub PWN} {approx} 2.1 and F{sub PWN}(2-10 keV) {approx} 9 x 10{sup -13} erg cm{sup -2} s{sup -1}. IGR J18490-0000 is also coincident with the compact TeV source HESS J1849-000. For an assumed distance of 7 kpc in the Scutum arm tangent region, the 0.35-10 TeV luminosity of HESS J1849-000 is 0.13% of the pulsar's spin-down energy, while the ratio F(0.35-10 TeV)/F{sub PWN}(2-10 keV) {approx} 2. These properties are consistent with leptonic models of TeV emission from PWNe, with PSR J1849-0001 in a stage of transition from a synchrotron X-ray source to an inverse Compton {gamma}-ray source.

  8. Flat-Spectrum Radio Sources as Likely Counterparts of Unidentified INTEGRAL Sources (Research Note)

    NASA Technical Reports Server (NTRS)

    Molina, M.; Landi, R.; Bassani, L.; Malizia, A.; Stephen, J. B.; Bazzano, A.; Bird, A. J.; Gehrels, N.

    2012-01-01

    Many sources in the fourth INTEGRAL/IBIS catalogue are still unidentified since they lack an optical counterpart. An important tool that can help in identifying and classifying these sources is the cross-correlation with radio catalogues, which are very sensitive and positionally accurate. Moreover, the radio properties of a source, such as the spectrum or morphology, could provide further insight into its nature. In particular, flat-spectrum radio sources at high Galactic latitudes are likely to be AGN, possibly associated to a blazar or to the compact core of a radio galaxy. Here we present a small sample of 6 sources extracted from the fourth INTEGRAL/IBIS catalogue that are still unidentified or unclassified, but which are very likely associated with a bright, flat-spectrum radio object. To confirm the association and to study the source X-ray spectral parameters, we performed X-ray follow-up observations with Swift/XRT of all objects. We report in this note the overall results obtained from this search and discuss the nature of each individual INTEGRAL source. We find that 5 of the 6 radio associations are also detected in X-rays; furthermore, in 3 cases they are the only counterpart found. More specifically, IGR J06073-0024 is a flat-spectrum radio quasar at z = 1.08, IGR J14488-4008 is a newly discovered radio galaxy, while IGR J18129-0649 is an AGN of a still unknown type. The nature of two sources (IGR J07225-3810 and IGR J19386-4653) is less well defined, since in both cases we find another X-ray source in the INTEGRAL error circle; nevertheless, the flat-spectrum radio source, likely to be a radio loud AGN, remains a viable and, in fact, a more convincing association in both cases. Only for the last object (IGR J11544-7618) could we not find any convincing counterpart since the radio association is not an X-ray emitter, while the only X-ray source seen in the field is a G star and therefore unlikely to produce the persistent emission seen by INTEGRAL.

  9. INTEGRAL IGR J18135-1751 = HESS J1813-178: A New Cosmic High-Energy Accelerator from keV to TeV Energies

    NASA Astrophysics Data System (ADS)

    Ubertini, P.; Bassani, L.; Malizia, A.; Bazzano, A.; Bird, A. J.; Dean, A. J.; De Rosa, A.; Lebrun, F.; Moran, L.; Renaud, M.; Stephen, J. B.; Terrier, R.; Walter, R.

    2005-08-01

    We report the discovery of a soft gamma-ray source, namely, IGR J18135-1751, detected with IBIS, the Imager on Board the INTEGRAL Satellite. The source is persistent and has a 20-100 keV luminosity of ~5.7× 1034 ergs s-1 (assuming a distance of 4 kpc). This source is coincident with one of the eight unidentified objects recently reported by the HESS collaboration as part of the first TeV survey of the inner part of the Galaxy. Two of these new sources found along the Galactic plane, HESS J1813-178 and HESS J1614-518, have no obvious lower energy counterparts, a fact that motivated the suggestion that they might be dark cosmic ray accelerators. HESS J1813-178 has a strongly absorbed X-ray counterpart, the ASCA source AGPS 273.4-17.8, showing a power-law spectrum with photon index ~1.8 and a total (Galactic plus intrinsic) absorption corresponding to NH~5×1022 cm-2. We hypothesize that the source is a pulsar wind nebula embedded in its supernova remnant. The lack of X-ray or gamma-ray variability, the radio morphology, and the ASCA spectrum are all compatible with this interpretation. In any case we rule out the hypothesis that HESS J1813-178 belongs to a new class of TeV objects or that it is a cosmic ``dark particle'' accelerator. Based on observations with INTEGRAL, an ESA project with instruments and science data center funded by ESA member states (especially the PI countries: Denmark, France, Germany, Italy, Switzerland, Spain), the Czech Republic, and Poland and with the participation of Russia and the US.

  10. Outbursts from IGR J17473-2721

    NASA Astrophysics Data System (ADS)

    Zhang, S.; Chen, Y.-P.; Wang, J.-M.; Torres, D. F.; Li, T.-P.

    2009-07-01

    Aims: IGR J17473-2721 was discovered by INTEGRAL as a neutron star low mass X-ray binary. To date, two outbursts have been detected in X-rays by RXTE/ASM and SWIFT: the one occurring in 2005 was weak and was characterized by a low/hard state spectrum; the one of March 2008 was strong and showed a 6-step evolution in its flux. We investigate their evolution, emphasizing the later outburst. Methods: We analyzed all available observations carried out by RXTE on IGR J17473-2721 during its later outburst. We analyzed as well all the available SWIFT/BAT data on this source. Results: The flux of the latter outburst rose in ~one month and then kept roughly constant for the following ~two months. During this time period, the source was in a low/hard state. The source moved to a high/soft state within the following three days, accompanied by the occurrence of an additional outburst at soft X-rays and the end of the preceding outburst in hard X-rays. During the decay of this soft outburst, the source went back to a low/hard state within 6 days, with a luminosity 4 times lower than the first transition. This shows a full cycle of the hysteresis in transition between the hard and the soft states. The fact that the flux remained roughly constant for ~two months at times prior to the spectral transition to a high/soft state might be regarded as the result of balancing the evaporation of the inner disk and the inward accretion flow, in a model in which the state transition is determined by the mass flow rate. Such a balance might be broken via an additional mass flow accreting onto the inner disk, which lightens the extra soft outburst and causes the state transition. However, the possibility of an origin of the emission from the jet during this time period cannot be excluded. The spectral analysis suggests an inclined XRB system for IGR J17473-2721. Such a long-lived preceding low/hard state makes IGR J17473-2721 resemble the behavior of outbursts seen in black hole X

  11. A Possible Magnetar Nature for IGR J16358-4726

    NASA Technical Reports Server (NTRS)

    Patel, S. K.; Zurita, J.; DelSanto, M.; Finger, M.; Kouveliotou, C.; Eichler, D.; Gogus, E.; Ubertini, P.; Walter, R.; Woods, P.; Wilson, C. A.; Wachter, S.; Bazzano, A.

    2007-01-01

    We present detailed spectral and timing analysis of the hard X-ray transient IGR J16358-4726 using multisatellite archival observations. A study of the source flux time history over 6 yr suggests that lower luminosity transient outbursts can be occurring in intervals of at most 1 yr. Joint spectral fits of the higher luminosity outburst using simultaneous Chandra ACIS and INTEGRAL ISGRI data reveal a spectrum well described by an absorbed power-law model with a high-energy cutoff plus an Fe line. We detected the 1.6 hr pulsations initially reported using Chandra ACIS also in the INTEGRAL ISGRI light curve and in subsequent XMM-Newton observations. Using the INTEGRAL data, we identified a spin-up of 94 s (P(sup(.)) = 1.6 x 10(exp -4), which strongly points to a neutron star nature for IGR J16358-4726. Assuming that the spin-up is due to disk accretion, we estimate that the source magnetic field ranges between 10(exp 13) and 10(exp 15) G, depending on its distance, possibly supporting a magnetar nature for IGR J16358-4726.

  12. A Possible Magnetar Nature for IGR J16358-4726

    NASA Technical Reports Server (NTRS)

    Patel, S.; Zurita, J.; DelSanto, M.; Finger, M.; Koueliotou, C.; Eichler, D.; Gogus, E.; Ubertini, P.; Walter, R.; Woods, P.

    2006-01-01

    We present detailed spectral and timing analysis of the hard x-ray transient IGR J16358-4726 using multi-satellite archival observations. A study of the source flux time history over 6 years, suggests that this transient outbursts can be occurring in intervals of at most 1 year. Joint spectral fits using simultaneous Chandra/ACIS and INTEGRAL/ISGRI data reveal a spectrum well described by an absorbed cut-off power law model plus an Fe line. We detected the pulsations initially reported using Chandra/ACIS also in the INTEGRAL/ISGRI light curve and in subsequent XMM-Newton observations. Using the INTEGRAL data we identified a pulse spin up of 94 s (P = 1.6 x 10(exp -4), which strongly points to a neutron star nature for IGR J16358-4726. Assuming that the spin up is due to disc accretion, we estimate that the source magnetic field ranges between 10(sup 13) approximately 10(sup 15) depending on its distance, possibly supporting a magnetar nature for IGR J16358-4726.

  13. On the Nature of the Hard X-Ray Sources SWIFT J1907.3-2050, IGR J12123-5802 and IGR J19552+0044

    NASA Technical Reports Server (NTRS)

    Bernardini, F.; deMartino, D; Mukai, K.; Falanga, M.; Andruchow, I.; Bonnet-Bidaud, J.-M.; Masetti, N.; GonzalezBuitrago, D. H.; Mouchet, M.; Tovmassian, G.

    2014-01-01

    The INTEGRAL and Swift hard X-ray surveys have identified a large number of new sources, among which many are proposed as Cataclysmic Variables (CVs). Here we present the first detailed study of three X-ray selected CVs, Swift J1907.3-2050, IGRJ12123-5802, and IGRJ19552+0044 based on XMM-Newton, Suzaku, Swift observations and ground based optical and archival nIR/IR data. Swift J1907.3-2050 is highly variable from hours to monthsyears at all wavelengths. No coherent X-ray pulses are detected but rather transient features. The X-ray spectrum reveals a multi-temperature optically thin plasma absorbed by complex neutral material and a soft black body component arising from a small area. These characteristics are remarkably similar to those observed in magnetic CVs. A supra-solar abundance of nitrogen could arise from nuclear processed material from the donor star. Swift J1907.3-2050 could be a peculiar magnetic CV with the second longest (20.82 h) binary period. IGRJ12123-5802 is variable in the X-rays on a timescale of approximately or greater than 7.6 h. No coherent pulsations are detected, but its spectral characteristics suggest that it could be a magnetic CV of the Intermediate Polar (IP) type. IGRJ19552+0044 shows two X-ray periods, approximately 1.38 h and approximately 1.69 h and a X-ray spectrum characterized by a multi-temperature plasma with little absorption.We derive a low accretion rate, consistent with a CV below the orbital period gap. Its peculiar nIR/IR spectrum suggests a contribution from cyclotron emission. It could either be a pre-polar or an IP with the lowest degree of asynchronism.

  14. On the Nature of the Hard X-ray Sources SWIFT J1907.3-2050, IGR J12123-5802 and IGR J19552+0044

    NASA Technical Reports Server (NTRS)

    Bernardini, F.; De Martino, D.; Mukai, K.; Falanga, M.; Andruchow, I.; Bonnet-Bidaud, J.-M.; Masetti, N.; Gonzalez Buitrago, D. H.; Mouchet, M.; Tovmassian, G.

    2013-01-01

    The INTEGRAL and Swift hard X-ray surveys have identified a large number of new sources, among which many are proposed as Cataclysmic Variables (CVs). Here we present the first detailed study of three X-ray selected CVs, Swift J1907.3-2050, IGRJ12123-5802, and IGRJ19552+0044 based on XMM-Newton, Suzaku, Swift observations and ground based optical and archival near-infrared/infrared data. Swift J1907.3-2050 is highly variable from hours to months-years at all wavelengths. No coherent X-ray pulses are detected but rather transient features. The X-ray spectrum reveals a multi-temperature optically thin plasma absorbed by complex neutral material and a soft black body component arising from a small area. These characteristics are remarkably similar to those observed in magnetic CVs. A supra-solar abundance of nitrogen could arise from nuclear processed material from the donor star. Swift J1907.3-2050 could be a peculiar magnetic CV with the second longest (20.82 hours) binary period. IGRJ12123-5802 is variable in the X-rays on a timescale of greater than or approximately 7.6 hours. No coherent pulsations are detected, but its spectral characteristics suggest that it could be a magnetic CV of the Intermediate Polar (IP) type. IGRJ19552+0044 shows two X-ray periods, approximately 1.38 hours and approximately 1.69 hours and a X-ray spectrum characterized by a multi-temperature plasma with little absorption. We derive a low accretion rate, consistent with a CV below the orbital period gap. Its peculiar near-infrared/infrared spectrum suggests a contribution from cyclotron emission. It could either be a pre-polar or an IP with the lowest degree of asynchronism.

  15. INTEGRAL and XMM-Newton observations of IGR J16418-4532: evidence of accretion regime transitions in a supergiant fast X-ray transient

    NASA Astrophysics Data System (ADS)

    Drave, S. P.; Bird, A. J.; Sidoli, L.; Sguera, V.; McBride, V. A.; Hill, A. B.; Bazzano, A.; Goossens, M. E.

    2013-07-01

    We report on combined INTEGRAL and XMM-Newton observations of the supergiant fast X-ray transient (SFXT) IGR J16418-4532. The observations targeted the X-ray eclipse region of IGR J16418-4532's orbit with continuous INTEGRAL observations across ˜25 per cent of orbital phase and two quasi-simultaneous XMM-Newton observations of length 20 and 14 ks, occurring during and just after the eclipse, respectively. An enhanced INTEGRAL emission history is provided with 19 previously unreported outbursts identified in the archival 18-60 keV data set. The XMM-Newton eclipse observation showed prominent Fe emission and a flux of 2.8 × 10-13 erg cm-2 s-1 (0.5-10 keV). Through the comparison of the detected eclipse and post-eclipse flux, the supergiant mass-loss rate through the stellar wind was determined as Ṁw = 2.3-3.8 × 10-7 M⊙ yr-1. The post-eclipse XMM-Newton observation showed a dynamic flux evolution with signatures of the X-ray pulsation, a period of flaring activity, structured nH variations and the first ever detection of an X-ray intensity dip, or `off-state', in a pulsating SFXT. Consideration is given to the origin of the X-ray dip, and we conclude that the most applicable of the current theories of X-ray dip generation is that of a transition between Compton-cooling-dominated and radiative-cooling-dominated subsonic accretion regimes within the `quasi-spherical' model of wind accretion. Under this interpretation, which requires additional confirmation, the neutron star in IGR J16418-4532 possesses a magnetic field of ˜1014 G, providing tentative observational evidence of a highly magnetized neutron star in a SFXT for the first time. The implications of these results on the nature of IGR J16418-4532 itself and the wider SFXT class are discussed.

  16. CHANDRA LOCALIZATIONS AND SPECTRA OF INTEGRAL SOURCES IN THE GALACTIC PLANE: THE CYCLE 9 SAMPLE

    SciTech Connect

    Tomsick, John A.; Chaty, Sylvain; Rodriguez, Jerome; Kaaret, Philip

    2009-08-10

    We report on 0.3-10 keV X-ray observations by the Chandra X-ray Observatory of the fields of 22 sources that were discovered as hard X-ray (20-100 keV) sources by the International Gamma-Ray Astrophysics Satellite ('IGR' sources). The observations were made during Chandra's 9th observing cycle, and their purpose is to localize the sources and to measure their soft X-ray spectra in order to determine the nature of the sources. We find very likely Chandra counterparts for 18 of the 22 sources. We discuss the implications for each source, considering previous results and new optical or infrared identifications, and we identify or suggest identifications for the nature of 16 of the sources. Two of the sources, IGR J14003-6326 and IGR J17448-3232, are extended on arcminute scales. We identify the former as a pulsar wind nebula with a surrounding supernova remnant (SNR) and the latter as an SNR. In the group of 242 IGR sources, there is only one other source that has previously been identified as an SNR. Seven of the sources are definite or candidate high-mass X-ray binaries (HMXBs). We confirm a previous identification of IGR J14331-6112 as an HMXB, and based on combinations of hard X-ray spectra, inferred distances and X-ray luminosities, and/or column density variations, we suggest that IGR J17404-3655, IGR J16287-5021, IGR J17354-3255, IGR J17507-2647, IGR J17586-2129, and IGR J13186-6257 are candidate HMXBs. Our results indicate or confirm that IGR J19267+1325, IGR J18173-2509, and IGR J18308-1232 are cataclysmic variables (CVs), and we suggest that IGR J15529-5029 may also be a CV. We confirm that IGR J14471-6414 is an active galactic nucleus (AGN), and we also suggest that IGR J19443+2117 and IGR J18485-0047 may be AGNs. Finally, we found Chandra counterparts for IGR J11098-6457 and IGR J18134-1636, but more information is required to determine the nature of these two sources.

  17. XMM-NEWTON OBSERVATIONS OF FIVE INTEGRAL SOURCES LOCATED TOWARD THE SCUTUM ARM

    SciTech Connect

    Bodaghee, A.; Tomsick, J. A.; Rodriguez, J.

    2012-07-01

    Results are presented for XMM-Newton observations of five hard X-ray sources discovered by INTEGRAL in the direction of the Scutum Arm. Each source received {approx}>20 ks of effective exposure time. We provide refined X-ray positions for all five targets enabling us to pinpoint the most likely counterpart in optical/infrared archives. Spectral and timing information (much of which is provided for the first time) allow us to give a firm classification for IGR J18462-0223 and to offer tentative classifications for the others. For IGR J18462-0223, we discovered a coherent pulsation period of 997 {+-} 1 s, which we attribute to the spin of a neutron star in a highly obscured (N{sub H} =2 Multiplication-Sign 10{sup 23} cm{sup -2}) high-mass X-ray binary (HMXB). This makes IGR J18462-0223 the seventh supergiant fast X-ray transient candidate with a confirmed pulsation period. IGR J18457+0244 is a highly absorbed (N{sub H} =8 Multiplication-Sign 10{sup 23} cm{sup -2}) source in which the possible detection of an iron line suggests an active galactic nucleus (AGN) of type Sey-2 situated at z = 0.07(1). A periodic signal at 4.4 ks could be a quasi-periodic oscillation which would make IGR J18457+0244 one of a handful of AGNs in which such features have been claimed, but a slowly rotating neutron star in an HMXB cannot be ruled out. IGR J18482+0049 represents a new obscured HMXB candidate with N{sub H} =4 Multiplication-Sign 10{sup 23} cm{sup -2}. We tentatively propose that IGR J18532+0416 is either an AGN or a pulsar in an HMXB system. The X-ray spectral properties of IGR J18538-0102 are consistent with the AGN classification that has been proposed for this source.

  18. Discovery of two new Fast X-ray Transients with INTEGRAL: IGR J03346+4414 and IGR J20344+3913

    NASA Astrophysics Data System (ADS)

    Sguera, V.; Sidoli, L.; Paizis, A.; Bird, A. J.

    2016-09-01

    We report on the discovery of two Fast X-ray Transients (FXTs) from analysis of archival INTEGRAL data. Both are characterized by a remarkable hard X-ray activity above 20 keV, in term of duration (˜ 15 and 30 minutes, respectively), peak-flux (˜ 10-9 erg cm-2 s-1) and dynamic range (˜ 2400 and 1360, respectively). Swift/XRT follow-up observations failed to detect any quiescent or low level soft X-ray emission from either of the two FXTs, providing an upper limit of the order of a few times 10-12 erg cm-2 s-1. The main spectral and temporal IBIS/ISGRI characteristics are presented and discussed with the aim of infering possible hints on their nature.

  19. XMM follow-up observations of two unidentified INTEGRAL sources

    NASA Astrophysics Data System (ADS)

    Molina, M.; Landi, R.; Bassani, L.; Bazzano, A.; Fiocchi, M.; Bird, A. J.; Drave, S. P.

    2012-07-01

    We report the results of X-ray follow-up observations performed with XMM-Newton of two unidentified hard X-ray sources, AX J1753.5-2745 and IGR J17348-2045 listed in the INTEGRAL/IBIS 9-year Galactic Hard X-ray Survey (Krivonos et al. 2012, arXiv:1205.3941) and in 4th IBIS Survey Catalogue (Bird et al. 2010, ApJS, 186, 1) respectively. We assume a conservative XMM positional uncertainty of 5".

  20. Sardinia Radio Telescope observations of IGR J17091-3624 - upper limit

    NASA Astrophysics Data System (ADS)

    Egron, E.; Pilia, M.; Bachetti, M.; Iacolina, M. N.; Pellizzoni, A.; Trois, A.; Loru, S.; Navarrini, A.; Ballhausen, R.; Corbel, S.; Eikmann, W.; Fuerst, F.; Grinberg, V.; Kreykenbohm, I.; Marongiu, M.; Nowak, M.; Possenti, A.; Pottschmidt, K.; Rodriguez, J.; Wilms, J.

    2016-03-01

    After about 3 years of quiescence, a renew of activity of the Galactic black-hole low mass X-ray binary IGR J17091-3624 was detected by Swift/BAT (Miller et al. 2016, ATel #8742) on 2016 February 26. The transient source was then monitored by Swift/XRT and INTEGRAL (Grinberg et al. 2016, #8761), which clearly indicated that the source was in the hard state.

  1. Orbit Solution for the Millisecond Pulsar IGR J00291+5934

    NASA Astrophysics Data System (ADS)

    Markwardt, C. B.; Galloway, D. K.; Chakrabarty, D.; Morgan, E. H.; Strohmayer, T. E.

    2004-12-01

    The INTEGRAL Transient IGR J00291+5934 (ATEL #352), now known to be a 1.67 millisecond X-ray pulsar (ATEL #353), was observed by the RXTE PCA on Dec 5 and 6. The source has decayed to approximately 27 mCrab (2-10 keV). The data were barycentered using the Fox & Kulkarni optical counterpart position (ATEL #354). Pulsations with a sinusoidal frequency modulation are clearly detected in each observation.

  2. INTEGRAL and RXTE spectral analysis of IGR J17480-2446, the new transient in Terzan 5.

    NASA Astrophysics Data System (ADS)

    Ferrigno, C.; Brandt, S.; Kuulkers, E.; Bordas, P.; Bozzo, E.; Chenevez, J.; Kouveliotou, C.; van der Horst, A. J.

    2010-10-01

    During the ongoing INTEGRAL ToO observation of MAXI J1659-152, IBIS/ISGRI detected again the recently discovered X-ray transient located in the direction of Terzan 5 (ATels #2919, #2920, #2922 ,#2924, #2929, #2932, #2933, #2937, #2939). An association of the source with the transient LMXB EXO 1745-248 was initially suggested (ATels #2919, #2920), but this was considered less likely after the reanalysis of archival Chandra and RXTE observations (ATels #2933, #2937).

  3. A ~100 mHz QPO in the X-ray emission from IGR J17361-4441

    NASA Astrophysics Data System (ADS)

    Bozzo, E.; Papitto, A.; Ferrigno, C.; Belloni, T. M.

    2014-10-01

    IGR J17361-4441 was discovered by INTEGRAL undergoing its first detectable X-ray outburst in 2011 and was initially classified as an accreting X-ray binary in the globular cluster NGC 6388. A reanalysis of the outburst data collected with INTEGRAL and Swift suggested that the enhanced X-ray emission from IGR J17361-4441 could have been caused by a rare tidal disruption event of a terrestrial-icy planet by a white dwarf. In this letter we report on the analysis of XMM-Newton data collected in 2011 during the outburst from IGR J17361-4441. Our analysis revealed the presence of a 100 mHz quasi-periodic oscillation in the X-ray emission from the source and confirmed the presence of a soft thermal component (kT~0.08 keV) in its spectrum. We discuss these findings in the context of the different possibilities proposed to explain the nature of IGR J17361-4441.

  4. Swift-XRT follow-up of 2 unidentified INTEGRAL sources

    NASA Astrophysics Data System (ADS)

    Malizia, A.; Landi, R.; Bassani, L.; Bird, A. Bazzano A. J.; Gehrels, N.; Kennea, J. A.

    2011-04-01

    In this telegram we report the X-ray follow-up observations performed with Swift-XRT of 2 unidentified INTEGRAL sources listed in Bird et al. 2010 (ApJS, 186, 1). IGR J11014-6103. Within the IBIS error circle, XRT detects an X-ray source with coordinates R.A.(J2000) = 11h 01m 46.4s and Dec.(J2000) = -61d 01m 21s and 6 arcsec positional uncertainty. XRT detection is at 7.7 sigma in the 0.3-10 keV band and 4.6 sigma above 3 keV.

  5. IGR J18293-1213 is an eclipsing cataclysmic variable

    NASA Astrophysics Data System (ADS)

    Clavel, M.; Tomsick, J. A.; Bodaghee, A.; Chiu, J.-L.; Fornasini, F. M.; Hong, J.; Krivonos, R.; Ponti, G.; Rahoui, F.; Stern, D.

    2016-09-01

    Studying the population of faint hard X-ray sources along the plane of the Galaxy is challenging because of high extinction and crowding, which make the identification of individual sources more difficult. IGR J18293-1213 is part of the population of persistent sources which have been discovered by the INTEGRAL satellite. We report on NuSTAR and Swift/XRT observations of this source, performed on 2015 September 11. We detected three eclipsing intervals in the NuSTAR light curve, allowing us to constrain the duration of these eclipses, Δ t= 30.8^{+6.3}_{-0.0} min, and the orbital period of the system, T = 6.92 ± 0.01 h. Even though we only report an upper limit on the amplitude of a putative spin modulation, the orbital period and the hard thermal bremsstrahlung spectrum of IGR J18293-1213 provide strong evidence that this source is a magnetic cataclysmic variable. Our NuSTAR and Swift/XRT joint spectral analysis places strong constraints on the white dwarf mass M_wd = 0.78^{+0.10}_{-0.09} M⊙. Assuming that the mass to radius ratio of the companion star M⋆/R⋆ = 1 (solar units) and using T, Δt, and Mwd, we derived the mass of the companion star M⋆ = 0.82 ± 0.01 M⊙, the orbital separation of the binary system a = 2.14 ± 0.04 R⊙, and its orbital inclination compared to the line of sight i=(72.2°^{+2.4}_{-0.0})± 1.0°.

  6. IGR J18293-1213 is an eclipsing Cataclysmic Variable

    NASA Astrophysics Data System (ADS)

    Clavel, M.; Tomsick, J. A.; Bodaghee, A.; Chiu, J.-L.; Fornasini, F. M.; Hong, J.; Krivonos, R.; Ponti, G.; Rahoui, F.; Stern, D.

    2016-06-01

    Studying the population of faint hard X-ray sources along the plane of the Galaxy is challenging because of high-extinction and crowding, which make the identification of individual sources more difficult. IGR J18293-1213 is part of the population of persistent sources which have been discovered by the INTEGRAL satellite. We report on NuSTAR and Swift/XRT observations of this source, performed on 2015 September 11. We detected three eclipsing intervals in the NuSTAR light curve, allowing us to constrain the duration of these eclipses, Δ t= 30.8^{+6.3}_{-0.0} min, and the orbital period of the system, T = 6.92 ± 0.01 hr. Even though we only report an upper limit on the amplitude of a putative spin modulation, the orbital period and the hard thermal Bremsstrahlung spectrum of IGR J18293-1213 provide strong evidence that this source is a magnetic Cataclysmic Variable (CV). Our NuSTAR and Swift/XRT joint spectral analysis places strong constraints on the white dwarf mass M_wd = 0.78^{+0.10}_{-0.09} M⊙. Assuming that the mass to radius ratio of the companion star M⋆/R⋆ = 1 (solar units) and using T, Δt and Mwd, we derived the mass of the companion star M⋆ = 0.82 ± 0.01 M⊙, the orbital separation of the binary system a = 2.14 ± 0.04 R⊙, and its orbital inclination compared to the line of sight i=(72.2^{+2.4}_{-0.0})± 1.0°.

  7. Swift detection of IGR16418-4532

    NASA Astrophysics Data System (ADS)

    Romano, P.; Barthelmy, S. D.; Kennea, J. A.; Esposito, P.; Evans, P. A.; Mangano, V.; Palmer, D. M.; Sakamoto, T.; Burrows, D. N.; Chester, M. M.; Krimm, H.; Vercellone, S.; Gehrels, N.

    2012-06-01

    Swift observed a new outburst from the SFXT IGR J16418-4532. The Swift/BAT triggered on it on 2012 Jun 03 at 18:08:48 UT (a 320-sec image trigger, 523489). This is the first detection using the new Sub-threshold Interesting Source BAT trigger criteria. Swift immediately slewed to the target. Using the BAT data set from T-221 to T+963 s from recent telemetry downlinks, we report that this is a very weak source in BAT, and as such a description of the mask-weighted light curve is problematic.

  8. IGR J015712-7259 (= SXP11.6): Optical Confirmation of the Orbital Period

    NASA Astrophysics Data System (ADS)

    Schmidtke, P. C.; Cowley, A. P.; Udalski, A.

    2013-10-01

    The transient X-ray source IGR J015712-7259, first seen in INTEGRAL data and subsequently observed with Swift and RXTE, shows X-ray pulsations with a period of 11.6 s (Coe et al., 2008, ATel #1882; McBride et al., 2010, MNRAS, 403, 709). Using long-term monitoring with the BAT instrument (Swift), Segreto et al. (2013, A&A, 557, A113) announced the discovery of a X-ray period of P=35.6 +/- 0.5 d. This is likely to be the orbital period.

  9. Integrated Power Source Grant

    NASA Technical Reports Server (NTRS)

    2001-01-01

    Traditional spacecraft power systems incorporate a solar array energy source, an energy storage element (battery), and battery charge control and bus voltage regulation electronics to provide continuous electrical power for spacecraft systems and instruments. Dedicated power conditioning components provide limited fault isolation between systems and instruments, while a centralized power-switching unit provides spacecraft load control. Battery undervoltage conditions are detected by the spacecraft processor, which removes fault conditions and non-critical loads before permanent battery damage can occur. Cost effective operation of a micro-sat constellation requires a fault tolerant spacecraft architecture that minimizes on-orbit operational costs by permitting autonomous reconfiguration in response to unexpected fault conditions. A new micro-sat power system architecture that enhances spacecraft fault tolerance and improves power system survivability by continuously managing the battery charge and discharge processes on a cell-by-cell basis has been developed. This architecture is based on the Integrated Power Source (US patent 5644207), which integrates dual junction solar cells, Lithium Ion battery cells, and processor based charge control electronics into a structural panel that can be deployed or used to form a portion of the outer shell of a micro-spacecraft. The first generation Integrated Power Source is configured as a one inch thick panel in which prismatic Lithium Ion battery cells are arranged in a 3x7 matrix (26VDC) and a 3x1 matrix (3.7VDC) to provide the required output voltages and load currents. A multi-layer structure holds the battery cells, as well as the thermal insulators that are necessary to protect the Lithium Ion battery cells from the extreme temperatures of the solar cell layer. Independent thermal radiators, located on the back of the panel, are dedicated to the solar cell array, the electronics, and the battery cell array. In deployed

  10. The long helical jet of the Lighthouse nebula, IGR J11014-6103

    NASA Astrophysics Data System (ADS)

    Pavan, L.; Bordas, P.; Pühlhofer, G.; Filipović, M. D.; De Horta, A.; O'Brien, A.; Balbo, M.; Walter, R.; Bozzo, E.; Ferrigno, C.; Crawford, E.; Stella, L.

