1E 0104.2 + 3153 - A broad absorption-line QSO viewed through a giant elliptical galaxy
NASA Technical Reports Server (NTRS)
Stocke, J. T.; Liebert, J.; Schild, R.; Gioia, I. M.; Maccacaro, T.
1984-01-01
The optical identification of the X-ray source 1E 0104.2 + 3153 is complicated by the close projection of a broad absorption-line (BAL) QSO (z = 2.027) 10 arcsec from a giant elliptical galaxy (z = 0.111) at the center of a compact group of galaxies. At only 1.2 de Vaucouleur radii (16 kpc for H sub 0 = 100 km/s Mpc) this QSO-galaxy projection is the closest yet discovered. Based upon current observations, the source of the X-ray emission cannot be conclusively determined. Present in the BAL QSO spectrum are extremely strong Ca II H and K absorption lines due to the intervening galaxy, the first optical detection of the cold interstellar medium in an elliptical galaxy. The strength of these lines (EW = 2 and 1 A) requires observation through several interstellar clouds in the line of sight to the QSO. By its proximity to the central regions of the elliptical galaxy and the relative distances of the galaxy and QSO, this QSO is a particularly good candidate for observing dramatic transient gravitational lensing phenomena due to halo stars in the foreground galaxy.
NASA Astrophysics Data System (ADS)
Bettoni, D.; Falomo, R.; Kotilainen, J. K.; Karhunen, K.
2017-04-01
We obtained optical spectroscopy of close (<80 kpc) companion objects of a sample of 12 low-redshift quasars (z < 0.3) selected from the SDSS Stripe82 area and that are in the subsample of 52 QSOs for which both multicolour host galaxies properties and galaxy environment were recently investigated in detail. We found that for 8 out of 12 sources the companion galaxy is associated with the QSO having a difference of radial velocity that is less than 400 km s-1. Many of these associated companions exhibit [OII] λ3727 Å emission lines suggestive of episodes of (recent) star formation possibly induced by past interactions. The star formation rate of the companion galaxies as derived from [O II] line luminosity is, however, modest, with a median value of 1.0 ± 0.8 M⊙ yr-1, and the emission lines are barely consistent with expectation from gas ionization by the QSO. The role of the QSO for inducing star formation in close companion galaxies appears meager. For three objects we also detect the starlight spectrum of the QSO host galaxy, which is characterized by absorption lines of old stellar population and [O II] emission line.
NASA Astrophysics Data System (ADS)
Farina, Emanuele P.; Venemans, Bram P.; Decarli, Roberto; Hennawi, Joseph F.; Walter, Fabian; Bañados, Eduardo; Mazzucchelli, Chiara; Cantalupo, Sebastiano; Arrigoni-Battaia, Fabrizio; McGreer, Ian D.
2017-10-01
We utilize the Multi Unit Spectroscopic Explorer (MUSE) on the Very Large Telescope to search for extended Lyα emission around the z ˜ 6.6 QSO J0305-3150. After carefully subtracting the point spread function, we reach a nominal 5σ surface-brightness limit of SB5σ = 1.9 × 10-18 erg s-1 cm-2 arcsec-2 over a 1 arcsec2 aperture, collapsing five wavelength slices centered at the expected location of the redshifted Lyα emission (I.e., at 9256 Å). Current data suggest the presence (5σ accounting for systematics) of a Lyα nebula that extends for 9 kpc around the QSO. This emission is displaced and redshifted by 155 km s-1 with respect to the location of the QSO host galaxy traced by the [{{C}} {{II}}] 158 μm emission line. The total luminosity is L({Ly}α ) = (3.0 ± 0.4) × 1042 erg s-1. Our analysis suggests that this emission is unlikely to rise from optically thick clouds illuminated by the ionizing radiation of the QSO. It is more plausible that the Lyα emission is due to the fluorescence of the highly ionized optically thin gas. This scenario implies a high hydrogen volume density of {n}{{H}}˜ 6 cm-3. In addition, we detect a Lyα emitter (LAE) in the immediate vicinity of the QSO, I.e., with a projected separation of ˜12.5 kpc and a line-of-sight velocity difference of 560 km s-1. The luminosity of the LAE is L({Ly}α ) = (2.1 ± 0.2) × 1042 erg s-1 and its inferred star-formation rate is SFR ˜ 1.3 M ⊙ yr-1. The probability of finding such a close LAE is one order of magnitude above the expectations based on the QSO-galaxy cross-correlation function. This discovery is in agreement with a scenario where dissipative interactions favor the rapid build-up of supermassive black holes at early cosmic times.
PHL 6625: A Minor Merger-associated QSO Behind NGC 247
DOE Office of Scientific and Technical Information (OSTI.GOV)
Tao, Lian; Feng, Hua; Shen, Yue
2017-06-01
PHL 6625 is a luminous quasi-stellar object (QSO) at z = 0.3954 located behind the nearby galaxy NGC 247 ( z = 0.0005). Hubble Space Telescope observations revealed an arc structure associated with it. We report on spectroscopic observations with the Very Large Telescope and multiwavelength observations from the radio to the X-ray band for the system, suggesting that PHL 6625 and the arc are a close pair of merging galaxies, instead of a strong gravitational lens system. The QSO host galaxy is estimated to be (4–28) × 10{sup 10} M {sub ☉} and the mass of the companion galaxymore » is estimated to be M {sub *} = (6.8 ± 2.4) × 10{sup 9} M {sub ☉}, suggesting that this is a minor merger system. The QSO displays typical broad emission lines, from which a black hole mass of about (2–5) × 10{sup 8} M {sub ☉} and an Eddington ratio of about 0.01–0.05 can be inferred. The system represents an interesting and rare case where a QSO is associated with an ongoing minor merger, analogous to Arp 142.« less
Galaxy Clustering Around Nearby Luminous Quasars
NASA Technical Reports Server (NTRS)
Fisher, Karl B.; Bahcall, John N.; Kirhakos, Sofia; Schneider, Donald P.
1996-01-01
We examine the clustering of galaxies around a sample of 20 luminous low redshift (z approx. less than 0.30) quasars observed with the Wide Field Camera-2 on the Hubble Space Telescope (HST). The HST resolution makes possible galaxy identification brighter than V = 24.5 and as close as 1 min or 2 min to the quasar. We find a significant enhancement of galaxies within a projected separation of approx. less than 100 1/h kpc of the quasars. If we model the QSO/galaxy correlation function as a power law with a slope given by the galaxy/galaxy correlation function, we find that the ratio of the QSO/galaxy to galaxy/galaxy correlation functions is 3.8 +/- 0.8. The galaxy counts within r less than 15 1/h kpc of the quasars are too high for the density profile to have an appreciable core radius (approx. greater than 100 1/h kpc). Our results reinforce the idea that low redshift quasars are located preferentially in groups of 10-20 galaxies rather than in rich clusters. We see no significant difference in the clustering amplitudes derived from radio-loud and radio-quiet subsamples.
On orthogonality preserving quadratic stochastic operators
DOE Office of Scientific and Technical Information (OSTI.GOV)
Mukhamedov, Farrukh; Taha, Muhammad Hafizuddin Mohd
2015-05-15
A quadratic stochastic operator (in short QSO) is usually used to present the time evolution of differing species in biology. Some quadratic stochastic operators have been studied by Lotka and Volterra. In the present paper, we first give a simple characterization of Volterra QSO in terms of absolutely continuity of discrete measures. Further, we introduce a notion of orthogonal preserving QSO, and describe such kind of operators defined on two dimensional simplex. It turns out that orthogonal preserving QSOs are permutations of Volterra QSO. The associativity of genetic algebras generated by orthogonal preserving QSO is studied too.
SOUTHERN COSMOLOGY SURVEY. III. QSOs FROM COMBINED GALEX AND OPTICAL PHOTOMETRY
DOE Office of Scientific and Technical Information (OSTI.GOV)
Jimenez, Raul; Verde, Licia; Spergel, David N.
2009-04-15
We present catalogs of QSO candidates selected using photometry from Galaxy Evolution Explorer (GALEX) combined with the Sloan Digital Sky Survey (SDSS) in the Stripe 82 region and Blanco Cosmology Survey (BCS) near declination -55 deg. The SDSS region contains {approx_equal}700 objects with magnitude i < 20 and {approx_equal}3600 objects with i < 21.5 in a {approx_equal}60 deg{sup 2} sky region, while the BCS region contains {approx_equal}280 objects with magnitude i < 20 and {approx}2000 objects with i < 21.5 for a 11 deg{sup 2} sky region that is being observed by three current microwave Sunyaev-Zeldovich surveys. Our QSO catalogmore » is the first one in the BCS region. Deep GALEX exposures ({approx}>2000 s in F {sub UV} and N {sub UV}, except in three fields) provide high signal-to-noise photometry in the GALEX bands (F {sub UV}, N {sub UV} < 24.5 mag). From this data, we select QSO candidates using only GALEX and optical r-band photometry, using the method given by Atlee and Gould. In the Stripe 82 field, 60% (30%) of the GALEX-selected QSOs with optical magnitude i < 20 (i < 21.5) also appear in the Richards et al. QSO catalog constructed using five-band optical SDSS photometry. Comparison with the same catalog by Richards et al. shows that the completeness of the sample is approximately 40% (25%). However, for regions of the sky with very low dust extinction, like the BCS 23-hr field and the Stripe 82 between 0{sup 0} and 10{sup 0} in R.A., our completeness is close to 95%, demonstrating that deep GALEX observations are almost as efficient as multiwavelength observations at finding QSOs. GALEX observations thus provide a viable alternate route to QSO catalogs in sky regions where u-band optical photometry is not available. The full catalog is available at http://www.ice.csic.es/personal/jimenez/PHOTOZ.« less
The Quasar Pairs Environment At z ∼ 0.5
NASA Astrophysics Data System (ADS)
Sandrinelli, Angela; Falomo, R.; Treves, A.; Scarpa, R.; Uslenghi, M.
2016-10-01
We analyze the environment of a sample of 20 quasar physical pairs at 0.4
Confining hot spots in 3C 196 - Implications for QSO-companion galaxies
NASA Technical Reports Server (NTRS)
Brown, R. L.; Broderick, J. J.; Mitchell, K. J.
1986-01-01
VLBI observations of the extremely compact hot spot in the northern radio lobe of the QSO 3C 196 reveal the angular size of its smallest substructure to be 0.065 arcsec x 0.045 arcsec or about 300 pc at the redshift distance. The morphology of the hot spot and its orientation relative to the more diffuse radio emission suggest that it is formed by an oblique interaction between the nuclear QSO jet and circum-QSO cloud. The inferred density in this cloud, together with its apparent size, imply that the cloud contains a galactic mass, greater than a billion solar masses of gas. The effect of the jet will be to hasten gravitational collapse of the cloud. If many QSOs such as 3C 196 are formed or found in gas-rich environments, the QSO radio phase may commonly stimulate the metamorphosis of circum-QSO gas to QSO-companion galaxies or it may play a significant part in catalyzing star formation in existing companions.
NASA Astrophysics Data System (ADS)
Husemann, B.; Bennert, V. N.; Scharwächter, J.; Woo, J.-H.; Choudhury, O. S.
2016-01-01
We report deep optical integral-field spectroscopy with the Multi-Unit Spectroscopic Explorer (MUSE) at the Very Large Telescope of the luminous radio-quiet quasi-stellar object (QSO) PG 1307+085 obtained during commissioning. Given the high sensitivity and spatial resolution delivered by MUSE, we are able to resolve the compact (re ˜ 1.3 arcsec) elliptical host galaxy. After spectroscopic deblending of the QSO and host galaxy emission, we infer a stellar velocity dispersion of σ* = 155 ± 19 km s-1. This places PG 1307+085 on the local MBH-σ* relation within its intrinsic scatter but offset towards a higher black hole mass with respect to the mean relation. The MUSE observations reveal a large extended narrow-line region (ENLR) around PG 1307+085 reaching out to ˜30 kpc. In addition, we detect a faint ionized gas bridge towards the most massive galaxy of the galaxy group at 50 kpc distance. The ionized gas kinematics does not show any evidence for gas outflows on kpc scales despite the high QSO luminosity of Lbol > 1046 erg s-1. Based on the ionized gas distribution, kinematics and metallicity we discuss the origin of the ENLR with respect to its group environments including minor mergers, ram-pressure stripping or gas accretion as the likely scenarios. We conclude that PG 1307+085 is a normal elliptical host in terms of the scaling relations, but that the gas is likely affected by the environment through gravity or ambient pressure. It is possible that the interaction with the environment, seen in the ionized gas, might be responsible for driving sufficient gas to the black hole.
Measuring BAO and non-Gaussianity via QSO clustering
NASA Astrophysics Data System (ADS)
Sawangwit, U.; Shanks, T.; Croom, S. M.; Drinkwater, M. J.; Fine, S.; Parkinson, D.; Ross, Nicholas P.
2012-03-01
Our goals are (i) to search for BAO and large-scale structure in current quasi-stellar object (QSO) survey data and (ii) to use these and simulation/forecast results to assess the science case for a new, ≳10 times larger, QSO survey. We first combine the Sloan Digital Sky Survey (SDSS), 2dF QSO Redshift Survey (2QZ) and 2dF-SDSS LRG and QSO (2SLAQ) surveys to form a survey of ≈60 000 QSOs. We find a hint of a peak in the QSO two-point correlation function, ξ(s), at the same scale (≈105 h-1 Mpc) as detected by Eisenstein et al. in their sample of Data Release 5 (DR5) Luminous Red Galaxies (LRGs) but only at low statistical significance. We then compare these data with QSO mock catalogues from the Hubble Volume N-body light-cone simulation used by Hoyle et al. and find that both routes give statistical error estimates that are consistent at ≈100 h-1 Mpc scales. Mock catalogues are then used to estimate the nominal survey size needed for a 3-4σ detection of the Baryon Acoustic Oscillations (BAO) peak. We find that a redshift survey of ≈250 000 z < 2.2 QSOs is required over ≈3000 deg2. This is further confirmed by static lognormal simulations where the BAO are clearly detectable in the QSO power spectrum and correlation function. The nominal survey would on its own produce the first detection of, for example, discontinuous dark energy evolution in the so far uncharted 1 < z < 2.2 redshift range. We further find that a survey with ≈50 per cent higher QSO sky densities and 50 per cent bigger area will give an ≈6σ BAO detection, leading to an error ≈60 per cent of the size of the BOSS error on the dark energy evolution parameter, wa. Another important aim of a QSO survey is to place new limits on primordial non-Gaussianity at large scales. In particular, it is important to test tentative evidence we have found for the evolution of the linear form of the combined SDSS+2QZ+2SLAQ QSO ξ(s) at z≈ 1.6, which may be caused by the existence of non-Gaussian clustering features at high redshift. Such a QSO survey will also determine the gravitational growth rate at z≈ 1.6 via redshift-space distortions, allow lensing tomography via QSO magnification bias while also measuring the exact luminosity dependence of small-scale QSO clustering.
The Host Galaxies of Nearby, Optically Luminous, AGN
NASA Astrophysics Data System (ADS)
Petric, Andreea
2016-01-01
Coevolution of galaxies and their central black holes (BH) has been the central theme of much of recent extragalactic astronomical research. Observations of the dynamics of stars and gas in the nuclear regions of nearby galaxies suggest that the majority of spheroidal galaxies in the local Universe contain massive BHs and that the masses of those central BH correlate with the velocity dispersions of the stars in the spheroid and the bulge luminosity. Cold ISM is the basic fuel for star-formation and BH growth so its study is essential to understanding how galaxies evolve.I will present high sensitivity observations taken with the Herschel Space Observatory to measure the cold dust content in a sample of 85 nearby (z <= 0.5) QSOs chosen from the optically luminous broad-line PG QSOs sample (QSO1s) and in a complementary sample of 85 narrow-line QSOs (QSO2s) chosen to match the redshift and optical luminosity distribution of the broad-line targets. The FIR data are combined with NIR and MIR measurements from the Two Micron All Sky Survey and the Wide-Field Infrared Survey Explorer to determine their IR spectral energy distributions which we use to assess and compare the aggregate dust properties of QSO1s and QSO2s. I will also present NIR spectroscopy obtained with Gemini's Near-Infrared Spectrograph of a sub-sample of QSO2s and QSO1s which I use to compare the ratio of cold to warm H2 gas that emits in the NIR in the hosts of QSO1s and QSO2s.Finally I will present a comparison of star-formation in QSO1s and QSO2s. For both QSO1s and QSO2s 3stimates of star-formation rates that are based on the total IR continuum emission correlate with those based on the 11.3 micron PAH feature. However, for the QSO1s, star-formation rates estimated from the FIR continuum are higher than those estimated from the 11.3 micron PAH emission. This result can be attributed to a variety of factors including the possible destruction of the PAHs and that, in some sources, a fraction of the FIR originates from dust heated by the active galactic nucleus and by old stars. For QSO2s the SFR derived from the 11.3 micron PAH feature match those derived from the 160micron emission.
High redshift QSOs and the x ray background
NASA Technical Reports Server (NTRS)
Impey, Chris
1993-01-01
ROSAT pointed observations were made of 9 QSO's from the Large Bright Quasar Survey (LBQS). The LBQS is based on machine measurement of objective prism plates taken with the UK Schmidt Telescope. Software has been used to select QSO's by both color and by the presence of spectral features and continuum breaks. The probability of detection can be calculated as a function of magnitude, redshift and spectral features, and the completeness of the survey can be accurately estimated. Nine out of 1040 QSO's in the LBQS have z greater than 3. The observations will provide an important data point in the X-ray luminosity function of QSO's at high redshift. The QSO's with z greater than 3 span less than a magnitude in M(sub B), so can be combined as a homogeneous sample. This analysis is only possible with a sample drawn from a large and complete catalog such as the LBQS. Four of the 9 QSO's that were observed with the ROSAT PSPC for this proposal were detected, including one of the most luminous X-ray sources ever observed. The April 1992 version of the PROS DETECT package was used to reduce the data. The results have been used to search for evolution of the X-ray properties of QSO's in redshift. The 9 QSO's lie in the range -28.7 less than M(sub B) less than -27.8. When combined with data for 16 QSO's in a similar luminosity range at lower redshift correlations with luminosity and redshift can be separated out. The LBQS sample also yields a new constraint on the contribution of high redshift QSO's to the X-ray background. An initial requirement is knowledge of the X-ray properties (alpha(sub OX)) as a function of redshift. Integration over the evolving luminosity function of the LBQS then gives the QSO contribution to the source counts.
NE VIII lambda 774 and time variable associated absorption in the QSO UM 675
NASA Technical Reports Server (NTRS)
Hamann, Fred; Barlow, Thomas A.; Beaver, E. A.; Burbidge, E. M.; Cohen, Ross D.; Junkkarinen, Vesa; Lyons, R.
1995-01-01
We discuss measurements of Ne VIII lambda 774 absorption and the time variability of other lines in the z(sub a) approximately equal z(sub e) absorption system of the z(sub e) = 2.15 QSO UM 675 (0150-203). The C IV lambda 1549 and N V 1240 doublets at z(sub a) = 2.1340 (shifted approximately 1500 km/s from z(sub e) strengthened by a factor of approximately 3 between observations by Sargent, Boksenberg and Steidel (1981 November) and our earliest measurements (1990 November and December). We have no information on changes in other z(sub a) approximately equal z(sub e) absorption lines. Continued monitoring since 1990 November shows no clear changes in any of the absorptions between approximately 1100 and 1640 A rest. The short timescale of the variability (less than or approximately equal to 2.9 yr rest) strongly suggests that the clouds are dense, compact, close to the QSO, and photoionized by the QSO continuum. If the line variability is caused by changes in the ionization, the timescale requires densities greater than approximately 4000/cu cm. Photoionization calculations place the absorbing clouds within approximately 200 pc of the continuum source. The full range of line ionizations (from Ne VIII lambda 774 to C III lambda 977) in optically thin gas (no Lyman limit) implies that the absorbing regions span a factor of more than approximately 10 in distance or approximately 100 in density. Across these regions, the total hydrogen (H I + H II) column ranges from a few times 10(exp 18)/sq cm in the low-ionization gas to approximately 10(exp 20)/sq cm where the Ne VIII doublet forms. The metallicity is roughly solar or higher, with nitrogen possibly more enhanced by factors of a few. The clouds might contribute significant line emission if they nearly envelop the QSO. The presence of highly ionized Ne VIII lambda 774 absorption near the QSO supports recent studies that link z(sub a) approximately equal to z(sub e) systems with X-ray 'wamr absorbers. We show that the Ne VIII absorbing gas would itself produce measurable warm absorption -- characterized by bound-free O VII or O VIII edegs near 0.8 keV -- if the column densities were N(sub H) greater than or approximately equal to 10(exp 21)/sq cm (for solar abundances).
NE VIII lambda 774 and time variable associated absorption in the QSO UM 675
NASA Astrophysics Data System (ADS)
Hamann, Fred; Barlow, Thomas A.; Beaver, E. A.; Burbidge, E. M.; Cohen, Ross D.; Junkkarinen, Vesa; Lyons, R.
1995-04-01
We discuss measurements of Ne VIII lambda 774 absorption and the time variability of other lines in the za approximately equal ze absorption system of the ze = 2.15 QSO UM 675 (0150-203). The C IV lambda 1549 and N V 1240 doublets at za = 2.1340 (shifted approximately 1500 km/s from ze strengthened by a factor of approximately 3 between observations by Sargent, Boksenberg and Steidel (1981 November) and our earliest measurements (1990 November and December). We have no information on changes in other za approximately equal ze absorption lines. Continued monitoring since 1990 November shows no clear changes in any of the absorptions between approximately 1100 and 1640 A rest. The short timescale of the variability (less than or approximately equal to 2.9 yr rest) strongly suggests that the clouds are dense, compact, close to the QSO, and photoionized by the QSO continuum. If the line variability is caused by changes in the ionization, the timescale requires densities greater than approximately 4000/cu cm. Photoionization calculations place the absorbing clouds within approximately 200 pc of the continuum source. The full range of line ionizations (from Ne VIII lambda 774 to C III lambda 977) in optically thin gas (no Lyman limit) implies that the absorbing regions span a factor of more than approximately 10 in distance or approximately 100 in density. Across these regions, the total hydrogen (H I + H II) column ranges from a few times 1018/sq cm in the low-ionization gas to approximately 1020/sq cm where the Ne VIII doublet forms. The metallicity is roughly solar or higher, with nitrogen possibly more enhanced by factors of a few. The clouds might contribute significant line emission if they nearly envelop the QSO. The presence of highly ionized Ne VIII lambda 774 absorption near the QSO supports recent studies that link za approximately equal to ze systems with X-ray 'wamr absorbers. We show that the Ne VIII absorbing gas would itself produce measurable warm absorption -- characterized by bound-free O VII or O VIII edegs near 0.8 keV -- if the column densities were NH greater than or approximately equal to 1021/sq cm (for solar abundances).
Probing the extent and content of low ionization gas in galaxies: QSO absorption and HI emission
NASA Technical Reports Server (NTRS)
Womble, Donna S.
1993-01-01
The small projected separations of some QSO's and low-redshift galaxies provide unique opportunities to study the extent and content of gas in galaxies through observation of absorption in the QSO spectra. Observations of these systems provide valuable information on the connection between the absorbing gas and the galaxy, as well as detailed information on the morphology and environment of the galaxy itself. While there is direct evidence that galaxies can produce the intervening-type QSO absorption lines, over the past decade, the study of such 'QSO-galaxy pairs' (at low redshift) has been considered unsuccessful because new detections of absorption were seldom made. A fundamental problem concerning the relation between these low-redshift systems and those seen at moderate to high redshift remains unresolved. Direct and indirect measures of galaxy absorption cross sections at moderate to high redshifts (z is approximately greater than 20.5) are much larger than the optical and HI sizes of local galaxies. However, direct comparison of the low and moderate to high redshift systems is difficult since different ions are observed in different redshift regimes. Observations are presented for a new sample of QSO-galaxy pairs. Nine new QSO's which shine through nearby galaxies (on the sky-plane) were observed to search for CaII absorption in the QSO spectra at the foreground galaxy redshifts.
Setting limits on q0 from gravitational lensing
NASA Technical Reports Server (NTRS)
Gott, J. Richard, III; Park, Myeong-Gu; Lee, Hyung Mok
1989-01-01
Gravitational lensing by galaxies in a wide variety of cosmological models is considered. For closed models, the lensing depends on the parameter beta(crit). If beta(crit) is greater than zero, a normal lensing case can be obtained with two bright images separated by an angle twice beta(crit) and a third, arbitrarily dim image between them coincident with the position of the lensing galaxy nucleus. As the QSO approaches the antipodal redshift, which can occur in models with large values of the cosmological constant, the cross sections for lensing blow up. An overfocused case where beta(crit) is less than zero can be obtained for a QSO beyond the antipodal redshift. In this case, when a lensing event occurs, only one arbitrarily dim image coincident with the position of the lensing galaxy nucleus is seen. If galaxy rotation curves are always flat or slowly rising, the overfocused case always produces one image.
Einstein X-ray observations of QSO's with absorption-line systems
NASA Technical Reports Server (NTRS)
Junkkarinen, V. T.; Marscher, A. P.; Burbidge, E. M.
1982-01-01
The detection of X-ray emission from eight QSO's is reported, plus an upper limit to the X-ray flux from one QSO, using the Einstein X-ray Observatory (HEAO-2). Each object in the sample contains at least one absorption-line system that has been identified in its optical spectrum. The present results are combined with those of other investigators to form a sample of 44 absorption-line QSO's (with 2 sub e greater than 1.2) which have been observed in the X-ray. This sample cannot be distinguished, in terms of X-ray properties, from one which consists of QSO's in which no absorption systems have been identified. These results are consistent with extrinsic models for absorption-line clouds, as well as with current versions of intrinsic models.
NASA Astrophysics Data System (ADS)
Finn, Charles W.; Morris, Simon L.; Crighton, Neil H. M.; Hamann, Fred; Done, Chris; Theuns, Tom; Fumagalli, Michele; Tejos, Nicolas; Worseck, Gabor
2014-06-01
We present HST/COS observations of highly ionized absorption lines associated with a radio-loud quasar (QSO) at z = 1.1319. The absorption system has multiple velocity components, with an overall width of ≈600 km s-1, tracing gas that is largely outflowing from the QSO at velocities of a few 100 km s-1. There is an unprecedented range in ionization, with detections of H I, N III, N IV, N V, O IV, O IV*, O V, O VI, Ne VIII, Mg X, S V and Ar VIII. We estimate the total hydrogen number density from the column density ratio N(OIV*) / N(OIV) to be log(nH/cm-3)˜3. Combined with constraints on the ionization parameter in the O IV bearing gas from photoionization equilibrium models, we derive a distance to the absorbing complex of 2.3≲R≲6.0kpc from the centre of the QSO. A range in ionization parameter, covering ˜two orders of magnitude, suggest absorption path lengths in the range 10-4.5≲labs≲1pc. In addition, the absorbing gas only partially covers the background emission from the QSO continuum, which suggests clouds with transverse sizes ltrans≲10-2.5 pc. Widely differing absorption path lengths, combined with covering fractions less than unity across all ions pose a challenge to models involving simple cloud geometries in associated absorption systems. These issues may be mitigated by the presence of non-equilibrium effects, which can be important in small, dynamically unstable clouds, together with the possibility of multiple gas temperatures. The dynamics and expected lifetimes of the gas clouds suggest that they do not originate from close to the active galactic nuclei, but are instead formed close to their observed location. Their inferred distance, outflow velocities and gas densities are broadly consistent with scenarios involving gas entrainment or condensations in winds driven by either supernovae, or the supermassive black hole accretion disc. In the case of the latter, the present data most likely does not trace the bulk of the outflow by mass, which could instead manifest itself as an accompanying warm absorber, detectable in X-rays.
The clustering of QSOs and the dark matter halos that host them
NASA Astrophysics Data System (ADS)
Zhao, Dong-Yao; Yan, Chang-Shuo; Lu, Youjun
2013-10-01
The spatial clustering of QSOs is an important measurable quantity which can be used to infer the properties of dark matter halos that host them. We construct a simple QSO model to explain the linear bias of QSOs measured by recent observations and explore the properties of dark matter halos that host a QSO. We assume that major mergers of dark matter halos can lead to the triggering of QSO phenomena, and the evolution of luminosity for a QSO generally shows two accretion phases, i.e., initially having a constant Eddington ratio due to the self-regulation of the accretion process when supply is sufficient, and then declining in rate with time as a power law due to either diminished supply or long term disk evolution. Using a Markov Chain Monte Carlo method, the model parameters are constrained by fitting the observationally determined QSO luminosity functions (LFs) in the hard X-ray and in the optical band simultaneously. Adopting the model parameters that best fit the QSO LFs, the linear bias of QSOs can be predicted and then compared with the observational measurements by accounting for various selection effects in different QSO surveys. We find that the latest measurements of the linear bias of QSOs from both the SDSS and BOSS QSO surveys can be well reproduced. The typical mass of SDSS QSOs at redshift 1.5 < z < 4.5 is ~ (3 - 6) × 1012 h-1 Msolar and the typical mass of BOSS QSOs at z ~ 2.4 is ~ 2 × 1012 h-1 Msolar. For relatively faint QSOs, the mass distribution of their host dark matter halos is wider than that of bright QSOs because faint QSOs can be hosted in both big halos and smaller halos, but bright QSOs are only hosted in big halos, which is part of the reason for the predicted weak dependence of the linear biases on the QSO luminosity.
NASA Technical Reports Server (NTRS)
Womble, Donna S.; Junkkarinen, Vesa T.; Cohen, Ross D.; Burbidge, E. Margaret
1990-01-01
In some of the few cases where the line of sight to a Quasi-Stellar Object (QSO) passes near a galaxy, the galaxy redshift is almost identical to an absorption redshift in the spectrum of the QSO. Although these relatively low redshift QSO-galaxy pairs may not be typical of the majority of the narrow heavy-element QSO absorption systems, they provide a direct measure of column densities in the outer parts of galaxies and some limits on the relative abundances of the gas. Observations are presented here of the QSO S4 0248+430 and a nearby anonymous galaxy (Kuhr 1977). The 14 second separation of the line of sight to the QSO (z sub e = 1.316) and the z=0.052 spiral galaxy, (a projected separation of 20 kpc ((h sub o = 50, q sub o = 0)), makes this a particularly suitable pair for probing the extent and content of gas in the galaxy. Low resolution (6A full width half maximum), long slit charge coupled device (CCD) spectra show strong CA II H and K lines in absorption at the redshift of the galaxy (Junkkarinen 1987). Higher resolution spectra showing both Ca II H and K and Na I D1 and D2 in absorption and direct images are reported here.