    2014-02-01

    Context. Jets from rotation-powered pulsars so far have only been observed in systems moving subsonically through their ambient medium and/or embedded in their progenitor supernova remnant (SNR). Supersonic runaway pulsars are also expected to produce jets, but they have not been confirmed to so far. Aims: We investigated the nature of the jet-like structure associated with the INTEGRAL source IGR J11014-6103 (the "Lighthouse nebula"). The source is a neutron star escaping its parent SNR MSH 11-61A supersonically at a velocity exceeding 1000 km s-1. Methods: We observed the Lighthouse nebula and its jet-like X-ray structure through dedicated high spatial resolution observations in X-rays (with Chandra) and in the radio band (with ATCA). Results: Our results show that the feature is a true pulsar's jet. It extends highly collimated over ≳11pc, displays a clear precession-like modulation, and propagates nearly perpendicular to the system direction of motion, implying that the neutron star's spin axis in IGR J11014-6103 is almost perpendicular to the direction of the kick received during the supernova explosion. Conclusions: Our findings suggest that jets are common to rotation-powered pulsars, and demonstrate that supernovae can impart high kick velocities to misaligned spinning neutron stars, possibly through distinct, exotic, core-collapse mechanisms.

  11. Swift/XRT follow-up observations of unidentified INTEGRAL sources

    NASA Astrophysics Data System (ADS)

    Maiorano, E.; Landi, R.; Parisi, P.; Masetti, N.; Bassani, L.; Malizia, A.; Bazzano, A.; Ubertini, P.; Bird, A. J.; Jimenez-Bailon, E.; Chavushyan, V.; Galaz, G.; Minniti, D.; Morelli, L.

    2010-10-01

    We report on X-ray follow-up observations performed with Swift/XRT of 3 unidentified INTEGRAL sources listed in the fourth IBIS Survey Catalogue (Bird et al. 2010, ApJS, 186, 1). IGR J08190-3835 Within the IBIS uncertainty XRT detects one source with a statistical significance of 5.8 sigma in the energy range 0.3-10 keV and 5.6 sigma above 3 keV. This object, located at RA(J2000) = 08h 19m 11.3s and Dec(J2000) = -38d 33m 09s (5 arcsec uncertainty), is associated with a 2MASS extended object (2MASX J08191136-3833104) classified as a galaxy in the NED archive and is positionally coincident with radio source NVSS J081910-383307.

  12. Swift/XRT follow-up of two unidentified INTEGRAL sources

    NASA Astrophysics Data System (ADS)

    Landi, R.; Malizia, A.; Bazzano, A.; Fiocchi, M.; Bird, A. J.; Gehrels, N.

    2011-02-01

    We report the results of X-ray follow-up observations performed with Swift/XRT of two unidentified INTEGRAL sources listed in the 4th IBIS Survey Catalogue (Bird et al. 2010, ApJS, 186, 1). IGR J06523+5334 There are two sources detected by XRT above 3 sigma c.l. and located within the 90% IBIS positional uncertainty: Source #1, detected at 6.1 sigma c.l. (0.3-10 keV), is located at R.A.(J2000) = 06h 52m 31.35s and Dec.(J2000) = +53d 31m 26.2s (4.7 arcsec uncertainty).

  13. Suzaku observation of IGR J16318-4848

    NASA Technical Reports Server (NTRS)

    Barragan, Laura; Wilms, Joern; Pottschmidt, Katja; Nowak, Michael A.; Kreykenbohm, Ingo; Walter, Roland; Tomsick, John A.

    2009-01-01

    We report on the first Suzaku observation of IGR J16318-4848, the most extreme example of a new group of highly absorbed X-ray binaries that have recently been discovered by the International Gamma-Ray Astrophysics Laboratory (INTEGRAL). The Suzaku observation was carried out between 2006 August 14 and 17, with a net exposure time of 97 ks. The average X-ray spectrum of the source can be well described (chi-square (sub red)= 0.99) with a continuum model typical for neutron stars i.e., a strongly absorbed power law continuum with a photon index of 0.676(42) and an exponential cutoff at 20.5(6) keY. The absorbing column is N(sub H) = 1.95(3) X 10(exp 24)/square cm. Consistent with earlier work, strong fluorescent emission lines of Fe K-alpha, Fe K-beta, and Ni K-alpha are observed. Despite the large N(sub H), no Compton shoulder is seen in the lines, arguing for a non-spherical and inhomogeneous absorber. Seen at an average 5-60 keV absorbed flux of 3.4 x 10(exp -10) erg/square cm/second, the source exhibits significant variability on timescales of hours.

  14. Swift-XRT follow-up of 2 unidentified INTEGRAL sources

    NASA Astrophysics Data System (ADS)

    Malizia, A.; Landi, R.; Bazzano, A.; Bird, A. J.; Gehrels, N.; Kennea, J. A.

    2011-05-01

    In this telegram we report the X-ray follow-up observations performed with Swift-XRT of 2 unidentified INTEGRAL sources listed in Bird et al. 2010 (ApJS, 186, 1). IGR J17472-7319. Within the IBIS error circle, XRT detects an X-ray source with coordinates R.A. (J2000) = 17h 43m 11.1s and Dec.(J2000) = -73d 19m 22.6s (5.0 arcsec positional uncertainty). The XRT detection is of 4.6 sigma in the 0.3-10 keV band and 2.4 sigma above 3 keV.

  15. X-Ray and Near-infrared Observations of the Obscured Accreting Pulsar IGR J18179-1621

    NASA Astrophysics Data System (ADS)

    Nowak, M. A.; Paizis, A.; Rodriguez, J.; Chaty, S.; Del Santo, M.; Grinberg, V.; Wilms, J.; Ubertini, P.; Chini, R.

    2012-10-01

    IGR J18179-1621 is an obscured accreting X-ray pulsar discovered by INTEGRAL on 2012 February 29. We report on our 20 ks Chandra-High Energy Transmission Gratings Spectrometer observation of the source performed on 2012 March 17, on two short contemporaneous Swift observations, and on our two near-infrared (Ks , Hn , and Jn ) observations performed on 2012 March 13 and 26. We determine the most accurate X-ray position of IGR J18179-1621, αJ2000 = 18h17m52.s18, δJ2000 = -16°21'31farcs68 (90% uncertainty of 0farcs6). A strong periodic variability at 11.82 s is clearly detected in the Chandra data, confirming the pulsating nature of the source, with the light-curve softening at the pulse peak. The quasi-simultaneous Chandra-Swift spectra of IGR J18179-1621 can be well fit by a heavily absorbed hard power law (N H = 2.2 ± 0.3 × 1023 cm-2 and photon index Γ = 0.4 ± 0.1) with an average absorbed 2-8 keV flux of 1.4 × 10-11 erg cm-2 s-1. At the Chandra-based position, a source is detected in our near-infrared (NIR) maps with Ks = 13.14 ± 0.04 mag, Hn = 16 ± 0.1 mag, and no Jn -band counterpart down to ~18 mag. The NIR source, compatible with 2MASS J18175218-1621316, shows no variability between 2012 March 13 and 26. Searches of the UKIDSS database show similar NIR flux levels at epochs six months prior to and after a 2007 February 11 archival Chandra observation where the source's X-ray flux was at least 87 times fainter. In many ways IGR J18179-1621 is unusual: its combination of a several week long outburst (without evidence of repeated outbursts in the historical record), high absorption column (a large fraction of which is likely local to the system), and 11.82 s period does not fit neatly into existing X-ray binary categories.

  16. A 49 Day Period in IGR J14488-5942/Swift J1448.4-5945 from Swift/BAT Observations

    NASA Astrophysics Data System (ADS)

    Corbet, R. H. D.; Barthelmy, S. D.; Baumgartner, W. H.; Krimm, H. A.; Markwardt, C. B.; Skinner, G. K.; Tueller, J.

    2010-05-01

    IGR J14488-5942 (Swift J1448.4-5945) is listed in the 4th INTEGRAL/IBIS Survey Catalogue (Bird et al. 2010, ApJ Supp, 186, 1) as a variable source. It is not present in the BAT 22 month survey (Tueller et al. 2010, ApJ Supp, 186, 376). We have analyzed the Swift BAT 58 month survey (Baumgartner et al. 2010, HEAD, 11, 1305) light curve of this source. The light curve covers the interval 2004-12-16 through 2009-09-30 (MJD 53,355 to 55,104) and we used an energy range of 15 - 100 keV.

  17. Igr J17418-12122 - USNO 0778-0495204 is an AGN.

    NASA Astrophysics Data System (ADS)

    Torres, M. A. P.; Garcia, M. R.; McClintock, J. E.; Steeghs, D.; Miller, J.; Callanan, P. J.; Zhao, P.; Berlind, P.

    2004-04-01

    The INTEGRAL/EINSTEIN/ROSAT/NVSS objects IGR J17418-12122, 2E 1739.1-1210, 1RXS J174155.3-121157 and NVSS J174155-121201 have recently been suggested to be the same and considered to be a microquasar candidate with likely counterparts at optical and IR wavelengths (Tsarevsky et al. 2004, ATEL #239; Bassani et al. 2004, ATEL #232). In order to establish the identity of these sources, a 10-min spectrum of the tentative optical counterpart USNO 0778-0495204 was acquired on March 26.5 2004 (UT) with the FAST spectrograph attached to the 1.5-m telescope at the F. L. Whipple Observatory.

  18. X-ray wind tomography of the highly absorbed HMXB IGR J17252-3616

    NASA Astrophysics Data System (ADS)

    Manousakis, A.; Walter, R.

    2011-02-01

    Context. About ten persistently highly absorbed super-giant high-mass X-ray binaries (sgHMXB) have been discovered by INTEGRAL as bright hard X-ray sources lacking bright X-ray counterparts. Besides IGR J16318-4848, which has peculiar characteristics, the other members of this family share many properties with the classical wind-fed sgHMXB systems. Aims: Our goal is to understand the characteristics of highly absorbed sgHMXB and in particular the companion stellar wind, which is thought to be responsible for the strong absorption. Methods: We monitored IGR J17252-3616, a highly absorbed system featuring eclipses, with XMM-Newton to study the variability of the column density and the Fe Kα emission line along the orbit and during the eclipses. We also compiled a 3D model of the stellar wind to reproduce the observed variability. Results: We first derive a refined orbital solution based on INTEGRAL, RXTE, and XMM-Newton data. We find that the XMM-Newton monitoring campaign reveals significant variations in the intrinsic absorbing column density along the orbit and the Fe Kα line equivalent width around the eclipse. The origin of the soft X-ray absorption is associated with a dense and extended hydrodynamical tail, trailing the neutron star. This structure extends along most of the orbit, indicating that the stellar wind has been strongly disrupted. The variability of the absorbing column density suggests that the wind velocity is smaller (\\upsilon∞ ≈ 400 km s-1) than observed in classical systems. This may also explain the much stronger density perturbation inferred from the observations. Most of the Fe Kα emission is generated in the innermost region of the hydrodynamical tail. This region, which extends over a few accretion radii, is ionized and does not contribute to the soft X-ray absorption. Conclusions: We present a qualitative model of the stellar wind of IGR J17252-3616 that can represent the observations, and we suggest that highly absorbed systems

  19. BROADBAND SUZAKU OBSERVATIONS OF IGR J16207-5129

    SciTech Connect

    Bodaghee, A.; Tomsick, J. A.; Rodriguez, J.; Chaty, S.; Walter, R.

    2010-08-10

    An analysis of IGR J16207-5129 is presented based on observations taken with Suzaku. The data set represents {approx}80 ks of effective exposure time in a broad energy range between 0.5 and 60 keV, including unprecedented spectral sensitivity above 15 keV. The average source spectrum is well described by an absorbed power law in which we measured a large intrinsic absorption of N {sub H} =(16.2{sup +0.9} {sub -1.1}) x 10{sup 22} cm{sup -2}. This confirms that IGR J16207-5129 belongs to the class of absorbed high-mass X-ray binaries. We were able to constrain the cutoff energy at 19{sup +8} {sub -4} keV, which argues in favor of a neutron star as the primary. Our observation includes an epoch in which the source count rate is compatible with no flux suggesting a possible eclipse. We discuss the nature of this source in light of these and of other recent results.

  20. THE OPTICAL COUNTERPART TO THE X-RAY TRANSIENT IGR J1824-24525 IN THE GLOBULAR CLUSTER M28

    SciTech Connect

    Pallanca, C.; Dalessandro, E.; Ferraro, F. R.; Lanzoni, B.

    2013-08-20

    We report on the identification of the optical counterpart to the recently detected INTEGRAL transient IGR J1824-24525 in the Galactic globular cluster M28. From analysis of a multi-epoch Hubble Space Telescope data set, we have identified a strongly variable star positionally coincident with the radio and Chandra X-ray sources associated with the INTEGRAL transient. The star has been detected during both a quiescent and an outburst state. In the former case it appears as a faint, unperturbed main-sequence star, while in the latter state it is about two magnitudes brighter and slightly bluer than main-sequence stars. We also detected H{alpha} excess during the outburst state, suggestive of active accretion processes by the neutron star.

  1. IGR J17463-2854, a possible symbiotic binary system in the galactic center region

    NASA Astrophysics Data System (ADS)

    Karasev, D. I.; Tsygankov, S. S.; Lutovinov, A. A.

    2015-08-01

    This paper is devoted to determining the nature of the hard X-ray source IGR J17463-2854 located toward the Galactic bulge. Using data from the INTEGRAL and Chandra X-ray observatories, we show that five point X-ray sources with approximately identical fluxes in the 2-10 keV energy band are detected in the error circle of the object under study. In addition, significant absorption at low energies has been detected in the spectra of all these sources. Based on data from the VVV (VISTA/ESO) infrared Galactic Bulge Survey, we have unambiguously identified three of the five sources, determined the J, H, and K magnitudes of the corresponding stars, and obtained upper limits on the fluxes for the remaining two sources. Analysis of the color-magnitude diagrams has shown that one of these objects most likely belongs to a class of rarely encountered objects, symbiotic binary systems (several tens are known with certainty), i.e., low-mass binary systems consisting of a white dwarf and a red giant. It is important to note that all our results were obtained using improved absorption values and an extinction law differing in this direction from the standard one.

  2. IGR J17451–3022: a dipping and eclipsing low mass X-ray binary

    NASA Astrophysics Data System (ADS)

    Bozzo, E.

    2016-06-01

    We report on the available X-ray data collected by INTEGRAL, Swift, and XMM-Newton during the first outburst of the INTEGRAL transient IGR J17451-3022, discovered in 2014 August. The emission of the source during the 9 months-long outburst was dominated by a thermal component (kT˜1.2 keV), most likely produced by an accretion disk. The XMM-Newton observation carried out during the outburst revealed the presence of multiple absorption features in the soft X-ray emission that could be associated to the presence of an ionized absorber lying above the accretion disk, as observed in many high-inclination low mass X-ray binaries. The XMM-Newton data also revealed the presence of partial and rectangular X-ray eclipses (lasting about 820 s), together with dips. The latter can be associated with increases in the overall absorption column density in the direction of the source. The detection of two consecutive X-ray eclipses in the XMM-Newton data allowed us to estimate the source orbital period at Porb=22620.5(‑1.8,+2.0) s (1σ c.l.).

  3. IGR J17451-3022: a dipping and eclipsing low mass X-ray binary

    NASA Astrophysics Data System (ADS)

    Bozzo, E.

    2016-06-01

    We report on the available X-ray data collected by INTEGRAL, Swift, and XMM-Newton during the first outburst of the INTEGRAL transient IGR J17451-3022, discovered in 2014 August. The emission of the source during the 9 months-long outburst was dominated by a thermal component (kT˜14;1.2 keV), most likely produced by an accretion disk. The XMM-Newton observation carried out during the outburst revealed the presence of multiple absorption features in the soft X-ray emission that could be associated to the presence of an ionized absorber lying above the accretion disk, as observed in many high-inclination low mass X-ray binaries. The XMM-Newton data also revealed the presence of partial and rectangular X-ray eclipses (lasting about 820 s), together with dips. The latter can be associated with increases in the overall absorption column density in the direction of the source. The detection of two consecutive X-ray eclipses in the XMM-Newton data allowed us to estimate the source orbital period at Porb=22620.5(-1.8,+2.0) s (1σ c.l.).

  4. IGR NO{sub x}/SO{sub x} control technology. [Quarterly] report, April 1, 1993--June 30, 1993

    SciTech Connect

    Not Available

    1993-07-25

    This reporting term covers the first full quarter subsequent to the program kick-off meeting and the DOE authorization to proceed with the contract work. As such the work of this term principally involves ordering, assembling, and de-bugging equipment as well as the development of the solid electrolyte materials and some initial electrochemical studies. These initial studies make use of the above instrumentation and act as a source of calibration for subsequent studies. Specifically the work during this reporting term has involved the optimization of the sintering of the ceramic electrolyte freeze dried powder to allow for optimum performance of the IGR ceramic composite, the determination of the electrochemical properties in air of the above stabilized ceramic solid oxide electrolyte material over the relevant ranges of applied voltage and temperatures, and the detailed planning, equipment/parts ordering, acquisition, and integration for the computer controlled electrochemical test apparatus for the electrocatalytic materials.

  5. New active galactic nuclei among the INTEGRAL and SWIFT X-ray sources

    NASA Astrophysics Data System (ADS)

    Burenin, R. A.; Mescheryakov, A. V.; Revnivtsev, M. G.; Sazonov, S. Yu.; Bikmaev, I. F.; Pavlinsky, M. N.; Sunyaev, R. A.

    2008-06-01

    We present the results of our optical identifications of a set of X-ray sources from the INTEGRAL and SWIFT all-sky surveys. The optical data have been obtained with the 1.5-m Russian-Turkish Telescope (RTT-150). Nine X-ray sources have been identified with active galactic nuclei (AGNs). Two of them are located in the nearby spiral galaxies MCG-01-05-047 and NGC 973 seen almost edge-on. One source, IGR J16562-3301, is probably a BL Lac object (blazar). The remaining AGNs are observed as the starlike nuclei of spiral galaxies whose spectra exhibit broad emission lines. The relation between the hard X-ray (17-60 keV) luminosity and the [O III] 5007 line luminosity, log L x/ L [O III] ≈ 2.1, holds good for most of the AGNs detected in hard X rays. However, the luminosities of some AGNs deviate from this relation. The fraction of such objects can reach ˜20%. In particular, the [O III] line flux is lower for two nearby edge-on spiral galaxies. This can be explained by the effect of absorption in the galactic disks.

  6. High-energy sources before INTEGRAL. INTEGRAL reference catalog

    NASA Astrophysics Data System (ADS)

    Ebisawa, K.; Bourban, G.; Bodaghee, A.; Mowlavi, N.; Courvoisier, T. J.-L.

    2003-11-01

    We describe the INTEGRAL reference catalog which classifies previously known bright X-ray and gamma-ray sources before the launch of INTEGRAL. These sources are, or have been at least once, brighter than ~ 1 mCrab above 3 keV, and are expected to be detected by INTEGRAL. This catalog is being used in the INTEGRAL Quick Look Analysis to discover new sources or significantly variable sources. We compiled several published X-ray and gamma-ray catalogs, and surveyed recent publications for new sources. Consequently, there are 1122 sources in our INTEGRAL reference catalog. In addition to the source positions, we show an approximate spectral model and expected flux for each source, based on which we derive expected INTEGRAL counting rates. Assuming the default instrument performances and at least ~ 105 s exposure time for any part of the sky, we expect that INTEGRAL will detect at least ~ 700 sources below 10 keV and ~ 400 sources above 20 keV over the mission life. The Catalog is available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?/A+A/411/L59

  7. DISENTANGLING THE SYSTEM GEOMETRY OF THE SUPERGIANT FAST X-RAY TRANSIENT IGR J11215-5952 WITH SWIFT

    SciTech Connect

    Romano, P.; Cusumano, G.; Vercellone, S.; Mangano, V.; Sidoli, L.; Krimm, H. A.

    2009-05-10

    IGR J11215-5952 is a hard X-ray transient source discovered in 2005 April with the International Gamma-Ray Astrophysics Laboratory (INTEGRAL) and a member of the new class of high-mass X-ray binaries, the supergiant fast X-ray transients (SFXTs). While INTEGRAL and Rossi X-Ray Timing Explorer observations have shown that the outbursts occur with a periodicity of {approx}330 days, Swift data have recently demonstrated that the true outburst period is {approx}165 days. IGR J11215-5952 is the first discovered SFXT displaying periodic outbursts, which are possibly related to the orbital period. The physical mechanism responsible for the X-ray outbursts in SFXTs is still debated. The main hypotheses proposed to date involve the structure of the companion wind or gated mechanisms related to the properties of the compact object. We test our proposed model which explains the outbursts from SFXTs as being due to the passage of the neutron star inside the equatorially enhanced wind from the supergiant companion. We performed a Guest Investigator observation with Swift that lasted 20 ks and several follow-up Target of Opportunity (ToO) observations, for a total of {approx}32 ks, during the expected 'apastron' passage (defined assuming an orbital period of {approx}330 days), between 2008 June 16 and July 4. The characteristics of this 'apastron' outburst are quite similar to those previously observed during the 'periastron' outburst of 2007 February 9. The mean spectrum of the bright peaks can be fitted with an absorbed power-law model with a photon index of 1 and an absorbing column of {approx}10{sup 22} cm{sup -2}. This outburst reached luminosities of {approx}10{sup 36} erg s{sup -1} (1-10 keV), comparable with those measured in 2007. The light curve can be modeled with the parameters obtained by Sidoli et al. for the 2007 February 9 outburst, although some differences can be observed in its shape. The properties of the rise to this new outburst and the comparison with the

  8. Multiwavelength study of the fast rotating supergiant high-mass X-ray binary IGR J16465-4507

    NASA Astrophysics Data System (ADS)

    Chaty, S.; LeReun, A.; Negueruela, I.; Coleiro, A.; Castro, N.; Simón-Díaz, S.; Zurita Heras, J. A.; Goldoni, P.; Goldwurm, A.

    2016-06-01

    Context. Since its launch, the X-ray and γ-ray observatory INTEGRAL satellite has revealed a new class of high-mass X-ray binaries (HMXB) displaying fast flares and hosting supergiant companion stars. Optical and infrared (OIR) observations in a multi-wavelength context are essential to understand the nature and evolution of these newly discovered celestial objects. Aims: The goal of this multiwavelength study (from ultraviolet to infrared) is to characterise the properties of IGR J16465-4507, to confirm its HMXB nature and that it hosts a supergiant star. Methods: We analysed all OIR, photometric and spectroscopic observations taken on this source, carried out at ESO facilities. Results: Using spectroscopic data, we constrained the spectral type of the companion star between B0.5 and B1 Ib, settling the debate on the true nature of this source. We measured a high rotation velocity of v = 320 ± 8km s-1 from fitting absorption and emission lines in a stellar spectral model. We then built a spectral energy distribution from photometric observations to evaluate the origin of the different components radiating at each energy range. Conclusions: We finally show that, having accurately determined the spectral type of the early-B supergiant in IGR J16465-4507, we firmly support its classification as an intermediate supergiant fast X-ray transient (SFXT). Based on observations made with ESO Telescopes at the La Silla Paranal Observatory under programme ID 077.D-0038, 077.D-0055, 077.D-0298, 077.D-0568 and 089.D-0056.

  9. Results of ongoing Swift/XRT monitoring of the low mass X-ray binary IGR J17091-3624

    NASA Astrophysics Data System (ADS)

    Ballhausen, Ralf; Grinberg, Victoria; Wilms, Joern; Fuerst, Felix; Eikmann, Wiebke; Bozzo, Enrico; Cadolle Bel, Marion; Egron, Elise; Favre, Thierry; Ferrigno, Carlo; Krauss, Felicia; Kreykenbohm, Ingo; Nowak, Michael A.; Pottschmidt, Katja; Rodriguez, Jerome; Bachetti, Matteo

    2016-03-01

    The low mass X-ray binary IGR J17091-3624 has been reported to be in outburst by Miller et al. (ATel #8742) on 2016 February 26. Subsequent observations by Swift/XRT and INTEGRAL revealed the transient to be in the hard/low state (Grinberg et al., ATel #8761).

  10. Learning models for multi-source integration

    SciTech Connect

    Tejada, S.; Knoblock, C.A.; Minton, S.

    1996-12-31

    Because of the growing number of information sources available through the internet there are many cases in which information needed to solve a problem or answer a question is spread across several information sources. For example, when given two sources, one about comic books and the other about super heroes, you might want to ask the question {open_quotes}Is Spiderman a Marvel Super Hero?{close_quotes} This query accesses both sources; therefore, it is necessary to have information about the relationships of the data within each source and between sources to properly access and integrate the data retrieved. The SIMS information broker captures this type of information in the form of a model. All the information sources map into the model providing the user a single interface to multiple sources.

  11. Hiccup accretion in the swinging pulsar IGR J18245-2452

    NASA Astrophysics Data System (ADS)

    Ferrigno, C.; Bozzo, E.; Papitto, A.; Rea, N.; Pavan, L.; Campana, S.; Wieringa, M.; Filipović, M.; Falanga, M.; Stella, L.

    2014-07-01

    The source IGR J18245-2452 is the fifteenth discovered accreting millisecond X-ray pulsar and the first neutron star to show direct evidence of a transition between accretion- and rotation-powered emission states. These swings provided the strongest confirmation to date of the pulsar recycling scenario. During the two XMM-Newton observations that were carried out while the source was in outburst in April 2013, IGR J18245-2452 displayed a unique and peculiar X-ray variability. In this work, we report on a detailed analysis of the XMM-Newton data and focus on the timing and spectral variability of the source. In the 0.4-11 keV energy band, IGR J18245-2452 continuously switched between lower and higher intensity states, with typical variations in flux by factor of ~100 on time scales as short as a few seconds. These variations in the source intensity were sometimes accompanied by dramatic spectral hardening, during which the X-ray power-law photon index varied from Γ = 1.7 to Γ = 0.9. The pulse profiles extracted at different count-rates, hardnesses, and energies also showed a complex variability. These phenomena were never observed in accreting millisecond X-ray pulsars, at least not on such a short time-scale. Fast variability was also found in the 5.5 and 9 GHz ATCA radio observations that were carried out for about 6 h during the outburst. We interpret the variability observed from IGR J18245-2452 in terms of a hiccup accretion phase, during which the accretion of material from the inner boundary of the Keplerian disk is reduced by the onset of centrifugal inhibition of accretion, possibly causing the launch of outflows. Changes across accretion and propeller regimes have been long predicted and reproduced by magnetohydrodynamic simulations of accreting millisecond X-ray pulsars, but have never observed to produce as extreme a variability as that shown by IGR J18245-2452.

  12. THE FAINT 'HEARTBEATS' OF IGR J17091-3624: AN EXCEPTIONAL BLACK HOLE CANDIDATE

    SciTech Connect

    Altamirano, D.; Van der Klis, M.; Wijnands, R.; Kalamkar, M.; Belloni, T.; Stiele, H.; Motta, S.; Munoz-Darias, T.; Linares, M.; Curran, P. A.; Krimm, H.

    2011-12-15

    We report on the first 180 days of Rossi X-Ray Timing Explorer observations of the outburst of the black hole candidate IGR J17091-3624. This source exhibits a broad variety of complex light curve patterns including periods of strong flares alternating with quiet intervals. Similar patterns in the X-ray light curves have been seen in the (up to now) unique black hole system GRS 1915+105. In the context of the variability classes defined by Belloni et al. for GRS 1915+105, we find that IGR J17091-3624 shows the {nu}, {rho}, {alpha}, {lambda}, {beta}, and {mu} classes as well as quiet periods which resemble the {chi} class, all occurring at 2-60 keV count rate levels which can be 10-50 times lower than observed in GRS 1915+105. The so-called {rho} class 'heartbeats' occur as fast as every few seconds and as slow as {approx}100 s, tracing a loop in the hardness-intensity diagram which resembles that previously seen in GRS 1915+105. However, while GRS 1915+105 traverses this loop clockwise, IGR J17091-3624 does so in the opposite sense. We briefly discuss our findings in the context of the models proposed for GRS 1915+105 and find that either all models requiring near Eddington luminosities for GRS 1915+105-like variability fail, or IGR J17091-3624 lies at a distance well in excess of 20 kpc, or it harbors one of the least massive black holes known (<3 M{sub Sun }).

  13. IS IGR J11014-6103 A PULSAR WITH THE HIGHEST KNOWN KICK VELOCITY?

    SciTech Connect

    Tomsick, John A.; Bodaghee, Arash; Fornasini, Francesca; Rodriguez, Jerome; Chaty, Sylvain; Rahoui, Farid

    2012-05-10

    We report on Chandra X-ray and Parkes radio observations of IGR J11014-6103, which is a possible pulsar wind nebula with a complex X-ray morphology and a likely radio counterpart. With the superb angular resolution of Chandra, we find evidence that a portion of the extended emission may be related to a bow shock due to the putative pulsar moving through the interstellar medium. The inferred direction of motion is consistent with IGR J11014-6103 having been born in the event that produced the supernova remnant (SNR) MSH 11-61A. If this association is correct, then previous constraints on the expansion of MSH 11-61A imply a transverse velocity for IGR J11014-6103 of 2400-2900 km s{sup -1}, depending on the SNR model used. This would surpass the kick velocities of any known pulsars and rival or surpass the velocities of any compact objects that are associated with SNRs. While it is important to confirm the nature of the source, our radio pulsation search did not yield a detection.

  14. SWIFT-BAT HARD X-RAY SKY MONITORING UNVEILS THE ORBITAL PERIOD OF THE HMXB IGR J18219–1347

    SciTech Connect

    La Parola, V.; Cusumano, G.; Segreto, A.; D'Aì, A.; Masetti, N.; D'Elia, V.

    2013-09-20

    IGR J18219–1347 is a hard X-ray source discovered by INTEGRAL in 2010. We have analyzed the X-ray emission of this source exploiting the Burst Alert Telescope (BAT) survey data up to 2012 March and the X-Ray Telescope (XRT) data that include also an observing campaign performed in early 2012. The source is detected at a significance level of ∼13 standard deviations in the 88 month BAT survey data, and shows a strong variability along the survey monitoring, going from high intensity to quiescent states. A timing analysis on the BAT data revealed an intensity modulation with a period of P {sub 0} = 72.44 ± 0.3 days. The significance of this modulation is about seven standard deviations in Gaussian statistics. We interpret it as the orbital period of the binary system. The light curve folded at P {sub 0} shows a sharp peak covering ∼30% of the period, superimposed to a flat level roughly consistent with zero. In the soft X-rays the source is detected only in 5 out of 12 XRT observations, with the highest recorded count rate corresponding to a phase close to the BAT folded light-curve peak. The long orbital period and the evidence that the source emits only during a small fraction of the orbit suggests that the IGR J18219–1347 binary system hosts a Be star. The broadband XRT+BAT spectrum is well modeled with a flat absorbed power law with a high-energy exponential cutoff at ∼11 keV.

  15. Confirmation of IGR J01363 plus 6610 as a Be X-Ray Binary with Very Low Quiescent X-Ray Luminosity

    NASA Technical Reports Server (NTRS)

    Tomsick, John A.; Heinke, Craig; Halpern, Jules; Kaaret, Philip; Chaty, Sylvain; Rodriguez, Jerome; Bodaghee, Arash

    2011-01-01

    The field containing the candidate High Mass X-ray Binary IGR J01 363+6610 was observed by XMM-Newton on 2009 July 31 for 28 ks. A Be star was previously suggested as the possible counterpart of the INTEGRAL source, and although Chandra, during a 2007 observation, did not detect an X-ray source at the position of the Be star, we find a variable source (XMMU 101 3549.5+661243) with an average X-ray flux of 2 x 10(exp -13)ergs/sq cm/s (0.2-12 keV, unabsorbed) at this position with XMM-Newton. The spectrum of this source is consistent with a hard power law with a photon index of r = 1.4+/-0.3 and a column density of N(sub H) = (15(+0.7/-0.5)) x 10(exp 22)/sq cm (90% confidence errors). These results, along with our optical investigation of other X-ray sources in the field, make the association with the Be star very likely, and the 2 kpc distance estimate for the Be star indicates an X-ray luminosity of 9.1 x 10(exp 31) ergs/s. This is lower than typical for a Be X-ray binary, and the upper limit on the luminosity was even lower ( < 1.4 x 10(exp 3)ergs/s assuming the same spectral model) during the Chandra observation. We discuss possible implications of the very low quiescent luminosity for the physical properties of IGR 101363+6610.

  16. IMPLICATIONS OF BURST OSCILLATIONS FROM THE SLOWLY ROTATING ACCRETING PULSAR IGR J17480-2446 IN THE GLOBULAR CLUSTER TERZAN 5

    SciTech Connect

    Cavecchi, Y.; Patruno, A.; Haskell, B.; Watts, A. L.; Altamirano, D.; Wijnands, R.; Van der Klis, M.; Levin, Y.; Linares, M.

    2011-10-10

    The recently discovered accreting X-ray pulsar IGR J17480-2446 spins at a frequency of {approx}11 Hz. We show that Type I X-ray bursts from this source display oscillations at the same frequency as the stellar spin. IGR J17480-2446 is the first secure case of a slowly rotating neutron star (NS) which shows Type I burst oscillations (BOs), all other sources featuring such oscillations spin at hundreds of Hertz. This means that we can test BO models in a completely different regime. We explore the origin of Type I BOs in IGR J17480-2446 and conclude that they are not caused by global modes in the NS ocean. We also show that the Coriolis force is not able to confine an oscillation-producing hot spot on the stellar surface. The most likely scenario is that the BOs are produced by a hot spot confined by hydromagnetic stresses.

  17. Integrated-Circuit Broadband Infrared Sources

    NASA Technical Reports Server (NTRS)

    Lamb, G.; Jhabvala, M.; Burgess, A.

    1989-01-01

    Microscopic devices consume less power, run hotter, and are more reliable. Simple, compact, lightweight, rapidly-responding reference sources of broadband infrared radiation made available by integrated-circuit technology. Intended primarily for use in calibration of remote-sensing infrared instruments, devices eventually replace conventional infrared sources. New devices also replace present generation of miniature infrared sources. Self-passivating nature of poly-crystalline silicon adds to reliability of devices. Maximum operating temperature is 1,000 K, and power dissipation is only one-fourth that of prior devices.

  18. X-ray scattered halo around IGR J17544–2619

    SciTech Connect

    Mao, Junjie; Ling, Zhixing; Zhang, Shuang-Nan

    2014-04-10

    X-ray photons coming from an X-ray point source not only arrive at the detector directly, but also can be strongly forward-scattered by the interstellar dust along the line of sight (LOS), leading to a detectable diffuse halo around the X-ray point source. The geometry of small-angle X-ray scattering is straightforward, namely, the scattered photons travel longer paths and thus arrive later than the unscattered ones; thus, the delay time of X-ray scattered halo photons can reveal information of the distances of the interstellar dust and the point source. Here we present a study of the X-ray scattered halo around IGR J17544–2619, which is one of the so-called supergiant fast X-ray transients. IGR J17544–2619 underwent a striking outburst when observed with Chandra on 2004 July 3, providing a near δ-function light curve. We find that the X-ray scattered halo around IGR J17544–2619 is produced by two interstellar dust clouds along the LOS. The one that is closer to the observer gives the X-ray scattered halo at larger observational angles, whereas the farther one, which is in the vicinity of the point source, explains the halo with a smaller angular size. By comparing the observational angle of the scattered halo photons with that predicted by different dust grain models, we are able to determine the normalized dust distance. With the delay times of the scattered halo photons, we can determine the point source distance, given a dust grain model. Alternatively, we can discriminate between the dust grain models, if the point source distance is known independently.

  19. The long XMM-Newton observational campaign on IGR J17544-2619

    NASA Astrophysics Data System (ADS)

    Bozzo, E.

    2016-06-01

    eIn this talk we present the results obtained from the long XMM-Newton observational campaign on the prototype supergiant fast X-ray transient (SFXT) IGR J17544-2619. This is the longest continuum observation in the soft X-rays of an SFXT. The source underwent a bright outburst during the observation and displayed a total dynamic range of about 1E4 in the X-ray luminosity (0.5-10 keV energy range). We discuss the implications of these observational results for the theoretical models proposed so far to interpret these unique and extreme sources.

  20. ISINA: INTEGRAL Source Identification Network Algorithm

    NASA Astrophysics Data System (ADS)

    Scaringi, S.; Bird, A. J.; Clark, D. J.; Dean, A. J.; Hill, A. B.; McBride, V. A.; Shaw, S. E.

    2008-11-01

    We give an overview of ISINA: INTEGRAL Source Identification Network Algorithm. This machine learning algorithm, using random forests, is applied to the IBIS/ISGRI data set in order to ease the production of unbiased future soft gamma-ray source catalogues. First, we introduce the data set and the problems encountered when dealing with images obtained using the coded mask technique. The initial step of source candidate searching is introduced and an initial candidate list is created. A description of the feature extraction on the initial candidate list is then performed together with feature merging for these candidates. Three training and testing sets are created in order to deal with the diverse time-scales encountered when dealing with the gamma-ray sky. Three independent random forests are built: one dealing with faint persistent source recognition, one dealing with strong persistent sources and a final one dealing with transients. For the latter, a new transient detection technique is introduced and described: the transient matrix. Finally the performance of the network is assessed and discussed using the testing set and some illustrative source examples. Based on observations with INTEGRAL, an ESA project with instruments and science data centre funded by ESA member states (especially the PI countries: Denmark, France, Germany, Italy, Spain), Czech Republic and Poland, and the participation of Russia and the USA. E-mail: simo@astro.soton.ac.uk

  1. Heartbeat Oscillation detected in IGR J17091-3624

    NASA Astrophysics Data System (ADS)

    Reynolds, Mark; Miller, Jon; King, Askley

    2016-04-01

    We report on the results of ongoing monitoring observation of the Galactic micro-quasar IGR J17091-3624 with Swift/XRT in windowed timing mode. In an ~860s observation on 2016-04-13T13:05:46 UT (obsid: 00031921133), clear oscillations are detected consistent with the re-emergence of the so-called heartbeat oscillation (ATel #3230, #3418) in the accretion flow of this micro-quasar with a frequency of approximately 0.027 Hz. The source spectrum is well characterized by model consisting of the emission from an accretion disk and a hot optically thin Comptonizing corona, e.g., kT_disk ~ 0.9 keV, kT0_corona ~ 0.6 keV, tau_corona ~ 0.6, kT_e == 100 keV (chi^2/dof = 496/462), with a flux of f_x ~ 1.4e-09 erg/s/cm^2 corresponding to a luminosity of ~ 1e37 (d/8kpc)^2 erg/s in the 0.3-10.0 keV band.

  2. Infrared observations of IGR J17497-2821: 3 candidate counterparts

    NASA Astrophysics Data System (ADS)

    Chaty, S.; Matsuoka, Y.; Nagata, T.; Ueda, Y.

    2006-09-01

    We have obtained infrared (IR) observations in J, H and Ks bands of the field of IGR J17497-2821 (atel #885) at 1.4m IRSF at South African Astronomical Observatory on 3 consecutive nights, respectively starting at 2006-09-22 (UTC 17:47, 18:39 and 20:17), 2006-09-23 (UTC 18:49) and 2006-09-24 (UTC 17:33). The 3-band images were obtained simultaneously with the IR camera SIRIUS, from 5s x 10 dither integrations.

  3. Thermonuclear X-ray bursts from the 401-Hz accreting pulsar IGR J17498-2921: indication of burning in confined regions

    NASA Astrophysics Data System (ADS)

    Chakraborty, Manoneeta; Bhattacharyya, Sudip

    2012-05-01

    We use the 2011 Rossi X-ray Timing Explorer (RXTE) Proportional Counter Array (PCA) data of the 401-Hz accreting pulsar and burster IGR J17498-2921 to perform timing analysis and time-resolved spectroscopy of 12 thermonuclear X-ray bursts. We confirm previously reported burst oscillations from this source with a much higher significance (8.8σ). We note that the bursts can be divided into three groups: big photospheric radius expansion (PRE) bursts are about 10 times more luminous than medium bursts, while the latter are about 10 times more luminous than small bursts. The PCA field of view of these observations contains several known bursters, and hence some of the observed bursts might not be from IGR J17498-2921. The oscillations during big bursts at the known pulsar frequency show that these bursts were definitely from IGR J17498-2921. We find that at least several of the other bursts were also likely originated from IGR J17498-2921. Spectral analysis reveals that the luminosity differences among various bursts are primarily due to differences in normalizations, and not temperatures, even when we consider the effects of colour factor. This shows burning on a fraction of the stellar surface for those small and medium bursts, which originated from IGR J17498-2921. The low values of the upper limits of burst oscillation amplitude for these bursts suggest a small angle between the spin axis and the magnetic axis. We find indications of the PRE nature of a medium burst, which likely originated from IGR J17498-2921. If true, then, to the best of our knowledge, this is the first time that two PRE bursts with a peak count rate ratio of as high as ≈12 have been detected from the same source.

  4. The Seyfert 1 AGN nature of IGR J20450+7530

    NASA Astrophysics Data System (ADS)

    Parisi, P.; Masetti, N.; Landi, R.; Bassani, L.; Bazzano, A.; Bird, A. J.

    2010-09-01

    We report on an optical spectroscopic observation of object USNO-A2.0 1650-02316572 (RA(J2000) = 20h 44m 34.49s, Dec(J2000) = +75d 31m 58.9s), located in the Swift/XRT error box of the soft X-ray source #2 of Landi et al. (ATel #2830). This object according to these authors, is the likely counterpart of the hard X-ray object IGR J20450+7530 listed in the 4th IBIS Survey Catalog (Bird et al. 2010, ApJS, 186, 1).

  5. A Swift/BAT source inside the error circle of the AGILE Cygnus source

    NASA Astrophysics Data System (ADS)

    Ajello, M.; Greiner, J.; Gehrels, G. Kanbach N.

    2008-04-01

    We report on the presence of a Swift/BAT (15-55 keV) source in the error box of the AGILE source (Longo et al. 2008, ATEL #1492) located at l = 78.01 deg, b = 2.19 deg. In the ongoing BAT all-sky survey a source is detected at RA(J2000) = 304.650, Decl.(J2000)= +40.700 (3 arcmin error radius at 90% CL) which is positionally coincident with the INTEGRAL source IGR J20187+4041 (Bykov et al. 2006, ApJ 649, 21).

  6. Terzan 5 transient IGR J17480-2446: variation of burst and spectral properties with spectral states

    NASA Astrophysics Data System (ADS)

    Chakraborty, Manoneeta; Bhattacharyya, Sudip; Mukherjee, Arunava

    2011-11-01

    We study the spectral-state evolution of the Terzan 5 transient neutron star low-mass X-ray binary IGR J17480-2446, and how the best-fitting spectral parameters and burst properties evolved with these states, using the Rossi X-ray Timing Explorer data. As reported by other authors, this is the second source that showed transitions between atoll state and 'Z' state. We find large-scale hysteresis in the almost 'C'-like hardness-intensity track of the source in the atoll state. This discovery is likely to provide a missing piece of the jigsaw puzzle involving various types of hardness-intensity tracks from 'q' shaped for Aquila X-1, 4U 1608-52 and many black holes to 'C' shaped for many atoll sources. Furthermore, the regular pulsations, a diagonal transition between soft and hard states, and the large-scale hysteresis observed from IGR J17480-2446 argue against some of the previous suggestions involving magnetic field about atolls and millisecond pulsars. Our results also suggest that the nature of spectral evolution throughout an outburst does not, at least entirely, depend on the peak luminosity of the outburst. Besides, the source took at least a month to trace the softer banana state, as opposed to a few hours to a day, which is typical for an atoll source. In addition, while the soft colour usually increases with intensity in the softer portion of an atoll source, IGR J17480-2446 showed an opposite behaviour. From the detailed spectral fitting, we conclude that a blackbody+power-law model is the simplest one, which describes the source continuum spectra well throughout the outburst. We find that these two spectral components were plausibly connected to each other, and they worked together to cause the source-state evolution. Spectral parameters smoothly changed as IGR J17480-2446 transitioned between the atoll state and 'Z' state, and thermonuclear bursts disappeared in the softer parts of 'Z' tracks. Finally, based on the burst properties, we suggest that IGR

  7. Open Source GIS based integrated watershed management

    NASA Astrophysics Data System (ADS)

    Byrne, J. M.; Lindsay, J.; Berg, A. A.

    2013-12-01

    Optimal land and water management to address future and current resource stresses and allocation challenges requires the development of state-of-the-art geomatics and hydrological modelling tools. Future hydrological modelling tools should be of high resolution, process based with real-time capability to assess changing resource issues critical to short, medium and long-term enviromental management. The objective here is to merge two renowned, well published resource modeling programs to create an source toolbox for integrated land and water management applications. This work will facilitate a much increased efficiency in land and water resource security, management and planning. Following an 'open-source' philosophy, the tools will be computer platform independent with source code freely available, maximizing knowledge transfer and the global value of the proposed research. The envisioned set of water resource management tools will be housed within 'Whitebox Geospatial Analysis Tools'. Whitebox, is an open-source geographical information system (GIS) developed by Dr. John Lindsay at the University of Guelph. The emphasis of the Whitebox project has been to develop a user-friendly interface for advanced spatial analysis in environmental applications. The plugin architecture of the software is ideal for the tight-integration of spatially distributed models and spatial analysis algorithms such as those contained within the GENESYS suite. Open-source development extends knowledge and technology transfer to a broad range of end-users and builds Canadian capability to address complex resource management problems with better tools and expertise for managers in Canada and around the world. GENESYS (Generate Earth Systems Science input) is an innovative, efficient, high-resolution hydro- and agro-meteorological model for complex terrain watersheds developed under the direction of Dr. James Byrne. GENESYS is an outstanding research and applications tool to address

  8. Variability study of the High Mass X-ray Binary IGR J18027-2016 with Swift-XRT

    NASA Astrophysics Data System (ADS)

    Aftab, Nafisa; Islam, Nazma; Paul, Biswajit

    2016-08-01

    We report the results from pulsations and spectral analysis of a large number of observations of the HMXB pulsar IGR J18027-2016 with Swift-XRT, carried out at different orbital phases. In some orbital phases, as seen in different XRT observations, the X-ray intensity is found to vary by a large factor, of about ˜50. In all the observations with sufficient number of source X-ray photons, pulsations have been detected around the previously known pulse period of ˜140 sec, When detected, the pulse profiles do not show any significant variation over a flux difference of a factor of ˜3. The absorption column density is found to be large before and after the eclipse. We discuss various possible reasons for intensity and spectral variations in IGR J18027-2016, such as clumpy wind and hydrodynamic instabilities.

  9. The Faint "Heartbeats" of IGR J17091-3624: An Exceptional Black Hole Candidate

    NASA Technical Reports Server (NTRS)

    Altamirano, D.; Belloni, T.; Linares, M.; VanDerKlis, M.; Wunands, R.; Curran, P. A.; Kalamkar, M.; Stiele, H.; Motta, S.; Munoz-Darias, T.; Casella, P.; Krimm, H.

    2011-01-01

    We report on the first 180 days of Rossi X-Ray Timing Explorer observations of the outburst of the black hole candidate IGR Jl7091-3624. This source exhibits a broad variety of complex light curve patterns including periods of strong flares alternating with quiet intervals. Similar patterns in the X-ray light curves have been seen in the (up to now) unique black hole system GRS 1915+105. In the context of the variability classes defined by Belloni et al. for GRS 1915+105, we find that JGR J17091-3624 shows the nu, rho, alpha, lambda, Beta, and mu classes as well as quiet periods which resemble the chi class, all occurring at 2-60 keY count rate levels which can be 10-50 times lower than observed in GRS 1915+\\05. The so-called rho class "heartbeats" occur as fast as every few seconds and as slow as approx 100 s, tracing a loop in the hardness-intensity diagram which resembles that previously seen in GRS 1915+\\05. However, while GRS 1915+105 traverses this loop clockwise, IGR Jl7091-3624 does so in the opposite sense. We briefly discuss our findings in the context of the models proposed for GRS 1915+105 and find that either all models requiring near Eddington luminosities for GRS 1915+105-like variability fail, or IGR Il7091-3624 lies at a distance well in excess of 20 kpc, or it harbors one of the least massive black holes known( <3 solar M).

  10. The Discovery Outburst of the X-Ray Transient IGR J17497-2821 Observed with RXTE and ATCA

    NASA Technical Reports Server (NTRS)

    Rodriquez, Jerome; Bel, Marion Cadolle; Tomsick, John A.; Corbel, Stephane; Brocksopp, Catherine; Paizis, Ada; Shaw, Simon E.; Bodaghee, Arash

    2007-01-01

    We report the results of a series of RXTE and ATCA observations of the recently discovered X-ray transient IGR J17497-2821. Our 3-200 keV PCA+HEXTE spectral analysis shows very little variations over a period of approx.10 days around the maximum of the outburst. IGR J17497-2821 is found in a typical low-hard state (LHS) of X-ray binaries (XRBs), well represented by an absorbed Comptonized spectrum with an iron edge at about 7 keV. The high value of the absorption (approx.4 x 10(exp 22/sq cm suggests that the source is located at a large distance, either close to the Galactic center or beyond. The timing analysis shows no particular features, while the shape of the power density spectra is also typical of the LHS of XRBs, with apprrox.36% rms variability. No radio counterpart is found down to a limit of 0.21 mJy at 4.80 and 8.64 GHz. Although the position of IGR J17497-2821 in the radio to X-ray flux diagram is well below the correlation usually observed in the LHS of black holes, the comparison of its X-ray properties with those of other sources leads us to suggest that it is a black hole candidate.

  11. Swift reveals the eclipsing nature of the high-mass X-ray binary IGR J16195-4945

    NASA Astrophysics Data System (ADS)

    Cusumano, G.; La Parola, V.; Segreto, A.; D'Aì, A.

    2016-03-01

    IGR J16195-4945 is a hard X-ray source discovered by INTEGRAL during the Core Programme observations performed in 2003. We analysed the X-ray emission of this source exploiting the Swift-Burst Alert Telescope (BAT) survey data from 2004 December to 2015 March, and all the available Swift-X-ray Telescope (XRT)-pointed observations. The source is detected at a high significance level in the 123-month BAT survey data, with an average 15-150 keV flux of the source of ˜1.6 mCrab. The timing analysis on the BAT data reveals with a significance higher than six standard deviations the presence of a modulated signal with a period of 3.945 d, that we interpret as the orbital period of the binary system. The folded light curve shows a flat profile with a narrow full eclipse lasting ˜3.5 per cent of the orbital period. We requested phase-constrained XRT observations to obtain a more detailed characterization of the eclipse in the soft X-ray range. Adopting reasonable guess values for the mass and radius of the companion star, we derive a semimajor orbital axis of ˜ 31 R⊙, equivalent to ˜1.8 times the radius of the companion star. From these estimates and from the duration of the eclipse, we derive an orbital inclination between 55 and 60 deg. The broad-band time-averaged XRT+BAT spectrum is well modelled with a strongly absorbed flat power law, with absorbing column NH = 7 × 1022 cm-2 and photon index Γ = 0.5, modified by a high energy exponential cutoff at Ecut = 14 keV.

  12. SUBARCSECOND LOCATION OF IGR J17480-2446 WITH ROSSI XTE

    SciTech Connect

    Riggio, A.; Burderi, L.; Egron, E.; Di Salvo, T.; D'Ai, A.; Iaria, R.; Robba, N. R.; Papitto, A.; Belloni, T.; Motta, S.; Floris, M.; Testa, V.; Menna, M. T.

    2012-07-20

    On 2010 October 13, the X-ray astronomical satellite Rossi XTE, during the observation of the newly discovered accretion powered X-ray pulsar IGR J17480-2446, detected a lunar occultation of the source. From knowledge of the lunar topography and Earth, Moon, and spacecraft ephemerides at the epoch of the event, we determined the source position with an accuracy of 40 mas (1{sigma} c.l.), which is interesting, given the very poor imaging capabilities of RXTE ({approx}1 Degree-Sign ). For the first time, using a non-imaging X-ray observatory, the position of an X-ray source with a subarcsecond accuracy is derived, demonstrating the neat capabilities of a technique that can be fruitfully applied to current and future X-ray missions.

  13. Swift/XRT localization of IGR J00569-7226, a likely new Be/X-ray binary

    NASA Astrophysics Data System (ADS)

    Kennea, J. A.

    2013-11-01

    We report on Swift target-of-opportunity observations of the recently reported transient IGR J00569-7226 (Coe et al., ATEL #5547). Beginning 23:42UT on November 5th, 2013, Swift performed a 1ks observation of the INTEGRAL error circle. In XRT Photon Counting mode data, we detect a previously uncatalogued transient inside the INTEGRAL error circle. Correcting for systematic errors in the astrometry utilizing UVOT attitude correction, we find a position of: RA/Dec(J2000) = 14.25973, -72.43204, equivalent to:

  14. Broadband ESO/VISIR-Spitzer Infrared Spectroscopy of the Obscured Supergiant X-Ray Binary IGR J16318-4848

    NASA Astrophysics Data System (ADS)

    Chaty, S.; Rahoui, F.

    2012-06-01

    A new class of X-ray binaries has recently been discovered by the high-energy observatory INTEGRAL. It is composed of intrinsically obscured supergiant high-mass X-ray binaries, unveiled by means of multi-wavelength X-ray, optical, near- and mid-infrared observations, in particular, photometric and spectroscopic observations using ESO facilities. However, the fundamental questions about these intriguing sources, namely, their formation, evolution, and the nature of their environment, are still unsolved. Among them, IGR J16318-4848, a compact object orbiting around a supergiant B[e] star, seems to be one of the most extraordinary celestial sources of our Galaxy. We present here new ESO/Very Large Telescope (VLT) VISIR mid-infrared (MIR) spectroscopic observations of this source. First, line diagnostics allow us to confirm the presence of absorbing material (dust and cold gas) enshrouding the whole binary system, and to characterize the nature of this material. Second, by fitting broadband near- to mid-infrared spectral energy distribution, including ESO NTT/SofI, VLT/VISIR, and Spitzer data, with a phenomenological model for sgB[e] stars, we show that the star is surrounded by an irradiated rim heated to a temperature of ~3800-5500 K, along with a viscous disk component at an inner temperature of ~750 K. VISIR data allow us to exclude the spherical geometry for the dust component. This detailed study will allow us in the future to get better constraints on the formation and evolution of such rare and short-living high-mass X-ray binary systems in our Galaxy.

  15. Discovery of the radio counterpart for 2MASX J20183871+4041003 within the error-box of IGR J2018-4043 and of the AGILE variable gamma-ray source in the Cygnus region

    NASA Astrophysics Data System (ADS)

    Dubner, G.; Giacani, E.; Bykov, A. M.; Krassilchtchikov, A. M.; Uvarov, Yu. A.

    2008-05-01

    Based on C-configuration VLA observations carried out on December 9 and 12, 2006 at 1423 and 4885 MHz (program ag728), we report on the presence of a radio point source centered exactly at the position of 2MASX J20183871+4041003 within the error box of the discovered AGILE variable gamma-ray source (ATEL #1492, ATEL #1497 and ATEL #1498).

  16. Bd +60 73 = Igr J00370+6122

    NASA Astrophysics Data System (ADS)

    Negueruela, Ignacio; Reig, Pablo

    2004-05-01

    A classification spectrum of BD +60 73, reported to be the optical counterpart to IGR J00370+6122 (ATel #281), was taken on the night of 2003 July 7th with the 2.5-m Issac Newton telescope at La Palma. The derived spectral type is BN0.5II-III, where the composite luminosity class indicates an intermediate luminosity. The Nitrogen enhancement is moderately high, with numerous NII lines being rather stronger than corresponds to the spectral type.

  17. Mechanistic role of structurally dynamic regions in Dicistroviridae IGR IRESs.

    PubMed

    Pfingsten, Jennifer S; Castile, Alice E; Kieft, Jeffrey S

    2010-01-01

    Dicistroviridae intergenic region (IGR) internal ribosome entry site(s) (IRES) RNAs drive a cap-independent pathway of translation initiation, recruiting both small and large ribosomal subunits to viral RNA without the use of any canonical translation initiation factors. This ability is conferred by the folded three-dimensional structure of the IRES RNA, which has been solved by X-ray crystallography. Here, we report the chemical probing of Plautia stali intestine virus IGR IRES in the unbound form, in the 40S-subunit-bound form, and in the 80S-ribosome-bound form. The results, when combined with an analysis of crystal structures, suggest that parts of the IRES RNA change structure as the preinitiation complex forms. Using mutagenesis coupled with native gel electrophoresis, preinitiation complex assembly assays, and translation initiation assays, we show that these potentially structurally dynamic elements of the IRES are involved in different steps in the pathway of ribosome recruitment and translation initiation. Like tRNAs, it appears that the IGR IRES undergoes local structural changes that are coordinated with structural changes in the ribosome, and these are critical for the IRES mechanism of action. PMID:19878683

  18. Integrating multiple data sources for malware classification

    DOEpatents

    Anderson, Blake Harrell; Storlie, Curtis B; Lane, Terran

    2015-04-28

    Disclosed herein are representative embodiments of tools and techniques for classifying programs. According to one exemplary technique, at least one graph representation of at least one dynamic data source of at least one program is generated. Also, at least one graph representation of at least one static data source of the at least one program is generated. Additionally, at least using the at least one graph representation of the at least one dynamic data source and the at least one graph representation of the at least one static data source, the at least one program is classified.

  19. Archivists as Educators: Integrating Primary Sources into the Curriculum

    ERIC Educational Resources Information Center

    Carini, Peter

    2009-01-01

    Primary source materials are increasingly being thought of as curricular resources and archivists are being asked to play the role of educator. This article, based on the session "Archivists as Educators: Integrating Primary Sources into the Curriculum" looks at the role of the primary source in undergraduate and secondary school curricula and…

  20. A study of variation in accretion disk parameters with phases of `heartbeats' in IGR J17091-3624

    NASA Astrophysics Data System (ADS)

    Rao, Anjali; Vadawale, Santosh V.

    The standard accretion disk model is based on a famous Shakura-Sunyaev viscosity prescription in which viscous stress is scaled with total pressure. Though the model has been very successful to explain various properties of accretion disk, it was known that Shakura-Sunyaev disk is inherently unstable in the radiation pressure dominated inner accretion disk region, particularly when local mass accretion rate is high. This instability, known as radiation pressure instability (RPI), is expected to give rise to a limit cycle behavior in which source may exhibit a series of quasi-periodic bursts. So far such behavior, popularly known as `heartbeats' was observed only in GRS 1915+105. Recently, IGR J17091-3624, a transient black hole candidate, became the second source showing 'heartbeat' type variability during its last outburst in 2011. Here we carry out a comparative study of the variation of accretion disk parameters during such variability in both IGR J17091-3624 and GRS 1915+105. We find that the radiation pressure instability alone may not be sufficient to explain the observed spectral variability in both the sources.

  1. Astrophysical parameters and orbital solution of the peculiar X-ray transient IGR J00370+6122

    NASA Astrophysics Data System (ADS)

    González-Galán, A.; Negueruela, I.; Castro, N.; Simón-Díaz, S.; Lorenzo, J.; Vilardell, F.

    2014-06-01

    Context. BD + 60° 73 is the optical counterpart of the X-ray source IGR J00370+6122, a probable accretion-powered X-ray pulsar. The X-ray light curve of this binary system shows clear periodicity at 15.7 d, which has been interpreted as repeated outbursts around the periastron of an eccentric orbit. Aims: We aim to characterise the binary system IGR J00370+6122 by deriving its orbital and physical parameters. Methods: We obtained high-resolution spectra of BD + 60° 73 at different epochs. We used the fastwind code to generate a stellar atmosphere model to fit the observed spectrum and obtain physical magnitudes. The synthetic spectrum was used as a template for cross-correlation with the observed spectra to measure radial velocities. The radial velocity curve provided an orbital solution for the system. We also analysed the RXTE/ASM and Swift/BAT light curves to confirm the stability of the periodicity. Results: BD + 60° 73 is a BN0.7 Ib low-luminosity supergiant located at a distance ~3.1 kpc, in the Cas OB4 association. We derive Teff = 24 000 K and log gc = 3.0, and chemical abundances consistent with a moderately high level of evolution. The spectroscopic and evolutionary masses are consistent at the 1-σ level with a mass M∗ ≈ 15 M⊙. The recurrence time of the X-ray flares is the orbital period of the system. The neutron star is in a high-eccentricity (e = 0.56 ± 0.07) orbit, and the X-ray emission is strongly peaked around orbital phase φ = 0.2, though the observations are consistent with some level of X-ray activity happening at all orbital phases. Conclusions: The X-ray behaviour of IGR J00370+6122 is reminiscent of "intermediate" supergiant X-ray transients, though its peak luminosity is rather low. The orbit is somewhat wider than those of classical persistent supergiant X-ray binaries, which when combined with the low luminosity of the mass donor, explains the low X-ray luminosity. IGR J00370+6122 will very likely evolve towards a persistent

  2. 19 CFR 10.532 - Integrated Sourcing Initiative.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... THE TREASURY ARTICLES CONDITIONALLY FREE, SUBJECT TO A REDUCED RATE, ETC. United States-Singapore Free Trade Agreement Rules of Origin § 10.532 Integrated Sourcing Initiative. (a) For purposes of...

  3. Integrating an Automatic Judge into an Open Source LMS

    ERIC Educational Resources Information Center

    Georgouli, Katerina; Guerreiro, Pedro

    2011-01-01

    This paper presents the successful integration of the evaluation engine of Mooshak into the open source learning management system Claroline. Mooshak is an open source online automatic judge that has been used for international and national programming competitions. although it was originally designed for programming competitions, Mooshak has also…

  4. Integrated Geophysical Detection of DNAPL Source Zones

    NASA Astrophysics Data System (ADS)

    2001-11-01

    Identification of subsurface organic contamination, particularly dense nonaqueous phase liquids (DNAPLs) is one of the highest priorities - and among the most difficult - for remediation of numerous sites, including those of the DOD and DOE. Complex resistivity (CR) is the only geophysical method that has been demonstrated in the laboratory to have high sensitivity to organic compounds, by detecting responses indicative of clay-organic electrochemistry. However, direct detection of organics in the field has been elusive, in part due to the difficulty of obtaining robust measurements at very low contaminant levels in the presence of heterogeneous geological materials and cultural interference (such as metallic utilities and remediation plumbing). This project sought to improve the capability to detect DNAPL by (1) better geophysical imaging of geological pathways that control DNAPL movement and (2) direct detection by detailed comparison of CR lab to field data using this improved imaging. For the first goal, algorithms were developed for the joint tomographic imaging of seismic and resistivity data. The method requires that an empirical relationship can be established between seismic and resistivity; if values are ultimately tied to specific lithologies, then the final tomographic product can be an actual geological cross-section. Because shallow subsurface investigations are now commonly performed using a cone penetrometer (CPT) a new vibratory seismic source was developed to identify sites with clay-organic reactions measurable in the lab from core samples, perform reconnaissance field surveys, and proceed to detailed 2D or 3D cross-hole imaging.

  5. The effects of four insect growth-regulating (IGR) insecticides on honeybee (Apis mellifera L.) colony development, queen rearing and drone sperm production.