The X-rays of a bright QSO well within the epoch of reionization at z=7.54
NASA Astrophysics Data System (ADS)
Banados, Eduardo
2016-09-01
After almost a decade of intense search, our team has finally discovered a bright QSO well within the epoch of reionization, at z=7.54. This is by far the most distant QSO known (previous record: 7.08), at a cosmic age of 690 Myr, i.e., only 5% of our universe's current age. This is the first QSO whose spectrum shows clear evidence of an intergalactic medium that is >20% neutral and that reionization is underway. We propose Chandra observations of this unique object to (i) probe evolution of the X-ray-to-optical luminosity ratio (alpha-ox) to the highest accessible redshift; (ii) provide a more reliable estimate of the QSO's bolometric luminosity, and (iii) assess the feasibility of deeper Chandra and XMM observations for the upcoming cycles, which would allow us to test whether the first black holes are accreting at super-Eddington rates.
NASA Astrophysics Data System (ADS)
Rubin, Kate H. R.; Diamond-Stanic, Aleksandar M.; Coil, Alison L.; Crighton, Neil H. M.; Moustakas, John
2018-01-01
The spectroscopy of background QSO sightlines passing close to foreground galaxies is a potent technique for studying the circumgalactic medium (CGM). However, QSOs are effectively point sources, limiting their potential to constrain the size of circumgalactic gaseous structures. Here we present the first large Keck/Low-resolution Imaging Spectrometer (LRIS) and Very Large Telescope (VLT)/Focal Reducer/Low-dispersion Spectrograph 2 (FORS2) spectroscopic survey of bright ({B}{AB}< 22.3) background galaxies whose lines of sight probe Mg II λ λ 2796,2803 absorption from the CGM around close projected foreground galaxies at transverse distances 10 {kpc}< {R}\\perp < 150 {kpc}. Our sample of 72 projected pairs, drawn from the PRIsm MUlti-object Survey, includes 48 background galaxies that do not host bright active galactic nuclei, and both star-forming and quiescent foreground galaxies with stellar masses of 9.0< {log}{M}* /{M}ȯ < 11.2 at redshifts of 0.35< {z}{{f}/{{g}}}< 0.8. We detect Mg II absorption associated with these foreground galaxies with equivalent widths of 0.25 \\mathring{{A}} < {W}2796< 2.6 \\mathring{{A}} at > 2σ significance in 20 individual background sightlines passing within {R}\\perp < 50 {kpc} and place 2σ upper limits on W 2796 of ≲ 0.5 \\mathring{{A}} in an additional 11 close sightlines. Within {R}\\perp < 50 {kpc}, W 2796 is anticorrelated with R ⊥, consistent with analyses of Mg II absorption detected along background QSO sightlines. Subsamples of these foreground hosts divided at {log}{M}* /{M}ȯ =9.9 exhibit statistically inconsistent W 2796 distributions at 30 {kpc}< {R}\\perp < 50 {kpc}, with the higher-M * galaxies yielding a larger median W 2796 by 0.9 \\mathring{{A}} . Finally, we demonstrate that foreground galaxies with similar stellar masses exhibit the same median W 2796 at a given R ⊥ to within < 0.2 \\mathring{{A}} toward both background galaxies and toward QSO sightlines drawn from the literature. Analysis of these data sets constraining the spatial coherence scale of circumgalactic Mg II absorption is presented in a companion paper.
The Queued Service Observing Project at CFHT
NASA Astrophysics Data System (ADS)
Martin, Pierre; Savalle, Renaud; Vermeulen, Tom; Shapiro, Joshua N.
2002-12-01
In order to maximize the scientific productivity of the CFH12K mosaic wide-field imager (and soon MegaCam), the Queued Service Observing (QSO) mode was implemented at the Canada-France-Hawaii Telescope at the beginning of 2001. The QSO system consists of an ensemble of software components allowing for the submission of programs, the preparation of queues, and finally the execution and evaluation of observations. The QSO project is part of a broader system known as the New Observing Process (NOP). This system includes data acquisition, data reduction and analysis through a pipeline named Elixir, and a data archiving and distribution component (DADS). In this paper, we review several technical and operational aspects of the QSO project. In particular, we present our strategy, technical architecture, program submission system, and the tools developed for the preparation and execution of the queues. Our successful experience of over 150 nights of QSO operations is also discussed along with the future plans for queue observing with MegaCam and other instruments at CFHT.
NASA Astrophysics Data System (ADS)
Kakiichi, Koki; Graziani, Luca; Ciardi, Benedetta; Meiksin, Avery; Compostella, Michele; Eide, Marius B.; Zaroubi, Saleem
2017-07-01
We present a detailed analysis of the ionization and thermal structure of the intergalactic medium (IGM) around a high-redshift (z = 10) QSO, using a large suite of cosmological, multifrequency radiative transfer simulations, exploring the contribution from galaxies as well as the QSO, and the effect of X-rays and secondary ionization. We show that in high-z QSO environments both the central QSO and the surrounding galaxies concertedly control the reionization morphology of hydrogen and helium and have a non-linear impact on the thermal structure of the IGM. A QSO imprints a distinctive morphology on H II regions if its total ionizing photon budget exceeds that of the surrounding galaxies since the onset of hydrogen reionization; otherwise, the morphology shows little difference from that of H II regions produced only by galaxies. In addition, the spectral shape of the collective radiation field from galaxies and QSOs controls the thickness of the I-fronts. While a UV-obscured QSO can broaden the I-front, the contribution from other UV sources, either galaxies or unobscured QSOs, is sufficient to maintain a sharp I-front. X-ray photons from the QSO are responsible for a prominent extended tail of partial ionization ahead of the I-front. QSOs leave a unique imprint on the morphology of He II/He III regions. We suggest that, while the physical state of the IGM is modified by QSOs, the most direct test to understand the role of galaxies and QSOs during reionization is to perform galaxy surveys in a region of sky imaged by 21 cm tomography.
NASA Astrophysics Data System (ADS)
Ahnen, M. L.; Ansoldi, S.; Antonelli, L. A.; Antoranz, P.; Arcaro, C.; Babic, A.; Banerjee, B.; Bangale, P.; Barres de Almeida, U.; Barrio, J. A.; Becerra González, J.; Bednarek, W.; Bernardini, E.; Berti, A.; Biasuzzi, B.; Biland, A.; Blanch, O.; Bonnefoy, S.; Bonnoli, G.; Borracci, F.; Bretz, T.; Buson, S.; Carosi, A.; Chatterjee, A.; Clavero, R.; Colin, P.; Colombo, E.; Contreras, J. L.; Cortina, J.; Covino, S.; Da Vela, P.; Dazzi, F.; De Angelis, A.; De Lotto, B.; de Oña Wilhelmi, E.; Di Pierro, F.; Doert, M.; Domínguez, A.; Dominis Prester, D.; Dorner, D.; Doro, M.; Einecke, S.; Eisenacher Glawion, D.; Elsaesser, D.; Engelkemeier, M.; Fallah Ramazani, V.; Fernández-Barral, A.; Fidalgo, D.; Fonseca, M. V.; Font, L.; Frantzen, K.; Fruck, C.; Galindo, D.; García López, R. J.; Garczarczyk, M.; Garrido Terrats, D.; Gaug, M.; Giammaria, P.; Godinović, N.; Gora, D.; Guberman, D.; Hadasch, D.; Hahn, A.; Hayashida, M.; Herrera, J.; Hose, J.; Hrupec, D.; Hughes, G.; Idec, W.; Kodani, K.; Konno, Y.; Kubo, H.; Kushida, J.; La Barbera, A.; Lelas, D.; Lindfors, E.; Lombardi, S.; Longo, F.; López, M.; López-Coto, R.; Majumdar, P.; Makariev, M.; Mallot, K.; Maneva, G.; Manganaro, M.; Mannheim, K.; Maraschi, L.; Marcote, B.; Mariotti, M.; Martínez, M.; Mazin, D.; Menzel, U.; Miranda, J. M.; Mirzoyan, R.; Moralejo, A.; Moretti, E.; Nakajima, D.; Neustroev, V.; Niedzwiecki, A.; Nievas Rosillo, M.; Nilsson, K.; Nishijima, K.; Noda, K.; Nogués, L.; Paiano, S.; Palacio, J.; Palatiello, M.; Paneque, D.; Paoletti, R.; Paredes, J. M.; Paredes-Fortuny, X.; Pedaletti, G.; Peresano, M.; Perri, L.; Persic, M.; Poutanen, J.; Prada Moroni, P. G.; Prandini, E.; Puljak, I.; Garcia, J. R.; Reichardt, I.; Rhode, W.; Ribó, M.; Rico, J.; Saito, T.; Satalecka, K.; Schroeder, S.; Schweizer, T.; Shore, S. N.; Sillanpää, A.; Sitarek, J.; Snidaric, I.; Sobczynska, D.; Stamerra, A.; Strzys, M.; Surić, T.; Takalo, L.; Tavecchio, F.; Temnikov, P.; Terzić, T.; Tescaro, D.; Teshima, M.; Torres, D. F.; Toyama, T.; Treves, A.; Vanzo, G.; Verguilov, V.; Vovk, I.; Ward, J. E.; Will, M.; Wu, M. H.; Zanin, R.; Desiante, R.
2016-11-01
Context. QSO B0218+357 is a gravitationally lensed blazar located at a redshift of 0.944. The gravitational lensing splits the emitted radiation into two components that are spatially indistinguishable by gamma-ray instruments, but separated by a 10-12 day delay. In July 2014, QSO B0218+357 experienced a violent flare observed by the Fermi-LAT and followed by the MAGIC telescopes. Aims: The spectral energy distribution of QSO B0218+357 can give information on the energetics of z 1 very high energy gamma-ray sources. Moreover the gamma-ray emission can also be used as a probe of the extragalactic background light at z 1. Methods: MAGIC performed observations of QSO B0218+357 during the expected arrival time of the delayed component of the emission. The MAGIC and Fermi-LAT observations were accompanied by quasi-simultaneous optical data from the KVA telescope and X-ray observations by Swift-XRT. We construct a multiwavelength spectral energy distribution of QSO B0218+357 and use it to model the source. The GeV and sub-TeV data obtained by Fermi-LAT and MAGIC are used to set constraints on the extragalactic background light. Results: Very high energy gamma-ray emission was detected from the direction of QSO B0218+357 by the MAGIC telescopes during the expected time of arrival of the trailing component of the flare, making it the farthest very high energy gamma-ray source detected to date. The observed emission spans the energy range from 65 to 175 GeV. The combined MAGIC and Fermi-LAT spectral energy distribution of QSO B0218+357 is consistent with current extragalactic background light models. The broadband emission can be modeled in the framework of a two-zone external Compton scenario, where the GeV emission comes from an emission region in the jet, located outside the broad line region.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ahnen, M. L.; Ansoldi, S.; Antonelli, L. A.
QSO B0218+357 is a gravitationally lensed blazar located at a redshift of 0.944. The gravitational lensing splits the emitted radiation into two components that are spatially indistinguishable by gamma-ray instruments, but separated by a 10–12 day delay. In July 2014, QSO B0218+357 experienced a violent flare observed by the Fermi-LAT and followed by the MAGIC telescopes. The spectral energy distribution of QSO B0218+357 can give information on the energetics of z ~ 1 very high energy gamma-ray sources. Furthermore, the gamma-ray emission can also be used as a probe of the extragalactic background light at z ~ 1. MAGIC performedmore » observations of QSO B0218+357 during the expected arrival time of the delayed component of the emission. The MAGIC and Fermi-LAT observations were accompanied by quasi-simultaneous optical data from the KVA telescope and X-ray observations by Swift-XRT. We construct a multiwavelength spectral energy distribution of QSO B0218+357 and use it to model the source. The GeV and sub-TeV data obtained by Fermi-LAT and MAGIC are used to set constraints on the extragalactic background light. We detected very high energy gamma-ray emission from the direction of QSO B0218+357 by the MAGIC telescopes during the expected time of arrival of the trailing component of the flare, making it the farthest very high energy gamma-ray source detected to date. We also observed emission spans the energy range from 65 to 175 GeV. The combined MAGIC and Fermi-LAT spectral energy distribution of QSO B0218+357 is consistent with current extragalactic background light models. The broadband emission can be modeled in the framework of a two-zone external Compton scenario, where the GeV emission comes from an emission region in the jet, located outside the broad line region.« less
Ahnen, M. L.; Ansoldi, S.; Antonelli, L. A.; ...
2016-11-04
QSO B0218+357 is a gravitationally lensed blazar located at a redshift of 0.944. The gravitational lensing splits the emitted radiation into two components that are spatially indistinguishable by gamma-ray instruments, but separated by a 10–12 day delay. In July 2014, QSO B0218+357 experienced a violent flare observed by the Fermi-LAT and followed by the MAGIC telescopes. The spectral energy distribution of QSO B0218+357 can give information on the energetics of z ~ 1 very high energy gamma-ray sources. Furthermore, the gamma-ray emission can also be used as a probe of the extragalactic background light at z ~ 1. MAGIC performedmore » observations of QSO B0218+357 during the expected arrival time of the delayed component of the emission. The MAGIC and Fermi-LAT observations were accompanied by quasi-simultaneous optical data from the KVA telescope and X-ray observations by Swift-XRT. We construct a multiwavelength spectral energy distribution of QSO B0218+357 and use it to model the source. The GeV and sub-TeV data obtained by Fermi-LAT and MAGIC are used to set constraints on the extragalactic background light. We detected very high energy gamma-ray emission from the direction of QSO B0218+357 by the MAGIC telescopes during the expected time of arrival of the trailing component of the flare, making it the farthest very high energy gamma-ray source detected to date. We also observed emission spans the energy range from 65 to 175 GeV. The combined MAGIC and Fermi-LAT spectral energy distribution of QSO B0218+357 is consistent with current extragalactic background light models. The broadband emission can be modeled in the framework of a two-zone external Compton scenario, where the GeV emission comes from an emission region in the jet, located outside the broad line region.« less
New Ground Based facilities in QSO research; The GTC
NASA Astrophysics Data System (ADS)
Rodriguez Espinosa, J. M.
New ground based observing opportunities are becoming, or about to become, available to astronomers for QSO research. These, combined with state of the art focal plane instruments, provide unprecedented sensitivity for detecting faint surface brightness features. During the talk I will take the liberty of talking about one of these new large telescope facilities currently being built in Spain, and will discuss some of the advantages for QSO research offered by these new facilities.
No Ly α emitters detected around a QSO at z = 6.4: Suppressed by the QSO?★
NASA Astrophysics Data System (ADS)
Goto, Tomotsugu; Utsumi, Yousuke; Kikuta, Satoshi; Miyazaki, Satoshi; Shiki, Kensei; Hashimoto, Tetsuya
2017-09-01
Understanding how quasars' (QSOs') ultraviolet (UV) radiation affects galaxy formation is vital to our understanding of the reionization era. Using a custom-made narrow-band filter, NB906, on Subaru/Suprime-Cam, we investigated the number density of Ly α emitters (LAEs) around a QSO at z = 6.4. To date, this is the highest redshift narrow-band observation, where LAEs around a luminous QSO are investigated. Due to the large field of view of Suprime-Cam, our survey area is ˜5400 cMpc2, much larger than previous studies at z = 5.7 (˜200 cMpc2). In this field, we previously found a factor of 7 overdensity of Lyman break galaxies. Based on this, we expected to detect ˜100 LAEs down to NB906 = 25 ABmag. However, our 6.4 h exposure found none. The obtained upper limit on the number density of LAEs is more than an order lower than the blank fields. Furthermore, this lower density of LAEs spans a large scale of 10 pMpc across. A simple argument suggests that a strong UV radiation from the QSO can suppress star formation in haloes with Mvir < 1010 M⊙ within a pMpc from the QSO, but the deficit at the edge of the field (5 pMpc) remains to be explained.
NASA Astrophysics Data System (ADS)
Carilli, C. L.; Wang, Ran
2006-11-01
It has been pointed out to us that in three dimensions the mean angle of randomly oriented disks with respect to the sky plane is <θ>=30deg, and not the 45° assumed in the original paper. This lower angle for the (assumed) random distribution of submillimeter galaxies, coupled with the factor of 2.3 lower mean CO line width for high-z, far-IR-luminous QSO host galaxies relative to the submillimeter galaxies, implies a mean angle with respect to the sky plane for the QSO host galaxies of <θ>QSO=13deg, as opposed to the 18° quoted in the original paper. We thank Pat Hall for bringing this to our attention.
The z = 1.6748 C I Absorber Toward the QSO PKS 1756+237
NASA Astrophysics Data System (ADS)
Roth, Katherine C.; Bauer, James M.; Jim, Kevin T. C.
We have detected C I ground-state absorption at zabs = 1.6748 toward the QSO PKS 1756+237 (zem = 1.725), making this only the fourth known C I QSO absorber. The absence of excited-state fine-structure C I lines is compatible with the redshifted Cosmic Microwave Background Radiation at an expected temperature of TCMBR (1+z) = 7.291 K (Mather et al. 1994, ApJ, 354, L37). We find a 2 σ upper-limit on the C I excitation temperature of Tex <= 7.73(+0.53, -0.46) K (Roth & Bauer 1999, ApJ, submitted). Our Keck HIRES spectra (8.3 km s-1 FWHM) obtained in May 1997 also reveal the existence of Ni II and Fe II lines with a sub-solar Ni/Fe abundance ratio, presumably indicative of dust. We have obtained deep, high resolution (0.3'' FWHM) images in H+K' with the UH 2.2m Tip-Tilt system of the QSO field in order to identify the system responsible for the zabs = 1.6748 absorption. We detect two faint candidate systems within 1.5'' and 3'' (≅ 15 and 30 kpc, Hcirc = 65) of the QSO.
Properties of low-redshift QSO absorption systems - QSO-galaxy pairs
NASA Technical Reports Server (NTRS)
Womble, Donna S.
1993-01-01
The chance proximity of QSOs and galaxies provides unique opportunities to probe the extent and content of gas in the foreground galaxies through evaluation of the incidence and strength of absorption lines in the spectra of the background QSOs. Recent results on the observed properties of these low-redshift, heavy-element absorption systems are summarized. These results are discussed in the context of the galaxy morphologies and environments and are briefly compared with Galactic absorption and with the inferred properties of higher-redshift QSO absorption systems.
The Luminosity Function of QSO Host Galaxies
NASA Technical Reports Server (NTRS)
Hamilton, Timothy S.; Casertano, Stefano; Turnshek, David A.; White, Nicholas E. (Technical Monitor)
2002-01-01
We present some results from our HST archival image study of 71 QSO host galaxies. The objects are selected to have z less than or equal to 0.46 and total absolute magnitude M(sub v) less than or equal to -23 in our adopted cosmology (H(sub 0) = 50 kilometers per second Mpc(sup-1), q(sub 0) = 0.5, lambda = 0)). The aim of this initial study is to investigate the composition of the sample with respect to host morphology and radio loudness, as well as derive the QSO host galaxy luminosity function. We have analyzed available WFPC2 images in R or I band (U in one case), using a uniform set of procedures. The host galaxies span a narrow range of luminosities and are exceptionally bright, much more so than normal galaxies, usually L greater than L*(sub v). The QSOs are almost equally divided among three subclasses: radio-loud QSOs with elliptical hosts, radio-quiet QSOs with elliptical hosts, and radio-quiet QSOs with spiral hosts. Radio-loud QSOs with spiral hosts are extremely rare. Using a weighting procedure, we derive the combined luminosity function of QSO host galaxies. We find that the luminosity function of QSO hosts differs in shape from that of normal galaxies but that they coincide at the highest luminosities. The ratio of the number of quasar hosts to the number of normal galaxies at a luminosity L*(sub v) is R = (Lv/11.48L*(sub v))(sup 2.46), where L*(sub v) corresponds to M*(sub v)= -22.35, and a QSO is defined to be an object with total nuclear plus host light M(sub v) less than or equal to -23. This ratio can be interpreted as the probability that a galaxy with luminosity L(sub V) will host a QSO at redshift z approximately equal to 0.26.
QSO Narrow [OIII] Line Width and Host Galaxy Luminosity
NASA Astrophysics Data System (ADS)
Bonning, E. W.; Shields, G. A.; Salviander, S.
2004-05-01
Established correlations between galaxy bulge luminosity L, black hole mass MBH, and stellar velocity dispersion sigma in galaxies suggest a close relationship between the growth of supermassive black holes and their host galaxies. Measurements of the MBH - sigma relationship as a function of cosmic time may shed light on the origin of this relationship. One approach is to derive MBH and sigma from the widths of QSO broad and narrow lines, respectively (Shields et al. 2003, ApJ, 583, 124; Nelson 2000, ApJ, 544, L91). We investigate the utility of using the velocity of the narrow line emitting gas as a surrogate for stellar velocity dispersion in QSOs by examining host magnitudes and [OIII] line widths for low redshift QSOs. For our limited range of L, the increase in sigma with L predicted by the Faber-Jackson relation is substantially obscured by scatter. However, sigma([O III]) is consistent in the mean with host galaxy luminosity. EWB is a NASA GSRP fellow. GAS and SS are supported under Texas Advanced Research Program grant 003658-0177-2001 and NSF grant AST-0098594.
The x ray properties of a large, uniform QSO sample: Einstein observations of the LBQS
NASA Technical Reports Server (NTRS)
Margon, B.; Anderson, S. F.; Xu, X.; Green, P. J.; Foltz, C. B.
1992-01-01
Although there are large numbers of Quasi Stellar Objects (QSO's) now observed in X rays, extensive X-ray observations of uniformly selected, 'complete' QSO samples are more rare. The Large Bright QSO Survey (LBQS) consists of about 1000 objects with well understood properties, most brighter than B = 18.8 and thus amenable to X-ray detections in relatively brief exposures. The sample is thought to be highly complete in the range 0.2 less than z less than 3.3, a significantly broader interval than many other surveys. The Einstein IPC observed 150 of these objects, mostly serendipitously, during its lifetime. We report the results of an analysis of these IPC data, considering not only the 20 percent of the objects we find to have positive X-ray detections, but also the ensemble X-ray properties derived by 'image stacking'.
A new detection of an UFO in the X-ray spectrum of a lensed QSO
NASA Astrophysics Data System (ADS)
Dadina, M.
2017-10-01
The discovery of the "M_{SMBH}-σ relation" indicated that a connection between the central black-hole and the hosting galaxies acted during the cosmic time. With the discovery in X-rays of the ultra-fast outflows in nearby AGN, we have most probably probed one of the ingredients that are needed to build-up this mechanism. At high-z, however, such measurements were possible only in an handful of objects and this was possible mainly for the presence of gravitational lenses that magnified otherwise X-ray weak QSO. Following this, we proposed a program to use XMM-Newton and gravitational lenses as telescopes to point bright, lensed and distant QSO to characterize in detail their X-ray spectrum and to detect blushifted absorption lines at E˜7-10 keV (rest frame). Here we present the preliminary results obtained for the z=2.64 QSO MG J0414+0534.
Spectroscopic observations of a major flare in QSO TXS0917+624.
NASA Astrophysics Data System (ADS)
Wyrzykowski, L.; Gromadzki, M.; Kozlowski, Sz.; Mroz, P.; Shahbandeh, M.; Hsiao, E.; Berton, M.; Ciroi, S.; Pastorello, A.; Chen, S.; Reguitti, A.
2018-01-01
We report on optical and near-IR spectroscopy of QSO TXS0917+624 (radio and gamma source) which showed a major 2 magnitude flare on 9th of December 2017 (Spiridonova, Moskvitin and Vlasyuk 2017, ATEL #11048).
NASA Astrophysics Data System (ADS)
Massaro, F.; Paggi, A.; D'Abrusco, R.
2012-06-01
Following the near infrared NIR brightening of the QSO PKS1725+123 (=BZQJ1728+1215) (ATEL #4201), associated to the gamma-ray source 2FGL J1727.9+1220 in Nolan et al. (2012 ApJS, 199, 31), we searched in the Wide-field Infrared Survey Explorer (WISE; Wright et al. 2010 AJ, 140, 1868) catalog at the VLBI position of the QSO PKS1725+123 (R.A.(J2000): 17h28m07.0512s, Dec.(J2000): +12d15m39.485s) reported in Beasley et al.
Evolutional schemes for objects with active nuclei
NASA Technical Reports Server (NTRS)
Komberg, B. V.
1979-01-01
The observational properties of quasistellar objects (QSO) reveal that they are extremely violent nuclei of distant galaxies, but the evolutionary stage of these galaxies is still undetermined. Various published attempts to classify QSO under different criteria - including the one based on the morphological type of the surrounding galaxy E- or S- are analyzed. There are evidences that radioactive quasars reside in E-, while radio-quiet quasars reside in both E- and S- systems. The latter may be evolutionary connected to Seyfert-like objects. A correlation between the nuclei activity level in systems of different morphological type and the relative amount of gas in them is noted. From the point of view of activity level and the duration of active stage of nuclei it is concluded that an interaction of galaxies with the intergalactic medium is of particular importance and must be most conspicuous in spheriodal systems of central regions of rich clusters, in tight groups and binary galaxies.
A search for quasars in the Virgo cluster region
NASA Technical Reports Server (NTRS)
He, X.-T.; Cannon, R. D.; Peacock, J. A.; Smith, M. G.; Oke, J. B.
1984-01-01
Using objective-prism plates taken with the 44-arcmin objective prism mounted on the UK Schmidt telescope, 53 emission-line quasar candidates and 29 ultraviolet-excess objects (possible low-redshift quasars) have been found in a 5 x 5-degree field centered on 12 h 27 m, + 13 deg 30 min (1950) in the Virgo cluster of galaxies. Eighteen of these 82 candidates were observed using the double spectrograph on the Palomar 5-meter telescope; 13 of the observed objects proved to be quasars. The broad-absorption-line QSO Q1232 + 134 is the first example of the class to show broad low-ionization absorption lines (such as Mg II 2798 A) in addition to the usual high-excitation lines such as Nv 1240 A. Although no conclusive evidence for quasar-galaxy associations is found in this field, there do exist nonuniformities in the distribution of the quasar candidates which may merit further investigation. These objects will provide a useful network of probes for absorbing material in the Virgo cluster. The lines-of-sight to two of the confirmed quasars pass very close to NGC galaxies; the respective projected QSO-galaxy separations are only 4 and 11 kpc at the assumed distance of the Virgo cluster.
Luminous Quasars Do Not Live in Overdense Regions of LBGS at z 4
NASA Astrophysics Data System (ADS)
Uchiyama, Hisakazu
2017-07-01
We present the cross-correlation between 151 luminous QSOs and 179 protoclustercandidates at z 4 using Hyper Suprime-Cam data. We found that only 2 QSOs reside inregions that are more overdense compared to the average field at > 4σ. The distributionsof the distance between QSOs and the nearest protoclusters and the signicance of theoverdensity at the position of QSOs are statistically identical to those found for LBGs,suggesting that QSOs tend to reside in almost the same environment as LBGs at thisredshift. Using stacking analysis, we found that the average density of LBGs around QSOsis slightly higher than that around LBGs on 1.0-2.5 pMpc scales, while at < 0.5 pMpcthat around QSOs tends to be lower. We also found that QSOs with higher UV-luminosityor with more massive black holes tend to avoid the most overdense regions, and that theQSO near zone sizes are anti-correlated with overdensity. These findings are consistentwith a scenario in which the average QSO at z 4 resides in structures that are lessmassive than those expected for the progenitors of today's rich clusters, and possibly thatluminous QSOs may be suppressing star formation in their close vicinity.
NASA Astrophysics Data System (ADS)
Massaro, F.; D'Abrusco, R.; Paggi, A.
2012-06-01
Following the rapid optical variability detected in the QSO GB6 J1604+5714 (=BZQJ1604+5714) (ATEL #4184), associated to the gamma-ray source 2FGL J1604.6+5710 (=1FGL J1604.3+5710) in Nolan et al. (2012 ApJS, 199, 31), we searched in the Wide-field Infrared Survey Explorer (WISE; Wright et al. 2010 AJ, 140, 1868) catalog at the VLBI position of the QSO GB6 J1604+5714 (R.A.(J2000): 16h04m37.3546s, Dec.(J2000): +57d14m36.660s) reported in Beasley et al......
DOE Office of Scientific and Technical Information (OSTI.GOV)
Shields, G.A.
1976-03-01
Models of photoionized QSO emission-line regions show that measurements of O iii/N iv/C iv or N iii/C iii can yield the C/N/O ratios to an accuracy of a factor 2 or better. The N iii/C iii intensity ratios observed for the QSO PKS 1756+237 (z=1.72) implies a N/C abundance ratio 5 times larger than the solar value. This is comparable with the nitrogen overabundance in the nuclei of nearby galaxies, and it points to advanced chemical evolution in this QSO, with Zapproximately-greater-thanZ/sub sun/. Such a large abundance of nitrogen appears to be exceptional; composite spectra indicate that most QSOs havemore » (N/O) approximately one-fourth to one-half the solar value. (AIP)« less
A molecular Einstein ring: imaging a starburst disk surrounding a quasi-stellar object.
Carilli, C L; Lewis, G F; Djorgovski, S G; Mahabal, A; Cox, P; Bertoldi, F; Omont, A
2003-05-02
Images of the molecular CO 2-1 line emission and the radio continuum emission from the redshift 4.12 gravitationally lensed quasi-stellar object (QSO) PSS J2322+1944 reveal an Einstein ring with a diameter of 1.5". These observations are modeled as a star-forming disk surrounding the QSO nucleus with a radius of 2 kiloparsecs. The implied massive star formation rate is 900 solar masses per year. At this rate, a substantial fraction of the stars in a large elliptical galaxy could form on a dynamical time scale of 108 years. The observation of active star formation in the host galaxy of a high-redshift QSO supports the hypothesis of coeval formation of supermassive black holes and stars in spheroidal galaxies.
NASA Astrophysics Data System (ADS)
Orellana, G.; Nagar, N. M.; Isaak, K. G.; Priddey, R.; Maiolino, R.; McMahon, R.; Marconi, A.; Oliva, E.