    PubMed

    Thompson, Helen M; Wilkins, Selwyn; Battersby, Alastair H; Waite, Ruth J; Wilkinson, David

    2005-10-01

    This study assessed the effects of exposure to IGRs on the long-term development of the honeybee colony, viability of queens and sperm production in drones and integrated the data into a honeybee population model. Colonies treated with diflubenzuron resulted in a short-term reduction in the numbers of adult bees and brood. Colonies treated with fenoxycarb declined during the season earlier and started the season slower. The number of queens that successfully mated and laid eggs was affected in the fenoxycarb treatment group but there were no significant differences in the drone sperm counts between the colonies. An existing honeybee population model was modified to include exposure to IGRs. In the model, fenoxycarb reduced the winter size of the colony, with the greatest effects following a June or an August application. Assuming a 'larvae per nurse bee' ratio of 1.5 for brood rearing capability, the reduction in winter size of a colony following a fenoxycarb application was at its worst about 8%. However, even if only those bees reared within 2 weeks of the IGR being applied are subject to premature ageing, this might significantly reduce the size of over-wintering colonies, and increase the chance of the bee population dwindling and dying in late winter or early spring. PMID:16160749

  6. Building a global normalized ontology for integrating geographic data sources

    NASA Astrophysics Data System (ADS)

    Buccella, Agustina; Cechich, Alejandra; Gendarmi, Domenico; Lanubile, Filippo; Semeraro, Giovanni; Colagrossi, Attilio

    2011-07-01

    Nowadays, the proliferation of geographic information systems has caused great interest in integration. However, an integration process is not as simple as joining several systems, since any effort at information sharing runs into the problem of semantic heterogeneity, which requires the identification and representation of all semantics useful in performing schema integration. On several research lines, including research on geographic information system integration, ontologies have been introduced to facilitate knowledge sharing among various agents. Particularly, one of the aspects of ontology sharing is performing some sort of mapping between ontology constructs. Further, some research suggests that we should also be able to combine ontologies where the product of this combination will be, at the very least, the intersection of the two given ontologies. However, few approaches built integrations upon standard and normalized information, which might improve accuracy of mappings and therefore commitment and understandability of the integration. In this work, we propose a novel system (called GeoMergeP) to integrate geographic sources by formalizing their information as normalized ontologies. Our integral merging process—including structural, syntactic and semantic aspects—assists users in finding the more suitable correspondences. The system has been empirically tested in the context of projects of the Italian Institute for Environmental Protection and Research (ISPRA, ex APAT), providing a consistent and complete integration of their sources.

  7. Integrated spatial multiplexing of heralded single-photon sources

    PubMed Central

    Collins, M.J.; Xiong, C.; Rey, I.H.; Vo, T.D.; He, J.; Shahnia, S.; Reardon, C.; Krauss, T.F.; Steel, M.J.; Clark, A.S.; Eggleton, B.J.

    2013-01-01

    The non-deterministic nature of photon sources is a key limitation for single-photon quantum processors. Spatial multiplexing overcomes this by enhancing the heralded single-photon yield without enhancing the output noise. Here the intrinsic statistical limit of an individual source is surpassed by spatially multiplexing two monolithic silicon-based correlated photon pair sources in the telecommunications band, demonstrating a 62.4% increase in the heralded single-photon output without an increase in unwanted multipair generation. We further demonstrate the scalability of this scheme by multiplexing photons generated in two waveguides pumped via an integrated coupler with a 63.1% increase in the heralded photon rate. This demonstration paves the way for a scalable architecture for multiplexing many photon sources in a compact integrated platform and achieving efficient two-photon interference, required at the core of optical quantum computing and quantum communication protocols. PMID:24107840

  8. Insect growth regulators: I. Biological activity of some IGR's against the susceptible and resistant strains of Culex pipiens larvae. II. Pattern of cross resistance to IGR's in carbaryl-resistant strain.

    PubMed

    Bakr, R F; Abo Gabal, N M; Hussein, M A

    1989-12-01

    The biological activity and cross-resistance of some IGR's, Dimilin, BAY SIR 8514 and Chlorofluzuron against susceptible and carbaryl-resistant strains of Culex pipiens were determined. The results indicated that these compounds are highly effective against the larvae of C. pipiens but more potent larvicides against the susceptible larvae than against the resistant ones. The pattern of cross-resistance to the used IGR's in the carbaryl-resistant strain were obtained. The data revealed no three IGR's as larvicides against the susceptible and resistant Culex pipiens. The pattern of cross resistance to other potent IGR's was also studies. PMID:2504825

  9. Identifying IGR J14091-6108 as a magnetic CV with a massive white dwarf using X-ray and optical observations

    NASA Astrophysics Data System (ADS)

    Tomsick, John A.; Rahoui, Farid; Krivonos, Roman; Clavel, Maïca; Strader, Jay; Chomiuk, Laura

    2016-07-01

    INTEGRAL Gamma-Ray (IGR) J14091-6108 is a Galactic X-ray source known to have an iron emission line, a hard X-ray spectrum, and an optical counterpart. Here, we report on X-ray observations of the source with XMM-Newton and NuSTAR as well as optical spectroscopy with European Southern Obseratory/Very Large Telescope and National Optical Astronomy Observatory/Southern Astrophysical Research Telescope. In the X-rays, this provides data with much better statistical quality than the previous observations, and this is the first report of the optical spectrum. Timing analysis of the XMM data shows a very significant detection of 576.3 ± 0.6 s period. The signal has a pulsed fraction of 30 ± 3 per cent in the 0.3-12 keV range and shows a strong drop with energy. The optical spectra show strong emission lines with significant variability in the lines and continuum, indicating that they come from an irradiated accretion disc. Based on these measurements, we identify the source as a magnetic cataclysmic variable of intermediate polar (IP) type where the white dwarf spin period is 576.3 s. The X-ray spectrum is consistent with the continuum emission mechanism being due to thermal bremsstrahlung, but partial covering absorption and reflection are also required. In addition, we use the IP mass model, which suggests that the white dwarf in this system has a high mass, possibly approaching the Chandrasekhar limit.

  10. Information Integration from Semantically Heterogeneous Biological Data Sources.

    PubMed

    Caragea, Doina; Bao, Jie; Pathak, Jyotishman; Silvescu, Adrian; Andorf, Carson; Dobbs, Drena; Honavar, Vasant

    2005-08-26

    We present the first prototype of INDUS (Intelligent Data Understanding System), a federated, query-centric system for information integration and knowledge acquisition from distributed, semantically heterogeneous data sources that can be viewed (conceptually) as tables. INDUS employs ontologies and inter-ontology mappings, to enable a user to view a collection of such data sources (regardless of location, internal structure and query interfaces) as though they were a collection of tables structured according to an ontology supplied by the user. This allows INDUS to answer user queries against distributed, semantically heterogeneous data sources without the need for a centralized data warehouse or a common global ontology. PMID:20802821

  11. Better Assessment Science Integrating Point and Nonpoint Sources

    EPA Science Inventory

    Better Assessment Science Integrating Point and Nonpoint Sources (BASINS) is not a model per se, but is a multipurpose environmental decision support system for use by regional, state, and local agencies in performing watershed- and water-quality-based studies. BASI...

  12. The Influence of Sourcing and Relatedness on Event Integration

    ERIC Educational Resources Information Center

    Kim, Hyun-Jeong Joyce; Millis, Keith

    2006-01-01

    This study investigated the influence of sourcing and relatedness on the integration of events embedded in simple stories. Participants read pairs of "breaking news stories" from either 1 or 2 news agencies that were believed to be from the Internet. The stories within each pair were either related by virtue of shared situational dimensions (e.g.,…

  13. Method and system of integrating information from multiple sources

    DOEpatents

    Alford, Francine A.; Brinkerhoff, David L.

    2006-08-15

    A system and method of integrating information from multiple sources in a document centric application system. A plurality of application systems are connected through an object request broker to a central repository. The information may then be posted on a webpage. An example of an implementation of the method and system is an online procurement system.

  14. Chinese Localisation of Evergreen: An Open Source Integrated Library System

    ERIC Educational Resources Information Center

    Zou, Qing; Liu, Guoying

    2009-01-01

    Purpose: The purpose of this paper is to investigate various issues related to Chinese language localisation in Evergreen, an open source integrated library system (ILS). Design/methodology/approach: A Simplified Chinese version of Evergreen was implemented and tested and various issues such as encoding, indexing, searching, and sorting…

  15. Integrating Multi-Source Imagery Data in a GIS System

    NASA Astrophysics Data System (ADS)

    Liu, Q.

    2013-07-01

    More and more volumes of high quality imagery data are becoming available than ever and it brings a challenge to the industry on how to integrate data from multi-sources effectively and timely to extract information of improved accuracy for a widespread field of applications. Over the past decade, we have witnessed the advance of tightening integration of imagery data in a GIS system. Imagery data takes advantage of the geodatabase management architecture and enriches the GIS system. Empowered with intuitive user interface and advanced tools, ArcGIS provides a great platform for one-stop integration of multi-source, multi-resolution, and multi-temporal imagery data with pre-processing, managing, visualizing, analyzing and sharing functionalities. This paper will discuss some of the core imagery capabilities in ArcGIS including interactive and automatic data correction and registration, intelligent and versatile data models for data crawling, on-the-fly data processing, and data disseminating.

  16. Building integrated business environments: analysing open-source ESB

    NASA Astrophysics Data System (ADS)

    Martínez-Carreras, M. A.; García Jimenez, F. J.; Gómez Skarmeta, A. F.

    2015-05-01

    Integration and interoperability are two concepts that have gained significant prominence in the business field, providing tools which enable enterprise application integration (EAI). In this sense, enterprise service bus (ESB) has played a crucial role as the underpinning technology for creating integrated environments in which companies may connect all their legacy-applications. However, the potential of these technologies remains unknown and some important features are not used to develop suitable business environments. The aim of this paper is to describe and detail the elements for building the next generation of integrated business environments (IBE) and to analyse the features of ESBs as the core of this infrastructure. For this purpose, we evaluate how well-known open-source ESB products fulfil these needs. Moreover, we introduce a scenario in which the collaborative system 'Alfresco' is integrated in the business infrastructure. Finally, we provide a comparison of the different open-source ESBs available for IBE requirements. According to this study, Fuse ESB provides the best results, considering features such as support for a wide variety of standards and specifications, documentation and implementation, security, advanced business trends, ease of integration and performance.

  17. Multiwavelength study of the transient X-ray binary IGR J01583+6713

    NASA Astrophysics Data System (ADS)

    Kaur, Ramanpreet; Paul, Biswajit; Kumar, Brijesh; Sagar, Ram

    2008-06-01

    We have investigated multiband optical photometric variability and stability of the Hα line profile of the transient X-ray binary IGR J01583+6713. We set an upper limit of 0.05 mag on photometric variations in the V band over a time-scale of three months. The Hα line is found to consist of non-Gaussian profile and quite stable for a duration of two months. We have identified the spectral type of the companion star to be B2 IVe while the distance to the source is estimated to be ~4.0 kpc. Along with the optical observations, we have also carried out analysis of X-ray data from three short observations of the source, two with the Swift-XRT and one with the RXTE-PCA. We have detected a variation in the absorption column density, from a value of 22.0 × 1022 cm-2 immediately after the outburst down to 2.6 × 1022 cm-2 four months afterwards. In the quiescent state, the X-ray absorption is consistent with the optical reddening measurement of E(B - V) = 1.46 mag. From one of the Swift observations, during which the X-ray intensity was higher, we have a possible pulse detection with a period of 469.2 s. For a Be X-ray binary, this indicates an orbital period in the range of 216-561 d for this binary system.

  18. OpenStudio: An Open Source Integrated Analysis Platform; Preprint

    SciTech Connect

    Guglielmetti, R.; Macumber, D.; Long, N.

    2011-12-01

    High-performance buildings require an integrated design approach for all systems to work together optimally; systems integration needs to be incorporated in the earliest stages of design for efforts to be cost and energy-use effective. Building designers need a full-featured software framework to support rigorous, multidisciplinary building simulation. An open source framework - the OpenStudio Software Development Kit (SDK) - is being developed to address this need. In this paper, we discuss the needs that drive OpenStudio's system architecture and goals, provide a development status report (the SDK is currently in alpha release), and present a brief case study that illustrates its utility and flexibility.

  19. Suzaku Captures a Possible Eclipse in IGR J16207-5129 and Identifies a Weak-Flaring State in IGR J17391-3021

    NASA Technical Reports Server (NTRS)

    Bodaghee, Arash; Tomsick, John A.; Rodriquez, Jerome; Chaty, Sylvain; Pottschmidt, Katja; Walter, Roland; Romano, Patrizia

    2011-01-01

    We present the results from analyses of Suzaku observations of the supergiant X-ray binaries IGR Jl6207-5129 and IGR Jl7391-3021. For IGR Jl6207-5129, we provide the first broadband (0.5-60 keV) spectrum from which we confirm a large intrinsic column density (N(sub H) = 16 X 10(exp 22)/square cm), and constrain the cutoff energy for the first time (E(sub c) 19 keV). We observed a prolonged (> 30 ks) attenuation of the X-ray flux which we tentatively attribute to an eclipse of the probable neutron star by its massive companion. For IGR Jl739J-3021, we witnessed a transition from quiescence to a low-activity phase punctuated by weak flares whose peak luminosities in the 0.5-10 keV band are only a factor of 5 times that of the pre-flare emission. The weak flaring is accompanied by an increase in the absorbing column which suggests the accretion of obscuring clumps of wind. Placing this observation in the context of the recent Swift monitoring campaign, we now recognize that these low-activity epochs constitute the most common emission phase for this system, and perhaps in other supergiant fast X-ray transients (SFXTs) as well.

  20. Evaluated Rayleigh integrals for pulsed planar expanding ring sources

    SciTech Connect

    Warshaw, S.I.

    1985-12-20

    Time-domain analytic and semianalytic pressure fields acoustically radiated from expanding pulsed ring sources imbedded in a planar rigid baffle have been calculated. The source functions are radially symmetric delta-function distributions whose amplitude and argument have simple functional dependencies on radius and time. Certain cases yield closed analytic results, while others result in elliptic integrals, which are evaluated to high accuracy by Gauss-Chebyshev and modified Gauss-Legendre quadrature. These results are of value for calibrating computer simulations and convolution procedures, and estimating fields from more complex planar radiators. 3 refs., 4 figs.

  1. Interplay between heartbeat oscillations and wind outflow in microquasar IGR J17091-3624

    NASA Astrophysics Data System (ADS)

    Janiuk, Agnieszka; Grzedzielski, Mikolaj; Capitanio, Fiamma; Bianchi, Stefano

    2015-02-01

    Aims: During the bright outburst in 2011, the black hole candidate IGR J17091-3624 exhibited strong quasi-periodic flare-like events (on timescales of tens of seconds) in some characteristic states, the so-called heartbeat state. From the theoretical point of view, these oscillations may be modeled by the process of accretion disk instability, driven by the dominant radiation pressure and enhanced heating of the plasma. Although the mean accretion rate in this source is probably below the Eddington limit, the oscillations will still have large amplitudes. As the observations show, the source can exhibit strong wind outflow during the soft state. This wind may help to partially or even completely stabilize the heartbeat. Methods: Using our hydrodynamical code GLADIS, we modeled the evolution of an accretion disk responsible for X-ray emission of the source. We accounted for a variable wind outflow from the disk surface. We examined the data archive from the Chandra and XMM-Newton satellites to find the observed limitations on the wind physical properties, such as its velocity and ionization state. We also investigated the long-term evolution of this source, which lasted over about 600 days of observations, using the data collected by the Swift and RXTE satellites. During this long period, the oscillations pattern and the observable wind properties changed systematically. Results: We found that this source probably exhibits observable outbursts of appropriate timescales and amplitudes as a result of the disk instability. Our model requires a substantial wind component to explain the proper variability pattern, and even complete suppression of flares in some states. The wind mass-loss rate extracted from the data agrees quantitatively well with our scenario.

  2. How to Integrate Variable Power Source into a Power Grid

    NASA Astrophysics Data System (ADS)

    Asano, Hiroshi

    This paper discusses how to integrate variable power source such as wind power and photovoltaic generation into a power grid. The intermittent renewable generation is expected to penetrate for less carbon intensive power supply system, but it causes voltage control problem in the distribution system, and supply-demand imbalance problem in a whole power system. Cooperative control of customers' energy storage equipment such as water heater with storage tank for reducing inverse power flow from the roof-top PV system, the operation technique using a battery system and the solar radiation forecast for stabilizing output of variable generation, smart charging of plug-in hybrid electric vehicles for load frequency control (LFC), and other methods to integrate variable power source with improving social benefits are surveyed.

  3. Neuronal integration of dynamic sources: Bayesian learning and Bayesian inference

    NASA Astrophysics Data System (ADS)

    Siegelmann, Hava T.; Holzman, Lars E.

    2010-09-01

    One of the brain's most basic functions is integrating sensory data from diverse sources. This ability causes us to question whether the neural system is computationally capable of intelligently integrating data, not only when sources have known, fixed relative dependencies but also when it must determine such relative weightings based on dynamic conditions, and then use these learned weightings to accurately infer information about the world. We suggest that the brain is, in fact, fully capable of computing this parallel task in a single network and describe a neural inspired circuit with this property. Our implementation suggests the possibility that evidence learning requires a more complex organization of the network than was previously assumed, where neurons have different specialties, whose emergence brings the desired adaptivity seen in human online inference.

  4. Towards A Topological Framework for Integrating Semantic Information Sources

    SciTech Connect

    Joslyn, Cliff A.; Hogan, Emilie A.; Robinson, Michael

    2014-09-07

    In this position paper we argue for the role that topological modeling principles can play in providing a framework for sensor integration. While used successfully in standard (quantitative) sensors, we are developing this methodology in new directions to make it appropriate specifically for semantic information sources, including keyterms, ontology terms, and other general Boolean, categorical, ordinal, and partially-ordered data types. We illustrate the basics of the methodology in an extended use case/example, and discuss path forward.

  5. Survey of insect growth regulator (IGR) resistance in house flies (Musca domestica L.) from southwestern Turkey.

    PubMed

    Cetin, Huseyin; Erler, Fedai; Yanikoglu, Atila

    2009-12-01

    Insect growth regulators (IGRs) are currently the fastest-growing class of insecticides, and in Turkey these products represent a new approach to pest control. In recent years, several IGRs were also registered for the control of the house fly, Musca domestica L. (Diptera: Muscidae), in Turkey. A field survey was conducted in the summers of 2006 and 2007 to evaluate resistance to some agriculturally and medically used IGRs on house flies from livestock farms and garbage dumps in the greenhouse production areas (Merkez, Kumluca, Manavgat, and Serik) of Antalya province (Southwestern Turkey). The results of larval feeding assay with technical diflubenzuron, methoprene, novaluron, pyripoxyfen, and triflumuron indicate that low levels (RF<10-fold) of resistance to the IGRs exist in the house fly populations from Antalya province. Exceptions, however, were two populations, Guzoren and Toptas, from the Kumluca area which showed moderate resistance to diflubenzuron with 11.8-fold in 2006 and 13.2-fold in 2007, respectively. We found substantial variation in susceptibility of field-collected house fly populations from year to year and from product to product. We generally observed an increase in resistance at many localities sampled from 2006 to 2007. The implications of these results to the future use of IGRs for house fly control are discussed. It will be critically important to continue monitoring efforts so that appropriate steps can be taken if resistance levels start to increase. PMID:20836837

  6. Fiber-integrated 780 nm source for visible parametric generation.

    PubMed

    Hu, D J J; Murray, R T; Legg, T; Runcorn, T H; Zhang, M; Woodward, R I; Lim, J L; Wang, Y; Luan, F; Gu, B; Shum, P P; Kelleher, E J R; Popov, S V; Taylor, J R

    2014-12-01

    We report the development of a fully fiber-integrated pulsed master oscillator power fibre amplifier (MOPFA) source at 780 nm, producing 3.5 W of average power with 410 ps pulses at a repetition rate of 50 MHz. The source consists of an intensity modulated 1560 nm laser diode amplified in an erbium fiber amplifier chain, followed by a fiber coupled periodically poled lithium niobate crystal module for frequency doubling. The source is then used for generating visible light through four-wave mixing in a length of highly nonlinear photonic crystal fiber: 105 mW at 668 nm and 95 mW at 662 nm are obtained, with pump to anti-Stokes conversion slope efficiencies exceeding 6% in both cases. PMID:25606903

  7. XMM-Newton discovery of mHz quasi-periodic oscillations in the high-mass X-ray binary IGR J19140+0951

    NASA Astrophysics Data System (ADS)

    Sidoli, L.; Esposito, P.; Motta, S. E.; Israel, G. L.; Rodríguez Castillo, G. A.

    2016-08-01

    We report on the discovery of mHz quasi-periodic oscillations (QPOs) from the high-mass X-ray binary (HMXB) IGR J19140+0951, during a 40 ks XMM-Newton observation performed in 2015, which caught the source in its faintest state ever observed. At the start of the observation, IGR J19140+0951 was at a low flux of 2 × 10-12 erg cm-2 s-1 (2-10 keV; LX = 3 × 1033 erg s-1 at 3.6 kpc), then its emission rose reaching a flux ˜10 times higher, in a flare-like activity. The investigation of the power spectrum reveals the presence of QPOs, detected only in the second part of the observation, with a strong peak at a frequency of 1.46 ± 0.07 mHz, together with higher harmonics. The X-ray spectrum is highly absorbed (NH = 1023 cm-2), well fitted by a power law with a photon index in the range 1.2-1.8. The re-analysis of a Chandra archival observation shows a modulation at ˜0.17 ± 0.05 mHz, very likely the neutron-star spin period (although a QPO cannot be excluded). We discuss the origin of the 1.46 mHz QPO in the framework of both disc-fed and wind-fed HMXBs, favouring the quasi-spherical accretion scenario. The low flux observed by XMM-Newton leads to about three orders of magnitude the source dynamic range, overlapping with the one observed from Supergiant Fast X-ray Transients (SFXTs). However, since its duty cycle is not as low as in SFXTs, IGR J19140+0951 is an intermediate system between persistent supergiant HMXBs and SFXTs, suggesting a smooth transition between these two sub-classes.

  8. Comparing the three-dimensional structures of Dicistroviridae IGR IRES RNAs with other viral RNA structures.

    PubMed

    Kieft, Jeffrey S

    2009-02-01

    The intergenic region (IGR) internal ribosome entry site (IRES) RNAs do not require any of the canonical translation initiation factors to recruit the ribosome to the viral RNA, they eliminate the need for initiator tRNA, and they begin translation from the A-site. The function of these IRESs depends on a specific three-dimensional folded RNA structure. Thus, a complete understanding of the mechanisms of action of these IRESs requires that we understand their structure in detail. Recently, the structures of both domains of the IGR IRES RNAs were solved by X-ray crystallography, providing the first glimpse into an entire IRES RNA structure. Here, I present an analysis of these structures, emphasizing how the structures explain many aspects of IGR IRES function, discussing how these structures have similarities to motifs found in other viral RNAs, and illustrating how these structures give rise to new mechanistic hypotheses. PMID:18672012

  9. Drug discovery from plant sources: An integrated approach

    PubMed Central

    Katiyar, Chandrakant; Gupta, Arun; Kanjilal, Satyajyoti; Katiyar, Shefali

    2012-01-01

    New drug discovery is facing serious challenges due to reduction in number of new drug approvals coupled with exorbitant rising cost. Advent of combinatorial chemistry provided new hope of higher success rates of new chemical entities (NCEs); however, even this scientific development has failed to improve the success rate in new drug discovery. This scenario has prompted us to come out with a novel approach of integrated drug discovery, where Ayurvedic wisdom can synergize with drug discovery from plant sources. Initial steps in new drug discovery involve identification of NCEs, which can be either sourced through chemical synthesis or can be isolated from natural products through biological activity guided fractionation. The sources of many of the new drugs and active ingredients of medicines are derived from natural products. The starting point for plant-based new drug discovery should be identification of the right candidate plants by applying Ayurvedic wisdom, traditional documented use, tribal non-documented use, and exhaustive literature search. Frequency analysis of the ingredients of the ancient documented formulations and analysis of their Ayurvedic attributes may provide an in-depth idea of the predominance of particular Ayurvedic characteristics based on which appropriate candidate plants may be selected for bioactivity-based fractionation. The integration of Ayurvedic wisdom with drug discovery also brings the need for a paradigm shift in the extraction process from sequential to parallel extraction. Bioassay-guided fractionation of the identified plant may lead to standardized extract or isolated bioactive druggable compound as the new drug. This integrated approach would lead to saving of cost and time, coupled with enhanced success rate in drug discovery. PMID:23049178

  10. Towards monolithic integration of germanium light sources on silicon chips

    NASA Astrophysics Data System (ADS)

    Saito, Shinichi; Zaher Al-Attili, Abdelrahman; Oda, Katsuya; Ishikawa, Yasuhiko

    2016-04-01

    Germanium (Ge) is a group-IV indirect band gap semiconductor, and therefore bulk Ge cannot emit light efficiently. However, the direct band gap energy is close to the indirect one, and significant engineering efforts are being made to convert Ge into an efficient gain material monolithically integrated on a Si chip. In this article, we will review the engineering challenges of developing Ge light sources fabricated using nano-fabrication technologies compatible with complementary metal-oxide-semiconductor processes. In particular, we review recent progress in applying high-tensile strain to Ge to reduce the direct band gap. Another important technique is doping Ge with donor impurities to fill the indirect band gap valleys in the conduction band. Realization of carrier confinement structures and suitable optical cavities will be discussed. Finally, we will discuss possible applications of Ge light sources in potential photonics-electronics convergent systems.

  11. Carbon Sources for Polyhydroxyalkanoates and an Integrated Biorefinery

    PubMed Central

    Jiang, Guozhan; Hill, David J.; Kowalczuk, Marek; Johnston, Brian; Adamus, Grazyna; Irorere, Victor; Radecka, Iza

    2016-01-01

    Polyhydroxyalkanoates (PHAs) are a group of bioplastics that have a wide range of applications. Extensive progress has been made in our understanding of PHAs’ biosynthesis, and currently, it is possible to engineer bacterial strains to produce PHAs with desired properties. The substrates for the fermentative production of PHAs are primarily derived from food-based carbon sources, raising concerns over the sustainability of their production in terms of their impact on food prices. This paper gives an overview of the current carbon sources used for PHA production and the methods used to transform these sources into fermentable forms. This allows us to identify the opportunities and restraints linked to future sustainable PHA production. Hemicellulose hydrolysates and crude glycerol are identified as two promising carbon sources for a sustainable production of PHAs. Hemicellulose hydrolysates and crude glycerol can be produced on a large scale during various second generation biofuels’ production. An integration of PHA production within a modern biorefinery is therefore proposed to produce biofuels and bioplastics simultaneously. This will create the potential to offset the production cost of biofuels and reduce the overall production cost of PHAs. PMID:27447619

  12. Carbon Sources for Polyhydroxyalkanoates and an Integrated Biorefinery.

    PubMed

    Jiang, Guozhan; Hill, David J; Kowalczuk, Marek; Johnston, Brian; Adamus, Grazyna; Irorere, Victor; Radecka, Iza

    2016-01-01

    Polyhydroxyalkanoates (PHAs) are a group of bioplastics that have a wide range of applications. Extensive progress has been made in our understanding of PHAs' biosynthesis, and currently, it is possible to engineer bacterial strains to produce PHAs with desired properties. The substrates for the fermentative production of PHAs are primarily derived from food-based carbon sources, raising concerns over the sustainability of their production in terms of their impact on food prices. This paper gives an overview of the current carbon sources used for PHA production and the methods used to transform these sources into fermentable forms. This allows us to identify the opportunities and restraints linked to future sustainable PHA production. Hemicellulose hydrolysates and crude glycerol are identified as two promising carbon sources for a sustainable production of PHAs. Hemicellulose hydrolysates and crude glycerol can be produced on a large scale during various second generation biofuels' production. An integration of PHA production within a modern biorefinery is therefore proposed to produce biofuels and bioplastics simultaneously. This will create the potential to offset the production cost of biofuels and reduce the overall production cost of PHAs. PMID:27447619

  13. Interacting sources of interference during sensorimotor integration processes.

    PubMed

    Mückschel, Moritz; Stock, Ann-Kathrin; Dippel, Gabriel; Chmielewski, Witold; Beste, Christian

    2016-01-15

    Every day, a multitude of interfering sensory inputs needs to be integrated and adequately processed using response selection processes. Interference effects are typically investigated using classical paradigms like the Flanker and Simon task. The sources of interference for Flanker and Simon effect are known to be different and according to dual process accounts, two distinct functional pathways are involved in resolving these types of interference. It is an open question how far these sources of interference are related to each other and interact. We investigated this question in a system neurophysiological study utilizing a hybrid paradigm combining both Flanker effect-like and Simon effect-like features. We focus on event-related theta oscillations and use beamforming methods to examine functional neuroanatomical networks. The results show that Simon and Flanker interference interacted in a non-additive fashion by modulating theta band activity, probably reflecting the recruitment of cognitive control processes. Beamforming source reconstruction revealed that theta band activity was related to a broad neuronal network comprising prefrontal and cerebellar regions, including the MFG, SFG, IFG, and SMA. These regions were connected to interference processing and conflict resolution, but differed in the amount of specificity for different sources of interference. PMID:26596550

  14. Building an Open Source Framework for Integrated Catchment Modeling

    NASA Astrophysics Data System (ADS)

    Jagers, B.; Meijers, E.; Villars, M.

    2015-12-01

    In order to develop effective strategies and associated policies for environmental management, we need to understand the dynamics of the natural system as a whole and the human role therein. This understanding is gained by comparing our mental model of the world with observations from the field. However, to properly understand the system we should look at dynamics of water, sediments, water quality, and ecology throughout the whole system from catchment to coast both at the surface and in the subsurface. Numerical models are indispensable in helping us understand the interactions of the overall system, but we need to be able to update and adjust them to improve our understanding and test our hypotheses. To support researchers around the world with this challenging task we started a few years ago with the development of a new open source modeling environment DeltaShell that integrates distributed hydrological models with 1D, 2D, and 3D hydraulic models including generic components for the tracking of sediment, water quality, and ecological quantities throughout the hydrological cycle composed of the aforementioned components. The open source approach combined with a modular approach based on open standards, which allow for easy adjustment and expansion as demands and knowledge grow, provides an ideal starting point for addressing challenging integrated environmental questions.

  15. Closer view of the IGR J11014-6103 outflows

    NASA Astrophysics Data System (ADS)

    Pavan, L.; Pühlhofer, G.; Bordas, P.; Audard, M.; Balbo, M.; Bozzo, E.; Eckert, D.; Ferrigno, C.; Filipović, M. D.; Verdugo, M.; Walter, R.

    2016-06-01

    IGR J11014-6103 (also known as the Lighthouse Nebula) is composed of a bow-shock pulsar wind nebula (PWN) and large-scale X-ray jet-like features, all powered by PSR J1101-6101. Previous observations suggest that the jet features stem from a ballistic jet of relativistic particles. In order to confirm the nature of the jet and the counter-jet, we obtained a new deep 250 ks Chandra observation of the Lighthouse Nebula. We performed detailed spatial and spectral analysis of all X-ray components of the system. The X-ray PWN is now better resolved and shows a peculiar morphology resembling the shape of an arrow. The overall helical pattern of the main jet is confirmed. However, there are large deviations from a simple helical model at small and large scales. Significant extended emission is now detected, encompassing the main jet all along its length. The presence of an apparent gap along the main jet at ~50″ distance from the pulsar is confirmed; however, the surrounding extended emission prevents conclusions on the coherence at this position of the jet. The counter-jet is now detected at high statistical significance. In addition, we found two small-scale arcs departing from the pulsar towards the jets. We also looked for possible bow-shock emission due to the pulsar motion, with a short VLT/FORS2 H-α observation. No clear emission is found, most likely because of the contamination from a diffuse nebulosity. The results of our X-ray analysis show that both a ballistic jet scenario and an alternative scenario involving the diffusion of particles along pre-existing interstellar magnetic field lines are able to satisfactorily explain some of the observational evidence, but cannot fully reproduce the observations.

  16. BioZone Exploting Source-Capability Information for Integrated Access to Multiple Bioinformatics Data Sources

    SciTech Connect

    Liu, L; Buttler, D; Paques, H; Pu, C; Critchlow

    2002-01-28

    Modern Bioinformatics data sources are widely used by molecular biologists for homology searching and new drug discovery. User-friendly and yet responsive access is one of the most desirable properties for integrated access to the rapidly growing, heterogeneous, and distributed collection of data sources. The increasing volume and diversity of digital information related to bioinformatics (such as genomes, protein sequences, protein structures, etc.) have led to a growing problem that conventional data management systems do not have, namely finding which information sources out of many candidate choices are the most relevant and most accessible to answer a given user query. We refer to this problem as the query routing problem. In this paper we introduce the notation and issues of query routing, and present a practical solution for designing a scalable query routing system based on multi-level progressive pruning strategies. The key idea is to create and maintain source-capability profiles independently, and to provide algorithms that can dynamically discover relevant information sources for a given query through the smart use of source profiles. Compared to the keyword-based indexing techniques adopted in most of the search engines and software, our approach offers fine-granularity of interest matching, thus it is more powerful and effective for handling queries with complex conditions.