2011-07-01
Context. We present near-IR spectroscopy of a sample of luminous (MB - 27.5; Lbol > 1014 L⊙), sub-millimeter-detected, dusty (Md ~ 109 M⊙), radio-quiet quasi-stellar objects (QSOs) at z ~ 2. Aims: A primary aim is to provide a more accurate QSO redshift determination in order to trace kinematics and inflows/outflows in these sub-mm bright QSOs. Additionally, the Hα and continuum properties allow an estimation of the black hole mass and accretion rate, offering insights into the starburst-AGN connection in sub-mm bright QSOs. Methods: We measure the redshift, width, and luminosity of the Hα line, and the continuum luminosity near Hα. Relative velocity differences between Hα and rest-frame UV emission lines are used to study the presence and strength of outflows/inflows. Luminosities and line widths are used to estimate the black hole masses, bolometric luminosities, Eddington fractions, and accretion rates; these are compared to the star-formation-rate (SFR), estimated from the sub-mm derived far-infrared (FIR) luminosity. Finally our sub-mm-bright QSO sample is compared with other QSO samples at similar redshifts. Results: The Hα emission line was strongly detected in all sources. Two components - a very broad (≳5000 km s-1) Gaussian and an intermediate-width (≳1500 km s-1) Gaussian, were required to fit the Hα profile of all observed QSOs. Narrow (≲1000 km s-1) lines were not detected in the sample QSOs. The rest-frame UV emission lines in these sub-mm bright QSOs show larger than average blue-shifted velocities, potentially tracing strong - up to 3000 km s-1 - outflows in the broad line region. With the exception of the one QSO which shows exceptionally broad Hα lines, the black hole masses of the QSO sample are in the range log MBH = 9.0-9.7 and the Eddington fractions are between 0.5 and ~1. In black hole mass and accretion rate, this sub-mm bright QSO sample is indistinguishable from the Shemmer et al. (2004, ApJ, 614, 547) optically-bright QSO sample at z ~ 2; the latter is likely dominated by sub-mm dim QSOs. Previous authors have demonstrated a correlation, over six orders of magnitude, between SFR and accretion rate in active galaxies: the sub-mm bright QSOs lie at the upper extremes of both quantities and their SFR is an order of magnitude higher than that predicted from the correlation.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Aravena, M.; Wagg, J.; Papadopoulos, P. P.
We report the detection of the {sup 12}CO J = 1-0 emission line in [H89]1821+643, one of the most optically luminous quasi-stellar objects (QSOs) in the local universe, and a template ULIRG-to-QSO transition object, located in a rich, cool-core cluster at z = 0.297. The CO emission is likely to be extended, highly asymmetric with respect to the center of the host elliptical where the QSO resides, and correspond with a molecular gas mass of {approx}8.0 x 10{sup 9} M{sub sun}. The dynamical mass enclosed by the CO emission-line region could amount to {approx}1.7 x 10{sup 12} M{sub sun} (80%more » of the total mass of the elliptical host). The bulk of the CO emission is located at {approx}9 kpc southeast from the nuclei position, close to a faint optical structure, suggesting that the CO emission could either represent a gas-rich companion galaxy merging with the elliptical host or a tail-like structure reminiscent of a previous interaction. We argue that the first scenario is more likely given the large masses implied by the CO source, which would imply a highly asymmetric elliptical host. The close alignment between the CO emission's major axis and the radio plume suggests a possible role in the excitation of the ambient gas reservoir by the latter. The stacking technique was used to search for CO emission and 3-mm continuum emission from galaxies in the surrounding cluster. However, no detection was found toward individual galaxies or the stacked ensemble of galaxies, with a 3{sigma} limit of <1.1 x 10{sup 9} M{sub sun} for the molecular gas.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Saunders, Will; Smedley, Scott; Gillingham, Peter
We present Simulated Annealing fiber-to-target allocation simulations for the proposed DESI and 4MOST massively multiplexed spectroscopic surveys, and for both Poisson and realistically clustered mock target samples. We simulate both Echidna and theta-phi actuator designs, including the restrictions caused by the physical actuator characteristics during repositioning. For DESI, with theta-phi actuators, used in 5 passes over the sky for a mock ELG/LRG/QSO sample, with matched fiber and target densities, a total target allocation yield of 89.3% was achieved, but only 83.7% for the high-priority Ly-alpha QSOs. If Echidna actuators are used with the same pitch and number of passes, themore » yield increases by 5.7% and 16% respectively. Echidna also allows a factor-of-two increase in the number of close Ly-alpha QSO pairs that can be observed. Echidna spine tilt causes a variable loss of throughput, with average loss being the same as the loss at the rms tilt. With a natural tilt minimization scheme, we find an rms tilt always close to 0.58 x maximum. There is an additional but much smaller defocus loss, equivalent to an average defocus of 30microns. These tilt losses offset the gains in yield for Echidna, but because the survey strategy is driven by the higher priority targets, a clear survey speed advantage remains. For 4MOST, high and low latitude sample mock catalogs were supplied by the 4MOST team, and allocations were carried out with the proposed Echidna-based positioner geometry. At high latitudes, the resulting target completeness was 85.3% for LR targets and 78.9% for HR targets. At low latitude, the target completeness was 93.9% for LR targets and 71.2% for HR targets.« less
ASAS-SN Discovery of an Unprecedented >2 Magnitude Optical Flare from QSO B2 1420+32
NASA Astrophysics Data System (ADS)
Stanek, K. Z.; Kochanek, C. S.; Thompson, T. A.; Shappee, B. J.; Holoien, T. W.-S.; Prieto, J. L.; Dong, Subo; Dai, X.
2017-12-01
During the ongoing All Sky Automated Survey for SuperNovae (ASAS-SN, Shappee et al. 2014), using data from the quadruple 14-cm "Brutus" telescope in Haleakala, Hawaii, and the quadruple 14-cm "Leavitt" telescope in Fort Davis, Texas, we have discovered an unprecedented, factor of 10 optical brightening of QSO B2 1420+32 (SDSS J142230.37+322310.4, z=0.68).
Variability of the broad absorption lines in the QSO UM 232
NASA Technical Reports Server (NTRS)
Barlow, Thomas A.; Junkkarinen, Vesa T.; Burbidge, E. Margaret
1989-01-01
Low-resolution spectra of UM 232 taken in 1978, 1979, and 1988 at Lick Observatory are presented. Large changes in the Si IV lambda 1397, CIV lambda 1549, and Al III lambda 1857 broad absorption lines are apparent. The decrease in column density in all three ions and an observed brightening of the QSO suggests that these changes are due to an increase in the ionization level driven by an increase in the central source luminosity. This mechanism has been proposed by Smith and Penston to explain small changes in the absorption spectrum of the QSO 1246-057. The spectra of UM 232 show that the fractional decrease in optical depth is smaller at higher outflow velocies. The structure of the broad absorption-line region (BALR) is investigted by estimating an ionization parameter for each ion species as a function of velocity.
ALMA Reveals a Compact Starburst Around a Hidden QSO at z˜5
NASA Astrophysics Data System (ADS)
Gilli, R.; Norman, C. A.; Vignali, C.
2015-12-01
We present ALMA 1.3mm observations of XID403, an SMG at z=4.75 in the Chandra Deep Field South hosting a heavily obscured, Compton-thick QSO. The ALMA data show that the dust heated by star formation is distributed within ˜0.9 kpc from the nucleus (effective radius). The SFR and dust temperature obtained from the Herschel+ALMA far-IR SED, reveal a warm and compact starburst with surface density of 200 M⊙ yr-1 kpc-2. Our analysis suggest that, besides the mass, SFR and gas consumption timescale, objects like XID403 have also the right size to be the progenitors of the compact quiescent massive galaxies seen at z˜3. It is finally shown that the density of the gas co-spatial with the dust provides a substantial contribution to the absorbing column density towards the QSO as measured from the X-rays.
Mechanical Transformation of Task Heuristics into Operational Procedures
1981-04-14
Introduction A central theme of recent research in artificial intelligence is that *Intelligent task performance requires large amounts of knowledge...PLAY P1 C4] (. (LEADING (QSO)) (OR (CAN-LEAO- HEARrS (gSO)J (mEg (SUIT-OF C3) H])] C-) (FOLLOWING (QSO)) (OR [VOID (OSO) (SUIT-LED)3 [IN-SUIT C3 (SUIT...Production rules as a representation for a knowledge based consultation system. Artificial Intelligence 8:15-45, Spring, 1977. [Davis 77b] R. Davis
NASA Astrophysics Data System (ADS)
Ota, Kazuaki; Venemans, Bram P.; Taniguchi, Yoshiaki; Kashikawa, Nobunari; Nakata, Fumiaki; Harikane, Yuichi; Bañados, Eduardo; Overzier, Roderik; Riechers, Dominik A.; Walter, Fabian; Toshikawa, Jun; Shibuya, Takatoshi; Jiang, Linhua
2018-04-01
Quasars (QSOs) hosting supermassive black holes are believed to reside in massive halos harboring galaxy overdensities. However, many observations revealed average or low galaxy densities around z ≳ 6 QSOs. This could be partly because they measured galaxy densities in only tens of arcmin2 around QSOs and might have overlooked potential larger-scale galaxy overdensities. Some previous studies also observed only Lyman break galaxies (LBGs; massive older galaxies) and missed low-mass young galaxies, like Lyα emitters (LAEs), around QSOs. Here we present observations of LAE and LBG candidates in ∼700 arcmin2 around a z = 6.61 luminous QSO using the Subaru Telescope Suprime-Cam with narrowband/broadband. We compare their sky distributions, number densities, and angular correlation functions with those of LAEs/LBGs detected in the same manner and comparable data quality in our control blank field. In the QSO field, LAEs and LBGs are clustering in 4–20 comoving Mpc angular scales, but LAEs show mostly underdensity over the field while LBGs are forming 30 × 60 comoving Mpc2 large-scale structure containing 3σ–7σ high-density clumps. The highest-density clump includes a bright (23.78 mag in the narrowband) extended (≳16 kpc) Lyα blob candidate, indicative of a dense environment. The QSO could be part of the structure but is not located exactly at any of the high-density peaks. Near the QSO, LAEs show underdensity while LBGs average to 4σ excess densities compared to the control field. If these environments reflect halo mass, the QSO may not be in the most massive halo but still in a moderately massive one. Based on data collected at Subaru Telescope, which is operated by the National Astronomical Observatory of Japan.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lu, Nanyao; Xu, C. Kevin; Zhu, Lei
We present the results from Atacama Large Millimeter/submillimeter Array imaging in the [N ii] 205 μ m fine-structure line (hereafter [N ii]) and the underlying continuum of BRI 1202-0725, an interacting galaxy system at z = 4.7, consisting of a quasi-stellar object (QSO), a submillimeter galaxy (SMG), and two Ly α emitters, all within ∼25 kpc of the QSO. We detect the QSO and SMG in both [N ii] and continuum. At the ∼1″ (or 6.6 kpc) resolution, both the QSO and SMG are resolved in [N ii], with the de-convolved major axes of ∼9 and ∼14 kpc, respectively. Inmore » contrast, their continuum emissions are much more compact and unresolved even at an enhanced resolution of ∼0.″7. The ratio of the [N ii] flux to the existing CO(7−6) flux is used to constrain the dust temperature ( T {sub dust}) for a more accurate determination of the FIR luminosity L {sub FIR}. Our best estimated T {sub dust} equals 43 (±2) K for both galaxies (assuming an emissivity index β = 1.8). The resulting L {sub CO(7−6)}/ L {sub FIR} ratios are statistically consistent with that of local luminous infrared galaxies, confirming that L {sub CO(7−6)} traces the star formation (SF) rate (SFR) in these galaxies. We estimate that the ongoing SF of the QSO (SMG) has an SFR of 5.1 (6.9) × 10{sup 3} M {sub ⊙} yr{sup −1} (±30%) assuming Chabrier initial mass function, takes place within a diameter (at half maximum) of 1.3 (1.5) kpc, and will consume the existing 5 (5) × 10{sup 11} M {sub ⊙} of molecular gas in 10 (7) × 10{sup 7} years.« less
Strong Clustering of Lyman Break Galaxies around Luminous Quasars at Z ˜ 4
NASA Astrophysics Data System (ADS)
García-Vergara, Cristina; Hennawi, Joseph F.; Barrientos, L. Felipe; Rix, Hans-Walter
2017-10-01
In the standard picture of structure formation, the first massive galaxies are expected to form at the highest peaks of the density field, which constitute the cores of massive proto-clusters. Luminous quasars (QSOs) at z ˜ 4 are the most strongly clustered population known, and should thus reside in massive dark matter halos surrounded by large overdensities of galaxies, implying a strong QSO-galaxy cross-correlation function. We observed six z ˜ 4 QSO fields with VLT/FORS, exploiting a novel set of narrow-band filters custom designed to select Lyman Break Galaxies (LBGs) in a thin redshift slice of {{Δ }}z˜ 0.3, mitigating the projection effects that have limited the sensitivity of previous searches for galaxies around z≳ 4 QSOs. We find that LBGs are strongly clustered around QSOs, and present the first measurement of the QSO-LBG cross-correlation function at z ˜ 4, on scales of 0.1≲ R≲ 9 {h}-1 {Mpc} (comoving). Assuming a power-law form for the cross-correlation function ξ ={(r/{r}0{QG})}γ , we measure {r}0{QG}={8.83}-1.51+1.39 {h}-1 {Mpc} for a fixed slope of γ =2.0. This result is in agreement with the expected cross-correlation length deduced from measurements of the QSO and LBG auto-correlation function, and assuming a deterministic bias model. We also measure a strong auto-correlation of LBGs in our QSO fields, finding {r}0{GG}={21.59}-1.69+1.72 {h}-1 {Mpc} for a fixed slope of γ =1.5, which is ˜4 times larger than the LBG auto-correlation length in blank fields, providing further evidence that QSOs reside in overdensities of LBGs. Our results qualitatively support a picture where luminous QSOs inhabit exceptionally massive ({M}{halo}> {10}12 {M}⊙ ) dark matter halos at z ˜ 4.
Hubble Space Telescope Images and Spectra of Objects Around an Optically Violent Variable QSO
NASA Astrophysics Data System (ADS)
Burbidge, E. M.; Beaver, E. A.; Cohen, R. D.; Hamann, F.; Junkkarinen, V. T.; Lyons, R. W.; Zuo, L.
1995-12-01
The Arecibo Occultation radio source AO 0235+164 is a rapidly and violently variable QSO with ze = 0.94. It was originally designated as a BL Lac object since no emission lines were detected in its spectrum; two absorption redshifts at 0.524 and 0.851 were measured some years before weak emission lines at z = 0.94 were detected by Cohen et al. (ApJ,318,577,1987). A point-like companion (Smith et al., ApJ,218,611,1977) was found 2 arc sec south with an emission line redshift at 0.524. It was designated object A by Yanny et al. (ApJ,338,735,1989). This object has sometimes been called a ``normal'' galaxy, presumably giving rise to the absorption at 0.524 in the QSO. Recent observations of the surrounding field, using the post-repair WFPC 2 on the Hubble Space Telescope, have been analyzed and the nature of the companion object 2 arc sec south, and of a second companion 1.3 arc sec east of AO, have been studied. Spectra of companion object A have been obtained with the Faint Object Spectrograph with gratings G160L and G270H, and 1.0 arc sec aperture, and these show that it is an AGN or QSO with BAL-type broad absorption lines shortward of CIVlambda 1549, SiIVlambda 1397, and NVlambda 1240, also broad CIII]lambda 1909 emission. The second object, A1, 1.3 arc sec east of the QSO, originally identified by Yanny et al. (1989) and shown to have [0II]lambda 3727 at z=0.524, is slightly extended. The physical properties and nature of this remarkable configuration will be discussed. This research has been supported in part by NASA NAS5-29293 and NAG5-1630.
Einstein observations of active galaxies and quasars
NASA Technical Reports Server (NTRS)
Schreier, E. J.
1979-01-01
The radio galaxies Centaurus A and Signus B are discussed. In both these sources, a comparison of the radio and imaged X-ray flux is allowed for the measurement of the magnetic fields. Einstein observations of quasars are discussed. The number of known X-ray emitting QSO's was increased from 3 to 22 and the distances where these QSO's were seen to correspond to an age of 15 billion years. It was shown that these quasars contributed significantly to the X-ray background.
A study of the discrepant QSO X-ray luminosity function from the HEAO-2 data archive
NASA Technical Reports Server (NTRS)
Margon, B.
1986-01-01
Sensitive X-ray information for approximately 90 previously uncataloged Quasi-Stellar Objects (QSOs) in the redshift range 1.8 is less than or equal to z which is less than or equal to 3. Even with the longest esixting Einstein Observatory X-ray exposures, only 25% of these objects are positively detected in X-rays. The data were used to investigate the ensemble X-ray properties of high redshift QSOs, and the QSO population in general.
Extent of warm haloes around medium-redshift galaxies
NASA Technical Reports Server (NTRS)
Burbidge, E. M.; Barlow, T. A.; Cohen, R. D.; Junkkarinen, V. T.; Womble, D. S.
1989-01-01
The properties of low-to-medium ionization gaseous haloes around galaxies are briefly reviewed. New observations concerning such haloes are presented. For the galaxy-QSO pair in the field of the radio source 3C303, the higher-redshift QSO has been found to show Mg II absorption at the lower redshift of the faint nearby galaxy. Secondly, new data are presented on one of the galaxies in the environment of the well-known BL Lac object AO 0235 + 164.
ASAS-SN Discovery of an Unprecedented >1.5 Magnitude Optical Flare from QSO B0346-279
NASA Astrophysics Data System (ADS)
Vallely, P.; Stanek, K. Z.; Kochanek, C. S.; Shields, J. V.; Thompson, T. A.; Shappee, B. J.; Holoien, T. W.-S.; Prieto, J. L.; Bersier, D.; Dong, Subo; Bose, S.; Chen, Ping; Stritzinger, M.
2018-02-01
During the ongoing All Sky Automated Survey for SuperNovae (ASAS-SN, Shappee et al. 2014), using data from the quadruple 14-cm "Brutus" telescope in Haleakala, Hawaii, the quadruple 14-cm "Leavitt" telescope in Fort Davis, Texas, the quadruple 14-cm "Payne-Gaposchkin" telescope in Sutherland, South Africa, and the quadruple 14-cm "Cassius" and "Paczynski" telescopes in Cerro Tololo, Chile, we have discovered an unprecedented optical brightening of QSO B0346-279 (z 0.9874).
Detection of an unprecedented outburst in IDV QSO TXS0917+624
NASA Astrophysics Data System (ADS)
Spiridonova, O. I.; Moskvitin, A. S.; Vlasyuk, V. V.
2017-12-01
We report on an unprecedented optical flare of TXS0917+624 -- popular QSO (z=1.446) with effects of intraday variability in radio range. Our measurements, made with 1-meter telescope of SAO of RAS, equipped by UBVRI CCD photometer, showed that apparent magnitude of object in R-band increased up to 15.34 +/- 0.02 on December 8th, 2017 (MJD = 58096.5) and 15.31 +/- 0.03 on December 9th, 2017 (MJD = 58097.5).
SED Constraints on the Highest- z Blazar Jet: QSO J0906+6930
DOE Office of Scientific and Technical Information (OSTI.GOV)
An, Hongjun; Romani, Roger W.
Here, we report on Gemini, NuSTAR, and eight years of Fermi observations of the most distant blazar QSO J0906+6930 (z = 5.48). We construct a broadband spectral energy distribution (SED) and model the SED using a synchro-Compton model. The measurements yield a mass of ~4 × 10 9 M ⊙ for the black hole and a spectral break at ~4 keV in the combined fit of the new NuSTAR and archival Chandra data. The SED fitting constrains the bulk Doppler factor δ of the jet to 9 +2.5 –3 for QSO J0906+6930. Similar, but weaker, constraints on δ are derivedmore » from SED modeling of the three other claimed z > 5 blazars. Together, these extrapolate to ~620 similar sources, fully 20% of the optically bright, high-mass active galactic nuclei expected at 5 < z < 5.5. This has interesting implications for the early growth of massive black holes.« less
Ca II and Na I absorption in the QSO S4 0248 + 430 due to an intervening galaxy
NASA Technical Reports Server (NTRS)
Womble, Donna S.; Junkkarinen, Vesa T.; Cohen, Ross D.; Burbidge, E. Margaret
1990-01-01
Observations of the QSO S4 0248 + 430 and a nearby anonymous galaxy are presented. Two absorption components are found in both Ca II H and K and Na I D1 and D2 at z(a) = 0.0515, 0.0523. Column densities of log N(Ca II) = 13.29, 13.50, and log N(Na I) = 13.79, 14.18 are found for z(a) = 0.0515, 0.0523 absorption systems, respectively. The column density ratios imply considerable calcium depletion and disk-type absorbing gas. At least one and possibly both absorption components are produced by high-velocity gas. A broadband image of the field shows an asymmetrical armlike feature or possible tidal tail covering and extending past the position of the QSO. The presence of this extended feature and the apparent difference between the absorption velocities and galaxy rotation velocity suggest that the absorbing gas is not ordinary disk gas, but rather is a result of tidal disruption.
SED Constraints on the Highest-z Blazar Jet: QSO J0906+6930
NASA Astrophysics Data System (ADS)
An, Hongjun; Romani, Roger W.
2018-04-01
We report on Gemini, NuSTAR, and eight years of Fermi observations of the most distant blazar QSO J0906+6930 (z = 5.48). We construct a broadband spectral energy distribution (SED) and model the SED using a synchro-Compton model. The measurements yield a mass of ∼4 × 109 M ⊙ for the black hole and a spectral break at ∼4 keV in the combined fit of the new NuSTAR and archival Chandra data. The SED fitting constrains the bulk Doppler factor δ of the jet to 9+2.5 ‑3 for QSO J0906+6930. Similar, but weaker, constraints on δ are derived from SED modeling of the three other claimed z > 5 blazars. Together, these extrapolate to ∼620 similar sources, fully 20% of the optically bright, high-mass active galactic nuclei expected at 5 < z < 5.5. This has interesting implications for the early growth of massive black holes.
SED Constraints on the Highest- z Blazar Jet: QSO J0906+6930
An, Hongjun; Romani, Roger W.
2018-03-29
Here, we report on Gemini, NuSTAR, and eight years of Fermi observations of the most distant blazar QSO J0906+6930 (z = 5.48). We construct a broadband spectral energy distribution (SED) and model the SED using a synchro-Compton model. The measurements yield a mass of ~4 × 10 9 M ⊙ for the black hole and a spectral break at ~4 keV in the combined fit of the new NuSTAR and archival Chandra data. The SED fitting constrains the bulk Doppler factor δ of the jet to 9 +2.5 –3 for QSO J0906+6930. Similar, but weaker, constraints on δ are derivedmore » from SED modeling of the three other claimed z > 5 blazars. Together, these extrapolate to ~620 similar sources, fully 20% of the optically bright, high-mass active galactic nuclei expected at 5 < z < 5.5. This has interesting implications for the early growth of massive black holes.« less
Evidence of Primordial Clustering around the QSO SDSS J1030+0524 at z=6.28
NASA Astrophysics Data System (ADS)
Stiavelli, M.; Djorgovski, S. G.; Pavlovsky, C.; Scarlata, C.; Stern, D.; Mahabal, A.; Thompson, D.; Dickinson, M.; Panagia, N.; Meylan, G.
2005-03-01
We present tentative evidence of primordial clustering, manifested as an excess of color-selected objects in the field of the QSO SDSS J1030+0524 at redshift z=6.28. We have selected objects red in i775-z850 on the basis of Hubble Space Telescope Advanced Camera for Surveys imaging of a field centered on the QSO. Compared to data at comparable depth obtained by the Great Observatories Origins Deep Survey, we find an excess of objects with i775-z850>=1.5 in the QSO field. The significance of the detection is estimated to be ~97% on the basis of the counts alone and increases to 99.4% if one takes into account the color distribution. If confirmed, this would represent the highest redshift example of galaxy clustering and would have implications on models for the growth of structure. Bias-driven clustering of first luminous objects forming in the highest peaks of the primordial density field is expected in most models of early structure formation. The redshift of one of the candidates has been found to be z=5.970 by our spectroscopy with the Keck I Low Resolution Imaging Spectrometer, confirming the validity of our color selection. Based, in part, on data obtained at the W. M. Keck Observatory, which is operated as a scientific partnership between the California Institute of Technology, the University of California, and NASA, and was made possible by the generous financial support of the W. M. Keck Foundation.
NASA Astrophysics Data System (ADS)
Frank, S.; Mathur, S.; Pieri, M.; York, D. G.
2010-09-01
We report the results of a systematic search for signatures of metal lines in quasar spectra of the Sloan Digital Sky Survey (SDSS) data release 3 (DR3), focusing on finding intervening absorbers via detection of their O VI doublet. Here, we present the search algorithm and criteria for distinguishing candidates from spurious Lyα forest lines. In addition, we compare our findings with simulations of the Lyα forest in order to estimate the detectability of O VI doublets over various redshift intervals. We have obtained a sample of 1756 O VI doublet candidates with rest-frame equivalent width (EW) >=0.05 Å in 855 active galactic nuclei spectra (out of 3702 objects with redshifts in the accessible range for O VI detection). This sample is further subdivided into three groups according to the likelihood of being real and the potential for follow-up observation of the candidate. The group with the cleanest and most secure candidates is comprised of 145 candidates. Sixty-nine of these reside at a velocity separation >=5000 km s-1 from the QSO and can therefore be classified tentatively as intervening absorbers. Most of these absorbers have not been picked up by earlier, automated QSO absorption line detection algorithms. This sample increases the number of known O VI absorbers at redshifts beyond z abs>= 2.7 substantially.
GALAXY CLUSTERS IN THE LINE OF SIGHT TO BACKGROUND QUASARS. III. MULTI-OBJECT SPECTROSCOPY
DOE Office of Scientific and Technical Information (OSTI.GOV)
Andrews, H.; Barrientos, L. F.; Padilla, N.
2013-09-01
We present Gemini/GMOS-S multi-object spectroscopy of 31 galaxy cluster candidates at redshifts between 0.2 and 1.0 and centered on QSO sight lines taken from Lopez et al. The targets were selected based on the presence of an intervening Mg II absorption system at a similar redshift to that of a galaxy cluster candidate lying at a projected distance <2 h{sub 71}{sup -1} Mpc from the QSO sight line (a {sup p}hotometric hit{sup )}. The absorption systems span rest-frame equivalent widths between 0.015 and 2.028 A. Our aim was three-fold: (1) to identify the absorbing galaxies and determine their impact parameters,more » (2) to confirm the galaxy cluster candidates in the vicinity of each quasar sightline, and (3) to determine whether the absorbing galaxies reside in galaxy clusters. In this way, we are able to characterize the absorption systems associated with cluster members. Our main findings are as follows. (1) We identified 10 out of 24 absorbing galaxies with redshifts between 0.2509 {<=} z{sub gal} {<=} 1.0955, up to an impact parameter of 142 h{sub 71}{sup -1} kpc and a maximum velocity difference of 280 km s{sup -1}. (2) We spectroscopically confirmed 20 out of 31 cluster/group candidates, with most of the confirmed clusters/groups at z < 0.7. This relatively low efficiency results from the fact that we centered our observations on the QSO location, and thus occasionally some of the cluster centers were outside the instrument field of view. (3) Following from the results above, we spectroscopically confirmed of 10 out of 14 photometric hits within {approx}650 km s{sup -1} from galaxy clusters/groups, in addition to two new ones related to galaxy group environments. These numbers imply efficiencies of 71% in finding such systems with MOS spectroscopy. This is a remarkable result since we defined a photometric hit as those cluster-absorber pairs having a redshift difference {Delta}z = 0.1. The general population of our confirmed absorbing galaxies have luminosities L{sub B}{approx}L{sub B}{sup *} and mean rest-frame colors (R{sub c} - z') typical of S{sub cd} galaxies. From this sample, absorbing cluster galaxies hosting weak absorbers are consistent with lower star formation activity than the rest, which produce strong absorption and agree with typical Mg II absorbing galaxies found in the literature. Our spectroscopic confirmations lend support to the selection of photometric hits made in Lopez et al.« less
Detection of emission lines from z ˜ 3 DLAs towards the QSO J2358+0149
NASA Astrophysics Data System (ADS)
Srianand, Raghunathan; Hussain, Tanvir; Noterdaeme, Pasquier; Petitjean, Patrick; Krühler, Thomas; Japelj, Jure; Pâris, Isabelle; Kashikawa, Nobunari
2016-07-01
Using VLT/X-shooter, we searched for emission line galaxies associated with four damped Lyman α systems (DLAs) and one sub-DLA at 2.73 ≤z ≤3.25 towards QSO J2358+0149. We detect [O III] emission from a `low-cool' DLA at zabs = 2.9791 (having log N(H I) = 21.69 ± 0.10, [Zn/H] = -1.83 ± 0.18) at an impact parameter of, ρ ˜ 12 kpc. The associated galaxy is compact with a dynamical mass of (1-6) × 109 M⊙, very high excitation ([O III]/[O II] and [O III]/[Hβ] both greater than 10), 12+[O/H]≤8.5 and moderate star formation rate (SFR ≤2 M⊙ yr-1). Such properties are typically seen in the low-z extreme blue compact dwarf galaxies. The kinematics of the gas is inconsistent with that of an extended disc and the gas is part of either a large scale wind or cold accretion. We detect Lyα emission from the zabs = 3.2477 DLA [having log N(H I) = 21.12 ± 0.10 and [Zn/H] = -0.97 ± 0.13]. The Lyα emission is redshifted with respect to the metal absorption lines by 320 km s-1, consistent with the location of the red hump expected in radiative transport models. We derive SFR ˜0.2-1.7 M⊙ yr-1 and Lyα escape fraction of ≥10 per cent. No other emission line is detected from this system. Because the DLA has a small velocity separation from the quasar (˜500 km s-1) and the DLA emission is located within a small projected distance (ρ < 5 kpc), we also explore the possibility that the Lyα emission is being induced by the QSO itself. QSO-induced Lyα fluorescence is possible if the DLA is within a physical separation of 340 kpc to the QSO. Detection of stellar continuum light and/or the oxygen emission lines would disfavour this possibility. We do not detect any emission line from the remaining three systems.
A New Survey for Low-Redshift Damped Lyman-Alpha Lines in QSO MgII Systems
NASA Astrophysics Data System (ADS)
Rao, Sandhya
2000-07-01
Studies have shown that most of the observable neutral gas mass in the Universe resides in QSO damped LyAlpha {DLA} systems. However, at low redshift {z<1.65}, DLA can only be found by searching in the UV with HST. Such searches are crucial since z<1.65 corresponds to 3/4 of the age of the Universe. The identification of significant numbers of low- redshift DLA systems is imperative if we ever hope to effectively study this cosmologically massive component of neutral gas. To this end, we recently reported on the results of our initial HST survey to study low-redshift DLA absorbers in QSO MgII systems. We discovered 14 DLA systems and had a success rate of 14%. Now, based on these results and our improved understanding of the selection criteria for successful DLA searches, we propose a new survey for low-redshift DLA lines in QSO MgII systems. With our new revised selection criteria, we can empirically show that our success rate would be 35%. Specifically, we propose to observe the LyAlpha line of 55 MgII systems. We estimate that we will discover 19 new DLA systems with redshift z<1.65. Finding these systems will facilitate the type of research that can be done with DLA systems. By boot-strapping from the MgII statistics, we will be able to further improve the determination of the low- redshift statistical properties of DLA {their incidence and cosmological mass density} and open up new opportunities for studies at low redshift.
WEAVE-QSO: A Massive Intergalactic Medium Survey for the William Herschel Telescope
NASA Astrophysics Data System (ADS)
Pieri, M. M.; Bonoli, S.; Chaves-Montero, J.; Pâris, I.; Fumagalli, M.; Bolton, J. S.; Viel, M.; Noterdaeme, P.; Miralda-Escudé, J.; Busca, N. G.; Rahmani, H.; Peroux, C.; Font-Ribera, A.; Trager, S. C.
2016-12-01
In these proceedings we describe the WEAVE-QSO survey, which will observe around 400,000 high redshift quasars starting in 2018. This survey is part of a broader WEAVE survey to be conducted at the 4.2m William Herschel Telescope. We will focus on chiefly on the science goals, but will also briefly summarise the target selection methods anticipated and the expected survey plan. Understanding the apparent acceleration in the expansion of the Universe is one of the key scientific challenges of our time. Many experiments have been proposed to study this expansion, using a variety of techniques. Here we describe a survey that can measure this acceleration and therefore help elucidate the nature of dark energy: a survey of the Lyα forest (and quasar absorption in general) in spectra towards z>2 quasars (QSOs). Further constraints on neutrino masses and warm dark matter are also anticipated. The same data will also shed light on galaxy formation via study of the properties of inflowing/outflowing gas associated with nearby galaxies and in a cosmic web context. Gas properties are sensitive to density, temperature, UV radiation, metallicity and abundance pattern, and so constraint galaxy formation in a variety of ways. WEAVE-QSO will study absorbers with a dynamic range spanning more than 8 orders of magnitude in column density, their thermal broadening, and a host of elements and ionization species. A core principal of the WEAVE-QSO survey is the targeting of QSOs with near 100% efficiency principally through use of the J-PAS (r < 23.2) and Gaia (r ≲ 20) data.
Is QSO 1146 + 111B,C due to lensing by a cosmic string?
NASA Technical Reports Server (NTRS)
Gott, J. R., III
1986-01-01
A newly discovered lens candidate, QSO 1146 + 111B,C, is discussed which appears to consist of two images of equal brightness of a quasar at redshift 1.01 separated by 2.6 arcmin. If this is produced by a cosmic string, its mass per unit length is about 4.0 x 10 to the 23rd g/cm or more. This value is large enough to be interesting for string-assisted galaxy formation and near the upper limits implied by the isotropy of the cosmic microwave background and constraints on gravitational radiation.
AGN feedback through UFO and galaxy-wide winds in the early Universe
NASA Astrophysics Data System (ADS)
Feruglio, C.; Piconcelli, E.; Bischetti, M.; Zappacosta, L.; Fiore, F.
2017-10-01
AGN feedback through massive molecular winds is today routinely observed in local AGN host galaxies, but not as such in the early universe. I will present the first evidence for a massive, AGN-driven molecular wind in the z 4 QSO APM08279, which also hosts the most well studied and persistent nuclear semi-raltivistic wind (UFO). This observation directly probes the expansion mechanism of a nuclear wind into the ISM on galaxy wide scales, that so far was constrained by a couple of other objects only (Feruglio et al. 2015, Tombesi et al. 2015). This result also opens the path toward the exploration of molecular AGN-driven winds at early epochs, close after the end of the Epoch of Reionisation (EoR).
NASA Astrophysics Data System (ADS)
Kakiichi, Koki; Ellis, Richard S.; Laporte, Nicolas; Zitrin, Adi; Eilers, Anna-Christina; Ryan-Weber, Emma; Meyer, Romain A.; Robertson, Brant; Stark, Daniel P.; Bosman, Sarah E. I.
2018-05-01
We introduce a new method for determining the influence of galaxies and active galactic nuclei (AGN) on the intergalactic medium (IGM) at high redshift and illustrate its potential via a first application to the field of the z = 6.42 QSO J1148+5251. Correlating spatial positions Lyman break galaxies (LBGs) with the Lyman alpha forest seen in the spectrum of a background QSO, we provide a statistical measure of the typical escape fraction of Lyman continuum photons. Using Keck DEIMOS spectroscopy to locate 7 colour-selected LBGs in the range 5.3 ≲ z ≲ 6.4 we examine the spatial correlation between this sample and Lyα/Lyβ transmission fluctuations in a Keck ESI spectrum of the QSO. Interpreting the statistical H I proximity effect as arising from faint galaxies clustered around the LBGs, we translate the observed mean Lyα transmitted flux into a constraint on the mean escape fraction ⟨fesc⟩ ≥ 0.08 at z ≃ 6. We also report individual transverse H I proximity effect for a z = 6.177 luminous LBG via a Lyβ transmission spike and two broad Lyα transmission spikes around the z = 5.701 AGN. We discuss the origin of such associations which suggest that while faint galaxies are primarily driving reionisation, luminous galaxies and AGN may provide important contributions to the UV background or thermal fluctuations of the IGM at z ≃ 6. Although a limited sample, our results demonstrate the potential of making progress using this method in resolving one of the most challenging aspects of the contribution of galaxies and AGN to cosmic reionisation.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Frank, S.; Mathur, S.; Pieri, M.
2010-09-15
We report the results of a systematic search for signatures of metal lines in quasar spectra of the Sloan Digital Sky Survey (SDSS) data release 3 (DR3), focusing on finding intervening absorbers via detection of their O VI doublet. Here, we present the search algorithm and criteria for distinguishing candidates from spurious Ly{alpha} forest lines. In addition, we compare our findings with simulations of the Ly{alpha} forest in order to estimate the detectability of O VI doublets over various redshift intervals. We have obtained a sample of 1756 O VI doublet candidates with rest-frame equivalent width (EW) {>=}0.05 A inmore » 855 active galactic nuclei spectra (out of 3702 objects with redshifts in the accessible range for O VI detection). This sample is further subdivided into three groups according to the likelihood of being real and the potential for follow-up observation of the candidate. The group with the cleanest and most secure candidates is comprised of 145 candidates. Sixty-nine of these reside at a velocity separation {>=}5000 km s{sup -1} from the QSO and can therefore be classified tentatively as intervening absorbers. Most of these absorbers have not been picked up by earlier, automated QSO absorption line detection algorithms. This sample increases the number of known O VI absorbers at redshifts beyond z{sub abs{>=}} 2.7 substantially.« less
H I OBSERVATIONS OF THE Ca II ABSORBING GALAXIES Mrk 1456 AND SDSS J211701.26-002633.7
DOE Office of Scientific and Technical Information (OSTI.GOV)
Cherinka, B.; Schulte-Ladbeck, R. E.; Rosenberg, J. L.
2009-12-15
In an effort to study Damped Ly{alpha} (DLA) galaxies at low redshift, we have been using the Sloan Digital Sky Survey (SDSS) to identify galaxies projected onto quasi-stellar object (QSO) sight lines and to characterize their optical properties. For low-redshift galaxies, the H I 21 cm emission line can be used as an alternate tool for identifying possible DLA galaxies, since H I-emitting galaxies typically exhibit H I columns that are larger than the classical DLA limit. Here, we report on follow-up H I 21 cm emission-line observations of two DLA candidates that are both low-redshift spiral galaxies, Mrk 1456more » and SDSS J211701.26-002633.7. The observations were made using the Green Bank Telescope (GBT) and Arecibo telescope, respectively. Analysis of their H I properties reveal the galaxies to be about one and two M*{sub HI} galaxies, respectively, and to have average H I mass, gas richness, and gas-mass fraction for their morphological types. We consider Mrk 1456 and SDSS J211701.26-002633.7 to be candidate DLA systems based upon the strength of the Ca II absorption lines they cause in their QSO's spectra, and impact parameters to the QSO that are smaller than the stellar disk. Compared to the small numbers of other H I detected DLA and candidate DLA galaxies, Mrk 1456 and SDSS J211701.26-002633.7 have high H I masses. Mrk 1456 and SDSS J211701.26-002633.7 have also been found to lie in galaxy groups that are high in H I gas mass compared to the group containing SBS 1543+593, the only DLA galaxy previously known to be situated in a galaxy group. When compared with the expected properties of low-z DLAs from an H I-detected sample of galaxies, Mrk 1456 and SDSS J211701.26-002633.7 fall within the ranges for impact parameter and M{sub B} ; and the H I mass distribution for the H I-detected DLAs agrees with that of the expected H I mass distribution for low-z DLAs. Our observations support galaxy-evolution models in which high-mass galaxies make up an increasing contribution to the DLA cross section at lower redshifts. We also report on the 21 cm line emission of Mrk 1457, a Seyfert galaxy observed within the beam of the GBT.« less
QUANTITATIVE EVALUATION OF THE HYPOTHESIS THAT BL LACERTAE OBJECTS ARE QSO REMNANTS
DOE Office of Scientific and Technical Information (OSTI.GOV)
Borra, E. F.
2014-11-20
We evaluate with numerical simulations the hypothesis that BL Lacertae objects (BLLs) are the remnants of quasi-stellar objects. This hypothesis is based on their highly peculiar redshift evolution. They have a comoving space density that increases with decreasing redshift, contrary to all other active galactic nuclei. We assume that relativistic jets are below detection in young radio-quiet quasars and increase in strength with cosmic time so that they eventually are detected as BLLs. Our numerical simulations fit very well the observed redshift distributions of BLLs. There are strong indications that only the high-synchrotron-peaked BLLs could be QSO remnants.
Swift detections of the flaring blazar GAIA 18ayp (PKS 2333-415) in X-rays and the UV
NASA Astrophysics Data System (ADS)
Grupe, Dirk; Komossa, S.; Angioni, R.; Schartel, N.
2018-04-01
We report Swift observations of the z=1.41 QSO GAIA 18ayp (PKS 2333-415) which was detected by GAIA in an optically flaring state on 2018-April-14. Swift observed GAIA 18ayp on 2018 April 23 for a total of 1.4 ks. The QSO is clearly detected in X-rays and the UV. The X-ray position found using the enhanced XRT position (Goad et al. 2007, Evans et al. 2009) is RA-2000 = 23 36 34.1, Dec-2000 = -41 15 21.4 with an uncertainty of 3.0".
The Chemical Evolution of QSO Absorbers
NASA Astrophysics Data System (ADS)
Ellison, Sara L.
2000-06-01
The chemical evolution of the high redshift intergalactic and interstellar media of galaxies is studied using QSO absorption lines. The redshift evolution of damped Lyman alpha (DLA) system metallicity is studied down to z=0.5, and no significant increase in metals is found. The CIV/HI ratio in the Lyman alpha forest is investigated at z approximately 3 and traces of are metals found in the low density HI gas with optical depth of around 1. Finally, a new survey for DLAs in a radio-selected sample of QSOs is presented, with the aim of determining whether a significant dust bias may have affected previous surveys.
NASA Astrophysics Data System (ADS)
Fischer, Travis C.; Kraemer, S. B.; Schmitt, H. R.; Longo Micchi, L. F.; Crenshaw, D. M.; Revalski, M.; Vestergaard, M.; Elvis, M.; Gaskell, C. M.; Hamann, F.; Ho, L. C.; Hutchings, J.; Mushotzky, R.; Netzer, H.; Storchi-Bergmann, T.; Straughn, A.; Turner, T. J.; Ward, M. J.
2018-04-01
We present a Hubble Space Telescope survey of extended [O III] λ5007 emission for a sample of 12 nearby (z < 0.12), luminous Type 2 quasars (QSO2s), which we use to measure the extent and kinematics of their AGN-ionized gas. We find that the size of the observed [O III] regions scale with luminosity in comparison to nearby, less luminous Seyfert galaxies and radially outflowing kinematics to exist in all targets. We report an average maximum outflow radius of ∼600 pc, with gas continuing to be kinematically influenced by the central active galactic nucleus (AGN) out to an average radius of ∼1130 pc. These findings question the effectiveness of AGNs being capable of clearing material from their host bulge in the nearby universe and suggest that disruption of gas by AGN activity may prevent star formation without requiring evacuation. Additionally, we find a dichotomy in our targets when comparing [O III] radial extent and nuclear FWHM, where QSO2s with compact [O III] morphologies typically possess broader nuclear emission lines.
Quantum groups, roots of unity and particles on quantized Anti-de Sitter space
DOE Office of Scientific and Technical Information (OSTI.GOV)
Steinacker, Harold
1997-05-23
Quantum groups in general and the quantum Anti-de Sitter group U q(so(2,3)) in particular are studied from the point of view of quantum field theory. The author shows that if q is a suitable root of unity, there exist finite-dimensional, unitary representations corresponding to essentially all the classical one-particle representations with (half) integer spin, with the same structure at low energies as in the classical case. In the massless case for spin ≥ 1, "naive" representations are unitarizable only after factoring out a subspace of "pure gauges", as classically. Unitary many-particle representations are defined, with the correct classical limit. Furthermore,more » the author identifies a remarkable element Q in the center of U q(g), which plays the role of a BRST operator in the case of U q(so(2,3)) at roots of unity, for any spin ≥ 1. The associated ghosts are an intrinsic part of the indecomposable representations. The author shows how to define an involution on algebras of creation and anihilation operators at roots of unity, in an example corresponding to non-identical particles. It is shown how nonabelian gauge fields appear naturally in this framework, without having to define connections on fiber bundles. Integration on Quantum Euclidean space and sphere and on Anti-de Sitter space is studied as well. The author gives a conjecture how Q can be used in general to analyze the structure of indecomposable representations, and to define a new, completely reducible associative (tensor) product of representations at roots of unity, which generalizes the standard "truncated" tensor product as well as many-particle representations.« less
NASA Astrophysics Data System (ADS)
Husemann, B.; Wisotzki, L.; Jahnke, K.; Sánchez, S. F.
2011-11-01
The metallicities of active galactic nuclei (AGN) are usually well above solar in their narrow-line regions, often reaching up to several times solar in their broad-line regions independent of redshift. Low-metallicity AGN are rare objects that have so far always been associated with low-mass galaxies hosting low-mass black holes (MBH106M⊙). We present integral field spectroscopy data of the low-redshift (z = 0.212) quasi-stellar object (QSO) HE 2158 - 0107 for which we find strong evidence of sub-solar NLR metallicities associated with a massive black hole (MBH ~ 3 × 108M⊙). The QSO is surrounded by a large extended emission-line region reaching out to 30 kpc from the QSO in a tail-like geometry. We present optical and near-infrared images and investigate the properties of the host galaxy. The host of HE 2158 - 0107 is most likely a very compact bulge-dominated galaxy with a size of re ~ 1.4 kpc. The multi-colour spectral energy distribution (SED) of the host is quite blue, indicative of a significant young age stellar population formed within the last 1 Gyr. A 3σ upper limit of Lbulge,H < 4.5 × 1010L ⊙ ,H for the H-band luminosity and a corresponding stellar mass upper limit of Mbulge < 3.4 × 1010M⊙ show that the host is offset from the local black hole-bulge relations. This is independently supported by the kinematics of the gas. Although the stellar mass of the host galaxy is lower than expected, it cannot explain the exceptionally low metallicity of the gas. We suggest that the extended emission-line region and the galaxy growth are caused by the infall of nearly pristine gas from the environment of the QSO host. Minor mergers of low-metallicity dwarf galaxies or the theoretically predicted smooth accretion of cold (~ 104 K) gas are both potential drivers behind that process. Because the metallicity of the gas in the QSO narrow-line region is much lower than expected, we suspect that the external gas has already reached the galaxy centre and may even contribute to the current feeding of the black hole. HE 2158 - 0107 appears to represent a particular phase of substantial black hole and galaxy growth that can be observationally linked with the accretion of external material from its environment. Based on observations collected at the Centro Astronómico Hispano Alemán (CAHA) at Calar Alto, operated jointly by the Max-Planck-Institut für Astronomie and the Instituto de Astrofísica de Andalucía (CSIC) and on observations collected at the European Organisation for Astronomical Reasearch in the Southern Hemisphere, Chile (program 070.B-0418).
Molecular outflow and feedback in the obscured quasar XID2028 revealed by ALMA
NASA Astrophysics Data System (ADS)
Brusa, M.; Cresci, G.; Daddi, E.; Paladino, R.; Perna, M.; Bongiorno, A.; Lusso, E.; Sargent, M. T.; Casasola, V.; Feruglio, C.; Fraternali, F.; Georgiev, I.; Mainieri, V.; Carniani, S.; Comastri, A.; Duras, F.; Fiore, F.; Mannucci, F.; Marconi, A.; Piconcelli, E.; Zamorani, G.; Gilli, R.; La Franca, F.; Lanzuisi, G.; Lutz, D.; Santini, P.; Scoville, N. Z.; Vignali, C.; Vito, F.; Rabien, S.; Busoni, L.; Bonaglia, M.
2018-04-01
We imaged, with ALMA and ARGOS/LUCI, the molecular gas and dust and stellar continuum in XID2028, which is an obscured quasi-stellar object (QSO) at z = 1.593, where the presence of a massive outflow in the ionised gas component traced by the [OIII]5007 emission has been resolved up to 10 kpc. This target represents a unique test case to study QSO feedback in action at the peak epoch of AGN-galaxy co-evolution. The QSO was detected in the CO(5 - 4) transition and in the 1.3 mm continuum at 30 and 20σ significance, respectively; both emissions are confined in the central (<2 kpc) radius area. Our analysis suggests the presence of a fast rotating molecular disc (v 400 km s-1) on very compact scales well inside the galaxy extent seen in the rest-frame optical light ( 10 kpc, as inferred from the LUCI data). Adding available measurements in additional two CO transitions, CO(2 - 1) and CO(3 - 2), we could derive a total gas mass of 1010 M⊙, thanks to a critical assessment of CO excitation and the comparison with the Rayleigh-Jeans continuum estimate. This translates into a very low gas fraction (<5%) and depletion timescales of 40-75 Myr, reinforcing the result of atypical gas consumption conditions in XID2028, possibly because of feedback effects on the host galaxy. Finally, we also detect the presence of high velocity CO gas at 5σ, which we interpret as a signature of galaxy-scale molecular outflow that is spatially coincident with the ionised gas outflow. XID2028 therefore represents a unique case in which the measurement of total outflowing mass, of 500-800 M⊙ yr-1 including the molecular and atomic components in both the ionised and neutral phases, was attempted for a high-z QSO.
Cosmological test with the QSO Hubble diagram
NASA Astrophysics Data System (ADS)
López-Corredoira, M.; Melia, F.; Lusso, E.; Risaliti, G.
2016-03-01
A Hubble diagram (HD) has recently been constructed in the redshift range 0 ≲ z ≲ 6.5 using a nonlinear relation between the ultraviolet (UV) and X-ray luminosities of quasi stellar objects (QSOs). The Type Ia Supernovae (SN) HD has already provided a high-precision test of cosmological models, but the fact that the QSO distribution extends well beyond the supernova range (z ≲ 1.8), in principle provides us with an important complementary diagnostic whose significantly greater leverage in z can impose tighter constraints on the distance versus redshift relationship. In this paper, we therefore perform an independent test of nine different cosmological models, among which six are expanding, while three are static. Many of these are disfavored by other kinds of observations (including the aforementioned Type Ia SNe). We wish to examine whether the QSO HD confirms or rejects these earlier conclusions. We find that four of these models (Einstein-de Sitter, the Milne universe, the static universe with simple tired light and the static universe with plasma tired light) are excluded at the > 99% C.L. The quasi-steady state model is excluded at > 95% C.L. The remaining four models (ΛCDM/wCDM, the Rh = ct universe, the Friedmann open universe and a static universe with a linear Hubble law) all pass the test. However, only ΛCDM/wCDM and Rh = ct also pass the Alcock-Paczyński (AP) test. The optimized parameters in ΛCDM/wCDM are Ωm = 0.20-0.20+0.24 and wde = -1.2-∞+1.6 (the dark energy equation-of-state). Combined with the AP test, these values become Ωm = 0.38-0.19+0.20 and wde = -0.28-0.40+0.52. But whereas this optimization of parameters in ΛCDM/wCDM creates some tension with their concordance values, the Rh = ct universe has the advantage of fitting the QSO and AP data without any free parameters.
NASA Astrophysics Data System (ADS)
Roche, Nathan; Franzetti, Paolo; Garilli, Bianca; Zamorani, Giovanni; Cimatti, Andrea; Rossetti, Emanuel
2012-02-01
We investigate the prospects of extending observations of high-redshift quasi-stellar objects (QSOs) from the current z˜ 7 to z > 8 by means of a very wide-area near-infrared slitless spectroscopic survey, considering as an example the planned survey with the European Space Agency's Euclid telescope (scheduled for a 2019 launch). For any QSOs at z > 8.06, the strong Lyman α line will enter the wavelength range of the Euclid Near-Infrared Spectometer and Imaging Photometer (NISP). We perform a detailed simulation of near infrared spectrometer and imaging photometer (Euclid) NISP slitless spectroscopy (with the parameters of the wide survey) in an artificial field containing QSO spectra at all redshifts up to z= 12 and to a faint limit H= 22.5. QSO spectra are represented with a template based on a Sloan Digital Sky Survey composite spectrum, with the added effects of absorption from neutral hydrogen in the intergalactic medium. The spectra extracted from the simulation are analysed with an automated redshift finder, and a detection rate estimated as a function of H magnitude and redshift (defined as the proportion of spectra with both correct redshift measurements and classifications). We show that, as expected, spectroscopic identification of QSOs would reach deeper limits for the redshift ranges where either ? (0.67 < z < 2.05) or Lyman α (z > 8.06) is visible. Furthermore, if photometrically selected z > 8 spectra can be re-examined and refitted to minimize the effects of spectral contamination, the QSO detection rate in the Lyman α window will be increased by an estimated ˜60 per cent and will then be better here than at any other redshift, with an effective limit H≃ 21.5. With an extrapolated rate of QSO evolution, we predict that the Euclid wide (15 000 ?) spectroscopic survey will identify and measure spectroscopic redshifts for a total of 20-35 QSOs at z > 8.06 (reduced slightly to 19-33 if we apply a small correction for missed weak-lined QSOs). However, for a model with a faster rate of evolution, this prediction goes down to four or five. In any event, the survey will give important constraints on the evolution of QSO at z > 8 and therefore the formation of the first supermassive black holes. The z > 8.06 detections would be very luminous objects (with MB=-26 to -28) and many would also be detectable by the proposed Wide Field X-ray Telescope.
Tracing Star Formation Around Quasars With Polycyclic Aromatic Hydrocarbons
NASA Astrophysics Data System (ADS)
Bilton, Lawrence Edward
2016-09-01
The feedback processes linking quasar activity to galaxy stellar mass growth are not well understood. If star formation is closely causally linked to black hole accretion, one may expect star formation confined to nuclear regions rather than extended over several kpc scales. Since Polycyclic Aromatic Hydrocarbon (PAH) emission features are widely used as tracers of stellar formation, it is, therefore, possible to use PAH emission detected around QSOs to help resolve this question. PAH data from a sample of 63 QSOs procured from the Spitzer Space Telescope’s Infrared Spectrograph (IRS) is used, employing the Spectroscopic Modelling Analysis and Reduction Tool’s (SMART) Advanced Optimal (AdOpt) extraction routines. A composite spectrum was also produced to help determine the average conditions and compositions of star forming regions. It is found, from our high redshift (>1) sample of QSOs, there is a marginally significant extended star formation on average of 34 scales. At low redshift, the median extension after deconvolving the instrumental point spread function is 3.2 , potentially showing evolutionary variations in star formation activity. However, limitations of the spatial resolving power constrain the ability to make any absolute conclusive remarks. It is also found that the QSO/AGN composite has more neutral PAHs than the starbursting and the main sequence galaxies, consistent with the AGN having no contribution to heating the PAH emission, and also consistent with the average PAH emission found on scales (i.e. not confined to the nuclear regions). A tentative detection of water vapour emission from the gravitationally lensed Einstein Cross quasar, QSO J2237+0305, is also presented suggesting a strong molecular outflow possibly driven by the active nucleus.
On Local Ionization Equilibrium and Disk Winds in QSOs
NASA Astrophysics Data System (ADS)
Pereyra, Nicolas A.
2014-11-01
We present theoretical C IV λλ1548,1550 absorption line profiles for QSOs calculated assuming the accretion disk wind (ADW) scenario. The results suggest that the multiple absorption troughs seen in many QSOs may be due to the discontinuities in the ion balance of the wind (caused by X-rays), rather than discontinuities in the density/velocity structure. The profiles are calculated from a 2.5-dimensional time-dependent hydrodynamic simulation of a line-driven disk wind for a typical QSO black hole mass, a typical QSO luminosity, and for a standard Shakura-Sunyaev disk. We include the effects of ionizing X-rays originating from within the inner disk radius by assuming that the wind is shielded from the X-rays from a certain viewing angle up to 90° ("edge on"). In the shielded region, we assume constant ionization equilibrium, and thus constant line-force parameters. In the non-shielded region, we assume that both the line-force and the C IV populations are nonexistent. The model can account for P-Cygni absorption troughs (produced at edge on viewing angles), multiple absorption troughs (produced at viewing angles close to the angle that separates the shielded region and the non-shielded region), and for detached absorption troughs (produced at an angle in between the first two absorption line types); that is, the model can account for the general types of broad absorption lines seen in QSOs as a viewing angle effect. The steady nature of ADWs, in turn, may account for the steady nature of the absorption structure observed in multiple-trough broad absorption line QSOs. The model parameters are M bh = 109 M ⊙ and L disk = 1047 erg s-1.
Spectacular mergers at the cosmic dawn: a HST, ALMA, and JWST synergy
NASA Astrophysics Data System (ADS)
Banados, Eduardo
2016-10-01
How did the first massive galaxies in the universe form? Theoretical models predict that these form through mergers of gas-rich galaxies at very high-redshifts. These models are often invoked to explain the existence of massive 'red and dead' galaxies by z 2. We have unexpectedly identified a sample of six z>6 QSOs with close, gas-rich companions at the same redshifts through our on-going ALMA survey of [CII] and dust emission in QSO host galaxies. This is the first unambiguous direct observational evidence of gravitational interactions within the first Gyr of the universe, supporting the aforementioned theoretical models. These newly discovered QSO-galaxy pairs are a unique sample to demonstrate key capabilities of JWST in early science, such as the multi-object and IFU modes of NIRSpec. Remarkably, three of these systems are separated by less than 10 kpc (<2 arcsec), which makes them prime targets to exploit the unparalleled IFU capabilities of JWST/NIRSpec in early science. Such observations will allow us to map the morphology and kinematics of these gravitational interactions as function of separation from the QSOs, which will enlighten our understanding of early black hole and galaxy growth. Thus, it is of critical importance to characterize the rest-frame UV/optical properties of these companions before the JWST launch. Here we propose deep WFC3/IR F140W observations to set the first firm constraints on their rest-frame UV properties, which can only be achieved by the sensitivity and resolution of HST. These timely HST observations will be essential to enable a plethora of JWST early science programs.
Disentangling Quasar Nomenclature
NASA Astrophysics Data System (ADS)
Ross, Nicholas; Goulding, Andrew D.
2015-01-01
The terms Type 1, Type 2, Obscured, Unobscured, Compton-thin and Compton-thick are cemented naming conventions for describing AGN and QSOs. However, all too often, they are used interchangeably to describe seemingly similar/different entities, leading to confusion towards the physical mechanisms that give rise to them. Furthermore, as is often the case in scientific discovery, initial designations and acronyms become obsolete. In this poster, using data and new results from the SDSS, SDSS-III BOSS, Bootes, DEEP2 and WISE surveys, we present a comprehensive QSO Glossary giving clear definitions of numerous AGN terms and the physical interpretation behind them. We further elucidate to the physical nature of hot dust obscured galaxy population (``hot DOGs'') and the long-sought after high-z Type 2 QSO population.
The TESIS Project: Are Type 2 QSO Hidden in X-Ray Emitting EROs?
NASA Astrophysics Data System (ADS)
Severgnini, P.; Della Ceca, R.; Braito, V.; Saracco, P.; Longhetti, M.; Bender, R.; Drory, N.; Feulner, G.; Hopp, U.; Mannucci, F.; Maraston, C.
X-ray selected EROs are, on average, the hardest X-ray sources in medium and deep X-ray fields. This coupled with their extremely red colors (R-K > 5) suggest that they represent one of the most promising population where looking for high-luminosity (LX > 1044 erg s-1) and X-ray obscured (NH > 1022 cm-2) type2 AGNs, the so called QSO2 (e.g., [5]; [4]; Mignoli et al. submitted to A&A). These latter are predicted in large density by the synthesis model of the Cosmic X-ray background [9] even if only few observational evidences have been found so far (e.g., [1] and references therein; Caccianiga et al. A&A accepted).
Galaxy Clusters in the Line of Sight to Background Quasars. III. Multi-object Spectroscopy
NASA Astrophysics Data System (ADS)
Andrews, H.; Barrientos, L. F.; López, S.; Lira, P.; Padilla, N.; Gilbank, D. G.; Lacerna, I.; Maureira, M. J.; Ellingson, E.; Gladders, M. D.; Yee, H. K. C.
2013-09-01
We present Gemini/GMOS-S multi-object spectroscopy of 31 galaxy cluster candidates at redshifts between 0.2 and 1.0 and centered on QSO sight lines taken from López et al. The targets were selected based on the presence of an intervening Mg II absorption system at a similar redshift to that of a galaxy cluster candidate lying at a projected distance <2 h_{71}^{-1} Mpc from the QSO sight line (a "photometric hit"). The absorption systems span rest-frame equivalent widths between 0.015 and 2.028 Å. Our aim was three-fold: (1) to identify the absorbing galaxies and determine their impact parameters, (2) to confirm the galaxy cluster candidates in the vicinity of each quasar sightline, and (3) to determine whether the absorbing galaxies reside in galaxy clusters. In this way, we are able to characterize the absorption systems associated with cluster members. Our main findings are as follows. (1) We identified 10 out of 24 absorbing galaxies with redshifts between 0.2509 <= z gal <= 1.0955, up to an impact parameter of 142\\ h_{71}^{-1} kpc and a maximum velocity difference of 280 km s-1. (2) We spectroscopically confirmed 20 out of 31 cluster/group candidates, with most of the confirmed clusters/groups at z < 0.7. This relatively low efficiency results from the fact that we centered our observations on the QSO location, and thus occasionally some of the cluster centers were outside the instrument field of view. (3) Following from the results above, we spectroscopically confirmed of 10 out of 14 photometric hits within ~650 km s-1 from galaxy clusters/groups, in addition to two new ones related to galaxy group environments. These numbers imply efficiencies of 71% in finding such systems with MOS spectroscopy. This is a remarkable result since we defined a photometric hit as those cluster-absorber pairs having a redshift difference Δz = 0.1. The general population of our confirmed absorbing galaxies have luminosities L_{B} \\sim L_{B}^{\\ast } and mean rest-frame colors (Rc - z') typical of S cd galaxies. From this sample, absorbing cluster galaxies hosting weak absorbers are consistent with lower star formation activity than the rest, which produce strong absorption and agree with typical Mg II absorbing galaxies found in the literature. Our spectroscopic confirmations lend support to the selection of photometric hits made in López et al. Based on observations obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (United States), the Science and Technology Facilities Council (United Kingdom), the National Research Council (Canada), CONICYT (Chile), the Australian Research Council (Australia), Ministério da Ciência e Tecnologia (Brazil), and Ministerio de Ciencia, Tecnología e Innovación Productiva (Argentina).