  17. BioZoom: Exploiting Source-Capability Information for Integrated Access to Multiple Bioinformatics Data Sources

    SciTech Connect

    Liu, L; Buttler, D; Critchlow, T J; Han, W; Paques, H; Pu, C; Rocco, D

    2003-01-09

    Modern Bioinformatics data sources are widely used by molecular biologists for homology searching and new drug discovery. User-friendly and yet responsive access is one of the most desirable properties for integrated access to the rapidly growing, heterogeneous, and distributed collection of data sources. The increasing volume and diversity of digital information related to bioinformatics (such as genomes, protein sequences, protein structures, etc.) have led to a growing problem that conventional data management systems do not have, namely finding which information sources out of many candidate choices are the most relevant and most accessible to answer a given user query. We refer to this problem as the query routing problem. In this paper we introduce the notation and issues of query routing, and present a practical solution for designing a scalable query routing system based on multi-level progressive pruning strategies. The key idea is to create and maintain source-capability profiles independently, and to provide algorithms that can dynamically discover relevant information sources for a given query through the smart use of source profiles. Compared to the keyword-based indexing techniques adopted in most of the search engines and software, our approach offers fine-granularity of interest matching, thus it is more powerful and effective for handling queries with complex conditions.

  18. Oak Ridge Spallation Neutron Source (ORSNS) target station design integration

    SciTech Connect

    McManamy, T.; Booth, R.; Cleaves, J.; Gabriel, T.

    1996-06-01

    The conceptual design for a 1- to 3-MW short pulse spallation source with a liquid mercury target has been started recently. The design tools and methods being developed to define requirements, integrate the work, and provide early cost guidance will be presented with a summary of the current target station design status. The initial design point was selected with performance and cost estimate projections by a systems code. This code was developed recently using cost estimates from the Brookhaven Pulsed Spallation Neutron Source study and experience from the Advanced Neutron Source Project`s conceptual design. It will be updated and improved as the design develops. Performance was characterized by a simplified figure of merit based on a ratio of neutron production to costs. A work breakdown structure was developed, with simplified systems diagrams used to define interfaces and system responsibilities. A risk assessment method was used to identify potential problems, to identify required research and development (R&D), and to aid contingency development. Preliminary 3-D models of the target station are being used to develop remote maintenance concepts and to estimate costs.

  19. An integrated analysis of controlled- and passive source seismic data

    NASA Astrophysics Data System (ADS)

    Rumpfhuber, Eva-Maria

    This dissertation consists of two parts, which include a study using passive source seismic data, and one using the dataset from a large-scale refraction/wide-angle reflection seismic experiment as the basis for an integrated analysis. The goal of the dissertation is the integration of the two different datasets and a combined interpretation of the results of the "Continental Dynamics of the Rocky Mountains" (CD-ROM) 1999 seismic experiment. I have determined the crustal structure using four different receiver function methods using data collected from the northern transect of the CD-ROM passive seismic experiment. The resulting migrated image and crustal thickness determinations confirm and define prior crustal thickness measurements based on the CD-ROM and Deep Probe datasets. The new results show a very strong lower crustal layer (LCL) with variable thickness beneath the Wyoming Province. In addition, I was able to show that it terminates at 42° latitude and provide a seismic tie between the CD-ROM and Deep Probe seismic experiments so they represent a continuous N-S transect extending from New Mexico into Alberta, Canada. This new tie is particularly important because it occurs close to a major tectonic boundary, the Cheyenne belt, between an Archean craton and a Proterozoic terrane. The controlled-source seismic dataset was analyzed with the aid of forward modeling and inversion to establish a two-dimensional velocity and interface model of the area. I have developed a picking strategy, which helps identify the seismic phases, and improves quality and quantity of the picks. In addition, I was able to pick and identify S-wave phases, which furthermore allowed me to establish an independent S-wave model, and hence the Poisson's and Vp/Vs ratios. The final velocity and interface model was compared to prior results, and the results were jointly interpreted with the receiver function results. Thanks to the integration of the controlled-source and receiver function

  20. In silico gene prioritization by integrating multiple data sources.

    PubMed

    Chen, Yixuan; Wang, Wenhui; Zhou, Yingyao; Shields, Robert; Chanda, Sumit K; Elston, Robert C; Li, Jing

    2011-01-01

    Identifying disease genes is crucial to the understanding of disease pathogenesis, and to the improvement of disease diagnosis and treatment. In recent years, many researchers have proposed approaches to prioritize candidate genes by considering the relationship of candidate genes and existing known disease genes, reflected in other data sources. In this paper, we propose an expandable framework for gene prioritization that can integrate multiple heterogeneous data sources by taking advantage of a unified graphic representation. Gene-gene relationships and gene-disease relationships are then defined based on the overall topology of each network using a diffusion kernel measure. These relationship measures are in turn normalized to derive an overall measure across all networks, which is utilized to rank all candidate genes. Based on the informativeness of available data sources with respect to each specific disease, we also propose an adaptive threshold score to select a small subset of candidate genes for further validation studies. We performed large scale cross-validation analysis on 110 disease families using three data sources. Results have shown that our approach consistently outperforms other two state of the art programs. A case study using Parkinson disease (PD) has identified four candidate genes (UBB, SEPT5, GPR37 and TH) that ranked higher than our adaptive threshold, all of which are involved in the PD pathway. In particular, a very recent study has observed a deletion of TH in a patient with PD, which supports the importance of the TH gene in PD pathogenesis. A web tool has been implemented to assist scientists in their genetic studies. PMID:21731658

  1. Swift Monitoring Suggests IGR J17091-3624 is Transitioning to the Intermediate State

    NASA Astrophysics Data System (ADS)

    Court, J. M. C.; Motta, S. E.; Altamirano, D.

    2016-03-01

    The black hole candidate low mass X-Ray Binary IGR J17091-3624 was reported to re-enter outburst on 26th February 2016 by Miller et al. (ATel #8742) based on a steady rise seen in the Swift/BAT light curve.

  2. Characterizing IGR IRES-mediated translation initiation for use in yeast cell-free protein synthesis.

    PubMed

    Hodgman, C Eric; Jewett, Michael C

    2014-09-25

    Eukaryotic cell-free protein synthesis (CFPS) systems are limited, in part, by inefficient translation initiation. Here, we report three internal ribosome entry site (IRES) sequences from the Dicistroviridae family that are highly active in yeast CFPS. These include the intergenic region (IGR) IRES from cricket paralysis virus (CrPV), plautia stali intestine virus (PSIV) and Solenopsis invicta virus 1 (SINV1). Optimization of combined transcription and translation (Tx/Tl) CFPS reactions primed with linear DNA containing the CrPV IGR IRES resulted in batch synthesis yields of 0.92 ± 0.17 μg/mL luciferase. Further template engineering, such as including the first 12 nt of native CrPV gene, increased yields to 2.33 ± 0.11 μg/mL. We next observed that the inclusion of a 50 nt poly(A) to the 3' end of the IGR IRES-mediated message increased yields an additional 81% to 4.33 ± 0.37 μg/mL, without any effect on mRNA stability or copy number. This was surprising because the CrPV IGR IRES requires no known translation initiation factors. Lastly, we investigated a method to inhibit background expression through competitive inhibition by supplying the reaction with 5' cap structure analog. This study highlights the crucial role translation initiation plays in yeast CFPS and offers a simple platform to study IRES sequences. PMID:25017988

  3. A DOUBLE OUTBURST FROM IGR J00291+5934: IMPLICATIONS FOR ACCRETION DISK INSTABILITY THEORY

    SciTech Connect

    Hartman, Jacob M.; Galloway, Duncan K.; Chakrabarty, Deepto

    2011-01-01

    The accretion-powered millisecond pulsar IGR J00291+5934 underwent two {approx}10 day long outbursts during 2008, separated by 30 days in quiescence. Such a short quiescent period between outbursts has never been seen before from a neutron star X-ray transient. X-ray pulsations at the 599 Hz spin frequency are detected throughout both outbursts. For the first time, we derive a pulse phase model that connects two outbursts, providing a long baseline for spin frequency measurement. Comparison with the frequency measured during the 2004 outburst of this source gives a spin-down during quiescence of -(4 {+-} 1) x 10{sup -15} Hz s{sup -1}, approximately an order of magnitude larger than the long-term spin-down observed in the 401 Hz accretion-powered pulsar SAX J1808.4-3658. If this spin-down is due to magnetic dipole radiation, it requires a 2 x 10{sup 8} G field strength, and its high spin-down luminosity may be detectable with the Fermi Large Area Telescope. Alternatively, this large spin-down could be produced by gravitational wave emission from a fractional mass quadrupole moment of Q/I = 1 x 10{sup -9}. The rapid succession of the outbursts also provides a unique test of models for accretion in low-mass X-ray binaries. Disk instability models generally predict that an outburst will leave the accretion disk too depleted to fuel a second outburst after such a brief quiescence. We suggest a modification in which the outburst is shut off by the onset of a propeller effect before the disk is depleted. This model can explain the short quiescence and the unusually slow rise of the light curve of the second 2008 outburst.

  4. Hybrid silicon free-space source with integrated beam steering

    NASA Astrophysics Data System (ADS)

    Doylend, J. K.; Heck, M. J. R.; Bovington, J. T.; Peters, J. D.; Davenport, M. L.; Coldren, L. A.; Bowers, J. E.

    2013-02-01

    Free-space beam steering using optical phase arrays are desirable as a means of implementing Light Detection and Ranging (LIDAR) and free-space communication links without the need for moving parts, thus alleviating vulnerabilities due to vibrations and inertial forces. Implementing such an approach in silicon photonic integrated circuits is particularly desirable in order to take advantage of established CMOS processing techniques while reducing both device size and packaging complexity. In this work we demonstrate a free-space diode laser together with beam steering implemented on-chip in a silicon photonic circuit. A waveguide phased array, surface gratings, a hybrid III-V/silicon laser and an array of hybrid III/V silicon amplifiers were fabricated on-chip in order to achieve a fully integrated steerable free-space optical source with no external optical inputs, thus eliminating the need for fiber coupling altogether. The chip was fabricated using a modified version of the hybrid silicon process developed at UCSB, with modifications in order to incorporate diodes within the waveguide layer as well as within the III-V gain layer. Beam steering across a 12° field of view with +/-0.3° accuracy and 1.8°x0.6° beam width was achieved, with background peaks suppressed 7 dB relative to the main lobe within the field of view for arbitrarily chosen beam directions.

  5. Similarilies in accretion dynamics in IGR J17091-3624 and GRS 1915+105 as revealed by the study of Comptonizing Efficiency

    NASA Astrophysics Data System (ADS)

    Sarathi Pal, Partha; Chakrabarti, Sandip Kumar

    2016-07-01

    Variability classes in the enigmatic black hole candidate GRS 1915+105 are known to be correlated with the variation of the Comptonizing Efficiency (CE) which is defined to be the ratio between the number of power-law (hard) photons and seed (soft) photons injected into the Compton cloud. Similarities of light curves of several variability classes of GRS 1915+105 and IGR J17091-3624, some of which are already reported in the literature, motivated us to compute CE for IGR J17091-3624 as well. We find that they are similar to what were reported earlier for GRS 1915+105, even though masses of these objects could be different. The reason is that the both the sizes of the sources of the seed photons and of the Comptonizing corona scale in the same way as the mass of the black hole. This indicates that characterization of variability classes based on CE is likely to be black hole mass independent, in general.

  6. WHY IS IGR J17091-3624 SO FAINT? CONSTRAINTS ON DISTANCE, MASS, AND SPIN FROM 'PHASE-RESOLVED' SPECTROSCOPY OF THE 'HEARTBEAT' OSCILLATIONS

    SciTech Connect

    Rao, Anjali; Vadawale, S. V.

    2012-09-20

    IGR J17091-3624 is a transient X-ray source and is believed to be a Galactic black hole candidate. Recently, it has received considerable attention due to the detection of peculiar variability patterns known as 'heartbeats', which are quasi-periodic mini-outbursts repeated over timescales ranging between 5 and 70 s. So far, such variability patterns have been observed only in GRS 1915+105 and these are classified as {rho}- and {nu}-variability classes. Here, we present the results of 'phase-resolved' spectroscopy of the 'heartbeat' oscillations of IGR J17091-3624 using data from simultaneous observations made by RXTE and XMM-Newton. We find that the 0.7-35 keV spectra can be fitted with a 'canonical' model for black hole sources consisting of only two components-a multi-temperature disk blackbody and a power law (or its equivalent). We attempt to constrain the system parameters of the source by simultaneously fitting spectra during different phases of the burst profile while tying the system parameters across the phases. The results indicate that the source is a high inclination binary (i > 53 Degree-Sign ). Further, the observed low flux from the source can be explained only if the black hole spin is very low, along with constraints on the black hole mass (<5 M{sub Sun }) and distance (>20 kpc). For higher inclination angles, which is favored by the data, the black hole spin is required to be negative. Thus, low or retrograde spin could be the reason for the low luminosity of the source.

  7. A Close Investigation into Source Use in Integrated Second Language Writing Tasks

    ERIC Educational Resources Information Center

    Plakans, Lia; Gebril, Atta

    2012-01-01

    An increasing number of writing programs and assessments are employing writing-from-sources tasks in which reading and writing are integrated. The integration of reading and writing in such contexts raises a number of questions with regard to writers' use of sources in their writing, the functions these sources serve, and how proficiency affects…

  8. Measuring the stellar wind parameters in IGR J17544-2619 and Vela X-1 constrains the accretion physics in supergiant fast X-ray transient and classical supergiant X-ray binaries

    NASA Astrophysics Data System (ADS)

    Giménez-García, A.; Shenar, T.; Torrejón, J. M.; Oskinova, L.; Martínez-Núñez, S.; Hamann, W.-R.; Rodes-Roca, J. J.; González-Galán, A.; Alonso-Santiago, J.; González-Fernández, C.; Bernabeu, G.; Sander, A.

    2016-06-01

    Context. Classical supergiant X-ray binaries (SGXBs) and supergiant fast X-ray transients (SFXTs) are two types of high-mass X-ray binaries (HMXBs) that present similar donors but, at the same time, show very different behavior in the X-rays. The reason for this dichotomy of wind-fed HMXBs is still a matter of debate. Among the several explanations that have been proposed, some of them invoke specific stellar wind properties of the donor stars. Only dedicated empiric analysis of the donors' stellar wind can provide the required information to accomplish an adequate test of these theories. However, such analyses are scarce. Aims: To close this gap, we perform a comparative analysis of the optical companion in two important systems: IGR J17544-2619 (SFXT) and Vela X-1 (SGXB). We analyze the spectra of each star in detail and derive their stellar and wind properties. As a next step, we compare the wind parameters, giving us an excellent chance of recognizing key differences between donor winds in SFXTs and SGXBs. Methods: We use archival infrared, optical and ultraviolet observations, and analyze them with the non-local thermodynamic equilibrium (NLTE) Potsdam Wolf-Rayet model atmosphere code. We derive the physical properties of the stars and their stellar winds, accounting for the influence of X-rays on the stellar winds. Results: We find that the stellar parameters derived from the analysis generally agree well with the spectral types of the two donors: O9I (IGR J17544-2619) and B0.5Iae (Vela X-1). The distance to the sources have been revised and also agree well with the estimations already available in the literature. In IGR J17544-2619 we are able to narrow the uncertainty to d = 3.0 ± 0.2 kpc. From the stellar radius of the donor and its X-ray behavior, the eccentricity of IGR J17544-2619 is constrained to e< 0.25. The derived chemical abundances point to certain mixing during the lifetime of the donors. An important difference between the stellar winds of the

  9. Hubbell rectangular source integral calculation using a fast Chebyshev wavelets method.

    PubMed

    Manai, K; Belkadhi, K

    2016-07-01

    An integration method based on Chebyshev wavelets is presented and used to calculate the Hubbell rectangular source integral. A study of the convergence and the accuracy of the method was carried out by comparing it to previous studies. PMID:27152913

  10. Variability study of the High Mass X-ray binary IGR J18027-2016 with Swift -XRT

    NASA Astrophysics Data System (ADS)

    Aftab, Nafisa; Islam, Nazma

    2016-07-01

    We report the results from pulsations and spectral analysis of a large number of observations of the HMXB pulsar IGR J18027-2016 with Swift-XRT,carried out at different orbital phases. We found a significant intensity variations in the system at different orbital phases, higher than the orbital intensity modulation. In some orbital phases, as seen in different XRT observations, the X-ray intensity is found to vary by a large factor, of about ˜50. In all the observations with sufficient number of source X-ray photons, pulsations have been detected around the previously known pulse period of ˜140 sec, consistent with the source being a persistent pulsator. The pulse profiles,however, show a significant change from a double peaked pulse profiles in most cases to a singled peaked pulse profiles in some observations. The nature of the pulse profiles are found to be independent of the X-ray intensity. In some of the observations, a 6.4 keV Fe Kα emission line is detected with a high equivalent width (˜1 keV). The absorption column density is found to be large before and after the eclipse, consistent with most of it being due to the stellar wind of the companion star. Such X-ray intensity variations outside the X-ray eclipse and associated spectral properties indicates a variable accretion onto the neutron star, which could be caused by a clumpy nature of the stellar wind of the companion star.

  11. Swift-X-Ray Telescope Monitoring of the Candidate Supergiant Fast X-ray Transient IGR J16418-4532

    NASA Technical Reports Server (NTRS)

    Romano, P.; Mangano, V.; Ducci, L.; Esposito, P.; Evans, P. A.; Vercellone, S.; Kennea, J. A.; Burrows, D. N.; Gehrels, N.

    2012-01-01

    We report on the Swift monitoring of the candidate supergiant fast X-ray transient (SFXT) IGR J16418-4532, for which both orbital and spin periods are known (approx. 3.7 d and approx.1250 s, respectively). Our observations, for a total of approx. 43 ks, span over three orbital periods and represent the most intense and complete sampling of the light curve of this source with a sensitive X-ray instrument. With this unique set of observations, we can address the nature of this transient. By applying the clumpy wind model for blue supergiants to the observed X-ray light curve, and assuming a circular orbit, the X-ray emission from this source can be explained in terms of the accretion from a spherically symmetric clumpy wind, composed of clumps with different masses, ranging from approx. 5 × 10(exp 16) to 10(exp 21) g. Our data suggest, based on the X-ray behaviour, that this is an intermediate SFXT.

  12. Swift/XRT Monitoring of the Candidate Supergiant Fast X-ray Transient IGR J16418-4532

    NASA Technical Reports Server (NTRS)

    Romano, P.; Mangano, V.; Ducci, L.; Esposito, P.; Evans, P. A.; Vercellone, S.; Kennea, J. A.; Burrows, D. N.; Gehrels, N.

    2011-01-01

    We report on the Swift monitoring of the candidate supergiant fast X-ray transient (SFXT) IGR J16418.4532, for which both orbital and spin periods are known (approx. 3.7d and approx. 1250 s, respectively). Our observations, for a total of approx. 43 ks, span over three orbital periods and represent the most intense and complete sampling of the light curve of this source with a sensitive X-ray instrument. With this unique set of observations we can address the nature of this transient. By applying the clumpy wind model for blue supergiants to the observed X-ray light curve, and assuming a circular orbit, the X-ray emission from this source can be explained in terms of the accretion from a spherically symmetric clumpy wind, composed of clumps with different masses, ranging from 5 X 10(exp 16) g to 10(exp 21) g. Our data suggest, based on the X-ray behaviour, that this is an intermediate SFXT

  13. Fast spectral source integration in black hole perturbation calculations

    NASA Astrophysics Data System (ADS)

    Hopper, Seth; Forseth, Erik; Osburn, Thomas; Evans, Charles R.

    2015-08-01

    This paper presents a new technique for achieving spectral accuracy and fast computational performance in a class of black hole perturbation and gravitational self-force calculations involving extreme mass ratios and generic orbits. Called spectral source integration (SSI), this method should see widespread future use in problems that entail (i) a point-particle description of the small compact object, (ii) frequency domain decomposition, and (iii) the use of the background eccentric geodesic motion. Frequency domain approaches are widely used in both perturbation theory flux-balance calculations and in local gravitational self-force calculations. Recent self-force calculations in Lorenz gauge, using the frequency domain and method of extended homogeneous solutions, have been able to accurately reach eccentricities as high as e ≃0.7 . We show here SSI successfully applied to Lorenz gauge. In a double precision Lorenz gauge code, SSI enhances the accuracy of results and makes a factor of 3 improvement in the overall speed. The primary initial application of SSI—for us its the raison d'être—is in an arbitrary precision mathematica code that computes perturbations of eccentric orbits in the Regge-Wheeler gauge to extraordinarily high accuracy (e.g., 200 decimal places). These high-accuracy eccentric orbit calculations would not be possible without the exponential convergence of SSI. We believe the method will extend to work for inspirals on Kerr and will be the subject of a later publication. SSI borrows concepts from discrete-time signal processing and is used to calculate the mode normalization coefficients in perturbation theory via sums over modest numbers of points around an orbit. A variant of the idea is used to obtain spectral accuracy in a solution of the geodesic orbital motion.

  14. Development of a Residential Ground-Source Integrated Heat Pump

    SciTech Connect

    Rice, C Keith; Baxter, Van D; Hern, Shawn; McDowell, Tim; Munk, Jeffrey D; Shen, Bo

    2013-01-01

    A residential-size ground-source integrated heat pump (GSIHP) system has been developed and is currently being field tested. The system is a nominal 2-ton (7 kW) cooling capacity, variable-speed unit, which is multi-functional, e.g. space cooling, space heating, dedicated water heating, and simultaneous space cooling and water heating. High-efficiency brushless permanent-magnet (BPM) motors are used for the compressor, indoor blower, and pumps to obtain the highest component performance and system control flexibility. Laboratory test data were used to calibrate a vapor-compression simulation model (HPDM) for each of the four primary modes of operation. The model was used to optimize the internal control options and to simulate the selected internal control strategies, such as controlling to a constant air supply temperature in the space heating mode and a fixed water temperature rise in water heating modes. Equipment performance maps were generated for each operation mode as functions of all independent variables for use in TRNSYS annual energy simulations. These were performed for the GSIHP installed in a well-insulated 2600 ft2(242 m2) house and connected to a vertical ground loop heat exchanger(GLHE). We selected a 13 SEER (3.8 CSPF )/7.7 HSPF (2.3 HSPF, W/W) ASHP unit with 0.90 Energy Factor (EF) resistance water heater as the baseline for energy savings comparisons. The annual energy simulations were conducted over five US climate zones. In addition, appropriate ground loop sizes were determined for each location to meet 10-year minimum and maximum design entering water temperatures (EWTs) to the equipment. The prototype GSIHP system was predicted to use 52 to 59% less energy than the baseline system while meeting total annual space conditioning and water heating loads.

  15. IGR NO[sub x]/SO[sub x] control technology

    SciTech Connect

    Not Available

    1993-04-25

    The technical work during this reporting term has principally involved the continued development, optimization and improvement of freezing drying techniques for solid ceramic oxide electrolyte powder preparation, preliminary optimization of the calcining of the ceramic electrolyte freeze dried powders to allow for optimum processing to the IGR composite, and determining (initial) electrochemical properties of the stabilized ceramic solid electrolyte at a variety of temperatures in air.

  16. THE PECULIAR EVOLUTIONARY HISTORY OF IGR J17480-2446 IN TERZAN 5

    SciTech Connect

    Patruno, Alessandro; Alpar, M. Ali; Van der Klis, Michiel; Van den Heuvel, Ed P. J.

    2012-06-10

    The low-mass X-ray binary (LMXB) IGR J17480-2446 in the globular cluster Terzan 5 harbors an 11 Hz accreting pulsar. This is the first object discovered in a globular cluster with a pulsar spinning at such low rate. The accreting pulsar is anomalous because its characteristics are very different from the other five known slow accreting pulsars in galactic LMXBs. Many features of the 11 Hz pulsar are instead very similar to those of accreting millisecond pulsars, spinning at frequencies >100 Hz. Understanding this anomaly is valuable because IGR J17480-2446 could be the only accreting pulsar discovered so far which is in the process of becoming an accreting millisecond pulsar. We first verify that the neutron star (NS) in IGR J17480-2446 is indeed spinning up by carefully analyzing X-ray data with coherent timing techniques that account for the presence of timing noise. We then study the present Roche lobe overflow epoch and the two previous spin-down epochs dominated by magneto-dipole radiation and stellar wind accretion. We find that IGR J17480-2446 is very likely a mildly recycled pulsar and suggest that it has started a spin-up phase in an exceptionally recent time, which has lasted less than a few 10{sup 7} yr. We also find that the total age of the binary is surprisingly low ({approx}< 10{sup 8} yr) when considering typical parameters for the newborn NS and propose different scenarios to explain this anomaly.

  17. Ground Source Integrated Heat Pump (GS-IHP) Development

    SciTech Connect

    Baxter, V. D.; Rice, K.; Murphy, R.; Munk, J.; Ally, Moonis; Shen, Bo; Craddick, William; Hearn, Shawn A.

    2013-05-24

    Between October 2008 and May 2013 ORNL and ClimateMaster, Inc. (CM) engaged in a Cooperative Research and Development Agreement (CRADA) to develop a groundsource integrated heat pump (GS-IHP) system for the US residential market. A initial prototype was designed and fabricated, lab-tested, and modeled in TRNSYS (SOLAR Energy Laboratory, et al, 2010) to predict annual performance relative to 1) a baseline suite of equipment meeting minimum efficiency standards in effect in 2006 (combination of air-source heat pump (ASHP) and resistance water heater) and 2) a state-of-the-art (SOA) two-capacity ground-source heat pump with desuperheater water heater (WH) option (GSHPwDS). Predicted total annual energy savings, while providing space conditioning and water heating for a 2600 ft{sup 2} (242 m{sup 2}) house at 5 U.S. locations, ranged from 52 to 59%, averaging 55%, relative to the minimum efficiency suite. Predicted energy use for water heating was reduced 68 to 78% relative to resistance WH. Predicted total annual savings for the GSHPwDS relative to the same baseline averaged 22.6% with water heating energy use reduced by 10 to 30% from desuperheater contributions. The 1st generation (or alpha) prototype design for the GS-IHP was finalized in 2010 and field test samples were fabricated for testing by CM and by ORNL. Two of the alpha units were installed in 3700 ft{sup 2} (345 m{sup 2}) houses at the ZEBRAlliance site in Oak Ridge and field tested during 2011. Based on the steady-state performance demonstrated by the GS-IHPs it was projected that it would achieve >52% energy savings relative to the minimum efficiency suite at this specific site. A number of operational issues with the alpha units were identified indicating design changes needed to the system before market introduction could be accomplished. These were communicated to CM throughout the field test period. Based on the alpha unit test results and the diagnostic information coming from the field test

  18. BETTER ASSESSMENT SCIENCE INTEGRATING POINT AND NONPOINT SOURCES (BASINS)

    EPA Science Inventory

    BASINS IS A NEW TOOL WHICH INTEGRATES ENVIRONMENTAL DATA, GIS (ARCVIEW) AND MODELING TOOLS ON YOUR PC. BASINS INTEGRATES DATA ON WATER QUALITY FROM STORET AND DATA ON AQUATIC RESOURCES TO HELP IDENTIFY WATERBODIES WHICH MAY NOT BE MEETING WATER QUALITY STANDARDS. THE TOOL ALSO I...

  19. Photoacoustic imaging of clinical metal needle by a LED light source integrated transducer

    NASA Astrophysics Data System (ADS)

    Agano, Toshitaka; Sato, Naoto; Nakatsuka, Hitoshi; Kitagawa, Kazuo; Hanaoka, Takamitsu; Morisono, Koji; Shigeta, Yusuke; Tanaka, Chizuyo

    2016-03-01

    We have achieved penetration depth of 30mm by photoacoustic imaging system using LED light source integrated transducer to image a clinical metal needle inserted into a tissue mimicking phantom. We developed the transducer that integrated near-infrared LED array light source, which was connected to a photoacoustic imaging system which drove LED array light source and controlled photoacoustic data acquisition process. Conventionally solid-state laser has been used as the light source for photoacoustic imaging system. Because LED is diffused light source, laser safety glasses is not necessary, also inflexible fibers are not used to guide light close to a transducer, and we integrated LED light source inside the transducer, which became compact and practical size for conventional ultrasound equipment users. We made LED light source unit as detachable to the transducer easily, so wave-length of light can be selectable by changing the LED light source unit.

  20. Source Text Borrowing in an Integrated Reading/Writing Assessment

    ERIC Educational Resources Information Center

    Weigle, Sara Cushing; Parker, Keisha

    2012-01-01

    Source-based writing is becoming more common in tests of academic English, in part to make tests more reflective of authentic academic writing. However, the concern has been raised that over-reliance on language from the source texts in essays may mask gaps in proficiency and thus lead to an inaccurate assessment of writing skill. In this paper,…

  1. Evaluation of the Hubbell rectangular source integral using Haar wavelets method

    NASA Astrophysics Data System (ADS)

    Belkadhi, K.; Manai, K.

    2016-05-01

    Haar wavelets numerical integration method is exposed and used for evaluating the Hubbell rectangular source integral. The method convergence is studied to get the minimum iteration number for a desired precision. Haar wavelets results are finally compared to those obtained with other integration methods.

  2. Integrated source and channel encoded digital communication system design study

    NASA Technical Reports Server (NTRS)

    Huth, G. K.; Udalov, S.

    1974-01-01

    This study investigated the configuration and integration of a wideband communication system with a Ku-band rendezvous radar system. The goal of the study was to provide as much commonality between the two systems as possible. The antenna design was described with the only change being the requirement for dual polarization (linear for the radar system and circular for the communication system).

  3. INTEGRATED HUMAN EXPOSURE SOURCE-TO-DOSE MODELING

    EPA Science Inventory

    The NERL human exposure research program is designed to provide a sound, scientifically-based approach to understanding how people are actually exposed to pollutants and the factors and pathways influencing exposure and dose. This research project serves to integrate and incorpo...

  4. Source-Message-Receiver in Integrated Marketing Communication

    ERIC Educational Resources Information Center

    Broussard, Sharee LeBlanc

    2011-01-01

    This is an abbreviation of the author's dissertation. Because integrated marketing communication (IMC) research has traditionally been problematic, this study used an existing scale to determine that higher educational institutional advancement (alumni, marketing-communications, development) is an appropriate venue to study the process model of…

  5. Integrating Print and Electronic Resources: Joyner Library's "Pirate Source"

    ERIC Educational Resources Information Center

    Nall, Clark; Lewis, Janice Steed

    2005-01-01

    Valuable information in print is often neglected because of the rapid proliferation of electronic resources and the bias of many library users against print sources. At Joyner Library, it was decided to construct an interactive subject guide database that included resources in all formats to offer users a convenient starting point for research and…

  6. Swift observes an outburst of the high mass X-ray binary IGR J01572-7259 in the SMC

    NASA Astrophysics Data System (ADS)

    Krimm, H. A.; Kennea, J. A.; Barthelmy, S. D.; Cummings, J.; Gehrels, N.; Lien, A. Y.; Markwardt, C. B.; Palmer, D.; Sakamoto, T.; Stamatikos, M.; Ukwatta, T.

    2016-05-01

    The high-mass X-ray binary IGR J01572-7259 (IGR J015712-7259 = SXP 11.6) in the Small Magellanic Cloud is undergoing an outburst. An increase in counts was first detected in the BAT in a 4-day period beginning 15 April 2016 (MJD 57493), when it was detected at 0.0016 +/- 0.0004 ct cm-2 s-1 (~7 mCrab) . The flux peaked on 25 April 2016 (MJD 57503) at 0.0027 +/- 0.0005 ct cm-2 s-1 (~12 mCrab).

  7. Integrated Management Program Radioactive Sealed Sources in Egypt

    SciTech Connect

    Hasan, A.; Cochran, J. R.; El-Adham, K.; El-Sorougy, R.