Quasi-stellar objects in the intergalactic medium: Source for the cosmic X-ray background
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sherman, R.D.
1980-06-15
QSOs are regarded as sources of both electromagnetic radiation and ejected matter that heat and ionize a dense intergalactic medium (IGM). Using current estimates of QSO luminosity, number density, evolution, and spectral index, we study three viable models: the diffuse cosmic X-ray background is (1) due entirely to thermal Bremsstrahlung of the IGM, (2) completely supplied by QSO X-radiation, (3) or a combination of both. The upper limits on an IGM fractional density with respect to closure are ..cap omega..=0.26, 0.24, and 0.21 for pure collisional, photo/collisional mixture, and pure photoionization, respectively. These calculations give emission spectra, Compton distortion ofmore » the cosmic microwave background, and optical depths to distant OSOs for comparison with relevant data.« less
PROVIDING STRINGENT STAR FORMATION RATE LIMITS OF z ∼ 2 QSO HOST GALAXIES AT HIGH ANGULAR RESOLUTION
DOE Office of Scientific and Technical Information (OSTI.GOV)
Vayner, Andrey; Wright, Shelley A.; Do, Tuan
2016-04-10
We present integral field spectrograph (IFS) with laser guide star adaptive optics (LGS-AO) observations of z ∼ 2 quasi-stellar objects (QSOs) designed to resolve extended nebular line emission from the host galaxy. Our data was obtained with W. M. Keck and Gemini North Observatories, using OSIRIS and NIFS coupled with the LGS-AO systems, respectively. We have conducted a pilot survey of five QSOs, three observed with NIFS+AO and two observed with OSIRIS+AO at an average redshift of z = 2.2. We demonstrate that the combination of AO and IFSs provides the necessary spatial and spectral resolutions required to separate QSO emission from its host.more » We present our technique for generating a point-spread function (PSF) from the broad-line region of the QSO and performing PSF subtraction of the QSO emission to detect the host galaxy emission at a separation of ∼0.″2 (∼1.4 kpc). We detect Hα narrow-line emission for two sources, SDSS J1029+6510 (z{sub Hα} = 2.182) and SDSS J0925+0655 (z{sub Hα} = 2.197), that have evidence for both star formation and extended narrow-line emission. Assuming that the majority of narrow-line Hα emission is from star formation, we infer a star formation rate (SFR) for SDSS J1029+6510 of 78.4 M{sub ⊙} yr{sup −1} originating from a compact region that is kinematically offset by 290–350 km s{sup −1}. For SDSS J0925+0655 we infer a SFR of 29 M{sub ⊙} yr{sup −1} distributed over three clumps that are spatially offset by ∼7 kpc. The null detections on three of the QSOs are used to infer surface brightness limits and we find that at 1.4 kpc from the QSO the un-reddened star formation limit is ≲0.3 M{sub ⊙} yr{sup −1} kpc{sup −2}. If we assume typical extinction values for z = 2 type-1 QSOs, the dereddened SFR for our null detections would be ≲0.6 M{sub ⊙} yr{sup −1} kpc{sup −2}. These IFS observations indicate that while the central black hole is accreting mass at 10%–40% of the Eddington rate, if star formation is present in the host (1.4–20 kpc) it would have to occur diffusely with significant extinction and not in compact, clumpy regions.« less
The Effect of Clustering on Estimations of the UV Ionizing Background from the Proximity Effect
NASA Astrophysics Data System (ADS)
Pascarelle, S. M.; Lanzetta, K. M.; Chen, H. W.
1999-09-01
There have been several determinations of the ionizing background using the proximity effect observed in the distibution of Lyman-alpha absorption lines in the spectra of QSOs at high redshift. It is usually assumed that the distribution of lines should be the same at very small impact parameters to the QSO as it is at large impact parameters, and any decrease in line density at small impact parameters is due to ionizing radiation from the QSO. However, if these Lyman-alpha absorption lines arise in galaxies (Lanzetta et al. 1995, Chen et al. 1998), then the strength of the proximity effect may have been underestimated in previous work, since galaxies are known to cluster around QSOs. Therefore, the UV background estimations have likely been overestimated by the same factor.
The Elixir System: Data Characterization and Calibration at the Canada-France-Hawaii Telescope
NASA Astrophysics Data System (ADS)
Magnier, E. A.; Cuillandre, J.-C.
2004-05-01
The Elixir System at the Canada-France-Hawaii Telescope performs data characterization and calibration for all data from the wide-field mosaic imagers CFH12K and MegaPrime. The project has several related goals, including monitoring data quality, providing high-quality master detrend images, determining the photometric and astrometric calibrations, and automatic preprocessing of images for queued service observing (QSO). The Elixir system has been used for all data obtained with CFH12K since the QSO project began in 2001 January. In addition, it has been used to process archival data from the CFH12K and all MegaPrime observations beginning in 2002 December. The Elixir system has been extremely successful in providing well-characterized data to the end observers, who may otherwise be overwhelmed by data-processing concerns.
Optimizing the night time with dome vents and SNR-QSO at CFHT
NASA Astrophysics Data System (ADS)
Devost, Daniel; Mahoney, Billy; Moutou, Claire; CFHT QSO Team, CFHT software Group
2017-06-01
Night time is a precious and costly commodity and it is important to get everything we can out of every second of every night of observing. In 2012 the Canada-France-Hawaii Telescope started operating 12 new vent doors installed on the dome over the course of the previous two years. The project was highly successful and seeing measurements show that venting the dome greatly enhances image quality at the focal plane. In order to capitalize on the gains brought by the new vents, the observatory started exploring a new mode of observation called SNR-QSO. This mode consist of a new implementation inside our Queued Service Observation (QSO) system. Exposure times are adjusted for each frame depending on the weather conditions in order to reach a specific depth, Signal to Noise Ratio (SNR) at a certain magnitude. The goal of this new mode is to capitalize on the exquisite seeing provided by Maunakea, complemented by the minimized dome turbulence, to use the least amount of time to reach the depth required by the science programs. Specific implementations were successfully tested on two different instruments, our wide field camera MegaCam and our high resolution spectrograph ESPaDOnS. I will present the methods used for each instrument to achieve SNR observing and the gains produced by these new observing modes in order to reach the scientific goals of accepted programs in a shorter amount of time.
Probing the end of reionization with the near zones of z ≳ 6 QSOs
NASA Astrophysics Data System (ADS)
Keating, Laura C.; Haehnelt, Martin G.; Cantalupo, Sebastiano; Puchwein, Ewald
2015-11-01
QSO near zones are an important probe of the ionization state of the intergalactic medium (IGM) at z ˜ 6-7, at the end of reionization. We present here high-resolution cosmological 3D radiative transfer simulations of QSO environments for a wide range of host halo masses, 1010-12.5 M⊙. Our simulated near zones reproduce both the overall decrease of observed near-zone sizes at 6 < z < 7 and their scatter. The observable near-zone properties in our simulations depend only very weakly on the mass of the host halo. The size of the H II region expanding into the IGM is generally limited by (super-)Lyman Limit systems loosely associated with (low-mass) dark matter haloes. This leads to a strong dependence of near-zone size on direction and drives the large observed scatter. In the simulation centred on our most massive host halo, many sightlines show strong red damping wings even for initial volume averaged neutral hydrogen fractions as low as ˜10-3. For QSO lifetimes long enough to allow growth of the central supermassive black hole while optically bright, we can reproduce the observed near zone of ULAS J1120+0641 only with an IGM that is initially neutral. Our results suggest that larger samples of z > 7 QSOs will provide important constraints on the evolution of the neutral hydrogen fraction and thus on how late reionization ends.
Unveiling the Secrets of Metallicity and Massive Star Formation Using DLAs Along Gamma-Ray Bursts
NASA Technical Reports Server (NTRS)
Cucchiara, A.; Fumagalli, M.; Rafelski, M.; Kocevski, D.; Prochaska, J. X.; Cooke, R. J.; Becker, G. D.
2015-01-01
We present the largest, publicly available, sample of Damped Lyman-alpha systems (DLAs) along Swift discovered Gamma-ray Bursts (GRB) line of sights in order to investigate the environmental properties of long GRB hosts in the z = 1.8 - 6 redshift range. Compared with the most recent quasar DLAs sample (QSO-DLA), our analysis shows that GRB-DLAs probe a more metal enriched environment at z approximately greater than 3, up to [X/H] approximately -0.5. In the z = 2 - 3 redshift range, despite the large number of lower limits, there are hints that the two populations may be more similar (only at 90% significance level) than at higher redshifts. Also, at high-z, the GRB-DLA average metallicity seems to decline at a shallower rate than the QSO-DLAs: GRB-DLA hosts may be polluted with metals at least as far as approximately 2 kpc from the GRB explosion site, probably due to previous star-formation episodes and/or supernovae explosions. This shallow metallicity trend, extended now up to z approximately 5, confirms previous results that GRB hosts are star-forming and have, on average, higher metallicity than the general QSO-DLA population. Finally, our host metallicity measurements are broadly consistent with the predictions derived from the hypothesis of two channels of GRB progenitors, one of which is mildly affected by a metallicity bias, although more data are needed to constrain the models at z approximately greater than 4.
XMM-Newton reveals a Seyfert-like X-ray spectrum in the z = 3.6 QSO B1422+231
NASA Astrophysics Data System (ADS)
Dadina, M.; Vignali, C.; Cappi, M.; Lanzuisi, G.; Ponti, G.; De Marco, B.; Chartas, G.; Giustini, M.
2016-08-01
Context. Matter flows from the central regions of quasi-stellar objects (QSOs) during their active phases are probably responsible for the properties of the super-massive black holes and those of the bulges of host galaxies. To understand how this mechanism works, we need to characterize the geometry and the physical state of the accreting matter at cosmological redshifts, when QSO activity is at its peak. Aims: We aim to use X-ray data to probe the matter inflow at the very center of a QSO at z = 3.62. While complex absorption, the iron K emission line, reflection hump, and high-energy cutoff are known to be almost ubiquitous in nearby active galactic nuclei (AGN), only a few distant objects are known to exhibit some of them. Methods: The few high-quality spectra of distant QSO were collected by adding sparse pointings of single objects obtained during X-ray monitoring campaigns. This could have introduced spurious spectral features due to source variability and/or microlensing. To avoid such problems, we decided to collect a single-epoch and high-quality X-ray spectrum of a distant AGN. We thus picked up the z = 3.62 QSO B1422+231, whose flux, enhanced by gravitationally lensing, is proven to be among the brightest lensed QSOs in X-rays (F2-10 keV ~ 10-12 erg s-1 cm-2). Results: The X-ray spectrum of B1422+231 is found to be very similar to the one of a typical nearby Seyfert galaxy. Neutral absorption is clearly detected (NH ~ 5 × 1021 cm-2 at the redshift of the source), while a strong absorption edge is measured at E ~ 7.5 keV with an optical depth of τ ~ 0.14. We also find hints of the FeKα line in emission at E ~ 6.4 keV line (EW ≲ 70 eV), and a hump is detected in the E ~ 15 - 20 keV energy band (rest frame) in excess of what is predicted by a simple absorbed power-law. Conclusions: The spectrum can best be modeled with two rather complex models; one assumes ionized and partially covering matter along the line of sight, the other is characterized by a reflection component. We argue that reflection seems more plausible here on a statistical basis. In this scenario, the primary emission of B1422+231 is most probably dominated by the thermal Comptonization of UV seed photons in a corona with kT ~ 40 keV. We also detected a reflection component with relative direct-to-reflect normalization r ~ 1. These findings confirm that gravitational lensing is suitable for obtaining good-quality X-ray spectral information of QSOs at high-z, moreover, they support the idea that the same general picture characterizing AGN in the nearby Universe is also valid at high redshift.
THE FIRST OBSERVATIONS OF LOW-REDSHIFT DAMPED Ly{alpha} SYSTEMS WITH THE COSMIC ORIGINS SPECTROGRAPH
DOE Office of Scientific and Technical Information (OSTI.GOV)
Meiring, J. D.; Tripp, T. M.; Prochaska, J. X.
2011-05-01
We report on the first Cosmic Origins Spectrograph observations of damped Ly{alpha} systems (DLAs) and sub-damped Ly{alpha} systems (sub-DLAs) discovered in a new survey of the gaseous halos of low-redshift galaxies. From observations of 37 sightlines, we have discovered three DLAs and four sub-DLAs. We measure the neutral gas density {Omega}{sub HI}, and redshift density d N/d z, of DLA and sub-DLA systems at z < 0.35. We find d N/dz = 0.25{sup +0.24}-{sub 0.14} and {Omega}{sub HI} = 1.4{sup +1.3}{sub -0.7} x 10{sup -3} for DLAs, and d N/d z = 0.08{sup +0.19}{sub -0.06} with {Omega}{sub HI} = 4.2{supmore » +9.6}{sub -3.5} x 10{sup -5} for sub-DLAs over a redshift path {Delta}z = 11.9. To demonstrate the scientific potential of such systems, we present a detailed analysis of the DLA at z{sub abs} = 0.1140 in the spectrum of SDSS J1009+0713. Profile fits to the absorption lines determine log N(H I) = 20.68 {+-} 0.10 with a metallicity determined from the undepleted element sulfur of [S/H] = -0.62 {+-} 0.18. The abundance pattern of this DLA is similar to that of higher z DLAs, showing mild depletion of the refractory elements Fe and Ti with [S/Fe] = +0.24 {+-} 0.22 and [S/Ti] = +0.28 {+-} 0.15. Nitrogen is underabundant in this system with [N/H] = -1.40 {+-} 0.14, placing this DLA below the plateau of the [N/{alpha}] measurements in the local universe at similar metallicities. This DLA has a simple kinematic structure with only two components required to fit the profiles and a kinematic width of {Delta}v{sub 90} = 52 km s{sup -1}. Imaging of the QSO field with the Hubble Space Telescope/Wide Field Camera 3 reveals a spiral galaxy at very small impact parameter to the QSO and several galaxies within 10'', or 20 comoving kpc at the redshift of the DLA. Follow-up spectra with the Low Resolution Imaging Spectrometer on the Keck telescope reveal that none of the nearby galaxies are at the redshift of the DLA. The spiral galaxy is identified as the host galaxy of the QSO based on the near perfect alignment of the nucleus and disk of the galaxy as well as spectra of an H II region showing emission lines at the QSO redshift. A small feature appears 0.''70 from the nucleus of the QSO after point-spread function subtraction, providing another candidate for the host galaxy of the DLA system. Even with these supporting data, we are unable to unambiguously identify the host galaxy of the DLA, exemplifying some of the difficulties in determining DLA hosts even at low redshift.« less
Is High Primordial Deuterium Consistent with Galactic Evolution?
NASA Astrophysics Data System (ADS)
Tosi, Monica; Steigman, Gary; Matteucci, Francesca; Chiappini, Cristina
1998-05-01
Galactic destruction of primordial deuterium is inevitably linked through star formation to the chemical evolution of the Galaxy. The relatively high present gas content and low metallicity suggest only modest D destruction. In concert with deuterium abundances derived from solar system and/or interstellar observations, this suggests a primordial deuterium abundance in possible conflict with data from some high-redshift, low-metallicity QSO absorbers. We have explored a variety of chemical evolution models including infall of processed material and early, supernovae-driven winds with the aim of identifying models with large D destruction that are consistent with the observations of stellar-produced heavy elements. When such models are confronted with data, we reconfirm that only modest destruction of deuterium (less than a factor of 3) is permitted. When combined with solar system and interstellar data, these results favor the low deuterium abundances derived for the QSO absorbers by Tytler et al.
IUE and ROSAT monitoring of the bright QSO H1821+643
NASA Technical Reports Server (NTRS)
Halpern, Jules; Kolman, Michiel; Shrader, Chris; Filippenko, Alexei
1991-01-01
The analysis is presented of IUE observations of the bright QSO H1821+643, obtained during the ROSAT All Sky Survey (the RIASS program). The objectives were: (1) to establish whether the UV and soft X ray radiation have the same physical origin; and (2) to determine if this physical origin is an accretion disk. Supporting ground based spectrophotometry was also obtained. The analysis shows that the shape and flux level of the UV continuum did not vary among the seven IUE observation spanning one month, to an upper limit of about 8 percent. So it is of great interest to determine whether the soft X ray flux varied during this period. Since X ray variability in AGNs is often more rapid and of higher amplitude than in the UV, detection of X ray variability in the ROSAT data could severely challenge the accretion disk model for the soft X ray excess.
NASA Astrophysics Data System (ADS)
Moreau, O.; Libbrecht, C.; Lee, D.-W.; Surdej, J.
2005-06-01
Using an optimal image subtraction technique, we have derived the V and R light curves of the four lensed QSO components of Q2237+0305 from the monitoring CCD frames obtained by the GLITP collaboration with the 2.6 m NOT telescope in 1999/2000 (Alcalde et al. 2002). We give here a detailed account of the data reduction and analysis and of the error estimates. In agreement with Woźniak et al. (2000a,b), the good derived photometric accuracy of the GLITP data allows to discuss the possible interpretation of the light curve of component A as due to a microlensing event taking place in the deflecting galaxy. This interpretation is strengthened by the colour dependence of the early rise of the light curve of component A, as it probably corresponds to a caustics crossing by the QSO source.
Principles of Queued Service Observing at CFHT
NASA Astrophysics Data System (ADS)
Manset, Nadine; Burdullis, T.; Devost, D.
2011-03-01
CFHT started to use Queued Service Observing in 2001, and is now operating in that mode over 95% of the time. Ten years later, the observations are now carried out by Remote Observers who are not present at the telescope (see the companion presentation "Remote Queued Service Observing at CFHT"). The next phase at CFHT will likley involve assisted or autonomous service observing (see the presentation "Artificial Intelligence in Autonomous Telescopes"), which would not be possible without first having a Queued observations system already in place. The advantages and disadvantages of QSO at CFHT will be reviewed. The principles of QSO at CFHT, which allow CFHT to complete 90-100% of the top 30-40% programs and often up to 80% of other accepted programs, will be presented, along with the strategic use of overfill programs, the method of agency balance, and the suite of planning, scheduling, analysis and data quality assessment tools available to Queue Coordinators and Remote Observers.
Remeasurement of the H I Gunn-Peterson Effect toward QSO PKS 1937-101 with Keck Observations
NASA Astrophysics Data System (ADS)
Fang, Yihu; Fan, Xiaoming; Tytler, David; Crotts, Arlin P. S.
1998-04-01
We present the first measurement of the H I Gunn-Peterson effect using the Keck 10 m telescope, observing the high-redshift QSO PKS 1937-101 (z = 3.787). The high-resolution echelle (HIRES) spectra, with FWHM ~15 km s-1 and a signal-to-noise ratio (S/N) ~50 per spectral resolution element, allows us to resolve many weak lines down to NH I = 1012 cm-2, thus reducing the line-blanketing problem compared with previous data. Based on intensity-distribution analysis, we find that a maximum likelihood best fit yields a Gunn-Peterson type of opacity τGP = 0.113 +/- 0.020 in addition to a power-law Lyα absorption-line population with β of 1.7 down to NH I = 1012 cm-2. There remains systematic uncertainty in this result because of problems extrapolating the spectral continuum from the red side of the Lyα emission line. This is consistent with the previous study of the same QSO in low S/N data using weighted intensity function analysis (Fang & Crotts 1995). It indicates that this previous method succeeds in measuring the Lyα forest continuum level at low S/N, which is essential in extending the technique to possible fainter QSOs with minimum emission-line contamination for reliable continuum extrapolation. We further discuss problems of severe line blanketing, even in Keck spectra for QSOs at z >= 4.5, and show the effectiveness of the weighted intensity function method in measuring continuum levels in extremely crowded Lyα absorption spectra for redshifts as high as z > 5.
Multiwavelength Characterization of an ACT-selected, Lensed Dusty Star-forming Galaxy at z = 2.64
NASA Astrophysics Data System (ADS)
Roberts-Borsani, G. W.; Jiménez-Donaire, M. J.; Daprà, M.; Alatalo, K.; Aretxaga, I.; Álvarez-Márquez, J.; Baker, A. J.; Fujimoto, S.; Gallardo, P. A.; Gralla, M.; Hilton, M.; Hughes, J. P.; Jiménez, C.; Laporte, N.; Marriage, T. A.; Nati, F.; Rivera, J.; Sievers, A.; Weiß, A.; Wilson, G. W.; Wollack, E. J.; Yun, M. S.
2017-08-01
We present C I(2-1) and multi-transition 12CO observations of a dusty star-forming galaxy, ACT J2029+0120, which we spectroscopically confirm to lie at z = 2.64. We detect CO(3-2), CO(5-4), CO(7-6), CO(8-7), and C I(2-1) at high significance, tentatively detect HCO+(4-3), and place strong upper limits on the integrated strength of dense gas tracers (HCN(4-3) and CS(7-6)). Multi-transition CO observations and dense gas tracers can provide valuable constraints on the molecular gas content and excitation conditions in high-redshift galaxies. We therefore use this unique data set to construct a CO spectral line energy distribution (SLED) of the source, which is most consistent with that of a ULIRG/Seyfert or QSO host object in the taxonomy of the Herschel Comprehensive ULIRG Emission Survey. We employ RADEX models to fit the peak of the CO SLED, inferring a temperature of T ˜ 117 K and {n}{{{H}}2}˜ {10}5 cm-3, most consistent with a ULIRG/QSO object and the presence of high-density tracers. We also find that the velocity width of the C I line is potentially larger than seen in all CO transitions for this object, and that the {L}{{C} {{I}}(2-1)}\\prime /{L}{CO(3-2)}\\prime ratio is also larger than seen in other lensed and unlensed submillimeter galaxies and QSO hosts; if confirmed, this anomaly could be an effect of differential lensing of a shocked molecular outflow.
Surveying the CGM and IGM across 4 orders of magnitude in environmental density
NASA Astrophysics Data System (ADS)
Burchett, Joseph
2017-08-01
Environment matters when it comes to galaxy evolution, and the mechanisms driving this evolution are reflected in the diffuse gas residing within the large-scale structures enveloping the cosmic galaxy population. QSO absorption lines effectively probe the circumgalactic medium (CGM) and intragroup and intracluster media, and work thus far hints at profound environmental effects on the CGM. However, sample sizes remain small, and a unifying picture of the gas characteristics across diverse environments has yet to emerge. Within the Sloan Digital Sky Survey, we have identified a sample volume containing a remarkable diversity in large-scale environment with an array of voids, >10,000 groups, several filaments, and 5 clusters, including the Coma Supercluster and CfA Great Wall. Leveraging the Hubble Spectroscopic Legacy Archive (HSLA), we propose a study using >360 background QSOs probing this volume to study the effects of large-scale environment on CGM and intergalactic medium (IGM) gas. The z = 0.019-0.028 spectroscopic galaxy sample is uniformly complete to galaxies L > 0.03 L* and, with the HSLA, produces 200 galaxy/sightline pairs within 300-kpc impact parameters across a wide range of environmental densities and structures.Upon quantifying the galaxy environment and identifying/measuring the QSO absorption lines at z = 0.019-0.028, we will pursue the following primary science goals:1. Constrain the CGM/IGM physical conditions across four orders of magnitude in galaxy density2. Compare ionic abundances and ionization states in the CGM of galaxies in filaments vs. voids3. Statistically investigate the IGM/CGM gas properties from structure to structure
Gas-rich galaxy pair unveiled in the lensed quasar 0957+561
Planesas; Martin-Pintado; Neri; Colina
1999-12-24
Molecular gas in the host galaxy of the lensed quasar 0957+561 (QSO 0957+561) at the redshift of 1.41 has been detected in the carbon monoxide (CO) line. This detection shows the extended nature of the molecular gas distribution in the host galaxy and the pronounced lensing effects due to the differentially magnified CO luminosity at different velocities. The estimated mass of molecular gas is about 4 x 10(9) solar masses, a molecular gas mass typical of a spiral galaxy like the Milky Way. A second, weaker component of CO is interpreted as arising from a close companion galaxy that is rich in molecular gas and has remained undetected so far. Its estimated molecular gas mass is 1.4 x 10(9) solar masses, and its velocity relative to the main galaxy is 660 kilometers per second. The ability to probe the molecular gas distribution and kinematics of galaxies associated with high-redshift lensed quasars can be used to improve the determination of the Hubble constant H(0).
HST Detection of Extended Neutral Hydrogen in a Massive Elliptical at z = 0.4
NASA Astrophysics Data System (ADS)
Zahedy, Fakhri S.; Chen, Hsiao-Wen; Rauch, Michael; Zabludoff, Ann
2017-09-01
We report the first detection of extended neutral hydrogen (H I) gas in the interstellar medium (ISM) of a massive elliptical galaxy beyond z˜ 0. The observations utilize the doubly lensed images of QSO HE 0047-1756 at {z}{QSO}=1.676 as absorption-line probes of the ISM in the massive ({M}{star}≈ {10}11 {M}⊙ ) elliptical lens at z = 0.408, detecting gas at projected distances of d = 3.3 and 4.6 kpc on opposite sides of the lens. Using the Space Telescope Imaging Spectrograph, we obtain UV absorption spectra of the lensed QSO and identify a prominent flux discontinuity and associated absorption features matching the Lyman series transitions at z = 0.408 in both sightlines. The H I column density is log N({{H}} {{I}})=19.6{--}19.7 at both locations across the lens, comparable to what is seen in 21 cm images of nearby ellipticals. The H I gas kinematics are well-matched with the kinematics of the Fe II absorption complex revealed in ground-based echelle data, displaying a large velocity shear of ≈360 {\\text{km s}}-1 across the galaxy. We estimate an ISM Fe abundance of 0.3-0.4 solar at both locations. Including likely dust depletions increases the estimated Fe abundances to solar or supersolar, similar to those of the hot ISM and stars of nearby ellipticals. Assuming 100% covering fraction of this Fe-enriched gas, we infer a total Fe mass of {M}{cool}({Fe})˜ (5{--}8)× {10}4 {M}⊙ in the cool ISM of the massive elliptical lens, which is no more than 5% of the total Fe mass observed in the hot ISM.
Luminosity of serendipitous x-ray QSOs
DOE Office of Scientific and Technical Information (OSTI.GOV)
Margon, B.; Chanan, G.A.; Downes, R.A.
1982-02-01
We have identified the optical counterparts of 47 serendipitously discovered Einstein Observatory X-ray sources with previously unreported quasi-stellar objects. The mean ratio of X-ray to optical luminosity of this sample agrees reasonably well with that derived from X-ray observations of previously known QSOs. However, despite the fact that our limiting magnitude V = 18.5 should permit detection of typical QSOs (i.e., M/sub c/ = -26) to z = 0.9, the mean redshift of our sample is only z = 0.42 Thus the mean luminosity of these objects, M/sub c/ = -24, differs significantly from that of previous QSO surveys withmore » similar optical thresholds. The existence of large numbers of these lower luminosity QSOs which are difficult to discover by previous selection techniques, provides observational confirmation of the steep luminosity function inferred indirectly from optical counts. However, possible explanations for the lack of higher luminosity QSOs in our sample prove even more interesting. If one accepts the global value of the X-ray to optical luminosity ratio proposed by Zamorani et al, and Ku, Helfand, and Lucy, then reconciliation of this ratio with our observations severely constrains the QSO space density and luminosity functions. Alternatively, the ''typical'' QSO-a radio quiet, high redshift (z>1), optically luminous but not superluminous (M/sub c/> or =-27) object-may not be a strong X-ray source. This inference is not in conflict with existing results from Einstein X-ray surveys of preselected QSOs, which also fail to detect such objects. The contribution of QSOs to the diffuse X-ray background radiation is therefore highly uncertain, but may be quite small. Current X-ray data probably do not place significant constraints on the optical number counts of faint QSOs.« less
A Narrowband Imaging Search for [O III] Emission from Galaxies at z > 3
NASA Astrophysics Data System (ADS)
Teplitz, Harry I.; Malkan, Matthew A.; McLean, Ian S.
1999-03-01
We present the results of a narrowband survey of quasi-stellar-object (QSO) fields at redshifts that place the [O III] (5007 Å) emission line in the Δλ/λ~1% 2.16 μm filter. We have observed 3 arcmin2 and detected one emission-line candidate object in the field around PC 1109+4642. We discuss the possibilities that this object is a star-forming galaxy at the QSO redshift, zem=3.313, or a Seyfert galaxy. In the former case, we infer a star formation rate of 170 Msolar yr-1 for this K'=21.3 object. The galaxy has a compact but resolved morphology, with an FWHM=0.6" or 4.2 kpc at z=3.313 (H0=50 km s-1 Mpc-1 and q0=0.5). The comoving density of such objects in QSO environments appears to be 0.0033 Mpc-3, marginally lower (<=3 σ) than the density observed for Hα-emitters in absorption-line fields at z~2.5 but similar to the density of Lyman-break galaxies at z~3. If, on the other hand, most of the line emission is [O III] from a Seyfert 2 nucleus at z=3.31, then the high inferred volume density could imply a large evolution in the Seyfert 2 luminosity function from the current epoch. We find the field containing the object to also contain many faint extended objects in the K' image but little significant excess over the expected number-magnitude relation. We discuss the implication of the emission line being a longer wavelength line at a lower redshift.
NASA Astrophysics Data System (ADS)
Schmidt, Tobias M.; Worseck, Gabor; Hennawi, Joseph F.; Prochaska, J. Xavier; Crighton, Neil H. M.
2017-09-01
The He II transverse proximity effect—enhanced He II {Ly}α transmission in a background sightline caused by the ionizing radiation of a foreground quasar—offers a unique opportunity to probe the morphology of quasar-driven He II reionization. We conduct a comprehensive spectroscopic survey to find z˜ 3 quasars in the foreground of 22 background quasar sightlines with Hubble Space Telescope/COS He II {Ly}α transmission spectra. With our two-tiered survey strategy, consisting of a deep pencil-beam survey and a shallow wide-field survey, we discover 131 new quasars, which we complement with known SDSS/BOSS quasars in our fields. Using a restricted sample of 66 foreground quasars with inferred He II photoionization rates greater than the expected UV background at these redshifts ({{{Γ }}}{QSO}{He {{II}}}> 5× {10}-16 {{{s}}}-1) we perform the first statistical analysis of the He II transverse proximity effect. Our results show qualitative evidence for a large object-to-object variance: among the four foreground quasars with the highest {{{Γ }}}{QSO}{He {{II}}} only one (previously known) quasar is associated with a significant He II transmission spike. We perform a stacking analysis to average down these fluctuations, and detect an excess in the average He II transmission near the foreground quasars at 3σ significance. This statistical evidence for the transverse proximity effect is corroborated by a clear dependence of the signal strength on {{{Γ }}}{QSO}{He {{II}}}. Our detection places a purely geometrical lower limit on the quasar lifetime of {t}{{Q}}> 25 {Myr}. Improved modeling would additionally constrain quasar obscuration and the mean free path of He II-ionizing photons.