    2003-02-26

    The radioactive materials in ''public'' locations are typically contained in small, stainless steel capsules known as sealed radiation sources (RS). These capsules seal in the radioactive materials, but not the radiation, because it is the radiation that is needed for a wide variety of applications at hospitals, medical clinics, manufacturing plants, universities, construction sites, and other facilities in the public sector. Radiation sources are readily available, and worldwide there are hundreds of thousands of RS. The IMPRSS Project is a cooperative development between the Egyptian Atomic Energy Authority (EAEA), Egyptian Ministry of Health (MOH), Sandia National Laboratories (SNL), New Mexico Tech University (NMT), and Agriculture Cooperative Development International (ACDI/VOCA). SNL will coordinate the work scope between the participant organizations.

  8. Integrating HCI Specialists into Open Source Software Development Projects

    NASA Astrophysics Data System (ADS)

    Hedberg, Henrik; Iivari, Netta

    Typical open source software (OSS) development projects are organized around technically talented developers, whose communication is based on technical aspects and source code. Decision-making power is gained through proven competence and activity in the project, and non-technical end-user opinions are too many times neglected. In addition, also human-computer interaction (HCI) specialists have encountered difficulties in trying to participate in OSS projects, because there seems to be no clear authority and responsibility for them. In this paper, based on HCI and OSS literature, we introduce an extended OSS development project organization model that adds a new level of communication and roles for attending human aspects of software. The proposed model makes the existence of HCI specialists visible in the projects, and promotes interaction between developers and the HCI specialists in the course of a project.

  9. A CHANDRA OBSERVATION OF THE BURSTING MILLISECOND X-RAY PULSAR IGR J17511-3057

    SciTech Connect

    Paizis, A.; Nowak, M. A.; Rodriguez, J.; Chaty, S.; Del Santo, M.; Ubertini, P. E-mail: mnowak@space.mit.edu

    2012-08-10

    IGR J17511-3057 is a low-mass X-ray binary hosting a neutron star and is one of the few accreting millisecond X-ray pulsars with X-ray bursts. We report on a 20 ks Chandra grating observation of IGR J17511-3057, performed on 2009 September 22. We determine the most accurate X-ray position of IGR J17511-3057, {alpha}{sub J2000} = 17{sup h}51{sup m}08.{sup s}66, {delta}{sub J2000} = -30 Degree-Sign 57'41.''0 (90% uncertainty of 0.''6). During the observation, a {approx}54 s long type-I X-ray burst is detected. The persistent (non-burst) emission has an absorbed 0.5-8 keV luminosity of 1.7 Multiplication-Sign 10{sup 36} erg s{sup -1} (at 6.9 kpc) and can be well described by a thermal Comptonization model of soft, {approx}0.6 keV, seed photons upscattered by a hot corona. The type-I X-ray burst spectrum, with average luminosity over the 54 s duration L{sub 0.5-8{sub keV}} = 1.6 Multiplication-Sign 10{sup 37} erg s{sup -1}, can be well described by a blackbody with kT{sub bb} {approx} 1.6 keV and R{sub bb} {approx} 5 km. While an evolution in temperature of the blackbody can be appreciated throughout the burst (average peak kT{sub bb} = 2.5{sup +0.8}{sub -0.4} keV to tail kT{sub bb} = 1.3{sup +0.2}{sub -0.1} keV), the relative emitting surface shows no evolution. The overall persistent and type-I burst properties observed during the Chandra observation are consistent with what was previously reported during the 2009 outburst of IGR J17511-3057.

  10. GROND optical/NIR and Swift/XRT observation of IGR J17091-3624

    NASA Astrophysics Data System (ADS)

    Greiner, J.; Bolmer, J.; Gandhi, P.; Altamirano, D.; Charles, P. A.; Court, J. M.; Kann, D. A.; Walton, D. J.

    2016-03-01

    The black hole transient IGR J17091-3624, similar in X-ray behaviour to GRS 1915+105 (Greiner et al. 1996, ApJ 473, L107; Altamirano et al. 2011, ApJ 742, 17; Altamirano & Belloni 2012, ApJ 747, 4), has been recently reported to be in outburst based on an increased Swift/BAT rate and subsequent Swift/XRT ToO (Miller et al. 2016, ATel #8742; Grinberg et al. 2016, ATel #8761 and Barthelmy et al. 2016, GCN #19155 -- Swift/BAT Trigger 677981).

  11. Swift observations of a new outburst of the SFXT IGR J17544-2619

    NASA Astrophysics Data System (ADS)

    Romano, P.; Krimm, H.; Sakamoto, T.; Burrows, D. N.; Barthelmy, S. D.; Chester, M. M.; D'Avanzo, P.; Kennea, J. A.; Esposito, P.; Evans, P. A.; Gehrels, N.; Mangano, V.; Palmer, D. M.; Sbarufatti, B.; Vercellone, S.

    2012-07-01

    The Swift Burst Alert Telescope (BAT) triggered on a new outburst from the Supergiant Fast X-ray Transient (SFXT) IGR J17544-2619 on 2012 July 24 at 04:52:46 (image trigger=528432). Swift immediately slewed to the target, so that the narrow field instruments started observing about 398.9 s after the trigger. Using the BAT data set from T-239 to T+963 s from the full telemetry downlink, we report that the time-averaged spectrum from T+0 to T+320 s is best fit by a simple power-law model with a photon index of 2.71 +/- 0.85.

  12. Spectroscopic observations of the counterpart of IGR J00291+5934

    NASA Astrophysics Data System (ADS)

    Roelofs, G.; Jonker, P. G.; Steeghs, D.; Torres, M.; Nelemans, G.

    2004-12-01

    Spectroscopic observations of the optical counterpart of the millisecond X-ray pulsar IGR J00291+5934 (Atel #352, 353) reported in an Atel by Fox & Kulkarni were obtained (Dec 5 00:29-01:15 UT) with the ISIS spectrograph mounted on the 4.2m William Herschel Telescope on La Palma. Weather conditions were not optimal with a seeing of ~2" and thin clouds. The spectra show weak evidence for broad emission line features near the HeII line at 4686 Angstrom and near the Halpha line at 6563 Angstrom.

  13. Integrated source and channel encoded digital communications system design study

    NASA Technical Reports Server (NTRS)

    Huth, G. K.

    1974-01-01

    Studies on the digital communication system for the direct communication links from ground to space shuttle and the links involving the Tracking and Data Relay Satellite (TDRS). Three main tasks were performed:(1) Channel encoding/decoding parameter optimization for forward and reverse TDRS links,(2)integration of command encoding/decoding and channel encoding/decoding; and (3) modulation coding interface study. The general communication environment is presented to provide the necessary background for the tasks and to provide an understanding of the implications of the results of the studies.

  14. Characterization and application of a LED-driven integrating sphere source

    NASA Astrophysics Data System (ADS)

    Ding, Leibo; Georgieva, Elena M.; Butler, James J.; Cooper, John W.; Georgiev, Georgi T.; Smith, Gilbert R.

    2015-09-01

    A Light-Emitting Diode (LED)-driven integrating sphere light source has been fabricated and assembled in the NASA Goddard Space Flight Center (GSFC) Code 618 Biospheric Sciences Laboratory's Calibration Facility. This light source is a 30.5 cm diameter integrating sphere lined with Spectralon. A set of four LEDs of different wavelengths are mounted on the integrating sphere's wall ports. A National Institute of Standards and Technology (NIST) characterized Si detector is mounted on a port to provide real-time monitoring data for reference. The measurement results presented here include the short-term and long-term stability and polarization characterization of the output from this LED-driven integrating sphere light source. As an initial application, this light source is used to characterize detector/pre-amplifier gain linearity in light detection systems. The measurement results will be presented and discussed.

  15. Development of alternate methods of determining integrated SMR source terms

    SciTech Connect

    Barry, Kenneth

    2014-06-10

    The Nuclear Energy Institute (NEI) Small Modular Reactor (SMR) Licensing Task Force (TF) has been evaluating licensing issues unique and important to iPWRs, ranking these issues, and developing NEI position papers for submittal to the U.S. Nuclear Regulatory Commission (NRC) during the past three years. Papers have been developed and submitted to the NRC in a range of areas including: Price-Anderson Act, NRC annual fees, security, modularity, and staffing. In December, 2012, NEI completed a draft position paper on SMR source terms and participated in an NRC public meeting presenting a summary of this paper, which was subsequently submitted to the NRC. One important conclusion of the source term paper was the evaluation and selection of high importance areas where additional research would have a significant impact on source terms. The highest ranked research area was iPWR containment aerosol natural deposition. The NRC accepts the use of existing aerosol deposition correlations in Regulatory Guide 1.183, but these were developed for large light water reactor (LWR) containments. Application of these correlations to an iPWR design has resulted in greater than a ten-fold reduction of containment airborne aerosol inventory as compared to large LWRs. Development and experimental justification of containment aerosol natural deposition correlations specifically for the unique iPWR containments is expected to result in a large reduction of design basis and beyond-design-basis accident source terms with concomitantly smaller dose to workers and the public. Therefore, NRC acceptance of iPWR containment aerosol natural deposition correlations will directly support the industry’s goal of reducing the Emergency Planning Zone (EPZ) for SMRs. Based on the results in this work, it is clear that thermophoresis is relatively unimportant for iPWRs. Gravitational settling is well understood, and may be the dominant process for a dry environment. Diffusiophoresis and enhanced

  16. Normal incidence collector for LPP sources with integrated debris mitigation

    NASA Astrophysics Data System (ADS)

    Giovannini, Andrea Z.; Dieterich, Franz; Henderson, Ian; Chokani, Ndaona; Abhari, Reza S.

    2010-04-01

    The leading candidate for the manufacture of next generation semi-conductor devices is extreme ultraviolet lithography, with laser-produced plasmas as a candidate 13.5nm light source. A primary challenge for continuous operation is elimination of the debris load on the collector, without compromising the radiation intensity at the intermediate focus. A novel combination of thermal management and debris mitigation is developed in order to reduce the deformation and degradation of collector optics. This patent-pending novel debris mitigation technique enables the continuous operation of the source. The paper shows atomic force microscope measurements of the collector surface deposition. The debris mitigation system run at 50% design operating condition gives 90% debris mitigation effectiveness. The average temperature of the cooled collector is 36.5°C at the design point, with a peak-to-peak difference of 0.8°C. The collector geometry, after being adapted to compensate the thermal deformation, yields a spot size of 30μm at IF. Computational simulations, using ETH's multi-scale computational tools, complement the presented experimental results.

  17. An Integrated Risk Management Model for Source Water Protection Areas

    PubMed Central

    Chiueh, Pei-Te; Shang, Wei-Ting; Lo, Shang-Lien

    2012-01-01

    Watersheds are recognized as the most effective management unit for the protection of water resources. For surface water supplies that use water from upstream watersheds, evaluating threats to water quality and implementing a watershed management plan are crucial for the maintenance of drinking water safe for humans. The aim of this article is to establish a risk assessment model that provides basic information for identifying critical pollutants and areas at high risk for degraded water quality. In this study, a quantitative risk model that uses hazard quotients for each water quality parameter was combined with a qualitative risk model that uses the relative risk level of potential pollution events in order to characterize the current condition and potential risk of watersheds providing drinking water. In a case study of Taipei Source Water Area in northern Taiwan, total coliforms and total phosphorus were the top two pollutants of concern. Intensive tea-growing and recreational activities around the riparian zone may contribute the greatest pollution to the watershed. Our risk assessment tool may be enhanced by developing, recording, and updating information on pollution sources in the water supply watersheds. Moreover, management authorities could use the resultant information to create watershed risk management plans. PMID:23202770

  18. The role of octopamine receptor agonists in the synergistic toxicity of certain insect growth regulators (IGRs) in controlling Dengue vector Aedes aegypti (Diptera: Culicidae) mosquito.

    PubMed

    Ahmed, Mohamed Ahmed Ibrahim; Vogel, Christoph Franz Adam

    2016-03-01

    The synergistic action of octopamine receptor agonists (OR agonists) on many insecticide classes (e.g., organophosphorus, pyrethroids, and neonicotinoids) on Aedes aegypti L. has been reported recently. An investigation of OR agonist's effect on insect growth regulators (IGRs) was undertaken to provide a better understanding of the mechanism of action. Based on the IGR bioassay, pyriproxyfen was the most potent IGR insecticide tested (EC50=0.0019ng/ml). However, the lethal toxicity results indicate that diafenthiuron was the most potent insecticide (LC50=56ng/cm(2)) on A. aegypti adults after 24h of exposure. The same trend was true after 48 and 72h of exposure. Further, the synergistic effects of OR agonists plus amitraz (AMZ) or chlordimeform (CDM) was significant on adults. Among the tested synergists, AMZ increased the potency of the selected IGRs on adults the greatest. As results, OR agonists were largely synergistic with the selected IGRs. OR agonists enhanced the lethal toxicity of IGRs, which is a valuable new tool in the field of A. aegypti control. However, further field experiments need to be done to understand the unique potential role of OR agonists and their synergistic action on IGRs. PMID:26672383

  19. Tramline wheelings as diffuse pollution sources: integrating across spatial scales

    NASA Astrophysics Data System (ADS)

    Silgram, Martyn; Collins, Adrian

    2010-05-01

    Identifying the sources of diffuse pollution, characterising transport pathways, and understanding the factors controlling delivery to water bodies, are generic challenges faced by scientists and policymakers supporting the implementation of the EU Water Framework Directive and other water quality legislation. Land management is intrinsically field scale, which is the scale at which much fieldwork is focused. However, processes identified at plot or field scale may not be significant in terms of water quality at catchment scale, which poses the problem of how best to upscale relevant field-scale characterisations. A consistent framework is urgently needed which is capable of bringing together experimental techniques at these disparate spatial scales (plot, field and river catchment scale), to provide high resolution evidence to support catchment characterisations (which identify "hot spots") and the spatial targeting of mitigation measures aimed at diffuse pollution control. In the absence of such frameworks, comparing existing data from disparate projects represents a starting point for assessing scaling issues. The emerging evidence base is increasingly underscoring the importance of tramline wheelings as sources and pathways for diffuse pollution loss to the edge of cereal fields. Recent UK research has demonstrated that these compacted, unvegetated areas (which are used as markers in spraying operations) can account for over 80% of surface losses of runoff, sediment and phosphorus to edge-of-field. Current government and industry-funded projects are now exploring a range of novel practical land management techniques to minimise these field-scale losses. However, given the mitigating role of field headlands and boundaries, and riparian buffer strips in limiting connectivity and delivery to water bodies, it has not been clear whether such losses represent an important element of the net pollutant load reaching catchment outlets. Such scaling issues represent an

  20. Beyond the Reading Room: Integrating Primary and Secondary Sources in the Library Classroom

    ERIC Educational Resources Information Center

    Sutton, Shan; Knight, Lorrie

    2006-01-01

    Information-literate students should understand the relationships between primary and secondary sources. This article presents a new model for integrating primary and secondary sources into general library instruction. The model is based on collaboration between a Special Collections librarian and an instruction librarian. It emphasizes the use of…

  1. Broadband Suzaku Observations of IGR J16207-5129

    NASA Technical Reports Server (NTRS)

    Bodaghee, A.; Tomsick, J. A.; Rodriguez, J.; Chaty, S.; Pottschmidt, K.; Walter, R.

    2010-01-01

    An analysis of IGRJ16207-5129 is presented based on observations taken with Suzaku. The data set represents approximately 80 ks of effective exposure time in a broad energy range between 0.5 and 60 keV, including unprecedented spectral sensitivity above 15 keV. The average source spectrum is well described by an absorbed power law in which we measured a large intrinsic absorption of N(sub H) = (16.2 (sup +0.9)(sub -1.1) x 10(sup 22) per square centimeter. This confirms that IGRJ16207-5129 belongs to the class of absorbed HMXBs. We were able to constrain the cutoff energy at 19(sup +8)(sub -4)keV which argues in favor of a neutron star as the primary. Our observation includes an epoch in which the source count rate is compatible with no flux suggesting a possible eclipse. We discuss the nature of this source in light of these and of other recent results.

  2. Integrated seismic source model of the 2015 Gorkha, Nepal, earthquake

    NASA Astrophysics Data System (ADS)

    Yagi, Yuji; Okuwaki, Ryo

    2015-08-01

    We compared spatiotemporal slip-rate and high-frequency (around 1 Hz) radiation distributions from teleseismic P wave data to infer the seismic rupture process of the 2015 Gorkha, Nepal, earthquake. For these estimates, we applied a novel waveform inversion formulation that mitigates the effect of Green's functions uncertainty and a hybrid backprojection method that mitigates contamination by depth phases. Our model showed that the dynamic rupture front propagated eastward from the hypocenter at 3.0 km/s and triggered a large-slip event centered about 50 km to the east. It also showed that the large-slip event included a rapid rupture acceleration event and an irregular deceleration of rupture propagation before the rupture termination. Heterogeneity of the stress drop or fracture energy in the eastern part of the rupture area, where aftershock activity was high, inhibited rupture growth. High-frequency radiation sources tended to be in the deeper part of the large-slip area, which suggests that heterogeneity of the stress drop or fracture energy there may have contributed to the damage in and around Kathmandu.

  3. IGR NO{sub x}/SO{sub x} control technology. [Quarterly] report, July 1, 1993--September 30, 1993

    SciTech Connect

    Not Available

    1993-12-31

    During the term of this report substantial progress was made in two areas critical to the IGR NOx/SOx control technology. First, an acceptable methodology was developed for the preparation of the selective electrocatalysts required for NOx/SOx destruction. Second, a clear and reproducible destruction of both SOx and NOx was achieved in separate tests using electrocatalysts prepared by the current methodology.

  4. DISCOVERY OF HIGH-FREQUENCY QUASI-PERIODIC OSCILLATIONS IN THE BLACK HOLE CANDIDATE IGR J17091-3624

    SciTech Connect

    Altamirano, D.; Belloni, T.

    2012-03-15

    We report the discovery of 8.5{sigma} high-frequency quasi-periodic oscillations (HFQPOs) at 66 Hz in the Rossi X-ray Timing Explorer data of the black hole candidate IGR J17091-3624, a system whose X-ray properties are very similar to those of microquasar GRS 1915+105. The centroid frequency of the strongest peak is {approx}66 Hz, its quality factor above five, and its rms is between 4% and 10%. We found a possible additional peak at 164 Hz when selecting a subset of the data; however, at the 4.5{sigma} level we consider this detection marginal. These QPOs have hard spectrum and are stronger in observations performed between 2011 September and October, during which IGR J17091-3624 displayed for the first time light curves that resemble those of the {gamma} variability class in GRS 1915+105. We find that the 66 Hz QPO is also present in previous observations (4.5{sigma}), but only when averaging {approx}235 ks of relatively high count rate data. The fact that the HFQPOs frequency in IGR J17091-3624 matches surprisingly well with that seen in GRS 1915+105 raises questions on the mass scaling of QPOs frequency in these two systems. We discuss some possible interpretations; however, they all strongly depend on the distance and mass of IGR J17091-3624, both completely unconstrained today.

  5. Integration and beyond: linking information from disparate sources and into workflow.

    PubMed

    Stead, W W; Miller, R A; Musen, M A; Hersh, W R

    2000-01-01

    The vision of integrating information-from a variety of sources, into the way people work, to improve decisions and process-is one of the cornerstones of biomedical informatics. Thoughts on how this vision might be realized have evolved as improvements in information and communication technologies, together with discoveries in biomedical informatics, and have changed the art of the possible. This review identified three distinct generations of "integration" projects. First-generation projects create a database and use it for multiple purposes. Second-generation projects integrate by bringing information from various sources together through enterprise information architecture. Third-generation projects inter-relate disparate but accessible information sources to provide the appearance of integration. The review suggests that the ideas developed in the earlier generations have not been supplanted by ideas from subsequent generations. Instead, the ideas represent a continuum of progress along the three dimensions of workflow, structure, and extraction. PMID:10730596

  6. Development and Performance of a Filter Radiometer Monitor System for Integrating Sphere Sources

    NASA Technical Reports Server (NTRS)

    Ding, Leibo; Kowalewski, Matthew G.; Cooper, John W.; Smith, GIlbert R.; Barnes, Robert A.; Waluschka, Eugene; Butler, James J.

    2011-01-01

    The NASA Goddard Space Flight Center (GSFC) Radiometric Calibration Laboratory (RCL) maintains several large integrating sphere sources covering the visible to the shortwave infrared wavelength range. Two critical, functional requirements of an integrating sphere source are short and long-term operational stability and repeatability. Monitoring the source is essential in determining the origin of systemic errors, thus increasing confidence in source performance and quantifying repeatability. If monitor data falls outside the established parameters, this could be an indication that the source requires maintenance or re-calibration against the National Institute of Science and Technology (NIST) irradiance standard. The GSFC RCL has developed a Filter Radiometer Monitoring System (FRMS) to continuously monitor the performance of its integrating sphere calibration sources in the 400 to 2400nm region. Sphere output change mechanisms include lamp aging, coating (e.g. BaSO4) deterioration, and ambient water vapor level. The Filter Radiometer Monitor System (FRMS) wavelength bands are selected to quantify changes caused by these mechanisms. The FRMS design and operation are presented, as well as data from monitoring four of the RCL s integrating sphere sources.

  7. Determination of PM2.5 sources using time-resolved integrated source and receptor models.

    PubMed

    García, José H; Li, Wen-Whai; Cárdenas, Nidia; Arimoto, Richard; Walton, John; Trujillo, David

    2006-12-01

    Multivariate statistical techniques are applied to particulate matter (PM) and meteorological data to identify the sources responsible for evening PM spikes at Sunland Park, NM (USA). The statistical techniques applied are principal components analysis (PCA), redundancy analysis (RDA), and absolute principal components scores analysis (APCSA), and the data evaluated are 3-h average (6-9 p.m.) PM(2.5) mass and chemical composition and 1-h average PM(2.5) and PM(10) mass and environmental data collected in the winter of 2002. Although the interpretation of the data was complicated by the presence of sources which are likely changing in time (e.g. brick kilns), the multivariate analyses indicate that the evening high PM(2.5) is associated with burning-activities occurring to the south of Sunland Park, and these emissions are characterized by elevated Sb, Cl(-), and elemental carbon; approximately 68% of the PM(2.5) mass can be attributed to this source. The PM(10) evening peaks, on the other hand, are mainly caused by resuspended dust generated by vehicular movements south of the site and transported by the local terrain-induced drainage flow. PMID:16901530

  8. Semantic integration of gene expression analysis tools and data sources using software connectors

    PubMed Central

    2013-01-01

    Background The study and analysis of gene expression measurements is the primary focus of functional genomics. Once expression data is available, biologists are faced with the task of extracting (new) knowledge associated to the underlying biological phenomenon. Most often, in order to perform this task, biologists execute a number of analysis activities on the available gene expression dataset rather than a single analysis activity. The integration of heteregeneous tools and data sources to create an integrated analysis environment represents a challenging and error-prone task. Semantic integration enables the assignment of unambiguous meanings to data shared among different applications in an integrated environment, allowing the exchange of data in a semantically consistent and meaningful way. This work aims at developing an ontology-based methodology for the semantic integration of gene expression analysis tools and data sources. The proposed methodology relies on software connectors to support not only the access to heterogeneous data sources but also the definition of transformation rules on exchanged data. Results We have studied the different challenges involved in the integration of computer systems and the role software connectors play in this task. We have also studied a number of gene expression technologies, analysis tools and related ontologies in order to devise basic integration scenarios and propose a reference ontology for the gene expression domain. Then, we have defined a number of activities and associated guidelines to prescribe how the development of connectors should be carried out. Finally, we have applied the proposed methodology in the construction of three different integration scenarios involving the use of different tools for the analysis of different types of gene expression data. Conclusions The proposed methodology facilitates the development of connectors capable of semantically integrating different gene expression analysis tools

  9. Source Region Modeling of Explosions 2 and 3 from the Source Physics Experiment Using the Rayleigh Integral Method

    NASA Astrophysics Data System (ADS)

    Jones, K. R.; Arrowsmith, S.; Whitaker, R. W.

    2012-12-01

    The overall mission of the National Center for Nuclear Security (NCNS) Source Physics Experiment at the National Nuclear Security Site (SPE-N) near Las Vegas, Nevada is to improve upon and develop new physics based models for underground nuclear explosions using scaled, underground chemical explosions as proxies. To this end, we use the Rayleigh integral as an approximation to the Helmholz-Kirchoff integral, [Whitaker, 2007 and Arrowsmith et al., 2011], to model infrasound generation in the far-field. Infrasound generated by single-point explosive sources above ground can typically be treated as monopole point-sources. While the source is relatively simple, the research needed to model above ground point-sources is complicated by path effects related to the propagation of the acoustic signal and out of the scope of this study. In contrast, for explosions that occur below ground, including the SPE explosions, the source region is more complicated but the observation distances are much closer (< 5 km), thus greatly reducing the complication of path effects. In this case, elastic energy from the explosions radiates upward and spreads out, depending on depth, to a more distributed region at the surface. Due to this broad surface perturbation of the atmosphere we cannot model the source as a simple monopole point-source. Instead, we use the analogy of a piston mounted in a rigid, infinite baffle, where the surface area that moves as a result of the explosion is the piston and the surrounding region is the baffle. The area of the "piston" is determined by the depth and explosive yield of the event. In this study we look at data from SPE-N-2 and SPE-N-3. Both shots had an explosive yield of 1 ton at a depth of 45 m. We collected infrasound data with up to eight stations and 32 sensors within a 5 km radius of ground zero. To determine the area of the surface acceleration, we used data from twelve surface accelerometers installed within 100 m radially about ground zero

  10. Solid angle subtended by a cylindrical detector at a point source in terms of elliptic integrals

    NASA Astrophysics Data System (ADS)

    Prata, M. J.

    2003-07-01

    The solid angle subtended by a right circular cylinder at a point source located at an arbitrary position generally consists of a sum of two terms: that defined by the cylindrical surface (Ω cyl) and the other by either of the end circles (Ω circ) . We derive an expression for Ω cyl in terms of elliptic integrals of the first and third kinds and give similar expressions for Ω circ using integrals of the first and second kinds. These latter can be used alternatively to an expression also in terms of elliptic integrals, due to Philip A. Macklin and included as a footnote in Masket (Rev. Sci. Instrum. 28 (3) (1957) 191). The solid angle subtended by the whole cylinder when the source is located at an arbitrary location can then be calculated using elliptic integrals.

  11. Towards virtual knowledge broker services for semantic integration of life science literature and data sources.

    PubMed

    Harrow, Ian; Filsell, Wendy; Woollard, Peter; Dix, Ian; Braxenthaler, Michael; Gedye, Richard; Hoole, David; Kidd, Richard; Wilson, Jabe; Rebholz-Schuhmann, Dietrich

    2013-05-01

    Research in the life sciences requires ready access to primary data, derived information and relevant knowledge from a multitude of sources. Integration and interoperability of such resources are crucial for sharing content across research domains relevant to the life sciences. In this article we present a perspective review of data integration with emphasis on a semantics driven approach to data integration that pushes content into a shared infrastructure, reduces data redundancy and clarifies any inconsistencies. This enables much improved access to life science data from numerous primary sources. The Semantic Enrichment of the Scientific Literature (SESL) pilot project demonstrates feasibility for using already available open semantic web standards and technologies to integrate public and proprietary data resources, which span structured and unstructured content. This has been accomplished through a precompetitive consortium, which provides a cost effective approach for numerous stakeholders to work together to solve common problems. PMID:23247259

  12. Identifying IGR J14091-6108 as a magnetic CV with a massive white dwarf using X-ray and optical observations

    NASA Astrophysics Data System (ADS)

    Tomsick, John A.; Rahoui, Farid; Krivonos, Roman; Clavel, Maïca; Strader, Jay; Chomiuk, Laura

    2016-04-01

    IGR J14091-6108 is a Galactic X-ray source known to have an iron emission line, a hard X-ray spectrum, and an optical counterpart. Here, we report on X-ray observations of the source with XMM-Newton and NuSTAR as well as optical spectroscopy with ESO/VLT and NOAO/SOAR. In the X-rays, this provides data with much better statistical quality than the previous observations, and this is the first report of the optical spectrum. Timing analysis of the XMM data shows a very significant detection of 576.3 ± 0.6 s period. The signal has a pulsed fraction of 30 ± 3% in the 0.3-12 keV range and shows a strong drop with energy. The optical spectra show strong emission lines with significant variability in the lines and continuum, indicating that they come from an irradiated accretion disk. Based on these measurements, we identify the source as a magnetic Cataclysmic Variable of Intermediate Polar (IP) type where the white dwarf spin period is 576.3 s. The X-ray spectrum is consistent with the continuum emission mechanism being due to thermal Bremsstrahlung, but partial covering absorption and reflection are also required. In addition, we use the IP mass (IPM) model, which suggests that the white dwarf in this system has a high mass, possibly approaching the Chandrasekhar limit.

  13. Integrating a Traveling Wave Tube into an AECR-U ion source

    SciTech Connect

    Covo, Michel Kireeff; Benitez, Janilee Y.; Ratti, Alessandro; Vujic, Jasmina L.

    2011-07-01

    An RF system of 500W - 10.75 to 12.75 GHz was designed and integrated into the Advanced Electron Cyclotron Resonance - Upgrade (AECR-U) ion source of the 88-Inch Cyclotron at Lawrence Berkeley National Laboratory. The AECR-U produces ion beams for the Cyclotron giving large flexibility of ion species and charge states. The broadband frequency of a Traveling Wave Tube (TWT) allows modifying the volume that couples and heats the plasma. The TWT system design and integration with the AECR-U ion source and results from commissioning are presented.

  14. Total luminous flux measurement for flexible surface sources with an integrating sphere photometer

    NASA Astrophysics Data System (ADS)

    Yu, Hsueh-Ling; Liu, Wen-Chun

    2014-01-01

    Applying an integrating sphere photometer for total luminous flux measurement is a widely used method. However, the measurement accuracy depends on the spatial uniformity of the integrating sphere, especially when the test sample has a different light distribution from that of the standard source. Therefore, spatial correction is needed to eliminate the effect caused by non-uniformity. To reduce the inconvenience of spatial correction but retain the measurement accuracy, a new type of working standard is designed for flexible and curved surface sources. Applying this new type standard source, the measurement deviation due to different orientations is reduced by an order of magnitude compared with using a naked incandescent lamp as the standard source.

  15. Multi-Sensor Integration to Map Odor Distribution for the Detection of Chemical Sources

    PubMed Central

    Gao, Xiang; Acar, Levent

    2016-01-01

    This paper addresses the problem of mapping odor distribution derived from a chemical source using multi-sensor integration and reasoning system design. Odor localization is the problem of finding the source of an odor or other volatile chemical. Most localization methods require a mobile vehicle to follow an odor plume along its entire path, which is time consuming and may be especially difficult in a cluttered environment. To solve both of the above challenges, this paper proposes a novel algorithm that combines data from odor and anemometer sensors, and combine sensors’ data at different positions. Initially, a multi-sensor integration method, together with the path of airflow was used to map the pattern of odor particle movement. Then, more sensors are introduced at specific regions to determine the probable location of the odor source. Finally, the results of odor source location simulation and a real experiment are presented. PMID:27384568

  16. Multi-Sensor Integration to Map Odor Distribution for the Detection of Chemical Sources.

    PubMed

    Gao, Xiang; Acar, Levent

    2016-01-01

    This paper addresses the problem of mapping odor distribution derived from a chemical source using multi-sensor integration and reasoning system design. Odor localization is the problem of finding the source of an odor or other volatile chemical. Most localization methods require a mobile vehicle to follow an odor plume along its entire path, which is time consuming and may be especially difficult in a cluttered environment. To solve both of the above challenges, this paper proposes a novel algorithm that combines data from odor and anemometer sensors, and combine sensors' data at different positions. Initially, a multi-sensor integration method, together with the path of airflow was used to map the pattern of odor particle movement. Then, more sensors are introduced at specific regions to determine the probable location of the odor source. Finally, the results of odor source location simulation and a real experiment are presented. PMID:27384568

  17. The integration of renewable energy sources into electric power transmission systems

    SciTech Connect

    Barnes, P.R.; Dykas, W.P.; Kirby, B.J.; Purucker, S.L.; Lawler, J.S.