Variable X-Ray Absorption in the Mini-BAL QSO PG 1126-041
NASA Technical Reports Server (NTRS)
Giustini, M.; Cappi, M.; Chartas, G.; Dadina, M.; Eracleous, M.; Ponti, G.; Proga, D.; Tombesi, F.; Vignali, C.; Palumbo, G. G. C.
2011-01-01
Context. X-ray studies of AGN with powerful nuclear winds are important to constrain the physics of the inner accretion/ejection flow around SMBH, and to understand the impact of such winds on the AGN environment. Aims. Our main scientific goal is to constrain the properties of a variable outflowing absorber that is thought to be launched near the SMBH of the mini-BAL QSO PG 1126-041 using a multi-epoch observational campaign performed with XMM-Newton. Methods. We performed temporally resolved X-ray spectroscopy and simultaneous UV and X-ray photometry on the most complete set of observations and on the deepest X-ray exposure of a mini-BAL QSO to date. Results. We found complex X-ray spectral variability on time scales of both months and hours, best reproduced by means of variable massive ionized absorbers along the line of sight. As a consequence, the observed optical-to-X-ray spectral index is found to be variable with time. In the highest signal-to-noise observation we detected highly ionized X-ray absorbing material outflowing much faster (u(sub X) approx. 16 500 km/s) than the UV absorbing one (u(sub uv) approx. 5,000 km/s). This highly ionized absorber is found to be variable on very short (a few kiloseconds) time scales. Conclusions. Our findings are qualitatively consistent with line driven accretion disk winds scenarios. Our observations have opened the time-resolved X-ray spectral analysis field for mini-BAL QSOs; only with future deep studies will we be able to map the dynamics of the inner flow and understand the physics of AGN winds and their impact on the environment.
Spectral Energy Distribution of Far-infrared Bright Quasar Sample in the Lockman Hole
NASA Astrophysics Data System (ADS)
Dai, Y.; Huang, J.-S.; Omont, A.; Hatziminaoglou, E.; Willmer, C.; Fazio, G.; Elvis, M.; Bergeron, J.; Rigopoulou, D.; Perez-Fournon, I.
2011-10-01
The far-infrared (FIR) properties of Quasi-Stellar Objects (QSOs) is important in connecting the Starburst (SB) and Active Galactic Nucleus (AGN) activities. Therefore, we constructed a 24 μ m selected QSO sample to study their FIR behavior. All sources were spectroscopically identified from MMT or the Sloan Digital Sky Survey (SDSS) as broadline quasars. Of the total ˜330 sources, 37 have secure FIR detections in the Herschel-HERMES field. We compared their SEDs to previous QSO templates, and found that those FIR bright quasars differ from existing AGNs only by an additional dust component(s). Further studies on the origin for the FIR emission reveals the relative roles starburst and AGN play in powering the dust emission, based on the dust temperature, FIR luminosity, and the shapes of individual SEDs. The dust temperatures have a wide range from 20K to 80K with a median of ˜ 30K, indicating homogeneous heating mechanisms that could later be related to the origin of these cold dust emissions.
The X-ray spectrum of QSO 0241+622. [OSO-8 observations
NASA Technical Reports Server (NTRS)
Worrall, D. M.; Boldt, E. A.; Holt, S. S.; Serlemitsos, P. J.
1980-01-01
Proportional counters on the OsO-8 spacecraft measured the X-ray spectrum of QSR 0241+622 in the range 2-50 keV. The best power law fit has a proton spectral index and 90 percent errors gamma = 1.93 (+0.5, -0.3) and low energy absorption consistent with reported gas column densities, but a thermal bremsstrahlung form with temperature 13.1 keV cannot be excluded. No indication of spectral variability is found in three observations of the source with HEAO-A2, although a possible 15-30 percent intensity change over a period of 6 months was observed. The quasar is similar to 3C 273 in the proportion of energy emitted in various bands, excluding the radio, if reported radiation above 50 keV from its direction is indeed associated with QSO 0241+622. The two quasars are compared and possible energy generation scenarios are discussed. Implications concerning quasar contributions to the diffuse background are discussed.
CASBaH: the Multiphase Circumgalactic Medium During the Decline of Cosmic Star Formation
NASA Astrophysics Data System (ADS)
Burchett, Joseph N.; Tripp, Todd; Prochaska, Jason; Werk, Jessica; Willmer, Christopher; Ford, Amanda Brady; Howk, Chris
2018-01-01
The COS Absorption Survey of Baryon Harbors (CASBaH) comprises high-S/N spectra of nine z > 0.9 QSOs with coverage from the far-ultraviolet to the optical. These sightlines access the rich suite of rest-frame extreme-ultraviolet (600 - 1000 Angstroms) spectral transitions, such as Ne VIII, Mg X, and O II/III/IV, in addition to those more well studied at longer wavelengths (O VI, C III, Mg II). We have undertaken a large ground-based spectroscopic follow-up campaign to identify galaxies projected near the QSO sightlines and leverage the myriad diagnostics within the QSO spectra to study the circumgalactic medium (CGM) at 0.2 < z < 1 over the crucial epoch when star formation activity in the Universe was in sharp decline. We will present results from this multiwavelength study characterizing the CGM across multiple ionization states, focusing on the O VI and Ne VIII-probed warm-hot (105-106 K) gas within the halos of our galaxy sample.
NASA Technical Reports Server (NTRS)
Young, P. J.; Shields, G. A.; Wheeler, J. C.
1977-01-01
The paper develops certain aspects of a model wherein a QSO is a massive black hole located in a dense galactic nucleus, with its growth and luminosity fueled by tidal disruption of passing stars. Cross sections for tidal disruptions are calculated, taking into account the thermal energy of stars, relativistic effects, and partial disruption removing only the outer layers of a star. Accretion rates are computed for a realistic distribution of stellar masses and evolutionary phases, the effect of the black hole on the cluster distribution is examined, and the red-giant disruption rate is evaluated for hole mass of at least 300 million solar masses, the cutoff of disruption of main-sequence stars. The results show that this black-tide model can explain QSO luminosities of at least 1 trillion suns if the black hole remains almost maximally Kerr as it grows above 100 million solar masses and if 'loss-cone' depletion of the number of stars in disruptive orbits is unimportant.
Cooper, Elizabeth
2013-01-01
Improved patient safety and quality are priority goals for nurses and schools of nursing. This article describes the innovative new role of quality and safety officer (QSO) developed by one university in response to the Quality and Safety Education for Nurses challenge to increase quality and safety education for prelicensure nursing students. The article also describes the results of a study conducted by the QSO, obtaining information from prelicensure nursing students about the use of safety tools and identifying the students' perceptions of safety issues, communication, and safety reporting in the clinical setting. Responses of 145 prelicensure nursing students suggest that it is difficult to get all errors and near-miss events reported. Barriers for nursing students are similar to the barriers nurses and physicians identify in reporting errors and near-miss events. The survey reveals that safety for the patient is the primary concern of the student nurse. Copyright © 2013 Elsevier Inc. All rights reserved.
New simulation of QSO X-ray heating during the Cosmic Dawn
NASA Astrophysics Data System (ADS)
Ross, Hannah E.; Dixon, Keri; Iliev, Ilian; Mellema, Garrelt
2018-05-01
The upcoming radio interferometer Square Kilometre Array is expected to directly detect the redshifted 21-cm signal from the Cosmic Dawn for the first time. In this era temperature fluctuations from X-ray heating of the neutral intergalactic medium can impact this signal dramatically. Previously, in Ross et al. (2017), we presented the first large-volume, 244 h-1 Mpc=349 Mpc a side, fully numerical radiative transfer simulations of X-ray heating. This work is a follow-up where we now also consider QSO-like sources in addition to high mass X-ray binaries. Images of the two cases are clearly distinguishable at SKA1-LOW resolution and have RMS fluctuations above the expected noise. The inclusion of QSOs leads to a dramatic increase in non-Gaussianity of the signal, as measured by the skewness and kurtosis of the 21-cm signal. We conclude that this increased non-Gaussianity is a promising signature of early QSOs.
A study of the discrepant QSO X-ray luminosity function from the HEAO-2 data archive
NASA Technical Reports Server (NTRS)
Margon, B.
1984-01-01
An in-progress investigation aimed at characterizing the X-ray luminosity of very faint QSOs is described. More than 100 faint, previously uncataloged QSOs which lie in areas imaged in X rays at very high sensitivity were discovered.
Ionized and Neutral Outflows in the QUEST QSOs
NASA Astrophysics Data System (ADS)
Veilleux, Sylvain
2011-10-01
The role of galactic winds in gas-rich mergers is of crucial importance to understand galaxy and SMBH evolution. In recent months, our group has had three major scientific breakthroughs in this area: {1} The discovery with Herschel of massive molecular {OH-absorbing} outflows in several ULIRGs, including the nearest quasar, Mrk 231. {2} The independent discovery from mm-wave interferometric observations in the same object of a spatially resolved molecular {CO-emitting} wind with estimated mass outflow rate 3x larger than the star formation rate and spatially coincident with blueshifted neutral {Na ID-absorbing} gas in optical long-slit spectra. {3} The unambiguous determination from recent Gemini/IFU observations that the Na ID outflow in this object is wide-angle, thus driven by a QSO wind rather than a jet. This powerful outflow may be the long-sought "smoking gun" of quasar mechanical feedback purported to transform gas-rich mergers. However, our Herschel survey excludes all FIR-faint {UV-bright} "classic" QSOs by necessity. So here we propose a complementary FUV absorption-line survey of all FIR-bright -and- FIR-faint QSOs from the same parent sample. New {19 targets} and archival {11} spectra will be used to study, for the first time, the gaseous environments of QSOs as a function of host properties and age across the merger sequence ULIRG -> QSO. These data will allow us to distinguish between ionized & neutral quasar-driven outflows, starburst-driven winds, and tidal debris around the mergers. They will also be uniquely suited for a shallow but broad study of the warm & warm-hot intergalactic media, complementary to on-going surveys that are deeper but narrower.
The recent NIR Flare of the Blazar CTA102
NASA Astrophysics Data System (ADS)
Carrasco, L.; Escobedo, G.; Porras, A.; Recillas, E.; Chavushyan, V.; Mayya, D. Y.
2018-01-01
Following the report of increased Gamma-Ray activity detected by AGILE of the high redshift QSO (z=1.037) CTA102 cross identified with the radio source 4C+11.69 and the Gamma-ray source 2FGLJ2232.4+1143 by Lucarelli et al.(ATEL #11045).
Molecule Formation at High Extinction and Low Metallicity in the Magellanic Clouds
NASA Technical Reports Server (NTRS)
Shull, J. Michael
2005-01-01
During 2005, our FUSE research group prepared two major FUSE surveys of interstellar molecular hydrogen: 1. Galactic Disk Sightlines. We measured N(H2) in rotational states J = 0 and 1 and in higher states, J = 2,3,4,5, sometimes up to J = l, for 139 sightlines to Galactic OB stars. 2. High-Latitude QSO sightlines. We surveyed 50 sightlines to high-latitude QSOs, finding H2 in most of them (44 of 50). 3 . Molecular Hydrogen in Infrared Cirrus. Related to the high-latitude H2 survey (#2), we examined the high-latitude infrared cirrus and its correlation with H2. In addition, we are accumulating H2 measurements for additional 0 stars in the Magellanic Clouds (LMC and SMC) to add to the previously published survey.
The Sightline to Q2343-BX415: Clues to Galaxy Formation in a Quasar Environment
NASA Astrophysics Data System (ADS)
Rix, Samantha A.; Pettini, Max; Steidel, Charles C.; Reddy, Naveen A.; Adelberger, Kurt L.; Erb, Dawn K.; Shapley, Alice E.
2007-11-01
We have discovered a strong DLA coincident in redshift with the faint QSO Q2343-BX415 (R=20.2, zem=2.57393). Follow-up observations at intermediate spectral resolution reveal that the metal lines associated with this proximate DLA (PDLA) consist of two sets of absorption components. One set is moving toward the quasar with velocities of ~150-600 km s-1 this gas is highly ionized and does not fully cover the continuum source, suggesting that it is physically close to the active nucleus. The other, which accounts for most of the neutral gas, is blueshifted relative to the QSO, with the strongest component at ~-160 km s-1. We consider the possibility that the PDLA arises in the outflowing interstellar medium of the host galaxy of Q2343-BX415, an interpretation supported by strong C IV and N V absorption at nearby velocities, and by the intense radiation field longward of the Lyman limit implied by the high C II*/H I ratio. If Q2343-BX415 is the main source of these UV photons, then the PDLA is located at either ~8 or ~37 kpc from the active nucleus. Alternatively, the absorber may be a foreground star-forming galaxy unrelated to the quasar and coincidentally at the same redshift, but our deep imaging and follow-up spectroscopy of the field of Q2343-BX415 has not yet produced a likely candidate. We measure the abundances of 14 elements in the PDLA, finding an overall metallicity of ~1/5 solar and a normal pattern of relative element abundances for this metallicity. Thus, in this PDLA there is no evidence for the supersolar metallicities that have been claimed for some proximate, high-ionization, systems. Based on data obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and NASA, and was made possible by the generous financial support of the W. M. Keck Foundation.
On the 10 μm Silicate Feature in Active Galactic Nuclei
NASA Astrophysics Data System (ADS)
Nikutta, Robert; Elitzur, Moshe; Lacy, Mark
2009-12-01
The 10 μm silicate feature observed with Spitzer in active galactic nuclei (AGNs) reveals some puzzling behavior. It (1) has been detected in emission in type 2 sources, (2) shows broad, flat-topped emission peaks shifted toward long wavelengths in several type 1 sources, and (3) is not seen in deep absorption in any source observed so far. We solve all three puzzles with our clumpy dust radiative transfer formalism. Addressing (1), we present the spectral energy distribution (SED) of SST1721+6012, the first type 2 quasar observed to show a clear 10 μm silicate feature in emission. Such emission arises in models of the AGN torus easily when its clumpy nature is taken into account. We constructed a large database of clumpy torus models and performed extensive fitting of the observed SED. We find that the cloud radial distribution varies as r -1.5 and the torus contains 2-4 clouds along radial equatorial rays, each with optical depth at visual ~60-80. The source bolometric luminosity is ~3 × 1012 Lsun. Our modeling suggests that lsim35% of objects with tori sharing these characteristics and geometry would have their central engines obscured. This relatively low obscuration probability can explain the clear appearance of the 10 μm emission feature in SST1721+6012 together with its rarity among other QSO2. Investigating (2), we also fitted the SED of PG1211+143, one of the first type 1 QSOs with a 10 μm silicate feature detected in emission. Together with other similar sources, this QSO appears to display an unusually broadened feature whose peak is shifted toward longer wavelengths. Although this led to suggestions of non-standard dust chemistry in these sources, our analysis fits such SEDs with standard galactic dust; the apparent peak shifts arise from simple radiative transfer effects. Regarding (3), we find additionally that the distribution of silicate feature strengths among clumpy torus models closely resembles the observed distribution, and the feature never occurs deeply absorbed. Comparing such distributions in several AGN samples we also show that the silicate emission feature becomes stronger in the transition from Seyfert to quasar luminosities.
Quasara: Ancient, Awesome Violence. Exploring the Universe.
ERIC Educational Resources Information Center
Harrington, Sherwood, Comp.
This information packet on quasars consists of an introductory paper, four articles from "Mercury," a journal of the Astronomical Society of the Pacific, and a bibliography. Methods used to measure distances in the universe and the nature of quasi-stellar objects (QSO's), the name preferred by many workers in the field, are discussed in…
NASA Technical Reports Server (NTRS)
Monier, Eric M.; Mathur, Smita; Wilkes, Belinda; Elvis, Martin
2001-01-01
The presence of a 'warm absorber' was first suggested to explain spectral variability in an X-ray spectrum of the radio-quiet quasi-stellar object (QSO) MR 2251-178. A unified picture, in which X-ray warm absorbers and 'intrinsic' UV absorbers are the same, offers the opportunity to probe the nuclear environment of active galactic nuclei. To test this scenario and understand the physical properties of the absorber, we obtained a UV spectrum of MR 2251-178 with the Faint Object Spectrograph on board the Hubble Space Telescope (HST). The HST spectrum clearly shows absorption due to Lyalpha, N v, and C IV, blueshifted by 300 km s(exp -1) from the emission redshift of the QSO. The rarity of both X-ray and UV absorbers in radio-quiet QSOs suggests these absorbers are physically related, if not identical. Assuming the unified scenario, we place constraints on the physical parameters of the absorber and conclude the mass outflow rate is essentially the same as the accretion rate in MR 2251-178.
Yet another UFO in the X-ray spectrum of a high-z lensed QSO
NASA Astrophysics Data System (ADS)
Dadina, M.; Vignali, C.; Cappi, M.; Lanzuisi, G.; Ponti, G.; Torresi, E.; De Marco, B.; Chartas, G.; Giustini, M.
2018-02-01
Aim. Ultra-fast outflows (UFO) appear to be common in local active galactic nuclei (AGN) and may be powerful enough (Ėkin ≥ 1% of Lbol) to effectively quench the star formation in their host galaxies. To test feedback models based on AGN outflows, it is mandatory to investigate UFOs near the peak of AGN activity, that is, at high-z where only a few studies are available to date. Methods: UFOs produce Fe resonant absorption lines measured above ≈7 keV. The most critical problem in detecting such features in distant objects is the difficulty in obtaining X-ray data with sufficient signal-to-noise. We therefore selected a distant QSO that gravitational lensing made bright enough for these purposes, the z = 2.64 QSO MG J0414+0534, and observed it with XMM-Newton for ≈78 ks. Results: The X-ray spectrum of MG J0414+0534 is complex and shows signatures of cold absorption (NH ≈ 4 × 1022 cm-2) and of the presence of an iron emission line (E ≈ 6.4 keV, EW = 95 ± 53 eV) consistent with it originating in the cold absorber. Our main result, however, is the robust detection (more than 5σ) of an absorption line at Eint ≈ 9.2 keV (Eobs ≈ 2.5 keV observer frame). If interpreted as due to FeXXVI, it implies gas outflowing at vout ≈ 0.3c. To our knowledge, this is the first detection of an UFO in a radio-loud quasar at z ≥ 1.5. We estimated that the UFO mechanical output is Ėkin ≈ 2.5Lbol with ṗout/ṗrad ≈ 17 indicating that it is capable of installing significant feedback between the super-massive black hole and the bulge of the host galaxy. We argue that this also suggests a magnetic driving origin of the UFO.
NASA Technical Reports Server (NTRS)
Zheng, W.; Kriss, G. A.; Wang, J. X.; Brotherton, M.; Oegerle, W. R.; Blair, W. P.; Davidsen, A. F.; Green, R. F.; Hutchings, J. B.; Kaiser, M. E.;
2001-01-01
We present a moderate-resolution (approximately 20 km s(exp -1) spectrum of the mini broad absorption line QSO PG 1351+64 between 915-1180 A, obtained with the Far Ultraviolet Spectroscopic Explorer (FUSE). Additional low-resolution spectra at longer wavelengths were also obtained with the Hubble Space Telescope (HST) and ground-based telescopes. Broad absorption is present on the blue wings of C III (lambda)977, Ly(beta), O VI (lambda)(lambda)1032,1038, Ly(alpha), N V (lambda)(lambda)1238,1242, Si IV (lambda)(lambda)1393,1402, and C IV (lambda)(lambda)1548,1450. The absorption profile can be fitted with five components at velocities of approximately -780, -1049, -1629, -1833, and -3054 km s(exp -1) with respect to the emission-line redshift of z = 0.088. All the absorption components cover a large fraction of the continuum source as well as the broad-line region. The O VI emission feature is very weak, and the O VI/Ly(alpha) flux ratio is 0.08, one of the lowest among low-redshift active galaxies and QSOs. The UV (ultraviolet) continuum shows a significant change in slope near 1050 A in the restframe. The steeper continuum shortward of the Lyman limit extrapolates well to the observed weak X-ray flux level. The absorbers' properties are similar to those of high-redshift broad absorption-line QSOs. The derived total column density of the UV absorbers is on the order of 10(exp 21) cm(exp -2), unlikely to produce significant opacity above 1 keV in the X-ray. Unless there is a separate, high-ionization X-ray absorber, the QSO's weak X-ray flux may be intrinsic. The ionization level of the absorbing components is comparable to that anticipated in the broad-line region, therefore the absorbers may be related to broad-line clouds along the line of sight.
NASA Technical Reports Server (NTRS)
Zheng, W.; Kriss, G. A.; Wang, J. X.; Brotherton, M.; Oegerle, W. R.; Blair, W. P.; Davidsen, A. F.; Green, R. F.; Hutchings, J. B.; Kaiser, M. E.;
2001-01-01
We present a moderate-resolution (approximately 20 km/s) spectrum of the broad-absorption line QSO PG 1351+64 between 915-1180 angstroms, obtained with the Far Ultraviolet Spectroscopic Explorer (FUSE). Additional low-resolution spectra at longer wavelengths were also obtained with the Hubble Space Telescope (HST) and ground-based telescopes. Broad absorption is present on the blue wings of C III lambda977, Ly-beta, O VI lambda-lambda-1032,1038, Ly-alpha, N V lambda-lambda-1238,1242, Si IV lambda-lambda-1393,1402, and C IV lambda-lambda-1548,1450. The absorption profile can be fitted with five components at velocities of approximately -780, -1049, -1629, -1833, and -3054 km/s with respect to the emission-line redshift of z = 0.088. All the absorption components cover a large fraction of the continuum source as well as the broad-line region. The O VI emission feature is very weak, and the O VI/Ly-alpha flux ratio is 0.08, one of the lowest among low-redshift active galaxies and QSOs. The ultraviolet continuum shows a significant change in slope near 1050 angstroms in the restframe. The steeper continuum shortward of the Lyman limit extrapolates well to the observed weak X-ray flux level. The absorbers' properties are similar to those of high-redshift broad absorption-line QSOs. The derived total column density of the UV absorbers is on the order of 10(exp 21)/s, unlikely to produce significant opacity above 1 keV in the X-ray. Unless there is a separate, high-ionization X-ray absorber, the QSO's weak X-ray flux may be intrinsic. The ionization level of the absorbing components is comparable to that anticipated in the broad-line region, therefore the absorbers may be related to broad-line clouds along the line of sight.
NASA Astrophysics Data System (ADS)
Chiaberge, M.; Ely, J. C.; Meyer, E. T.; Georganopoulos, M.; Marinucci, A.; Bianchi, S.; Tremblay, G. R.; Hilbert, B.; Kotyla, J. P.; Capetti, A.; Baum, S. A.; Macchetto, F. D.; Miley, G.; O'Dea, C. P.; Perlman, E. S.; Sparks, W. B.; Norman, C.
2017-04-01
Context. Radio-loud active galactic nuclei with powerful relativistic jets are thought to be associated with rapidly spinning black holes (BHs). BH spin-up may result from a number of processes, including accretion of matter onto the BH itself, and catastrophic events such as BH-BH mergers. Aims: We study the intriguing properties of the powerful (Lbol 1047 erg s-1) radio-loud quasar 3C 186. This object shows peculiar features both in the images and in the spectra. Methods: We utilize near-IR Hubble Space Telescope (HST) images to study the properties of the host galaxy, and HST UV and Sloan Digital Sky Survey optical spectra to study the kinematics of the source. Chandra X-ray data are also used to better constrain the physical interpretation. Results: HST imaging shows that the active nucleus is offset by 1.3 ± 0.1 arcsec (I.e. 11 kpc) with respect to the center of the host galaxy. Spectroscopic data show that the broad emission lines are offset by -2140 ± 390 km s-1 with respect to the narrow lines. Velocity shifts are often seen in QSO spectra, in particular in high-ionization broad emission lines. The host galaxy of the quasar displays a distorted morphology with possible tidal features that are typical of the late stages of a galaxy merger. Conclusions: A number of scenarios can be envisaged to account for the observed features. While the presence of a peculiar outflow cannot be completely ruled out, all of the observed features are consistent with those expected if the QSO is associated with a gravitational wave (GW) recoiling BH. Future detailed studies of this object will allow us to confirm this type of scenario and will enable a better understanding of both the physics of BH-BH mergers and the phenomena associated with the emission of GW from astrophysical sources.
NASA Astrophysics Data System (ADS)
Husemann, B.; Wisotzki, L.; Sánchez, S. F.; Jahnke, K.
2013-01-01
We present a detailed analysis of a large sample of 31 low-redshift, mostly radio-quiet type 1 quasi-stellar objects (QSOs) observed with integral field spectroscopy to study their extended emission-line regions (EELRs). We focus on the ionisation state of the gas, size and luminosity of extended narrow line regions (ENLRs), which corresponds to those parts of the EELR dominated by ionisation from the QSO, as well as the kinematics of the ionised gas. We detect EELRs around 19 of our 31 QSOs (61%) after deblending the unresolved QSO emission and the extended host galaxy light in the integral field data with a new dedicated algorithm. Based on standard emission-line diagnostics we identify 13 EELRs to be entirely ionised by the QSO radiation, 3 EELRs are composed of H ii regions and 3 EELRs display signatures of both ionisation mechanisms at different locations. The typical size of the ENLR is ~10 kpc at a median nuclear [O iii] luminosity of log (L([O iii])/ [ergs-1]) = 42.7 ± 0.15. We show that the ENLR sizes are least a factor of ~2 larger than determined with the Hubble Space Telescope, but are consistent with those of recently reported type 2 QSOs at matching [O iii] luminosities. The ENLR of type 1 and type 2 QSOs therefore appear to follow the same size-luminosity relation. Furthermore, we show for the first time that the ENLR size is much better correlated with the QSO continuum luminosity than with the total/nuclear [O iii] luminosity. We show that ENLR luminosity and radio luminosity are correlated, and argue that radio jets even in radio-quiet QSOs are important for shaping the properties of the ENLR. Strikingly, the kinematics of the ionised gas is quiescent and likely gravitationally driven in the majority of cases and we find only 3 objects with radial gas velocities exceeding >400 km s-1 in specific regions of the EELR that can be associate with radio jets. In general, these are significantly lower outflow velocities and detection rates compared to starburst galaxies or radio-loud QSOs. This represent a challenge for some theoretical feedback models in which luminous QSOs are expected to radiatively drive an outflow out to scales of the entire host galaxy. Based on observations collected at the Centro Astronómico Hispano Alemán (CAHA) at Calar Alto, operated jointly by the Max- Planck-Institut für Astronomie and the Instituto de Astrofísica de Andalucía (CSIC).Tables 3, 4, and 7 are available in electronic form at http://www.aanda.org
VizieR Online Data Catalog: QSO eHAQ0111+0641 spectra (Fynbo+, 2017)
NASA Astrophysics Data System (ADS)
Fynbo, J. P. U.; Krogager, J.-K.; Heintz, K. E.; Geier, S.; Moller, P.; Noterdaeme, P.; Christensen, L.; Ledoux, C.; Jakobsson, P.
2017-09-01
eHAQ0111+0641 was observed with the OSIRIS instrument at the Gran Telescopio Canarias (GTC) as part of a larger sample of candidate red quasars. We secured spectroscopy with OSIRIS and a range of grisms to better constrain the spectral energy distribution, metal lines, and hydrogen Lyα line. (2 data files).
Optical confirmation of Gaia18ayp brightness increase
NASA Astrophysics Data System (ADS)
Spano, M.; Blanco-Cuaresma, S.; Roelens, M.; Mowlavi, N.; Eyer, L.
2018-04-01
We report confirmation of Gaia_Science_Alerts, brightness increase of the QSO [VV2006] J233633.0-411547, Gaia18ayp . Images were obtained through modified Gunn R and V band filter of the ECAM instrument installed on the Swiss 1.2m Euler telescope at La Silla, on 2018 April 21- 22. Magnitudes according to the MJD of observations.
Highly ionized collimated outflow from HE 0238-1904
NASA Astrophysics Data System (ADS)
Muzahid, S.; Srianand, R.; Savage, B. D.; Narayanan, A.; Mohan, V.; Dewangan, G. C.
2012-07-01
We present a detailed analysis of a highly ionized, multiphased and collimated outflowing gas detected through O V, O VI, Ne VIII and Mg X absorption associated with the QSO HE 0238-1904 (zem≃ 0.629). Based on the similarities in the absorption-line profiles and estimated covering fractions, we find that the O VI and Ne VIII absorption trace the same phase of the absorbing gas. Simple photoionization models can reproduce the observed ?, ? and ? from a single phase whereas the low-ionization species (e.g. N III, N IV and O IV) originate from a different phase. The measured ? ratio is found to be remarkably similar (within a factor of ˜2) in several individual absorption components kinematically spread over ˜1800 km s-1. Under photoionization this requires a fine-tuning between hydrogen density (nH) and the distance of the absorbing gas from the Quasi Stellar Object (QSO). Alternatively, this can also be explained by collisional ionization in hot gas with T≥ 105.7 K. Long-term stability favours the absorbing gas being located outside the broad-line region. We speculate that the collimated flow of such a hot gas could possibly be triggered by the radio jet interaction.
A comprehensive study of the cool gas content of massive dark matter halos
NASA Astrophysics Data System (ADS)
Gauthier, Jean-Rene
2011-09-01
This thesis is based on the results of an on-going investigation of the cool, T ˜ 104 K, gas present in massive dark matter halos traced by luminous red galaxies (LRGs) at z ˜ 0.5. It consists of three parts. The first part (Chapter 2) presents a series of measurements of the large-scale clustering of MgII lambdalambda 2796,2803 absorbers with respect to a population of LRGs. From the cross-correlation measurements between the absorbers and the galaxies, the mean bias of the dark matter halos in which the absorbers reside is derived. One finds a 1-sigma anti-correlation between mean halo bias and absorber strength W r(2796) that translates into a 1-sigma anti-correlation between mean galaxy mass and Wr(2796). The results indicate that a significant fraction of the MgII absorber population of W r(2796) = 1-1.5A are found in group-size dark matter halos of log Mh < 13.4, whereas absorbers of Wr(2796) > 1.5A are primarily seen in halos of log Mh < 12.7. In the second part of this thesis, a series of constraints on the covering fraction of cool gas are derived in Chapter 3. The results of an on-going spectroscopic follow-up of close LRG-Mg II absorber pairs are presented in Chapter 4. This spectroscopic sample consists of 70 photometrically selected LRGs at physical projected separations rho <˜ 400 kpc/h from a QSO sightline. The moderate-resolution spectra confirm a physical association between the cool gas revealed by the presence of MgII absorption features and the LRG halo in 15 cases. From a pair sample with no prior knowledge of the presence/absence of MgII absorbers, a covering fraction kappa = 0.13+0.05-0.06 is found for Wr(2796) > 0.3A and rho < 400 kpc/h. The third part of this thesis addresses the results of a stellar population synthesis analysis done on stacked spectra of MgII absorbing and non-absorbing LRG subsamples. The main finding of this analysis is that LRGs with or without associated MgII absorbers share similar star formation histories and are best described by old stellar population models (>˜ 1 Gyr). Younger stellar populations (<˜1 Gyr) fail to reproduce their spectra. The primarily old stellar populations in the LRGs indicate that recent starburst driven outflows are unlikely to explain the observed MgII absorbers at large distances from the LRGs. Finally, high-resolution spectra of seven MgII absorbers found in the vicinity of LRGs and associated deep, R-band images of the QSO-LRG fields are presented in Appendix A. These new data are crucial to study the kinematics of the gas and constrain its physical origin.
The X-ray properties of high redshift, optically selected QSOs. Ph.D. Thesis
NASA Technical Reports Server (NTRS)
Anderson, S. F.
1985-01-01
In order to study the X-ray properties of high redshift QSOs, grism/grens plates covering 17 deg. of sky previously imaged to very sensitive X-ray flux levels with the Einstein Observatory were taken. Following optical selection of the QSO, the archived X-ray image is examined to extract an X-ray flux detection or a sensitive upper limit.
NASA Astrophysics Data System (ADS)
Ge, Jian; Bechtold, Jill; Kulkarni, Varsha P.
2001-01-01
We report the detection of strong molecular hydrogen (H2) absorption lines in the z=2.34 damped Lyα absorber (DLA) toward QSO 1232+0815. This is the second detection in our survey for high-redshift molecules. The new ultraviolet spectrum of the QSO 1232+0815 at 0.9 Å resolution, taken with the Multiple Mirror Telescope Blue Channel Spectrograph, shows the υ=0-0 up to 10-0 Lyman bands and also the Werner υ=0-0 band of H2 associated with the z=2.34 DLA. We have estimated the total H2 column density in this system. It ranges from ~3×1019 cm-2 to ~3×1017 cm-2 depending on the Doppler parameters, b=6 or 10 km s-1. Based on the best fit with b=6 km s-1, the estimated kinetic temperature is TK~80 K. The measurements of the abundance of zinc and iron in the same DLA show that the metallicity measured by the relatively undepleted element zinc is [Zn/H]=-0.86, while the relative abundance ratio [Fe/Zn] is -1.04, indicating dust depletion. Combining our work with previous results on H2 and relative heavy-element depletion, we find that there is a correlation between them, which suggests that the formation of H2 on dust grains is perhaps the dominant formation process in high-redshift DLAs. Detections of strong absorption from the ground and excited states of neutral carbon (C I) in the z=2.34 DLA are also presented. The excitation temperature between the two fine-structure levels of C I is 15.7+/-3.5 K, an upper limit for the cosmic microwave background radiation temperature at z=2.34. This value is consistent with the prediction by the standard big bang cosmology. Observations here were obtained with the Multiple Mirror Telescope, a joint facility of the University of Arizona and the Smithsonian Institution.
A Toolkit for Eye Recognition of LAMOST Spectroscopy
NASA Astrophysics Data System (ADS)
Yuan, H.; Zhang, H.; Zhang, Y.; Lei, Y.; Dong, Y.; Zhao, Y.
2014-05-01
The Large sky Area Multi-Object fiber Spectroscopic Telescope (LAMOST, also named the Guo Shou Jing Telescope) has finished the pilot survey and now begun the normal survey by the end of 2012 September. There have already been millions of targets observed, including thousands of quasar candidates. Because of the difficulty in the automatic identification of quasar spectra, eye recognition is always necessary and efficient. However massive spectra identification by eye is a huge job. In order to improve the efficiency and effectiveness of spectra , a toolkit for eye recognition of LAMOST spectroscopy is developed. Spectral cross-correlation templates from the Sloan Digital Sky Survey (SDSS) are applied as references, including O star, O/B transition star, B star, A star, F/A transition star, F star, G star, K star, M1 star, M3 star,M5 star,M8 star, L1 star, magnetic white dwarf, carbon star, white dwarf, B white dwarf, low metallicity K sub-dwarf, "Early-type" galaxy, galaxy, "Later-type" galaxy, Luminous Red Galaxy, QSO, QSO with some BAL activity and High-luminosity QSO. By adjusting the redshift and flux ratio of the template spectra in an interactive graphic interface, the spectral type of the target can be discriminated in a easy and feasible way and the redshift is estimated at the same time with a precision of about millesimal. The advantage of the tool in dealing with low quality spectra is indicated. Spectra from the Pilot Survey of LAMSOT are applied as examples and spectra from SDSS are also tested from comparison. Target spectra in both image format and fits format are supported. For convenience several spectra accessing manners are provided. All the spectra from LAMOST pilot survey can be located and acquired via the VOTable files on the internet as suggested by International Virtual Observatory Alliance (IVOA). After the construction of the Simple Spectral Access Protocol (SSAP) service by the Chinese Astronomical Data Center (CAsDC), spectra can be obtained and analyzed in a more efficient way.
The distant red galaxy neighbour population of 1 <~ z <~ 2 QSOs and optically obscured sources
NASA Astrophysics Data System (ADS)
Bornancini, Carlos G.; García Lambas, Diego
2007-05-01
We study the distant red galaxy (DRG; J - Ks > 2.3) neighbour population of quasi-stellar objects (QSOs) selected from the Sloan Digital Sky Survey (SDSS) in the redshift range 1 <~ z <~ 2. We perform a similar analysis for optically obscured active galactic nuclei (AGNs; i.e. with a limiting magnitude I > 24) detected in the mid-infrared (24 μm) with the Spitzer Space Telescope and a mean redshift z ~ 2.2 in the Flamingos Extragalactic Survey (FLAMEX). Both QSOs and obscured AGN target samples cover 4.7 deg2 in the same region of the sky. We find a significant difference in the environment of these two target samples. Neighbouring galaxies close to QSOs tend to be bluer than galaxies in optically obscured source environments. We also present results on the cross-correlation function of DRGs around QSOs and optically faint mid-infrared sources. The corresponding correlation length obtained for the QSO sample targets is r0 = 5.4 +/- 1.6 Mpc h-1 and a slope of γ = 1.94 +/- 0.10. For the optically obscured galaxy sample, we find r0 = 8.9 +/- 1.4 Mpc h-1 and a slope of γ = 2.27 +/- 0.20. These results indicate that optically faint obscured sources are located in denser environment of evolved red galaxies compared to QSOs. Based on observations and/or data products by the Flamingos Extragalactic Survey. FLAMINGOS was designed and constructed by the IR instrumentation group (PI: R. Elston) at the University of Florida, Department of Astronomy, with support from NSF grant AST97-31180 and Kitt Peak National Observatory. E-mail: bornancini@oac.uncor.edu
NASA Astrophysics Data System (ADS)
Thakur, R. K.; Sood, R. K.
1980-11-01
Thakur and Sapre (1979) suggested that a QSO consists of a bright central object embedded in an extended nebulosity. This paper presents independent evidence in favor of this hypothesis. Alpha(U-B) and alpha(B-V), the spectral indices in (U-B) and (B-V) colors, were plotted for a sample of 80 QSOs with a redshift of z not greater than 0.76. An empirical criterion for the detectability of nebulosities around QSOs is suggested.
Finding the Edge of the Galactic Wind's Influence
NASA Astrophysics Data System (ADS)
Werk, Jessica; Prochaska, J. Xavier; Tumlinson, Jason; Tripp, Todd; Thom, Christopher; Ford, Amanda Brady
2011-08-01
Brand new results from the HST Cosmic Origins Spectrograph on the low-z IGM combined with low-resolution optical spectroscopy of galaxy absorbers indicate that there is a correlation between the total star formation rates of L* galaxies and the strength of the OVI absorption in their halos out to 150 kpc. That diffuse, highly-ionized metals surrounding L* galaxies are a sensitive function of recent star formation suggests we may be seeing the effects of feedback in action in the far reaches of a galaxy's halo. Here, we propose to examine this correlation over a broader range of parameters, for galaxies with luminosities ranging from 0.01 L* to L*, having data- rich QSO sightlines passing through their halos at impact parameters up to 300 kpc. Using a combination of GMOS-S imaging and multi-slit spectroscopy, we will determine the star formation rates and metallicities of galaxies from the recently-published LCO/WFCCD redshift survey. We will use existing UV spectral data for the 14 QSO sightlines to analyze the OVI absorption in the circumgalactic medium of the surveyed galaxies. Our goal is to measure the radius at which OVI absorption no longer correlates with galaxy SFR. This observational estimate for the extent to which galactic winds propagate will provide robust constraints on the simulations that model their effects.
The Cambridge-Cambridge X-ray Serendipity Survey: I X-ray luminous galaxies
NASA Technical Reports Server (NTRS)
Boyle, B. J.; Mcmahon, R. G.; Wilkes, B. J.; Elvis, M.
1994-01-01
We report on the first results obtained from a new optical identification program of 123 faint X-ray sources with S(0.5-2 keV) greater than 2 x 10(exp -14) erg/s/sq cm serendipitously detected in ROSAT PSPC pointed observations. We have spectroscopically identified the optical counterparts to more than 100 sources in this survey. Although the majority of the sample (68 objects) are QSO's, we have also identified 12 narrow emission line galaxies which have extreme X-ray luminosities (10(exp 42) less than L(sub X) less than 10(exp 43.5) erg/s). Subsequent spectroscopy reveals them to be a mixture of star-burst galaxies and Seyfert 2 galaxies in approximately equal numbers. Combined with potentially similar objects identified in the Einstein Extended Medium Sensitivity Survey, these X-ray luminous galaxies exhibit a rate of cosmological evolution, L(sub X) varies as (1 + z)(exp 2.5 +/- 1.0), consistent with that derived for X-ray QSO's. This evolution, coupled with the steep slope determined for the faint end of the X-ray luminosity function (Phi(L(sub X)) varies as L(sub X)(exp -1.9)), implies that such objects could comprise 15-35% of the soft (1-2 keV) X-ray background.
Quasar target selection fiber efficiency
NASA Astrophysics Data System (ADS)
Newberg, Heidi; Yanny, Brian
1996-05-01
We present estimates of the efficiency for finding QSOs as a function of limiting magnitude and galactic latitude. From these estimates, we have formulated a target selection strategy that should net 80,000 QSOs in the north galactic cap with an average of 70 fibers per plate, not including fibers reserved for high-redshift quasars. With this plan, we expect 54% of the targets to be QSOs. The North Galactic Cap is divided into two zones of high and low stellar density. We use about five times as many fibers for QSO candidates in the half of the survey with the lower stellar density as we use in the half with higher stellar density. The current plan assigns 15% of the fibers to FIRST radio sources; if these are not available, those fibers would be allocated to lower probability QSO sources, dropping the total number of QSOs by a small factor (5%). We will find about 17,000 additional quasars in the southern strips, and maybe a few more at very high redshift. Use was made of two data sets: the star and quasar simulated test data generated by Don Schneider, and the data from UJFN plate surveys by Koo (1986) and Kron (1980). This data was compared to results from the Palomar-Green Survey and a recent survey by Pat Osmer and collaborators.
High energy spectrum of spherically accreting black holes
NASA Technical Reports Server (NTRS)
Meszaros, P.; Ostriker, J. P.
1983-01-01
Spherically accreting black holes may sustain strong collisionless shocks, downstream of which the fluid approximation is not valid. The proton-electron Coulomb exchange provides for the downstream matter diffusion into the hole. Energy conversion efficiencies upward of 10-30 percent are obtained, with most of the luminosity in hard X-rays and gamma-rays. The whole spectrum and its application for radio-quiet QSO's and galactic X- and gamma-ray sources are discussed.
The Physical Constraints on a New LoBAL QSO at z = 4.82
DOE Office of Scientific and Technical Information (OSTI.GOV)
Yi, Weimin; Bai, Jin-Ming; Green, Richard
Very few low-ionization broad absorption line (LoBAL) QSOs have been found at high redshifts, to date. One high-redshift LoBAL QSO, J0122+1216, was recently discovered by the Lijiang 2.4 m Telescope, with an initial redshift determination of 4.76. Aiming to investigate its physical properties, we carried out follow-up observations in the optical and near-IR spectroscopy. Near-IR spectra from UKIRT and P200 confirm that it is a LoBAL, with a new redshift determination of 4.82 ± 0.01 based on the Mg ii emission-line. The new Mg ii redshift determination reveals strong blueshifts and asymmetry of the high-ionization emission lines. We estimate amore » black hole mass of ∼2.3 × 10{sup 9} M {sub ⊙} and Eddington ratio of ∼1.0 according to the empirical Mg ii-based single-epoch relation and bolometric correction factor. It is possible that strong outflows are the result of an extreme quasar environment driven by the high Eddington ratio. A lower limit on the outflowing kinetic power (>0.9% L {sub Edd}) is derived from both emission and absorption lines, indicating that these outflows play a significant role in the feedback process that regulates the growth of its black hole, as well as host galaxy evolution.« less
On the mean radiative efficiency of accreting massive black holes in AGNs and QSOs
NASA Astrophysics Data System (ADS)
Zhang, XiaoXia; Lu, YouJun
2017-10-01
Radiative efficiency is an important physical parameter that describes the fraction of accretion material converted to radiative energy for accretion onto massive black holes (MBHs). With the simplest Sołtan argument, the radiative efficiency of MBHs can be estimated by matching the mass density of MBHs in the local universe to the accreted mass density by MBHs during AGN/QSO phases. In this paper, we estimate the local MBH mass density through a combination of various determinations of the correlations between the masses of MBHs and the properties of MBH host galaxies, with the distribution functions of those galaxy properties. We also estimate the total energy density radiated by AGNs and QSOs by using various AGN/QSO X-ray luminosity functions in the literature. We then obtain several hundred estimates of the mean radiative efficiency of AGNs/QSOs. Under the assumption that those estimates are independent of each other and free of systematic effects, we apply the median statistics as described by Gott et al. and find the mean radiative efficiency of AGNs/QSOs is ɛ = 0.105 -0.008 +0.006 , which is consistent with the canonical value 0.1. Considering that about 20% Compton-thick objects may be missed from current available X-ray surveys, the true mean radiative efficiency may be actually 0.12.
The Dust-to-Gas Ratio in the Damped Ly alpha Clouds Towards the Gravitationally Lensed QSO 0957+561
NASA Technical Reports Server (NTRS)
Zuo, Lin; Beaver, E. A.; Burbidge, E. Margaret; Cohen, Ross D.; Junkkarinen, Vesa T.; Lyons, R. W.
1997-01-01
We present HST/FOS spectra of the two bright images (A and B) of the gravitationally lensed QSO 0957+561 in the wavelength range 2200-3300 A. We find that the absorption system (Z(sub abs)) = 1.3911) near z(sub em) is a weak, damped Ly alpha system with strong Ly alpha absorption lines seen in both images. However, the H(I) column densities are different, with the line of sight to image A intersecting a larger column density. The continuum shapes of the two spectra differ in the sense that the flux level of image A increases more slowly toward shorter wavelengths than that of image B. We explain this as the result of differential reddening by dust grains in the damped Ly alpha absorber. A direct outcome of this explanation is a determination of the dust-to-gas ratio, k, in the damped Ly alpha system. We derive k = 0.55 + 0.18 for a simple 1/lambda extinction law and k = 0.31 + 0.10 for the Galactic extinction curve. For gravitationally lensed systems with damped Ly alpha absorbers, our method is a powerful tool for determining the values and dispersion of k, and the shapes of extinction curves, especially in the FUV and EUV regions. We compare our results with previous work.
QSO absorption spectroscopy and baryonic dark matter
NASA Astrophysics Data System (ADS)
Cirković, Milan M.
2005-04-01
The present book should serve a double purpose: first, as an introduction into the host of tightly related topics in astrophysics and cosmology all dealing with the history and evolution of the baryonic matter in the universe. Secondly, it gives argument for still somewhat controversial view that large baryonic reservoirs are present (at least in the low-redshift regime) in form of huge gaseous galactic haloes surrounding normal luminous galaxies, and manifesting through the Lyman-α absorption lines in spectra of background sources. If accepted, this view would profoundly impact our understanding of the galactic structure and evolution, and will deeply influence our views of the future evolution of galactic systems. After an introduction into cosmological jargon and symbols used throughout, and other important introductory material given in Chapter 1, the bulk of the argumentation is given in Chapter 2, which exposes phenomenology of Lyα absorption systems and various theories advanced to account for their physical origin. Chapter 3 deals with models of absorbing gas in the extended haloes of normal galaxies, and Chapter 4 gives a global discussion of main candidates for the reservoirs of the still elusive baryonic dark matter. A set of closely related technical issues which are used at several places in the main narrative are given in the appendices.
The Variable Fast Soft X-Ray Wind in PG 1211+143
NASA Astrophysics Data System (ADS)
Reeves, J. N.; Lobban, A.; Pounds, K. A.
2018-02-01
The analysis of a series of seven observations of the nearby (z = 0.0809) QSO PG 1211+143, taken with the Reflection Grating Spectrometer (RGS) onboard XMM-Newton in 2014, are presented. The high-resolution soft X-ray spectrum, with a total exposure exceeding 600 ks, shows a series of blueshifted absorption lines from the He and H-like transitions of N, O, and Ne, as well as from L-shell Fe. The strongest absorption lines are all systematically blueshifted by ‑0.06c, originating in two absorption zones from low- and high-ionization gas. Both zones are variable on timescales of days, with the variations in absorber opacity effectively explained by either column density changes or the absorber ionization responding directly to the continuum flux. We find that the soft X-ray absorbers probably exist in a two-phase wind at a radial distance of ∼1017–1018 cm from the black hole with the lower-ionization gas as denser clumps embedded within a higher-ionization outflow. The overall mass outflow rate of the soft X-ray wind may be as high as 2{M}ȯ yr‑1, close to the Eddington rate for PG 1211+143 and similar to that previously deduced from the Fe K absorption.
NASA Astrophysics Data System (ADS)
Fan, Lulu; Han, Yunkun; Nikutta, Robert; Drouart, Guillaume; Knudsen, Kirsten K.
2016-06-01
We utilize a Bayesian approach to fit the observed mid-IR-to-submillimeter/millimeter spectral energy distributions (SEDs) of 22 WISE-selected and submillimeter-detected, hyperluminous hot dust-obscured galaxies (Hot DOGs), with spectroscopic redshift ranging from 1.7 to 4.6. We compare the Bayesian evidence of a torus plusgraybody (Torus+GB) model with that of a torus-only (Torus) model and find that the Torus+GB model has higher Bayesian evidence for all 22 Hot DOGs than the torus-only model, which presents strong evidence in favor of the Torus+GB model. By adopting the Torus+GB model, we decompose the observed IR SEDs of Hot DOGs into torus and cold dust components. The main results are as follows. (1) Hot DOGs in our submillimeter-detected sample are hyperluminous ({L}{IR}≥slant {10}13{L}⊙ ), with torus emission dominating the IR energy output. However, cold dust emission is non-negligible, contributing on average ˜ 24% of total IR luminosity. (2) Compared to QSO and starburst SED templates, the median SED of Hot DOGs shows the highest luminosity ratio between mid-IR and submillimeter at rest frame, while it is very similar to that of QSOs at ˜ 10{--}50 μ {{m}}, suggesting that the heating sources of Hot DOGs should be buried AGNs. (3) Hot DOGs have high dust temperatures ({T}{dust}˜ 72 K) and high IR luminosity of cold dust. The {T}{dust}{--}{L}{IR} relation of Hot DOGs suggests that the increase in IR luminosity for Hot DOGs is mostly due to the increase of the dust temperature, rather than dust mass. Hot DOGs have lower dust masses than submillimeter galaxies (SMGs) and QSOs within a similar redshift range. Both high IR luminosity of cold dust and relatively low dust mass in Hot DOGs can be expected by their relatively high dust temperatures. (4) Hot DOGs have high dust-covering factors (CFs), which deviate from the previously proposed trend of the dust CF decreasing with increasing bolometric luminosity. Finally, we can reproduce the observed properties in Hot DOGs by employing a physical model of galaxy evolution. This result suggests that Hot DOGs may lie at or close to peaks of both star formation and black hole growth histories, and represent a transit phase during the evolutions of massive galaxies, transforming them from the dusty starburst-dominated phase to the optically bright QSO phase.
NASA Astrophysics Data System (ADS)
Husemann, B.; Bielby, R.; Jahnke, K.; Arrigoni-Battaia, F.; Worseck, G.; Shanks, T.; Wardlow, J.; Scholtz, J.
2018-06-01
We recently discovered that the luminous radio-quiet quasi-stellar objects (QSO) LBQS 0302-0019 at z = 3.286 is likely accompanied by an obscured AGN at 20 kpc projected distance, which we dubbed Jil. It represents the tightest candidate system of an obscured and unobscured dual AGN at z > 3. To verify the dual AGN scenario, we obtained deep Ks band (rest-frame V band) imaging with the VLT/HAWK-I+GRAAL instrument at 0.″4 resolution during science verification in January 2018. We detect the individual host galaxies of the QSO and Jil with estimated stellar masses of log(M⋆/M⊙) = 11.4 ± 0.5 and log(M⋆/M⊙) = 0.9 ± 0.5, respectively. Near-IR spectra obtained with Very Large Telescope-K-band Multi Object Spectrograph (VLT-KMOS) reveal a clear [O III] λ5007 line detection at the location of Jil that does not contribute significantly to the Ks band flux. Both observations therefore corroborate the dual AGN scenario. A comparison to Illustris simulations suggests a parent halo mass of log(Mhalo/M⊙) = 13.2 ± 0.5 for this interacting galaxy system, corresponding to a massive dark matter halo at that epoch. Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere under ESO programme(s) 60.A-9471(A) and 100.A-0134(B).
C IV broad absorption line variability in QSO spectra from SDSS surveys
NASA Astrophysics Data System (ADS)
De Cicco, Demetra; Brandt, William N.; Grier, Catherine J.; Paolillo, Maurizio
2017-12-01
Broad absorption lines (BALs) in the spectra of quasi-stellar objects (QSOs) are thought to arise from outflowing winds along our line of sight; winds, in turn, are thought to originate from the accretion disk, in the very surroundings of the central supermassive black hole (SMBH), and they likely affect the accretion process onto the SMBH, as well as galaxy evolution. BALs can exhibit variability on timescales typically ranging from months to years. We analyze such variability and, in particular, BAL disappearance, with the aim of investigating QSO physics and structure. We search for disappearing C IV BALs in the spectra of 1319 QSOs from different programs from the Sloan Digital Sky Survey (SDSS); the analyzed time span covers 0.28-4.9 yr (rest frame), and the source redshifts are in the range 1.68-4.27. This is to date the largest sample ever used for such a study. We find 67 sources (5.1_{-0.6}^{+0.7}% of the sample) with 73 disappearing BALs in total (3.9_{-0.5}^{+0.5}% of the total number of C IV BALs detected; some sources have more than one BAL that disappears). We compare the sample of disappearing BALs to the whole sample of BALs, and investigate the correlation in the variability of multiple troughs in the same spectrum. We also derive estimates of the average lifetime of a BAL trough and of the BAL phase along our line of sight.
X-ray ionization of the intergalactic medium by quasars
NASA Astrophysics Data System (ADS)
Graziani, Luca; Ciardi, B.; Glatzle, M.
2018-06-01
We investigate the impact of quasars on the ionization of the surrounding intergalactic medium (IGM) with the radiative transfer code CRASH4, now accounting for X-rays and secondary electrons. After comparing with analytic solutions, we post-process a cosmic volume (≈1.5 × 104 Mpc3h-3) containing a ULAS J1120+0641-like quasar (QSO) hosted by a 5 × 1011M⊙h-1 dark matter (DM) halo. We find that: (i) the average HII region (R ˜ 3.2 pMpc in a lifetime tf = 107 yrs) is mainly set by UV flux, in agreement with semi-analytic scaling relations; (ii) a largely neutral (xHII < 0.001), warm (T ˜ 103 K) tail extends up to few Mpc beyond the ionization front, as a result of the X-ray flux; (iii) LyC-opaque inhomogeneities induce a line of sight (LOS) scatter in R as high as few physical Mpc, consistent with the DLA scenario proposed to explain the anomalous size of the ULAS J1120+0641 ionized region. On the other hand, with an ionization rate \\dot{N}_{γ ,0} ˜ 10^{57} s-1, the assumed DLA clustering and gas opacity, only one LOS shows an HII region compatible with the observed one. We deduce that either the ionization rate of the QSO is at least one order of magnitude lower or the ULAS J1120+0641 bright phase is shorter than 107 yrs.
The z = 0.8596 damped Ly-alpha absorbing galaxy toward PKS 0454+039
NASA Technical Reports Server (NTRS)
Steidel, Charles C.; Bowen, David V.; Blades, J. Chris; Dickenson, Mark
1995-01-01
We present Hubble Space Telescope (HST) and ground-based data on the Z(sub abs) = 0.8596 metal-line absorption system along the line of sight to PKS 0454+0356. The system is a moderate-redshift damped Ly-alpha system, with N(H I) = (5.7 +/- 0.3) x 10(exp 20)/sq cm as measured from the Faint Object Spectrograph (FOS) spectrum. We also present ground-based images which we use to identify the galaxy which most probably gives rise to the damped system; the most likely candidate is relatively underluminous by QSO absorber standards M(sub B) approximately -19.0 for A(sub 0) = 0.5 and H(sub 0) = 50 km/s/Mpc) and lies approximately 8.5/h kpc in projection from the QSO sight line. Ground-based measurements of Zn II, Cr II, and Fe II absorption lines from this system allow us to infer abundances of (Zn/H) = -1.1, (Cr/H) = -1.2, and (Fe/H) = -1.2 indicating overall metallicity similar to damped systems at z is greater than 2, and that the depletion of Cr and Fe onto dust grains may be even less important than in many of the high-redshift systems of comparable metallicity. Limits previously placed on the 21 cm optical depth in the z = 0.8596 system, together with our new N(H I) measurement, suggest a very high spin temperature for the H I, T(sub s) is greater than 580 K.
The ULIRG Monster Mash: The Evolution of Massive Mergers Since z~1
NASA Astrophysics Data System (ADS)
Rothberg, Barry; Fischer, Jacqueline; Pirzkal, Nor; Rodrigues, Myriam
2018-01-01
Theoretical models and observations in the local Universe indicate there is a clear progression from merger-induced star-formation (SF) to QSO activity via Ultraluminous Infrared Galaxies (ULIRGs), systems with L8-1000 µm ≥ 1012 LSun. Not all mergers are ULIRGs, but all local ULIRGs are mergers, and likely the progenitors of QSO host galaxies. At earlier epochs, this relationship is less well accepted. Here, we first present an overview of how the dynamical properties of local (z < 0.4) ULIRGs are statistically indistinguishable from Radio Loud and Radio Quiet QSOs. Then, transition to the critical redshift range 0.4 < z < 1.0, where the star-formation rates, gas fractions, and masses of galaxies are believed to be significantly higher than in the local universe. ULIRGs at these redshifts begin to dominate the SF activity and are responsible for up to 70% of the co-moving IR density. We use rest-frame UV & optical imaging and spectra to apply the same techniques used for local ULIRGs to a sample of "classically" selected (i.e via integrated 12, 25, 60 and 100μm fluxes) systems at 0.4 < z < 1.0. Although, in general, galaxies at z > 0.4 are not the same as those in the local Universe, these intermediate redshift ULIRGs are dynamically similar, but more powerful, than their local counterparts. Furthermore, they show evidence of merging, while containing a powerful AGN hosted within a massive galaxy.
Are we witnessing the epoch of reionisation at z = 7.1 from the spectrum of J1120+0641?
NASA Astrophysics Data System (ADS)
Greig, Bradley; Mesinger, Andrei; Haiman, Zoltán; Simcoe, Robert A.
2017-04-01
We quantify the presence of Lyα damping wing absorption from a partially neutral intergalactic medium (IGM) in the spectrum of the z = 7.08 QSO, ULASJ1120+0641. Using a Bayesian framework, we simultaneously account for uncertainties in: (I) the intrinsic QSO emission spectrum; and (II) the distribution of cosmic H I patches during the epoch of reionization (EoR). For (I), we use a new intrinsic Lyα emission line reconstruction method, sampling a covariance matrix of emission line properties built from a large data base of moderate-z QSOs. For (II), we use the Evolution of 21-cm Structure (EOS; Mesinger et al.) simulations, which span a range of physically motivated EoR models. We find strong evidence for the presence of damping wing absorption redward of Lyα (where there is no contamination from the Lyα forest). Our analysis implies that the EoR is not yet complete by z = 7.1, with the volume-weighted IGM neutral fraction constrained to \\bar{x}_{H I} = 0.40^{+0.21 }_{ -0.19} at 1σ (\\bar{x}_{H I} = 0.40^{+0.41 }_{ -0.32} at 2σ). This result is insensitive to the EoR morphology. Our detection of significant neutral H I in the IGM at z = 7.1 is consistent with the latest Planck 2016 measurements of the CMB Thompson scattering optical depth.
Low redshift Lyman alpha absorption lines and the dark matter halos of disk galaxies
NASA Technical Reports Server (NTRS)
Maloney, Philip
1993-01-01
Recent observations using the Hubble Space Telescope of the z = 0.156 QSO 3C 273 have discovered a surprisingly large number of Ly-alpha absorption lines. In particular, Morris et al. found 9 certain and 7 possible Ly-alpha lines with equivalent widths above 25 mA. This is much larger (by a factor of 5-10) than the number expected from extrapolation of the high-redshift behavior of the Ly-alpha forest. Within the context of pressure-confined models for the Ly-alpha clouds, this behavior can be understood if the ionizing background declines sharply between z is approximately 2 and z is approximately 0. However, this requires that the ionizing photon flux drop as rapidly as the QSO volume emissivity; moreover, the absorbers must have a space density n(sub O) is approximately 2.6(N/10)h/((D/100 kpc)(sup 2)) Mpc(sup -3) where D is the present-day diameter of the absorbers. It is somewhat surprising that such necessarily fragile objects could have survived in such numbers to the present day. It is shown that it is plausible that the atomic hydrogen extents of spiral and irregular galaxies are large enough to produce the observed number of Ly-alpha absorption lines toward 3C 273, and that the neutral column densities and doppler b-values expected under these conditions fall in the range found by Morris et al. (1991).