    1995-07-01

    Renewable energy technologies such as photovoltaics, solar thermal power plants, and wind turbines are nonconventional, environmentally attractive sources of energy that can be considered for electric power generation. Many of the areas with abundant renewable energy resources (very sunny or windy areas) are far removed from major load centers. Although electrical power can be transmitted over long distances of many hundreds of miles through high-voltage transmission lines, power transmission systems often operate near their limits with little excess capacity for new generation sources. This study assesses the available capacity of transmission systems in designated abundant renewable energy resource regions and identifies the requirements for high-capacity plant integration in selected cases. In general, about 50 MW of power from renewable sources can be integrated into existing transmission systems to supply local loads without transmission upgrades beyond the construction of a substation to connect to the grid. Except in the Southwest, significant investment to strengthen transmission systems will be required to support the development of high-capacity renewable sources of 1000 MW or greater in areas remote from major load centers. Cost estimates for new transmission facilities to integrate and dispatch some of these high-capacity renewable sources ranged from several million dollars to approximately one billion dollars, with the latter figure an increase in total investment of 35%, assuming that the renewable source is the only user of the transmission facility.

  18. Three transient X-ray sources during the INTEGRAL revolution 1710

    NASA Astrophysics Data System (ADS)

    Fiocchi, M.; Bazzano, A.; Bird, A. J.; Charles, Phil; Chenevez, J.; Ubertini, P.

    2016-08-01

    During recent INTEGRAL observations of the Musca and Norma regions (revolutions 1710) performed between 2016-08-05 16:00:36 UTC and 2016-08-07 21:02:14 UTC a renewed activity from the following transient X-ray sources has been detected.

  19. Decision Making and Sources of Knowledge: How Students Tackle Integrated Tasks in Science, Technology and Mathematics

    ERIC Educational Resources Information Center

    Venville, Grady; Rennie, Leonie; Wallace, John

    2004-01-01

    This article reports on students' decision making processes and sources of knowledge in an integrated teaching and learning setting. The study was conducted in a Year 9 classroom as students undertook a 10-week solar-powered boat project and were exposed to related concepts from science, technology and mathematics. Data collection involved…

  20. On the Prospects and Concerns of Integrating Open Source Software Environment in Software Engineering Education

    ERIC Educational Resources Information Center

    Kamthan, Pankaj

    2007-01-01

    Open Source Software (OSS) has introduced a new dimension in software community. As the development and use of OSS becomes prominent, the question of its integration in education arises. In this paper, the following practices fundamental to projects and processes in software engineering are examined from an OSS perspective: project management;…

  1. Integrating distributed data sources with OGSA-DAI DQP and VIEWS.

    PubMed

    Dobrzelecki, Bartosz; Krause, Amrey; Hume, Alastair C; Grant, Alistair; Antonioletti, Mario; Alemu, Tilaye Y; Atkinson, Malcolm; Jackson, Mike; Theocharopoulos, Elias

    2010-09-13

    OGSA-DAI (Open Grid Services Architecture Data Access and Integration) is a framework for building distributed data access and integration systems. Until recently, it lacked the built-in functionality that would allow easy creation of federations of distributed data sources. The latest release of the OGSA-DAI framework introduced the OGSA-DAI DQP (Distributed Query Processing) resource. The new resource encapsulates a distributed query processor, that is able to orchestrate distributed data sources when answering declarative user queries. The query processor has many extensibility points, making it easy to customize. We have also introduced a new OGSA-DAI Views resource that provides a flexible method for defining views over relational data. The interoperability of the two new resources, together with the flexibility of the OGSA-DAI framework, allows the building of highly customized data integration solutions. PMID:20679127

  2. The eye in hand: predicting others' behavior by integrating multiple sources of information.

    PubMed

    Ambrosini, Ettore; Pezzulo, Giovanni; Costantini, Marcello

    2015-04-01

    The ability to predict the outcome of other beings' actions confers significant adaptive advantages. Experiments have assessed that human action observation can use multiple information sources, but it is currently unknown how they are integrated and how conflicts between them are resolved. To address this issue, we designed an action observation paradigm requiring the integration of multiple, potentially conflicting sources of evidence about the action target: the actor's gaze direction, hand preshape, and arm trajectory, and their availability and relative uncertainty in time. In two experiments, we analyzed participants' action prediction ability by using eye tracking and behavioral measures. The results show that the information provided by the actor's gaze affected participants' explicit predictions. However, results also show that gaze information was disregarded as soon as information on the actor's hand preshape was available, and this latter information source had widespread effects on participants' prediction ability. Furthermore, as the action unfolded in time, participants relied increasingly more on the arm movement source, showing sensitivity to its increasing informativeness. Therefore, the results suggest that the brain forms a robust estimate of the actor's motor intention by integrating multiple sources of information. However, when informative motor cues such as a preshaped hand with a given grip are available and might help in selecting action targets, people tend to capitalize on such motor cues, thus turning out to be more accurate and fast in inferring the object to be manipulated by the other's hand. PMID:25568158

  3. The eye in hand: predicting others' behavior by integrating multiple sources of information

    PubMed Central

    Pezzulo, Giovanni; Costantini, Marcello

    2015-01-01

    The ability to predict the outcome of other beings' actions confers significant adaptive advantages. Experiments have assessed that human action observation can use multiple information sources, but it is currently unknown how they are integrated and how conflicts between them are resolved. To address this issue, we designed an action observation paradigm requiring the integration of multiple, potentially conflicting sources of evidence about the action target: the actor's gaze direction, hand preshape, and arm trajectory, and their availability and relative uncertainty in time. In two experiments, we analyzed participants' action prediction ability by using eye tracking and behavioral measures. The results show that the information provided by the actor's gaze affected participants' explicit predictions. However, results also show that gaze information was disregarded as soon as information on the actor's hand preshape was available, and this latter information source had widespread effects on participants' prediction ability. Furthermore, as the action unfolded in time, participants relied increasingly more on the arm movement source, showing sensitivity to its increasing informativeness. Therefore, the results suggest that the brain forms a robust estimate of the actor's motor intention by integrating multiple sources of information. However, when informative motor cues such as a preshaped hand with a given grip are available and might help in selecting action targets, people tend to capitalize on such motor cues, thus turning out to be more accurate and fast in inferring the object to be manipulated by the other's hand. PMID:25568158

  4. Indirect (source-free) integration method. I. Wave-forms from geodesic generic orbits of EMRIs

    NASA Astrophysics Data System (ADS)

    Ritter, Patxi; Aoudia, Sofiane; Spallicci, Alessandro D. A. M.; Cordier, Stéphane

    2016-12-01

    The Regge-Wheeler-Zerilli (RWZ) wave-equation describes Schwarzschild-Droste black hole perturbations. The source term contains a Dirac distribution and its derivative. We have previously designed a method of integration in time domain. It consists of a finite difference scheme where analytic expressions, dealing with the wave-function discontinuity through the jump conditions, replace the direct integration of the source and the potential. Herein, we successfully apply the same method to the geodesic generic orbits of EMRI (Extreme Mass Ratio Inspiral) sources, at second order. An EMRI is a Compact Star (CS) captured by a Super-Massive Black Hole (SMBH). These are considered the best probes for testing gravitation in strong regime. The gravitational wave-forms, the radiated energy and angular momentum at infinity are computed and extensively compared with other methods, for different orbits (circular, elliptic, parabolic, including zoom-whirl).

  5. IGR NO{sub x}/SO{sub x} control technology. Second technical progress report, January 1--March 31, 1993

    SciTech Connect

    Not Available

    1993-04-25

    The technical work during this reporting term has principally involved the continued development, optimization and improvement of freezing drying techniques for solid ceramic oxide electrolyte powder preparation, preliminary optimization of the calcining of the ceramic electrolyte freeze dried powders to allow for optimum processing to the IGR composite, and determining (initial) electrochemical properties of the stabilized ceramic solid electrolyte at a variety of temperatures in air.

  6. Decision Making and Sources of Knowledge: How Students Tackle Integrated Tasks in Science, Technology and Mathematics

    NASA Astrophysics Data System (ADS)

    Venville, Grady; Rennie, Léonie; Wallace, John

    2004-04-01

    This article reports on students'' decision making processes and sources of knowledge in an integrated teaching and learning setting. The study was conducted in a Year 9 classroom as students undertook a 10-week solar-powered boat project and were exposed to related concepts from science, technology and mathematics. Data collection involved detailed case studies of three pairs of students, interviews, classroom observation and analysis of the artefacts and portfolios produced by the students. Students were found to access knowledge from a variety of sources, including teacher''s notes from formal instruction, informal interactions with the teacher, observation of and interaction with other students, as well as sources outside the classroom. However, the utility of the knowledge sources was influenced by the nature of the task. When students were performing open-ended tasks, they drew on a wider variety of knowledge sources than when they were performing less open tasks. Moreover, subject discipline-based sources often were not as helpful in solving open tasks. The study leads to several important implications for designing teaching and learning in integrated curriculum settings.

  7. O Integrality of Perceptual Attributes Determined by Sound Source and Filter.

    NASA Astrophysics Data System (ADS)

    Li, Xiaofeng

    The production of a complex sound can be viewed as a sequential operation of sound production components: Power excites a sound source that produces an original sound, which is shaped by a certain filter response function. It is hypothesized that human listeners evaluate sound quality by decomposing the complex spectrum of the sound according to this production model. The current research investigates the perceptual relationship among spectral attributes induced by the sound source and the filter. Specifically, the capability of listeners to extract a global spectral attribute of spectral slope determined by a sound source is examined in the context of variation with other two background attributes: fundamental frequency (another source attribute) and ripple frequency (a filter characteristic). Spectral slope is judged to be integral with these background attributes if a significant decrement in slope discrimination occurs due to a varied, relative to fixed, background attribute. The five experiments used a XAB task with roving overall spectral intensity within trials to eliminate intensity cues. The presence of a significant decrement due to roving fundamental frequency indicates that spectral slope is integral with fundamental frequency. In contrast, a strikingly smaller decrement occurs as the filter characteristic is varied, suggesting that spectral slope is more easily separable from the ripple filter attribute than from fundamental frequency. Therefore, it is conjectured that the global source attribute of spectral slope is perceptually unitized with other source attributes, and listeners treat source attributes as an entity in describing the characteristics of the sound source. However, such an evaluation of sound source attributes is relatively orthogonal to the actual spectral envelope, which may be shaped by different filter functions. The current study have extended profile analysis and demonstrated human auditory capability to resolve a global spectral

  8. Golden Ratio Versus Pi as Random Sequence Sources for Monte Carlo Integration

    NASA Technical Reports Server (NTRS)

    Sen, S. K.; Agarwal, Ravi P.; Shaykhian, Gholam Ali

    2007-01-01

    We discuss here the relative merits of these numbers as possible random sequence sources. The quality of these sequences is not judged directly based on the outcome of all known tests for the randomness of a sequence. Instead, it is determined implicitly by the accuracy of the Monte Carlo integration in a statistical sense. Since our main motive of using a random sequence is to solve real world problems, it is more desirable if we compare the quality of the sequences based on their performances for these problems in terms of quality/accuracy of the output. We also compare these sources against those generated by a popular pseudo-random generator, viz., the Matlab rand and the quasi-random generator ha/ton both in terms of error and time complexity. Our study demonstrates that consecutive blocks of digits of each of these numbers produce a good random sequence source. It is observed that randomly chosen blocks of digits do not have any remarkable advantage over consecutive blocks for the accuracy of the Monte Carlo integration. Also, it reveals that pi is a better source of a random sequence than theta when the accuracy of the integration is concerned.

  9. A monolithically integrated polarization entangled photon pair source on a silicon chip

    PubMed Central

    Matsuda, Nobuyuki; Le Jeannic, Hanna; Fukuda, Hiroshi; Tsuchizawa, Tai; Munro, William John; Shimizu, Kaoru; Yamada, Koji; Tokura, Yasuhiro; Takesue, Hiroki

    2012-01-01

    Integrated photonic circuits are one of the most promising platforms for large-scale photonic quantum information systems due to their small physical size and stable interferometers with near-perfect lateral-mode overlaps. Since many quantum information protocols are based on qubits defined by the polarization of photons, we must develop integrated building blocks to generate, manipulate, and measure the polarization-encoded quantum state on a chip. The generation unit is particularly important. Here we show the first integrated polarization-entangled photon pair source on a chip. We have implemented the source as a simple and stable silicon-on-insulator photonic circuit that generates an entangled state with 91 ± 2% fidelity. The source is equipped with versatile interfaces for silica-on-silicon or other types of waveguide platforms that accommodate the polarization manipulation and projection devices as well as pump light sources. Therefore, we are ready for the full-scale implementation of photonic quantum information systems on a chip. PMID:23150781

  10. PathCase-SB: integrating data sources and providing tools for systems biology research

    PubMed Central

    2012-01-01

    Background Integration of metabolic pathways resources and metabolic network models, and deploying new tools on the integrated platform can help perform more effective and more efficient systems biology research on understanding the regulation of metabolic networks. Therefore, the tasks of (a) integrating under a single database environment regulatory metabolic networks and existing models, and (b) building tools to help with modeling and analysis are desirable and intellectually challenging computational tasks. Results PathCase Systems Biology (PathCase-SB) is built and released. This paper describes PathCase-SB user interfaces developed to date. The current PathCase-SB system provides a database-enabled framework and web-based computational tools towards facilitating the development of kinetic models for biological systems. PathCase-SB aims to integrate systems biology models data and metabolic network data of selected biological data sources on the web (currently, BioModels Database and KEGG, respectively), and to provide more powerful and/or new capabilities via the new web-based integrative framework. Conclusions Each of the current four PathCase-SB interfaces, namely, Browser, Visualization, Querying, and Simulation interfaces, have expanded and new capabilities as compared with the original data sources. PathCase-SB is already available on the web and being used by researchers across the globe. PMID:22697505

  11. Evaluation and selection of open-source EMR software packages based on integrated AHP and TOPSIS.

    PubMed

    Zaidan, A A; Zaidan, B B; Al-Haiqi, Ahmed; Kiah, M L M; Hussain, Muzammil; Abdulnabi, Mohamed

    2015-02-01

    Evaluating and selecting software packages that meet the requirements of an organization are difficult aspects of software engineering process. Selecting the wrong open-source EMR software package can be costly and may adversely affect business processes and functioning of the organization. This study aims to evaluate and select open-source EMR software packages based on multi-criteria decision-making. A hands-on study was performed and a set of open-source EMR software packages were implemented locally on separate virtual machines to examine the systems more closely. Several measures as evaluation basis were specified, and the systems were selected based a set of metric outcomes using Integrated Analytic Hierarchy Process (AHP) and TOPSIS. The experimental results showed that GNUmed and OpenEMR software can provide better basis on ranking score records than other open-source EMR software packages. PMID:25483886

  12. 3D simulation of integrated multi-coil ICP source with azimuthal modes

    NASA Astrophysics Data System (ADS)

    Brcka, Jozef

    2015-09-01

    Integrated multi-coil (IMC) planar ICP source with azimuthal motion is presented. Scaling ICP sources to larger substrate size is always complicated due to many technical issues and is challenged by the plasma chemistry. The source described in this work has capability of azimuthally moving plasma and has potential for large area and high density plasma applications. Hence, this system does not have an ideal axial symmetry, the 3D model approach has to be used to assess its transient performance. Moreover, reactor walls are imposing stronger boundary conditions on distribution of the radicals in ``off-axis reactive plasma.'' Intrinsic asymmetry of source and plasma were investigated by 3D fluid model developed under Plasma Module framework and supported by COMSOL Multiphysics solvers. Operation modes have potential to control plasma distribution, reaction chemistry and increase/modulate radicals' production. Simulation confirmed assumption that plasma distribution may essentially change in different gas. Under specific conditions integrated multi-coil ICP source is producing pulsed plasma. Temporal, spatial and population plasma characteristics were investigated in an inert carrier gas (Ar) and reactive plasma consisting of several gases (Ar, H2, CO and CH4).

  13. An integrated approach to assess heavy metal source apportionment in peri-urban agricultural soils.

    PubMed

    Huang, Ying; Li, Tingqiang; Wu, Chengxian; He, Zhenli; Japenga, Jan; Deng, Meihua; Yang, Xiaoe

    2015-12-15

    Three techniques (Isotope Ratio Analysis, GIS mapping, and Multivariate Statistical Analysis) were integrated to assess heavy metal pollution and source apportionment in peri-urban agricultural soils. The soils in the study area were moderately polluted with cadmium (Cd) and mercury (Hg), lightly polluted with lead (Pb), and chromium (Cr). GIS Mapping suggested Cd pollution originates from point sources, whereas Hg, Pb, Cr could be traced back to both point and non-point sources. Principal component analysis (PCA) indicated aluminum (Al), manganese (Mn), nickel (Ni) were mainly inherited from natural sources, while Hg, Pb, and Cd were associated with two different kinds of anthropogenic sources. Cluster analysis (CA) further identified fertilizers, waste water, industrial solid wastes, road dust, and atmospheric deposition as potential sources. Based on isotope ratio analysis (IRA) organic fertilizers and road dusts accounted for 74-100% and 0-24% of the total Hg input, while road dusts and solid wastes contributed for 0-80% and 19-100% of the Pb input. This study provides a reliable approach for heavy metal source apportionment in this particular peri-urban area, with a clear potential for future application in other regions. PMID:26257294

  14. A Stochastic Power Network Calculus for Integrating Renewable Energy Sources into the Power Grid

    SciTech Connect

    Wang, K; Ciucu, F; Lin, C; Low, SH

    2012-07-01

    Renewable energy such as solar and wind generation will constitute an important part of the future grid. As the availability of renewable sources may not match the load, energy storage is essential for grid stability. In this paper we investigate the feasibility of integrating solar photovoltaic (PV) panels and wind turbines into the grid by also accounting for energy storage. To deal with the fluctuation in both the power supply and demand, we extend and apply stochastic network calculus to analyze the power supply reliability with various renewable energy configurations. To illustrate the validity of the model, we conduct a case study for the integration of renewable energy sources into the power system of an island off the coast of Southern California. In particular, we asses the power supply reliability in terms of the average Fraction of Time that energy is Not-Served (FTNS).

  15. The semantic metadatabase (SEMEDA): ontology based integration of federated molecular biological data sources.

    PubMed

    Köhler, Jacob; Schulze-Kremer, Steffen

    2002-01-01

    A system for "intelligent" semantic integration and querying of federated databases is being implemented by using three main components: A component which enables SQL access to integrated databases by database federation (MARGBench), an ontology based semantic metadatabase (SEMEDA) and an ontology based query interface (SEMEDA-query). In this publication we explain and demonstrate the principles, architecture and the use of SEMEDA. Since SEMEDA is implemented as 3 tiered web application database providers can enter all relevant semantic and technical information about their databases by themselves via a web browser. SEMEDA' s collaborative ontology editing feature is not restricted to database integration, and might also be useful for ongoing ontology developments, such as the "Gene Ontology" [2]. SEMEDA can be found at http://www-bm.cs.uni-magdeburg.de/semeda/. We explain how this ontologically structured information can be used for semantic database integration. In addition, requirements to ontologies for molecular biological database integration are discussed and relevant existing ontologies are evaluated. We further discuss how ontologies and structured knowledge sources can be used in SEMEDA and whether they can be merged supplemented or updated to meet the requirements for semantic database integration. PMID:12542408

  16. Air-Source Integrated Heat Pump for Near-Zero Energy Houses: Technology Status Report

    SciTech Connect

    Murphy, Richard W; Rice, C Keith; Baxter, Van D; Craddick, William G

    2007-07-01

    This report documents the development of an air-source integrated heat pump (AS-IHP) through the third quarter of FY2007. It describes the design, analyses and testing of the AS-IHP, and provides performance specifications for a field test prototype and proposed control strategy. The results obtained so far continue to support the AS-IHP being a promising candidate to meet the energy service needs for DOE's development of a Zero Energy Home (ZEH) by the year 2020.

  17. Identification of Functional Modules by Integration of Multiple Data Sources Using a Bayesian Network Classifier

    PubMed Central

    Wang, Jinlian; Zuo, Yiming; Liu, Lun; Man, Yangao; Tadesse, Mahlet G.; Ressom, Habtom W

    2014-01-01

    Background Prediction of functional modules is indispensable for detecting protein deregulation in human complex diseases such as cancer. Bayesian network (BN) is one of the most commonly used models to integrate heterogeneous data from multiple sources such as protein domain, interactome, functional annotation, genome-wide gene expression, and the literature. Methods and Results In this paper, we present a BN classifier that is customized to: 1) increase the ability to integrate diverse information from different sources, 2) effectively predict protein-protein interactions, 3) infer aberrant networks with scale-free and small world properties, and 4) group molecules into functional modules or pathways based on the primary function and biological features. Application of this model on discovering protein biomarkers of hepatocelluar carcinoma (HCC) leads to the identification of functional modules that provide insights into the mechanism of the development and progression of HCC. These functional modules include cell cycle deregulation, increased angiogenesis (e.g., vascular endothelial growth factor, blood vessel morphogenesis), oxidative metabolic alterations, and aberrant activation of signaling pathways involved in cellular proliferation, survival, and differentiation. Conclusion The discoveries and conclusions derived from our customized BN classifier are consistent with previously published results. The proposed approach for determining BN structure facilitates the integration of heterogeneous data from multiple sources to elucidate the mechanisms of complex diseases. PMID:24736851

  18. Integrated population modelling reveals a perceived source to be a cryptic sink.

    PubMed

    Weegman, Mitch D; Bearhop, Stuart; Fox, Anthony D; Hilton, Geoff M; Walsh, Alyn J; McDonald, Jennifer L; Hodgson, David J

    2016-03-01

    Demographic links among fragmented populations are commonly studied as source-sink dynamics, whereby source populations exhibit net recruitment and net emigration, while sinks suffer net mortality but enjoy net immigration. It is commonly assumed that large, persistent aggregations of individuals must be sources, but this ignores the possibility that they are sinks instead, buoyed demographically by immigration. We tested this assumption using Bayesian integrated population modelling of Greenland white-fronted geese (Anser albifrons flavirostris) at their largest wintering site (Wexford, Ireland), combining capture-mark-recapture, census and recruitment data collected from 1982 to 2010. Management for this subspecies occurs largely on wintering areas; thus, study of source-sink dynamics of discrete regular wintering units provides unprecedented insights into population regulation and enables identification of likely processes influencing population dynamics at Wexford and among 70 other Greenland white-fronted goose wintering subpopulations. Using results from integrated population modelling, we parameterized an age-structured population projection matrix to determine the contribution of movement rates (emigration and immigration), recruitment and mortality to the dynamics of the Wexford subpopulation. Survival estimates for juvenile and adult birds at Wexford and adult birds elsewhere fluctuated over the 29-year study period, but were not identifiably different. However, per capita recruitment rates at Wexford in later years (post-1995) were identifiably lower than in earlier years (pre-1995). The observed persistence of the Wexford subpopulation was only possible with high rates of immigration, which exceeded emigration in each year. Thus, despite its apparent stability, Wexford has functioned as a sink over the entire study period. These results demonstrate that even large subpopulations can potentially be sinks, and that movement dynamics (e.g. immigration

  19. Path-integral method for the source apportionment of photochemical pollutants

    NASA Astrophysics Data System (ADS)

    Dunker, A. M.

    2015-06-01

    A new, path-integral method is presented for apportioning the concentrations of pollutants predicted by a photochemical model to emissions from different sources. A novel feature of the method is that it can apportion the difference in a species concentration between two simulations. For example, the anthropogenic ozone increment, which is the difference between a simulation with all emissions present and another simulation with only the background (e.g., biogenic) emissions included, can be allocated to the anthropogenic emission sources. The method is based on an existing, exact mathematical equation. This equation is applied to relate the concentration difference between simulations to line or path integrals of first-order sensitivity coefficients. The sensitivities describe the effects of changing the emissions and are accurately calculated by the decoupled direct method. The path represents a continuous variation of emissions between the two simulations, and each path can be viewed as a separate emission-control strategy. The method does not require auxiliary assumptions, e.g., whether ozone formation is limited by the availability of volatile organic compounds (VOCs) or nitrogen oxides (NOx), and can be used for all the species predicted by the model. A simplified configuration of the Comprehensive Air Quality Model with Extensions (CAMx) is used to evaluate the accuracy of different numerical integration procedures and the dependence of the source contributions on the path. A Gauss-Legendre formula using three or four points along the path gives good accuracy for apportioning the anthropogenic increments of ozone, nitrogen dioxide, formaldehyde, and nitric acid. Source contributions to these increments were obtained for paths representing proportional control of all anthropogenic emissions together, control of NOx emissions before VOC emissions, and control of VOC emissions before NOx emissions. There are similarities in the source contributions from the

  20. Integrated OLED as excitation light source in fluorescent lateral flow immunoassays.

    PubMed

    Venkatraman, Vishak; Steckl, Andrew J

    2015-12-15

    The integration of organic light emitting diodes (OLEDs) as excitation light sources for quantum dot-based fluorescent lateral flow immunoassay systems (LFIA) was investigated. This approach has the potential to deliver a sensitive visible detection scheme for low-cost, disposable lab-on-chip point-of-care (POC) diagnosis system. Thin film phosphorescent green OLEDs fabricated on plastic substrates were integrated on-chip to excite the test line of a quantum dot-based LFIA (QD-LFIA). OLEDs were fabricated by sequential deposition of organic thin films (total of ~100 nm) onto ITO-coated PET substrates. CdSe/ZnS QDs emitting at 655 nm and Au nanoparticles (NP - 10 nm size) conjugated antibodies were used for the fluorescence QD-LFIA and conventional reflection-mode Au NP-LFIA, respectively. Thin plastic color light filters were integrated for filtering the excitation light source and, thereby, increasing the contrast of the emitted light for optimized visual detection. Integration of the OLED and color filters with the analytical membrane was achieved using adhesive techniques facilitated by the planar nature of the layers, which suggests possible large scale manufacturing using roll-to-roll processing. Gray scale analysis from digital images captured with a digital camera was used to quantify the visual sensitivity. The signal intensity, signal-to-noise ratio (SNR) and the limit of detection (LOD) of OLED integrated QD-LFIAs were compared to Au NP LFIAs. OLED QD-LFIA exhibited superior performance in all signal aspects: 7-8× higher signal intensity and SNR, and a 7× lower LOD of 3 nM (measured at S/N=3). These results demonstrate the potential of OLED-integrated in LFIA devices for obtaining sensitive, fast and low-cost POC diagnostics. PMID:26134292

  1. Integration and Optimization of Alternative Sources of Energy in a Remote Region

    NASA Astrophysics Data System (ADS)

    Berberi, Pellumb; Inodnorjani, Spiro; Aleti, Riza

    2010-01-01

    In a remote coastal region supply of energy from national grid is insufficient for a sustainable development. Integration and optimization of local alternative renewable energy sources is an optional solution of the problem. In this paper we have studied the energetic potential of local sources of renewable energy (water, solar, wind and biomass). A bottom-up energy system optimization model is proposed in order to support planning policies for promoting the use of renewable energy sources. A software, based on multiple factors and constrains analysis for optimization energy flow is proposed, which provides detailed information for exploitation each source of energy, power and heat generation, GHG emissions and end-use sectors. Economical analysis shows that with existing technologies both stand alone and regional facilities may be feasible. Improving specific legislation will foster investments from Central or Local Governments and also from individuals, private companies or small families. The study is carried on the frame work of a FP6 project "Integrated Renewable Energy System."

  2. A novel integrated, compact OSA and ASE source for increased fober optic sensing capacity

    NASA Astrophysics Data System (ADS)

    West, Linda; Eigen, Daryl J.; Chavez-Pirson, Arturo

    2003-11-01

    Typical fiber Bragg sensing systems, in the 1500nm to 1600nm wavelength range, use gratings spaced approximately 5nm apart. This large spacing is preferred since optical power illuminating the gratings is limited and monitoring systems often have low performance and hence have difficulty in differentiating between closely spaced gratings. In this paper, we present a high power ASE source in combination with an extremely high performance Optical Spectrum Analyzer (OSA), that allows sensing gratings to be closely spaced so many sensing elements can be monitored while maintaining very good wavelength and power detection. The integrated unit can be provided on a PCI card, in a box or as an OEM module to enable a robust, handheld unit. The OSA is built around proprietary Compliant Micro Electro Mechanical (CMEMs) tunable filters, primarily developed for very densely populated Telecommunications applications. The OSA is wavelength calibrated and can be matched to the ASE source to compensate for any spectral power characteristic of the source. This integrated OSA and ASE source will allow the sensing industry to increase grating array sizes while maintaining low cost.

  3. Open source software integrated into data services of Japanese planetary explorations

    NASA Astrophysics Data System (ADS)

    Yamamoto, Y.; Ishihara, Y.; Otake, H.; Imai, K.; Masuda, K.

    2015-12-01

    Scientific data obtained by Japanese scientific satellites and lunar and planetary explorations are archived in DARTS (Data ARchives and Transmission System). DARTS provides the data with a simple method such as HTTP directory listing for long-term preservation while DARTS tries to provide rich web applications for ease of access with modern web technologies based on open source software. This presentation showcases availability of open source software through our services. KADIAS is a web-based application to search, analyze, and obtain scientific data measured by SELENE(Kaguya), a Japanese lunar orbiter. KADIAS uses OpenLayers to display maps distributed from Web Map Service (WMS). As a WMS server, open source software MapServer is adopted. KAGUYA 3D GIS (KAGUYA 3D Moon NAVI) provides a virtual globe for the SELENE's data. The main purpose of this application is public outreach. NASA World Wind Java SDK is used to develop. C3 (Cross-Cutting Comparisons) is a tool to compare data from various observations and simulations. It uses Highcharts to draw graphs on web browsers. Flow is a tool to simulate a Field-Of-View of an instrument onboard a spacecraft. This tool itself is open source software developed by JAXA/ISAS, and the license is BSD 3-Caluse License. SPICE Toolkit is essential to compile FLOW. SPICE Toolkit is also open source software developed by NASA/JPL, and the website distributes many spacecrafts' data. Nowadays, open source software is an indispensable tool to integrate DARTS services.

  4. Self-Consistent Sources for Integrable Equations Via Deformations of Binary Darboux Transformations

    NASA Astrophysics Data System (ADS)

    Chvartatskyi, Oleksandr; Dimakis, Aristophanes; Müller-Hoissen, Folkert

    2016-06-01

    We reveal the origin and structure of self-consistent source extensions of integrable equations from the perspective of binary Darboux transformations. They arise via a deformation of the potential that is central in this method. As examples, we obtain in particular matrix versions of self-consistent source extensions of the KdV, Boussinesq, sine-Gordon, nonlinear Schrödinger, KP, Davey-Stewartson, two-dimensional Toda lattice and discrete KP equation. We also recover a (2+1)-dimensional version of the Yajima-Oikawa system from a deformation of the pKP hierarchy. By construction, these systems are accompanied by a hetero binary Darboux transformation, which generates solutions of such a system from a solution of the source-free system and additionally solutions of an associated linear system and its adjoint. The essence of all this is encoded in universal equations in the framework of bidifferential calculus.

  5. Self-Consistent Sources for Integrable Equations Via Deformations of Binary Darboux Transformations

    NASA Astrophysics Data System (ADS)

    Chvartatskyi, Oleksandr; Dimakis, Aristophanes; Müller-Hoissen, Folkert

    2016-08-01

    We reveal the origin and structure of self-consistent source extensions of integrable equations from the perspective of binary Darboux transformations. They arise via a deformation of the potential that is central in this method. As examples, we obtain in particular matrix versions of self-consistent source extensions of the KdV, Boussinesq, sine-Gordon, nonlinear Schrödinger, KP, Davey-Stewartson, two-dimensional Toda lattice and discrete KP equation. We also recover a (2+1)-dimensional version of the Yajima-Oikawa system from a deformation of the pKP hierarchy. By construction, these systems are accompanied by a hetero binary Darboux transformation, which generates solutions of such a system from a solution of the source-free system and additionally solutions of an associated linear system and its adjoint. The essence of all this is encoded in universal equations in the framework of bidifferential calculus.

  6. Tin DPP source collector module (SoCoMo) ready for integration into Beta scanner

    NASA Astrophysics Data System (ADS)

    Yoshioka, Masaki; Teramoto, Yusuke; Jonkers, Jeroen; Schürmann, Max C.; Apetz, Rolf; Kilian, Volker; Corthout, Marc

    2011-04-01

    As the traditional techniques used in optical photolithography at 193 nm are running out of steam and are becoming prohibitively expensive, a new cost-effective, high power EUV (extreme ultra-violet) light source is needed to enable high volume manufacturing (HVM) of ever shrinking semiconductor devices. XTREME technologies GmbH and EUVA have jointly developed tin based LDP (Laser assisted Discharge Plasma) source systems during the last two years for the integration of such sources into scanners of the latest and future generations. The goals of the consortium are 1) to solve the wavelength gap - the growing gap between the printed critical dimensions (CD) driven by Moore's Law and the printing capability of lithographic exposure tools constrained by the wavelength of the light source - and 2) to enable the timely availability of EUV light sources for high volume manufacturing. A first Beta EUV Source Collector Module (SoCoMo) containing a tin based laser assisted discharge plasma source is in operation at XTREME technologies since September 2009. Alongside the power increase, the main focus of work emphasizes on the improvement of uptime and reliability of the system leveraging years of experience with the Alpha sources. Over the past period, a cumulated EUV dose of several hundreds of Mega Joules of EUV light has been generated at the intermediate focus, capable to expose more than a hundred thousand wafers with the right dose stability to create well-yielding transistors. During the last months, the entire system achieved an uptime - calculated according to the SEMI standards - of up to 80 %. This new SoCoMo has been successfully integrated and tested with a pre-production scanner and is now ready for first wafer exposures at a customer's site. In this paper we will emphasize what our innovative concept is against old type of Xe DPP and we will present the recent status of this system like power level, uptime and lifetime of components as well. In the second

  7. Influence of IGR treatment on oviposition of three species of vector mosquitos at sublethal concentrations.

    PubMed

    Vasuki, V

    1999-03-01

    Sublethal effect of hexaflumuron, an insect growth regulator (IGR), on the oviposition of three species of vector mosquitos. Culex quinquefasciatus, Aedes aegypti and Anopheles stephensi was studied. Significant reduction in oviposition was observed in the females of the above three species derived from fourth instar larvae and pupae exposed to sublethal (EI5 and EI50) doses. The reduction in egg laying is proportional to the dose of exposure and was found to be about twice higher in females of three species exposed to EI50 dose than those exposed to EI5 dose. Among the three species exposed at larval and pupal stages, Ae. aegypti showed maximum reduction in egg laying (29.3-46.6%). Blood feeding was also reduced in females exposed to EI50 dose at larval stage and a positive correlation was demonstrated between the quantity of blood meal taken and the proportion of eggs laid. Significant reduction in the quantum of blood ingested by the treated females may be responsible for the reduced egg laying. PMID:10695811

  8. DStat: A Versatile, Open-Source Potentiostat for Electroanalysis and Integration.

    PubMed

    Dryden, Michael D M; Wheeler, Aaron R

    2015-01-01

    Most electroanalytical techniques require the precise control of the potentials in an electrochemical cell using a potentiostat. Commercial potentiostats function as "black boxes," giving limited information about their circuitry and behaviour which can make development of new measurement techniques and integration with other instruments challenging. Recently, a number of lab-built potentiostats have emerged with various design goals including low manufacturing cost and field-portability, but notably lacking is an accessible potentiostat designed for general lab use, focusing on measurement quality combined with ease of use and versatility. To fill this gap, we introduce DStat (http://microfluidics.utoronto.ca/dstat), an open-source, general-purpose potentiostat for use alone or integrated with other instruments. DStat offers picoampere current measurement capabilities, a compact USB-powered design, and user-friendly cross-platform software. DStat is easy and inexpensive to build, may be modified freely, and achieves good performance at low current levels not accessible to other lab-built instruments. In head-to-head tests, DStat's voltammetric measurements are much more sensitive than those of "CheapStat" (a popular open-source potentiostat described previously), and are comparable to those of a compact commercial "black box" potentiostat. Likewise, in head-to-head tests, DStat's potentiometric precision is similar to that of a commercial pH meter. Most importantly, the versatility of DStat was demonstrated through integration with the open-source DropBot digital microfluidics platform. In sum, we propose that DStat is a valuable contribution to the "open source" movement in analytical science, which is allowing users to adapt their tools to their experiments rather than alter their experiments to be compatible with their tools. PMID:26510100

  9. Deterministic Integration of Single Photon Sources in Silicon Based Photonic Circuits.

    PubMed

    Zadeh, Iman Esmaeil; Elshaari, Ali W; Jöns, Klaus D; Fognini, Andreas; Dalacu, Dan; Poole, Philip J; Reimer, Michael E; Zwiller, Val

    2016-04-13

    A major step toward fully integrated quantum optics is the deterministic incorporation of high quality single photon sources in on-chip optical circuits. We show a novel hybrid approach in which preselected III-V single quantum dots in nanowires are transferred and integrated in silicon based photonic circuits. The quantum emitters maintain their high optical quality after integration as verified by measuring a low multiphoton probability of 0.07 ± 0.07 and emission line width as narrow as 3.45 ± 0.48 GHz. Our approach allows for optimum alignment of the quantum dot light emission to the fundamental waveguide mode resulting in very high coupling efficiencies. We estimate a coupling efficiency of 24.3 ± 1.7% from the studied single-photon source to the photonic channel and further show by finite-difference time-domain simulations that for an optimized choice of material and design the efficiency can exceed 90%. PMID:26954298

  10. Low-level radioactive waste source terms for the 1992 integrated data base

    SciTech Connect

    Loghry, S L; Kibbey, A H; Godbee, H W; Icenhour, A S; DePaoli, S M

    1995-01-01

    This technical manual presents updated generic source terms (i.e., unitized amounts and radionuclide compositions) which have been developed for use in the Integrated Data Base (IDB) Program of the U.S. Department of Energy (DOE). These source terms were used in the IDB annual report, Integrated Data Base for 1992: Spent Fuel and Radioactive Waste Inventories, Projections, and Characteristics, DOE/RW-0006, Rev. 8, October 1992. They are useful as a basis for projecting future amounts (volume and radioactivity) of low-level radioactive waste (LLW) shipped for disposal at commercial burial grounds or sent for storage at DOE solid-waste sites. Commercial fuel cycle LLW categories include boiling-water reactor, pressurized-water reactor, fuel fabrication, and uranium hexafluoride (UF{sub 6}) conversion. Commercial nonfuel cycle LLW includes institutional/industrial (I/I) waste. The LLW from DOE operations is category as uranium/thorium fission product, induced activity, tritium, alpha, and {open_quotes}other{close_quotes}. Fuel cycle commercial LLW source terms are normalized on the basis of net electrical output [MW(e)-year], except for UF{sub 6} conversion, which is normalized on the basis of heavy metal requirement [metric tons of initial heavy metal ]. The nonfuel cycle commercial LLW source term is normalized on the basis of volume (cubic meters) and radioactivity (curies) for each subclass within the I/I category. The DOE LLW is normalized in a manner similar to that for commercial I/I waste. The revised source terms are based on the best available historical data through 1992.

  11. Integrated guided wave generation and sensing using a single laser source and optical fibers

    NASA Astrophysics Data System (ADS)

    Lee, Hyeonseok; Park, Hyun-Jun; Sohn, Hoon; Kwon, Il-Bum

    2010-10-01

    This study proposes an integrated lead zirconate titanate/fiber Bragg grating (PZT/FBG) system that can generate and measure guided waves for structural health monitoring (SHM) using a common laser source and optical cables. Among various SHM devices used for guided wave generation and sensing, PZT transducers and FBG sensors have been widely used because of their light weight, non-intrusive nature and compactness. To take the best advantage of the merits of these SHM devices, a combination of PZT-based guided wave generation and FBG-based sensing has been attempted by some researchers. However, the existing hybrid approaches have two independent systems: a wave generation system using electrical devices and a sensing system with optical devices. We have developed a fully integrated PZT/FBG system that uses a single laser source and optical cables. This system can alleviate problems associated with conventional electrical cables, such as electromagnetic interference, signal attenuation and vulnerability to noise. A tunable laser, the common power source for guided wave generation and sensing, is modulated and amplified to excite PZT. This laser is also used with FBG sensors for measuring high-speed strain changes induced by guided waves. The feasibility of this system has been experimentally demonstrated using an aluminum plate.

  12. Plasma-based ambient sampling/ionization/transmission integrated source for mass spectrometry.

    PubMed

    Zhou, Yueming; Zhang, Ning; Li, Yafeng; Xiong, Caiqiao; Chen, Suming; Chen, Yongtai; Nie, Zongxiu

    2014-11-01

    Better sensitivity and interface of ambient sampling/ionization mass spectrometry remain a challenge. Herein, a novel, plasma-based, ambient sampling/ionization/transmission (PASIT) integrated source in a pin-to-funnel configuration was developed for the sensitive analysis of complex samples. With the funnel sleeve directly affected by direct-current discharge plasma, PASIT combines the ability to sample/ionize analyte molecules and then efficiently collect/transport charged mass species under atmospheric pressure and consequently shows an improved sensitivity. The integrated source enhances the signal intensity by more than 2 orders of magnitude compared with the previous pin-to-plate plasma source without significant background addition. A surface limit of detection (LOD) of 130 fmol mm-(2) (S/N = 3) has been achieved for clenbuterol on filter paper with an argon carrier gas. Demonstrated applications include the direct determination of active ingredients from drugs and symbolic compounds from natural plants and cholesterol from mouse brain tissue sections. PMID:25147876

  13. HPCAT: an integrated high-pressure synchrotron facility at the Advanced Photon Source

    SciTech Connect

    Shen, Guoyin; Chow, Paul; Xiao, Yuming; Sinogeikin, Stanislav; Meng, Yue; Yang, Wenge; Liermann, Hans-Peter; Shebanova, Olga; Rod, Eric; Bommannavar, Arunkumar; Mao, Ho-Kwang

    2008-10-24

    The high pressure collaborative access team (HPCAT) was established to advance cutting edge, multidisciplinary, high-pressure (HP) science and technology using synchrotron radiation at sector 16 of the Advanced Photon Source of Argonne National Laboratory. The integrated HPCAT facility has established four operating beamlines in nine hutches. Two beamlines are split in energy space from the insertion device (16ID) line, whereas the other two are spatially divided into two fans from the bending magnet (16BM) line. An array of novel X-ray diffraction and spectroscopic techniques has been integrated with HP and extreme temperature instrumentation at HPCAT. With a multidisciplinary approach and multi-institution collaborations, the HP program at the HPCAT has been enabling myriad scientific breakthroughs in HP physics, chemistry, materials, and Earth and planetary sciences.

  14. DStat: A Versatile, Open-Source Potentiostat for Electroanalysis and Integration

    PubMed Central

    Dryden, Michael D. M.; Wheeler, Aaron R.

    2015-01-01

    Most electroanalytical techniques require the precise control of the potentials in an electrochemical cell using a potentiostat. Commercial potentiostats function as “black boxes,” giving limited information about their circuitry and behaviour which can make development of new measurement techniques and integration with other instruments challenging. Recently, a number of lab-built potentiostats have emerged with various design goals including low manufacturing cost and field-portability, but notably lacking is an accessible potentiostat designed for general lab use, focusing on measurement quality combined with ease of use and versatility. To fill this gap, we introduce DStat (http://microfluidics.utoronto.ca/dstat), an open-source, general-purpose potentiostat for use alone or integrated with other instruments. DStat offers picoampere current measurement capabilities, a compact USB-powered design, and user-friendly cross-platform software. DStat is easy and inexpensive to build, may be modified freely, and achieves good performance at low current levels not accessible to other lab-built instruments. In head-to-head tests, DStat’s voltammetric measurements are much more sensitive than those of “CheapStat” (a popular open-source potentiostat described previously), and are comparable to those of a compact commercial “black box” potentiostat. Likewise, in head-to-head tests, DStat’s potentiometric precision is similar to that of a commercial pH meter. Most importantly, the versatility of DStat was demonstrated through integration with the open-source DropBot digital microfluidics platform. In sum, we propose that DStat is a valuable contribution to the “open source” movement in analytical science, which is allowing users to adapt their tools to their experiments rather than alter their experiments to be compatible with their tools. PMID:26510100

  15. A Practice Approach of Multi-source Geospatial Data Integration for Web-based Geoinformation Services

    NASA Astrophysics Data System (ADS)

    Huang, W.; Jiang, J.; Zha, Z.; Zhang, H.; Wang, C.; Zhang, J.

    2014-04-01

    Geospatial data resources are the foundation of the construction of geo portal which is designed to provide online geoinformation services for the government, enterprise and public. It is vital to keep geospatial data fresh, accurate and comprehensive in order to satisfy the requirements of application and development of geographic location, route navigation, geo search and so on. One of the major problems we are facing is data acquisition. For us, integrating multi-sources geospatial data is the mainly means of data acquisition. This paper introduced a practice integration approach of multi-source geospatial data with different data model, structure and format, which provided the construction of National Geospatial Information Service Platform of China (NGISP) with effective technical supports. NGISP is the China's official geo portal which provides online geoinformation services based on internet, e-government network and classified network. Within the NGISP architecture, there are three kinds of nodes: national, provincial and municipal. Therefore, the geospatial data is from these nodes and the different datasets are heterogeneous. According to the results of analysis of the heterogeneous datasets, the first thing we do is to define the basic principles of data fusion, including following aspects: 1. location precision; 2.geometric representation; 3. up-to-date state; 4. attribute values; and 5. spatial relationship. Then the technical procedure is researched and the method that used to process different categories of features such as road, railway, boundary, river, settlement and building is proposed based on the principles. A case study in Jiangsu province demonstrated the applicability of the principle, procedure and method of multi-source geospatial data integration.

  16. IGR J12580+0134: The First Tidal Disruption Event with an Off-beam Relativistic Jet

    NASA Astrophysics Data System (ADS)

    Lei, Wei-Hua; Yuan, Qiang; Zhang, Bing; Wang, Daniel

    2016-01-01

    Supermassive black holes (SMBHs) can capture and tidally disrupt stars or substellar objects orbiting nearby. The detections of Sw J1644+57-like events suggest that at least some TDEs can launch a relativistic jet beaming toward Earth. A natural expectation would be the existence of TDEs with a relativistic jet beaming away from Earth. The nearby TDE candidate IGR J12580+0134 provides new insights into the jet phenomenon. Combining several constraints, we find that the event invokes a 8-40 Jupiter mass object tidally disrupted by a 3× {10}5-1.8× {10}7{M}⊙ SMBH. Recently, a bright radio transient was discovered by Irwin et al. in association with IGR J12580+0134. We perform detailed modeling of the event based on a numerical jet model previously developed for the radio emission of Sw J1644+57. We find that the radio data of IGR J12580+0134 can be interpreted within an external forward shock model in the Newtonian regime. Using Sw J1644+57 as a template and properly correcting for its luminosity, we argue that the observed X-ray flux in early times is too faint to allow an on-beam relativistic jet unless the Lorentz factor is very small. Rather, the X-ray emission is likely from the disk or corona near the black hole. From various constraints, we find that the data are consistent with an off-beam relativistic jet with a viewing angle of {θ }{{obs}}≳ {30}{{o}}, and an initial Lorentz factor of {{{Γ }}}j≳ a few. This scenario can readily be tested in the upcoming very long baseline interferometry observations.

  17. CDApps: integrated software for experimental planning and data processing at beamline B23, Diamond Light Source

    PubMed Central

    Hussain, Rohanah; Benning, Kristian; Javorfi, Tamas; Longo, Edoardo; Rudd, Timothy R.; Pulford, Bill; Siligardi, Giuliano

    2015-01-01

    The B23 Circular Dichroism beamline at Diamond Light Source has been operational since 2009 and has seen visits from more than 200 user groups, who have generated large amounts of data. Based on the experience of overseeing the users’ progress at B23, four key areas requiring the most assistance are identified: planning of experiments and note-keeping; designing titration experiments; processing and analysis of the collected data; and production of experimental reports. To streamline these processes an integrated software package has been developed and made available for the users. The subsequent article summarizes the main features of the software. PMID:25723950

  18. SARNET: Integrating Severe Accident Research in Europe - Safety Issues in the Source Term Area

    SciTech Connect

    Haste, T.; Giordano, P.; Micaelli, J.-C.; Herranz, L.

    2006-07-01

    SARNET (Severe Accident Research Network) is a Network of Excellence of the EU 6. Framework Programme that integrates in a sustainable manner the research capabilities of about fifty European organisations to resolve important remaining uncertainties and safety issues concerning existing and future nuclear plant, especially water-cooled reactors, under hypothetical severe accident conditions. It emphasises integrating activities, spreading of excellence (including knowledge transfer) and jointly-executed research. This paper summarises the main results obtained at the middle of the current 4-year term, highlighting those concerning radioactive release to the environment. Integration is pursued through different methods: the ASTEC integral computer code for severe accident modelling, development of PSA level 2 methods, a means for definition, updating and resolution of safety issues, and development of a web database for storing experimental results. These activities are helped by an evolving Advanced Communication Tool, easing communication amongst partners. Concerning spreading of excellence, educational courses covering severe accident analysis methodology and level 2 PSA have been organised for early 2006. A text book on Severe Accident Phenomenology is being written. A mobility programme for students and young researchers has started. Results are disseminated mainly through open conference proceedings, with journal publications planned. The 1. European Review Meeting on Severe Accidents in November 2005 covered SARNET activities during its first 18 months. Jointly executed research activities concern key issues grouped in the Corium, Containment and Source Term areas. In Source Term, behaviour of the highly radio-toxic ruthenium under oxidising conditions, including air ingress, is investigated. Models are proposed for fuel and ruthenium oxidation. Experiments on transport of oxide ruthenium species are performed. Reactor scenario studies assist in defining

  19. System and method for integrating and accessing multiple data sources within a data warehouse architecture

    DOEpatents

    Musick, Charles R.; Critchlow, Terence; Ganesh, Madhaven; Slezak, Tom; Fidelis, Krzysztof

    2006-12-19

    A system and method is disclosed for integrating and accessing multiple data sources within a data warehouse architecture. The metadata formed by the present method provide a way to declaratively present domain specific knowledge, obtained by analyzing data sources, in a consistent and useable way. Four types of information are represented by the metadata: abstract concepts, databases, transformations and mappings. A mediator generator automatically generates data management computer code based on the metadata. The resulting code defines a translation library and a mediator class. The translation library provides a data representation for domain specific knowledge represented in a data warehouse, including "get" and "set" methods for attributes that call transformation methods and derive a value of an attribute if it is missing. The mediator class defines methods that take "distinguished" high-level objects as input and traverse their data structures and enter information into the data warehouse.

  20. SEARCHING FOR {gamma}-RAY BLAZAR CANDIDATES AMONG THE UNIDENTIFIED INTEGRAL SOURCES

    SciTech Connect

    Massaro, F.; Paggi, A.; D'Abrusco, R.; Tosti, G.

    2012-05-10

    The identification of low-energy counterparts for {gamma}-ray sources is one of the biggest challenges in modern {gamma}-ray astronomy. Recently, we developed and successfully applied a new association method to recognize {gamma}-ray blazar candidates that could be possible counterparts for the unidentified {gamma}-ray sources above 100 MeV in the second Fermi Large Area Telescope Catalog. This method is based on the infrared colors of the recent Wide-Field Infrared Survey Explorer (WISE) all-sky survey. In this Letter, we applied our new association method to the case of unidentified INTEGRAL sources (UISs) listed in the fourth soft gamma-ray source catalog. Only 86 UISs out of the 113 can be analyzed due to the sky coverage of the WISE Preliminary Data Release. Among these 86 UISs, we found that 18 appear to have a {gamma}-ray blazar candidate within their positional error region. Finally, we analyzed Swift archival data available for 10 out of these 18 {gamma}-ray blazar candidates, and we found that 7 out of 10 are clearly detected in soft X-rays and/or in the optical-ultraviolet band. We cannot confirm the associations between the UISs and the selected {gamma}-ray blazar candidates due to the discrepancies between the INTEGRAL and the soft X-ray spectra. However, the discovery of the soft X-ray counterparts for the selected {gamma}-ray blazar candidates adds an important clue to help us understand their origin and to confirm their blazar nature.

  1. Searching for Gamma-Ray Blazar Candidates Among the Unidentified INTEGRAL Sources

    SciTech Connect

    Massaro, F.; Paggi, A.; D'Abrusco, R.; Tosti, G.; /Perugia U.

    2012-04-02

    The identification of low-energy counterparts for {gamma}-ray sources is one of the biggest challenge in modern {gamma}-ray astronomy. Recently, we developed and successfully applied a new association method to recognize {gamma}-ray blazar candidates that could be possible counterparts for the unidentified {gamma}-ray sources above 100 MeV in the second Fermi Large Area Telescope (LAT) catalog (2FGL). This method is based on the Infrared (IR) colors of the recent Wide-Field Infrared Survey Explorer (WISE) all-sky survey. In this letter we applied our new association method to the case of unidentified INTEGRAL sources (UISs) listed in the fourth soft gamma-ray source catalog (4IC). Only 86 UISs out of the 113 can be analyzed, due to the sky coverage of the WISE Preliminary data release. Among these 86 UISs, we found that 18 appear to have a {gamma}-ray blazar candidate within their positional error region. Finally, we analyzed the Swift archival data available for 10 out these 18 {gamma}-ray blazar candidates, and we found that 7 out of 10 are clearly detected in soft X-rays and/or in the optical-ultraviolet band. We cannot confirm the associations between the UISs and the selected {gamma}-ray blazar candidates due to the discrepancies between the INTEGRAL and the soft X-ray spectra. However, the discovery of the soft X-ray counterparts for the selected {gamma}-ray blazar candidates adds an important clue to help understand their origin and to confirm their blazar nature.

  2. A Mathematical and Computational Approach for Integrating the Major Sources of Cell Population Heterogeneity

    PubMed Central

    Stamatakis, Michail; Zygourakis, Kyriacos

    2010-01-01

    Several approaches have been used in the past to model heterogeneity in bacterial cell populations, with each approach focusing on different source(s) of heterogeneity. However, a holistic approach that integrates all the major sources into a comprehensive framework applicable to cell populations is still lacking. In this work we present the mathematical formulation of a cell population master equation (CPME) that describes cell population dynamics and takes into account the major sources of heterogeneity, namely stochasticity in reaction, DNA-duplication, and division, as well as the random partitioning of species contents into the two daughter cells. The formulation also takes into account cell growth and respects the discrete nature of the molecular contents and cell numbers. We further develop a Monte Carlo algorithm for the simulation of the stochastic processes considered here. To benchmark our new framework, we first use it to quantify the effect of each source of heterogeneity on the intrinsic and the extrinsic phenotypic variability for the well-known two-promoter system used experimentally by Elowitz et al. (2002). We finally apply our framework to a more complicated system and demonstrate how the interplay between noisy gene expression and growth inhibition due to protein accumulation at the single cell level can result in complex behavior at the cell population level. The generality of our framework makes it suitable for studying a vast array of artificial and natural genetic networks. Using our Monte Carlo algorithm, cell population distributions can be predicted for the genetic architecture of interest, thereby quantifying the effect of stochasticity in intracellular reactions or the variability in the rate of physiological processes such as growth and division. Such in silico experiments can give insight into the behavior of cell populations and reveal the major sources contributing to cell population heterogeneity. PMID:20685607

  3. X-RAY EMISSION AND ABSORPTION FEATURES DURING AN ENERGETIC THERMONUCLEAR X-RAY BURST FROM IGR J17062-6143

    SciTech Connect

    Degenaar, N.; Miller, J. M.; Wijnands, R.; Altamirano, D.; Fabian, A. C.

    2013-04-20

    Type-I X-ray bursts are thermonuclear explosions occurring in the surface layers of accreting neutron stars. These events are powerful probes of the physics of neutron stars and their surrounding accretion flow. We analyze a very energetic type-I X-ray burst from the neutron star low-mass X-ray binary IGR J17062-6143 that was detected with Swift on 2012 June 25. The light curve of the {approx_equal}18 minute long X-ray burst tail shows an episode of {approx_equal}10 minutes during which the intensity is strongly fluctuating by a factor of {approx_equal}3 above and below the underlying decay trend on a timescale of seconds. The X-ray spectrum reveals a highly significant emission line around {approx_equal}1 keV, which can be interpreted as an Fe-L shell line caused by the irradiation of cold gas. We also detect significant absorption lines and edges in the Fe-K band, which are strongly suggestive of the presence of hot, highly ionized gas along the line of sight. None of these features are present in the persistent X-ray spectrum of the source. The timescale of the strong intensity variations, the velocity width of the Fe-L emission line (assuming Keplerian motion), and photoionization modeling of the Fe-K absorption features each independently point to gas at a radius of {approx_equal} 10{sup 3} km as the source of these features. The unusual X-ray light curve and spectral properties could have plausibly been caused by a disruption of the accretion disk due to the super-Eddington fluxes reached during the X-ray burst.

  4. M@IA: a modular open-source application for microarray workflow and integrative datamining.

    PubMed

    Le Béchec, Antony; Zindy, Pierre; Sierocinski, Thomas; Petritis, Dimitri; Bihouée, Audrey; Le Meur, Nolwenn; Léger, Jean; Théret, Nathalie

    2008-01-01

    Microarray technology is a widely used approach to gene expression analysis. Many tools for microarray management and data analysis have been developed, and recently new methods have been proposed for deciphering biological pathways by integrating microarray data with other data sources. However, to improve microarray analysis and provide meaningful gene interaction networks, integrated software solutions are still needed. Therefore, we developed M@IA, an environment for DNA microarray data analysis allowing gene network reconstruction. M@IA is a microarray integrated application which includes all of the steps of a microarray study, from MIAME-compliant raw data storage and processing gene expression analysis. Furthermore, M@IA allows automatic gene annotation based on ontology, metabolic/signalling pathways, protein interaction, miRNA and transcriptional factor associations, as well as integrative analysis of gene interaction networks. Statistical and graphical methods facilitate analysis, yielding new hypotheses on gene expression data. To illustrate our approach, we applied M@IA modules to microarray data taken from an experiment on liver tissue. We integrated differentially expressed genes with additional biological information, thus identifying new molecular interaction networks that are associated with fibrogenesis. M@IA is a new application for microarray management and data analysis, offering functional insights into microarray data by the combination of gene expression data and biological knowledge annotation based on interactive graphs. M@IA is an interactive multi-user interface based on a flexible modular architecture and it is freely available for academic users at http://maia.genouest.org. PMID:18430991

  5. The symbiotic star RT Cru entered a new hard X-ray state as detected by INTEGRAL

    NASA Astrophysics Data System (ADS)

    Sguera, V.; Bird, A. J.; Sidoli, L.

    2015-12-01

    The symbiotic star RT Cru (also known as IGR J12349-6434) was in the field of view of INTEGRAL during recent observations of the Musca region performed between 11 Dec 17:54 (UTC) and 17 Dec 20:43 (UTC).

  6. ToxPi GUI: An interactive visualization tool for transparent integration of data from diverse sources of evidence

    EPA Science Inventory

    Motivation: Scientists and regulators are often faced with complex decisions, where use of scarce resources must be prioritized using collections of diverse information. The Toxicological Prioritization Index (ToxPi™) was developed to enable integration of multiple sources of evi...

  7. Mechanical integration of an RF volume source and einzel lens LEBT to the SSC RFQ

    SciTech Connect

    Valicenti, R.A.; Lenz, J.; Okay, N.C.; Plesea, L.; Saadatmand, K.

    1993-05-01

    The Superconducting Super Collider (SSC) LINAC Injector is currently operating with an RF-driven volume ion source coupled with an einzel lens Low Energy Beam Transport (LEBT). The ion source, LEBT and beam diagnostics are integrated into a compact vacuum enclosure which is mounted to the ups endwall of the Radio Frequency Quadrupole (RFQ). Beam dynamic requirements imposed a minimum longitudinal of only 23.5 cm, thus creating a very challenging packaging problem. In addition, optimum beam matching to the RFQ specified a maximum gap of 1 cm between the LEBT and the entrance endwall face, thereby excluding the use of a bellows between the LEBT chamber and the RFQ. Vacuum system induced loads and vibrations are isolated from the beamline components by the use of a straddling frame which is an integral component of the vacuum system/support cart TWs paper will desirable some of the unique aspects of the mechanical design resulting from beam requirements, high gas load, availability of the vacuum system and the need for unconstrained attachment to the RFQ. In addition, the mobile installation cart and the fully automated vacuum control system will be discussed.

  8. Study of a Satellite Attitude Control System Using Integrating Gyros as Torque Sources

    NASA Technical Reports Server (NTRS)

    White, John S.; Hansen, Q. Marion

    1961-01-01

    This report considers the use of single-degree-of-freedom integrating gyros as torque sources for precise control of satellite attitude. Some general design criteria are derived and applied to the specific example of the Orbiting Astronomical Observatory. The results of the analytical design are compared with the results of an analog computer study and also with experimental results from a low-friction platform. The steady-state and transient behavior of the system, as determined by the analysis, by the analog study, and by the experimental platform agreed quite well. The results of this study show that systems using integrating gyros for precise satellite attitude control can be designed to have a reasonably rapid and well-damped transient response, as well as very small steady-state errors. Furthermore, it is shown that the gyros act as rate sensors, as well as torque sources, so that no rate stabilization networks are required, and when no error sensor is available, the vehicle is still rate stabilized. Hence, it is shown that a major advantage of a gyro control system is that when the target is occulted, an alternate reference is not required.

  9. Imaging with INTEGRAL. [instrument for fine spectroscopy of celestial gamma-ray sources

    NASA Technical Reports Server (NTRS)

    Dean, A. J.

    1993-01-01

    The INTEGRAL mission was proposed in response to the ESA M2 call for proposals and is dedicated to the fine spectroscopy and imaging of celestial gamma-ray sources in the energy range 15 keV to 10 MeV. Cosmic gamma-rays are emitted on a wide range of angular scales and structures for a diverse population of astronomical objects. The emission, which includes discrete spectral lines and continuum radiation is derived from point sources, localized regions, as well as a diffuse band along the Galactic plane. Much of the gamma-ray sky is composed from transient phenomena which range from the few second timescale associated with gamma-ray bursts to larger lived events lasting some days or more. These class of events pose the challenge of firstly identification and secondly that of precise positional location of 'random' short lived events which arrive isotropically. In this article the imaging requirements are evaluated in light of current observational astronomical data and practical solutions for the INTEGRAL telescope are discussed. Some of the key problems are highlighted.

  10. A graphical model method for integrating multiple sources of genome-scale data

    PubMed Central

    Dvorkin, Daniel; Biehs, Brian; Kechris, Katerina

    2016-01-01

    Making effective use of multiple data sources is a major challenge in modern bioinformatics. Genome-wide data such as measures of transcription factor binding, gene expression, and sequence conservation, which are used to identify binding regions and genes that are important to major biological processes such as development and disease, can be difficult to use together due to the different biological meanings and statistical distributions of the heterogeneous data types, but each can provide valuable information for understanding the processes under study. Here we present methods for integrating multiple data sources to gain a more complete picture of gene regulation and expression. Our goal is to identify genes and cis-regulatory regions which play specific biological roles. We describe a graphical mixture model approach for data integration, examine the effect of using different model topologies, and discuss methods for evaluating the effectiveness of the models. Model fitting is computationally efficient and produces results which have clear biological and statistical interpretations. The Hedgehog and Dorsal signaling pathways in Drosophila, which are critical in embryonic development, are used as examples. PMID:23934610