IUE observations of extragalactic objects
NASA Technical Reports Server (NTRS)
Boksenberg, A.; Snijders, M. A. J.; Wilson, R.; Benvenuti, P.; Clavell, J.; Macchetto, F.; Penston, M.; Boggess, A.; Gull, T. R.; Gondhalekar, P.
1978-01-01
During the commissioning phase of IUE several extragalactic objects were observed spectrally at low dispersion in the UV range lambda lambda 1150-3200: the Seyfert galaxies NGC4151 and NGC1068, the QSO 3C273, the BL Lacertae object B2 1101+38, the giant elliptical galaxy M87 and the spiral galaxy M81. The results obtained are presented and a preliminary analysis given for all six objects, discussing the continuous spectrum, extinction, emission line spectrum and absorption line spectrum, where possible for each case. Several new or confirmatory astrophysical results are obtained.
NASA Technical Reports Server (NTRS)
Arav, Nahum
2002-01-01
The main aim of this research program is to determine the ionization equilibrium and abundances in quasar outflows. Especially in the broad absorption line QSO PG 0946+301. We find that the outflow's metalicity is consistent with being solar, while the abundance ratio of phosphorus to other metals is at least ten times solar. These findings are based on diagnostics that are not sensitive to saturation and partial covering effects in the BALs (Broad Adsorption Lines), which considerably weakened previous claims for enhanced metalicity. Ample evidence for these effects is seen in the spectrum.
Optimal extraction of quasar Lyman limit absorption systems from the IUE archive
NASA Technical Reports Server (NTRS)
Tytler, David
1992-01-01
The IUE archive contains a wealth of information on Lyman limit absorption systems (LLS) in quasar spectra. QSO spectra from the IUE data base were optimally extracted, coadded, and analyzed to yield a homogeneous samples of LLS at low red shifts. This sample comprise 36 LLS, twice the number previously analyzed low z samples. These systems are ideal for the determination of the origin, redshift evolution, ionization, velocity dispersions and the metal abundances of absorption systems. Two of them are also excellent targets for the primordial Deuterium to Hydrogen ratio.
ORIGIN OF THE COMPLEX RADIO STRUCTURE IN BAL QSO 1045+352
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kunert-Bajraszewska, Magdalena; Gawronski, Marcin P.; Janiuk, Agnieszka
2010-08-01
We present new, more sensitive, high-resolution radio observations of a compact broad absorption line (BAL) quasar, 1045+352, made with the EVN+MERLIN at 5 GHz. These observations allowed us to trace the connection between the arcsecond structure and the radio core of the quasar. The radio morphology of 1045+352 is dominated by a knotty jet showing several bends. We discuss possible scenarios that could explain such a complex morphology: galaxy merger, accretion disk instability, precession of the jet, and jet-cloud interactions. It is possible that we are witnessing an ongoing jet precession in this source due to internal instabilities within themore » jet flow; however, a dense environment detected in the submillimeter band and an outflowing material suggested by the X-ray absorption could strongly interact with the jet. It is difficult to establish the orientation between the jet axis and the observer in 1045+352 because of the complex structure. Nevertheless, taking into account the most recent inner radio structure, we conclude that the radio jet is oriented close to the line of sight, which can mean that the opening angle of the accretion disk wind can be large in this source. We also suggest that there is no direct correlation between the jet-observer orientation and the possibility of observing BALs.« less
AO 0235+164 and Surrounding Field: Surprising HST Results
NASA Technical Reports Server (NTRS)
Burbidge, E. M.; Beaver, E. A.; Cohen, Ross D.; Junkkarinen, V. T.; Lyons, R. W.
1996-01-01
Results obtained with the Hubble Space Telescope on the highly variable radio, x-ray, and gamma-ray emitting QSO (or BL Lac object) AO 0235 + 164 are presented and analyzed. WFPC2 images were obtained in 1994 June, when AO 0235 + 164 was bright (m approx. 17), and the results are described in Sec. 3. After subtraction of the PSF of the QSO, hereafter called AO following the nomenclature of Yanny et al. (1989), the companion object named A, 2 sec south of AO, is discovered not to be an elliptical galaxy as hypothesized earlier, but to be an AGN object, with a central UV-bright point-source nucleus and faint surrounding nebulosity extending to AO. The second companion object 1.3 sec east of AO discovered by Yanny et al. (1989) and named object Al, appears more like a normal spiral galaxy. We have measured the positions, luminosities, and colors of some 30 faint objects in the field around AO 0235 + 16; most are extended and may be star-forming galaxies in a loose group or cluster. Our most surprising result of the HST observations comes from FOS spectra obtained in 1995 July, discussed in Sec. 4. Because of a positioning error of the telescope and AO's faintness at that time (m approx. 20), object A was observed instead of the intended target AO. Serendipitously, we discovered A to have broad deep BALQSO-type absorptions of C IV, Si IV, N V shortward of broad emissions. A is thus ejecting high velocity, highly ionized gas into the surrounding IGM. We discuss in Sec. 5 the relationship of the objects in the central 10 sec X 1O sec region around AO, where redshifts z(sub e) = 0.94, z(sub a) = 0.524, 0.851 in AO, (sub e) = 0.524 and Z(sub BAL)=0.511 in A, are found. We hypothesize that some of the 30 faint objects in the 77 sec. x 77 sec. field may be part of a large star-forming region at z approx. 0.5, as suggested for a few objects by Yanny et al. (1989). The proximity of two highly active extragalactic objects, AO 0235+164 and its AGN companion A, is remarkable and one of the authors (EMB) suggests it may require consideration of a non-cosmological component of redshift in AO 0235+164.
IDENTIFICATION OF 1.4 MILLION ACTIVE GALACTIC NUCLEI IN THE MID-INFRARED USING WISE DATA
DOE Office of Scientific and Technical Information (OSTI.GOV)
Secrest, N. J.; Dudik, R. P.; Dorland, B. N.
2015-11-15
We present an all-sky sample of ≈1.4 million active galactic nuclei (AGNs) meeting a two-color infrared photometric selection criteria for AGNs as applied to sources from the Wide-field Infrared Survey Explorer final catalog release (AllWISE). We assess the spatial distribution and optical properties of our sample and find that the results are consistent with expectations for AGNs. These sources have a mean density of ≈38 AGNs per square degree on the sky, and their apparent magnitude distribution peaks at g ≈ 20, extending to objects as faint as g ≈ 26. We test the AGN selection criteria against a largemore » sample of optically identified stars and determine the “leakage” (that is, the probability that a star detected in an optical survey will be misidentified as a quasi-stellar object (QSO) in our sample) rate to be ≤4.0 × 10{sup −5}. We conclude that our sample contains almost no optically identified stars (≤0.041%), making this sample highly promising for future celestial reference frame work as it significantly increases the number of all-sky, compact extragalactic objects. We further compare our sample to catalogs of known AGNs/QSOs and find a completeness value of ≳84% (that is, the probability of correctly identifying a known AGN/QSO is at least 84%) for AGNs brighter than a limiting magnitude of R ≲ 19. Our sample includes approximately 1.1 million previously uncataloged AGNs.« less
NASA Astrophysics Data System (ADS)
Husemann, B.; Davis, T. A.; Jahnke, K.; Dannerbauer, H.; Urrutia, T.; Hodge, J.
2017-09-01
We present single-dish 12CO(1-0) and 12CO(2-1) observations for 14 low-redshift quasi-stellar objects (QSOs). In combination with optical integral field spectroscopy, we study how the cold gas content relates to the star formation rate (SFR) and black hole accretion rate. 12CO(1-0) is detected in 8 of 14 targets and 12CO(2-1) is detected in 7 out of 11 cases. The majority of disc-dominated QSOs reveal gas fractions and depletion times matching normal star-forming systems. Two gas-rich major mergers show clear starburst signatures with higher than average gas fractions and shorter depletion times. Bulge-dominated QSO hosts are mainly undetected in 12CO(1-0), which corresponds, on average, to lower gas fractions than in disc-dominated counterparts. Their SFRs, however, imply shorter than average depletion times and higher star formation efficiencies. Negative QSO feedback through removal of cold gas seems to play a negligible role in our sample. We find a trend between black hole accretion rate and total molecular gas content for disc-dominated QSOs when combined with literature samples. We interpret this as an upper envelope for the nuclear activity and it is well represented by a scaling relation between the total and circumnuclear gas reservoir accessible for accretion. Bulge-dominated QSOs significantly differ from that scaling relation and appear uncorrelated with the total molecular gas content. This could be explained either by a more compact gas reservoir, blown out of the gas envelope through outflows, or a different interstellar medium phase composition.
Surveys, Fields, and Collections in the Astronomical Photographic Data Archive at PARI
NASA Astrophysics Data System (ADS)
Cline, J. D.; Castelaz, M. W.; Barker, T.
2014-01-01
A diverse set of photometric, astrometric, spectral and surface brightness data exist on more than 100 years of photographic glass plates. About 20 percent of the plates in North America are located in the Astronomical Photographic Data Archive (APDA) at the Pisgah Astronomical Research Institute (PARI). APDA was established in November 2007 and is dedicated to the task of collecting, restoring, preserving and storing astronomical photographic data and PARI continues to accept collections. APDA is also tasked with scanning each image and establishing a database of images that can be accessed via the Internet by the global community of scientists, researchers and students. APDA is a new type of astronomical observatory - one that harnesses analog data of the night sky taken for more than a century and making that data available in a digital format. APDA currently has 50 collections with more than 250,000 plates taken for QSO identification, parallax measurements, spectral classification and monitoring, Magellanic Cloud studies, H-alpha emission star surveys, novae evolution, and astrometry of asteroids, outer planet satellites and Pluto. Some examples of collections include the complete set of the Henize H-alpha Southern Survey plates taken between 1949 and 1952 (Henize 1954, AJ, 59, 325), the Case Western Objective Prism All Sky Survey from 1958-1976 (e.g. Pesch, Sanduleak, and Stephenson 1996, ApJS, 103, 513), and QSO Survey from 1980 to 1991 (e.g. Pesch and Stephenson 1983, ApJS, 51, 171). We feature the contents of the APDA collections to provide the opportunity to the astronomical community to advance new and established areas of study.
How Do Inflows and Outflows from Galaxies Create Their Inner Circumgalactic Medium?
NASA Astrophysics Data System (ADS)
Bowen, David
2017-08-01
We propose using COS to observe 7 QSO sightlines within half a virial radius each of two galaxies in order to probe their circumgalactic mediums (CGMs) along multiple sightlines. Results from higher redshift QSO absorption line surveys suggest that this is the region where most metal line absorbing gas clouds reside, but their origin remains controversial. The two spiral galaxies studied in this proposal are NGC 4565 (the Needle Galaxy) which is highly inclined (i=86 degrees), and NGC 3184, which has a very low inclination (i=9 degrees). Their orientation makes them ideal targets for looking for kinematic and metallicity signatures from outflows along the minor axis, or inflows into the disk along the major axis. For both galaxies, we will measure how HI and metal line column densities change globally with radius, and how the ionzation structure of the absorbers varies with position. We predict that the HI column densities we detect will be similar to the Lyman Limit, or partial-Lyman Limit systems, and that we will be able to measure the gas metallicity in these clouds. These measurements can be used to infer whether the absorbing gas is flowing into the galaxy from the IGM (where the metallicity is lower than in the galaxy) or out of the galaxy (which should be metal enriched). Given that LLS and pLLS have been shown to have a bimodal distribution in their metallicity, we will see which of the two regimes the gas in our galaxies belong to, and even whether the bimodality can be seen in a single galaxy towards different sightlines.
ESO & NOT photometric monitoring of the Cloverleaf quasar
NASA Astrophysics Data System (ADS)
Ostensen, R.; Remy, M.; Lindblad, P. O.; Refsdal, S.; Stabell, R.; Surdej, J.; Barthel, P. D.; Emanuelsen, P. I.; Festin, L.; Gosset, E.; Hainaut, O.; Hakala, P.; Hjelm, M.; Hjorth, J.; Hutsemekers, D.; Jablonski, M.; Kaas, A. A.; Kristen, H.; Larsson, S.; Magain, P.; Pettersson, B.; Pospieszalska-Surdej, A.; Smette, A.; Teuber, J.; Thomsen, B.; van Drom, E.
1997-12-01
The Cloverleaf quasar, H1413+117, has been photometrically monitored at ESO (La Silla, Chile) and with the NOT (La Palma, Spain) during the period 1987--1994. All good quality CCD frames have been successfully analysed using two independent methods (i.e. an automatic image decomposition technique and an interactive CLEAN algorithm). The photometric results from the two methods are found to be very similar, and they show that the four lensed QSO images vary significantly in brightness (by up to 0.45 mag), nearly in parallel. The lightcurve of the $D$ component presents some slight departures from the general trend which are very likely caused by micro-lensing effects. Upper limits, at the 99% confidence level, of 150 days on the absolute value for the time delays between the photometric lightcurves of this quadruply imaged variable QSO, are derived. This is unfortunately too large to constrain the lens model but there is little doubt that a better sampling of the lightcurves should allow to accurately derive these time delays. Pending a direct detection of the lensing galaxy (position and redshift), this system thus constitutes another good candidate for a direct and independent determination of the Hubble parameter. Based on observations collected at the European Southern Observatory (La Silla, Chile) and with the Nordic Optical Telescope (La Palma, Spain). Table 1. Logbook for the ESO and NOT observations together with photometric results for the Cloverleaf quasar. This long table can be accessed on the WWW at the URL address: http://vela.astro.ulg.ac.be/grav_lens/glp_homepage.html}
Multiwavelength Characterization of an ACT-Selected, Lensed Dusty Star-Forming Galaxy at zeta 2.64
NASA Technical Reports Server (NTRS)
Roberts-Borsani, G. W.; Jimenez-Donaire, M. J.; Dapra, M.; Alatalo, K.; Aretxaga, I.; Alvarez-Marquez, J.; Baker, A. J.; Fujimoto, S.; Gallardo, P. A.; Gralla, M.;
2017-01-01
We present C I(21) and multi-transition C-12 O observations of a dusty star-forming galaxy, ACT J2029+0120,which we spectroscopically confirm to lie at zeta = 2.64. We detect CO(3-2), CO(5-4), CO(7-6), CO(8-7), and C I(2-1) at high significance, tentatively detect HCO+(4-3), and place strong upper limits on the integrated strength of dense gas tracers (HCN(4-3) and CS(7-6)). Multi-transition CO observations and dense gas tracers can provide valuable constraints on the molecular gas content and excitation conditions in high-redshift galaxies. We therefore use this unique data set to construct a CO spectral line energy distribution (SLED) of the source, which is most consistent with that of a ULIRG Seyfert or QSO host object in the taxonomy of the Herschel Comprehensive ULIRG Emission Survey. We employ RADEX models to fit the peak of the CO SLED, inferring a temperature of T approximately 117 K and n(sub H2) approximately 10(exp5) cm(exp -3), most consistent with a ULIRGQSO object and the presence of high-density tracers. We also find that the velocity width of the C I line is potentially larger than seen in all CO transitions forth is object, and that the L'(sub Ci(2-1))/L'(sub CO(3-2))ratio is also larger than seen in other lensed and unlensed submillimeter galaxies and QSO hosts; if confirmed, this anomaly could be an effect of differential lensing of a shocked molecular outflow.
On the covering fraction variability in an EUV mini-BAL outflow from PG 1206+459
NASA Astrophysics Data System (ADS)
Muzahid, S.; Srianand, R.; Charlton, J.; Eracleous, M.
2016-04-01
We report on the first detection of extreme-ultraviolet (EUV) absorption variability in the Ne VIII λλ770, 780 mini-broad absorption line (mini-BAL) in the spectrum of the quasar (QSO) PG 1206+459. The observed equivalent width (EW) of the Ne VIII doublet shows a ˜4σ variation over a time-scale of 2.8 months in the QSO's rest frame. Both members of the Ne VIII doublet exhibit non-black saturation, indicating partial coverage of the continuum source. An increase in the Ne VIII covering fraction from fc = 0.59 ± 0.05 to 0.72 ± 0.03 is observed over the same period. The Ne VIII profiles are too highly saturated to be susceptible to changes in the ionization state of the absorbing gas. In fact, we do not observe any significant variation in the EW and/or column density after correcting the spectra for partial coverage. We, thus, propose transverse motions of the absorbing gas as the cause of the observed variability. Using a simple model of a transiting cloud we estimate a transverse speed of ˜1800 km s-1. For Keplerian motion, this corresponds to a distance between the absorber and the central engine of ˜1.3 pc, which places the absorber just outside the broad-line region. We further estimate a density of ˜5 × 106 cm-3 and a kinetic luminosity of ˜1043-1044 erg s-1. Such large kinetic powers suggest that outflows detected via EUV lines are potentially major contributors to active galactic nuclei feedback.
The nature of fifty Palermo Swift-BAT hard X-ray objects through optical spectroscopy
NASA Astrophysics Data System (ADS)
Rojas, A. F.; Masetti, N.; Minniti, D.; Jiménez-Bailón, E.; Chavushyan, V.; Hau, G.; McBride, V. A.; Bassani, L.; Bazzano, A.; Bird, A. J.; Galaz, G.; Gavignaud, I.; Landi, R.; Malizia, A.; Morelli, L.; Palazzi, E.; Patiño-álvarez, V.; Stephen, J. B.; Ubertini, P.
2017-07-01
We present the nature of 50 unidentified hard X-ray emitting objects detected with Swift-BAT and listed as of unidentified nature in the 54-month Palermo BAT catalogue. We found 45 extragalactic sources: 26 type 1 AGN, 15 type 2 AGN, one type 1 QSO, one starburst galaxy, one X-ray bright optically normal galaxy, and one LINER. We report 30 new redshift measurements, 13 confirmations and 2 more accurate redshift values. The remaining five objects are galactic sources: three are Cataclismic Variables, one is a X-ray Binary, and one is an active star.
NASA Astrophysics Data System (ADS)
Fynbo, J. P. U.; Krogager, J.-K.; Venemans, B.; Noterdaeme, P.; Vestergaard, M.; Møller, P.; Ledoux, C.; Geier, S.
2013-01-01
We present the results of a search for red QSOs using a selection based on optical imaging from the Sloan Digital Sky Survey (SDSS) and near-infrared imaging from UKIDSS. Our main goal with the selection is to search for QSOs reddened by foreground dusty absorber galaxies. For a sample of 58 candidates (including 20 objects fulfilling our selection criteria that already have spectra in the SDSS), 46 (79%) are confirmed to be QSOs. The QSOs are predominantly dust-reddened except for a handful at redshifts z >~ 3.5. However, the dust is most likely located in the QSO host galaxies (and for two, the reddening is primarily caused by Galactic dust) rather than in the intervening absorbers. More than half of the QSOs show evidence of associated absorption (BAL absorption). Four (7%) of the candidates turned out to be late-type stars, and another four (7%) are compact galaxies. We could not identify the remaining four objects. In terms of their optical spectra, these QSOs are similar to the QSOs selected in the FIRST-2MASS Red Quasar Survey except they are on average fainter, more distant, and only two are detected in the FIRST survey. As per the usual procedure, we estimate the amount of extinction using the SDSS QSO template reddened by Small-Magellanic-Cloud-(SMC) like dust. It is possible to get a good match to the observed (rest-frame ultraviolet) spectra, but it is not possible to match the observed near-IR photometry from UKIDSS for nearly all the reddened QSOs. The most likely reasons are that the SDSS QSO template is too red at optical wavelengths due to contaminating host galaxy light and because the assumed SMC extinction curve is too shallow. Three of the compact galaxies display old stellar populations with ages of several Gyr and masses of about 1010 M ⊙ (based on spectral energy distribution modeling). The inferred stellar densities in these galaxies exceed 1010 M ⊙ kpc-2, which is among the highest measured for early-type galaxies. Our survey has demonstrated that selection of QSOs based on near-IR photometry is an efficient way to select QSOs, including reddened QSOs, with only small contamination from late-type stars and compact galaxies. This will be useful with ongoing and future wide-field near-IR surveys such as the VISTA and EUCLID surveys. Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere, Chile, under program 088.A-0098, and on observations made with the Nordic Optical Telescope, jointly operated on the island of La Palma by Denmark, Finland, Iceland, Norway, and Sweden, in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias.
NASA Astrophysics Data System (ADS)
Pessa, Ismael; Tejos, Nicolas; Barrientos, L. Felipe; Werk, Jessica; Bielby, Richard; Padilla, Nelson; Morris, Simon L.; Prochaska, J. Xavier; Lopez, Sebastian; Hummels, Cameron
2018-07-01
Cosmological simulations predict that a significant fraction of the low-z baryon budget resides in large-scale filaments in the form of a diffuse plasma at temperatures T ˜ 105 - 107 K. However, direct observation of this so-called warm-hot intergalactic medium (WHIM) has been elusive. In the Λcold dark matter paradigm, galaxy clusters correspond to the nodes of the cosmic web at the intersection of several large-scale filamentary threads. In previous work, we used HST/COS data to conduct the first survey of broad H I Lyα absorbers (BLAs) potentially produced by WHIM in inter-cluster filaments. We targeted a single QSO, namely Q1410, whose sightline intersects seven independent inter-cluster axes at impact parameters <3 Mpc (comoving), and found a tentative excess of a factor of ˜4 with respect to the field. Here, we further investigate the origin of these BLAs by performing a blind galaxy survey within the Q1410 field using VLT/MUSE. We identified 77 sources and obtained the redshifts for 52 of them. Out of the total sample of seven BLAs in inter-cluster axes, we found three without any galaxy counterpart to stringent luminosity limits (˜4 × 108 L⊙ ˜0.01 L*), providing further evidence that these BLAs may represent genuine WHIM detections. We combined this sample with other suitable BLAs from the literature and inferred the corresponding baryon mean density for these filaments in the range Ω ^fil_bar= 0.02-0.04. Our rough estimates are consistent with the predictions from numerical simulations but still subject to large systematic uncertainties, mostly from the adopted geometry, ionization corrections, and density profile.
Do the Most Massive Black Holes at z = 2 Grow via Major Mergers?
NASA Astrophysics Data System (ADS)
Mechtley, M.; Jahnke, K.; Windhorst, R. A.; Andrae, R.; Cisternas, M.; Cohen, S. H.; Hewlett, T.; Koekemoer, A. M.; Schramm, M.; Schulze, A.; Silverman, J. D.; Villforth, C.; van der Wel, A.; Wisotzki, L.
2016-10-01
The most frequently proposed model for the origin of quasars holds that the high accretion rates seen in luminous active galactic nuclei (AGN) are primarily triggered during major mergers between gas-rich galaxies. While plausible for decades, this model has only begun to be tested with statistical rigor in the past few years. Here, we report on a Hubble Space Telescope study to test this hypothesis for z = 2 quasars with high supermassive black hole masses ({M}{BH}={10}9{--}{10}10 {M}⊙ ), which dominate cosmic black hole growth at this redshift. We compare Wide Field Camera 3 F160W (rest-frame V-band) imaging of 19 point source-subtracted quasar hosts to a matched sample of 84 inactive galaxies, testing whether the quasar hosts have greater evidence for strong gravitational interactions. Using an expert ranking procedure, we find that the quasar hosts are uniformly distributed within the merger sequence of inactive galaxies, with no preference for quasars in high-distortion hosts. Using a merger/non-merger cutoff approach, we recover distortion fractions of {f}{{m},{qso}}=0.39+/- 0.11 for quasar hosts and {f}{{m},{gal}}=0.30+/- 0.05 for inactive galaxies (distribution modes, 68% confidence intervals), with both measurements subjected to the same observational conditions and limitations. The slight enhancement in distorted fraction for quasar hosts over inactive galaxies is not significant, with a probability that the quasar fraction is higher P({f}{{m},{qso}}\\gt {f}{{m},{gal}})=0.78 (0.78σ ), in line with results for lower mass and lower z AGN. We find no evidence that major mergers are the primary triggering mechanism for the massive quasars that dominate accretion at the peak of cosmic quasar activity.
BAL QSOs AND EXTREME UFOs: THE EDDINGTON CONNECTION
DOE Office of Scientific and Technical Information (OSTI.GOV)
Zubovas, Kastytis; King, Andrew, E-mail: kastytis.zubovas@ftmc.lt
We suggest a common physical origin connecting the fast, highly ionized winds (UFOs) seen in nearby active galactic nuclei (AGNs), and the slower and less ionized winds of broad absorption line (BAL) QSOs. The primary difference is the mass-loss rate in the wind, which is ultimately determined by the rate at which mass is fed toward the central supermassive black hole (SMBH) on large scales. This is below the Eddington accretion rate in most UFOs, and slightly super-Eddington in extreme UFOs such as PG1211+143, but ranges up to {approx}10-50 times this in BAL QSOs. For UFOs this implies black holemore » accretion rates and wind mass-loss rates which are at most comparable to Eddington, giving fast, highly ionized winds. In contrast, BAL QSO black holes have mildly super-Eddington accretion rates, and drive winds whose mass-loss rates are significantly super-Eddington, and so are slower and less ionized. This picture correctly predicts the velocities and ionization states of the observed winds, including the recently discovered one in SDSS J1106+1939. We suggest that luminous AGNs may evolve through a sequence from BAL QSO through LoBAL to UFO-producing Seyfert or quasar as their Eddington factors drop during the decay of a bright accretion event. LoBALs correspond to a short-lived stage in which the AGN radiation pressure largely evacuates the ionization cone, but before the large-scale accretion rate has dropped to the Eddington value. We show that sub-Eddington wind rates would produce an M-{sigma} relation lying above that observed. We conclude that significant SMBH mass growth must occur in super-Eddington phases, either as BAL QSOs, extreme UFOs, or obscured from direct observation.« less
BAL QSOs and Extreme UFOs: The Eddington Connection
NASA Astrophysics Data System (ADS)
Zubovas, Kastytis; King, Andrew
2013-05-01
We suggest a common physical origin connecting the fast, highly ionized winds (UFOs) seen in nearby active galactic nuclei (AGNs), and the slower and less ionized winds of broad absorption line (BAL) QSOs. The primary difference is the mass-loss rate in the wind, which is ultimately determined by the rate at which mass is fed toward the central supermassive black hole (SMBH) on large scales. This is below the Eddington accretion rate in most UFOs, and slightly super-Eddington in extreme UFOs such as PG1211+143, but ranges up to ~10-50 times this in BAL QSOs. For UFOs this implies black hole accretion rates and wind mass-loss rates which are at most comparable to Eddington, giving fast, highly ionized winds. In contrast, BAL QSO black holes have mildly super-Eddington accretion rates, and drive winds whose mass-loss rates are significantly super-Eddington, and so are slower and less ionized. This picture correctly predicts the velocities and ionization states of the observed winds, including the recently discovered one in SDSS J1106+1939. We suggest that luminous AGNs may evolve through a sequence from BAL QSO through LoBAL to UFO-producing Seyfert or quasar as their Eddington factors drop during the decay of a bright accretion event. LoBALs correspond to a short-lived stage in which the AGN radiation pressure largely evacuates the ionization cone, but before the large-scale accretion rate has dropped to the Eddington value. We show that sub-Eddington wind rates would produce an M-σ relation lying above that observed. We conclude that significant SMBH mass growth must occur in super-Eddington phases, either as BAL QSOs, extreme UFOs, or obscured from direct observation.
Starburst or AGN dominance in submm-luminous candidate AGN
NASA Astrophysics Data System (ADS)
Coppin, Kristen; Alexander, Dave; Aretxaga, Itziar; Blain, Andrew; Chapman, Scott; Clements, Dave; Dunlop, James; Dunne, Loretta; Dye, Simon; Farrah, Duncan; Hughes, David; Ivison, Rob; Kim, Sungeun; Menendez-Delmestre, Karin; Oliver, Sebastian; Page, Mat; Pope, Alexandra; Rowan-Robinson, Michael; Scott, Douglas; Smail, Ian; Swinbank, Mark; Vaccari, Mattia; van Kampen, Eelco
2008-03-01
It is widely believed that starbursts/ULIRGs and AGN activity are triggered by galaxy interactions and merging; and sub-mm selected galaxies (SMGs) seem to be simply high redshift ULIRGs, observed near the peak of activity. In this evolutionary picture every SMG would host an AGN, which would eventually grow a black hole strong enough to blow off all of the gas and dust leaving an optically luminous QSO. In order to probe this evolutionary sequence, a crucial sub-sample to focus on would be the 'missing link' sources, which demonstrate both strong starburst and AGN signatures and to determine if the starburst is the main power source even in SMGs when we have evidence that an AGN is present. The best way to determine if a dominant AGN is present is to look in the mid-IR for their signatures, since often even deep X-ray observations miss identifying the presence of AGN in heavily dust-obscured SMGs. We have selected a sample of SMGs which are good candidates for harboring powerful AGN on the basis of their IRAC colours (S8um/S4.5um>2). Once we confirm these SMGs are AGN-dominated, we can then perform an audit of the energy balance between star-formation and AGN within this special sub-population of SMGs where the BH has grown appreciably to begin heating the dust emission. The proposed observations with IRS will probe the physics of how SMGs evolve from a cold-dust starburst-dominated ULIRG to an AGN/QSO by measuring the level of the mid-IR continuum, PAH luminosity, and Si absorption in these intermediate `transitory' AGN/SMGs.
THE NATURE OF A GALAXY ALONG THE SIGHT LINE TO PKS 0454+039
DOE Office of Scientific and Technical Information (OSTI.GOV)
Takamiya, Marianne; Chun, Mark; Kulkarni, Varsha P.
2012-10-01
We report on the properties of a faint blue galaxy (G1) along the line of sight to the QSO PKS 0454+039 from spectroscopic and imaging data. We measured emission lines of H{alpha}, [S II] {lambda}{lambda}6716, 6732, and [N II] {lambda}6584 in the spectrum of G1 obtained with the Gemini/GMOS instrument. The spectroscopic redshift of G1 is z = 0.0715 {+-} 0.0002. From the extinction-corrected H{alpha} flux, we determine a modest star formation rate of SFR = 0.07 M{sub Sun} yr{sup -1} and a specific SFR of log (sSFR) -8.4. Using three different abundance indicators, we determine a nebular abundance 12more » + log (O/H) ranging from 7.6 to 8.2. Based on the velocity dispersion inferred from the emission line widths and the observed surface brightness profile, we estimate the virial mass of G1 to be M{sub vir} {approx} 6.7 Multiplication-Sign 10{sup 9} M{sub Sun} with an effective radius of 2.0 kpc. We estimate the stellar mass of G1 using spectral energy distribution fitting to be M{sub *} Almost-Equal-To 1.2 Multiplication-Sign 10{sup 7} M{sub Sun} and an r'-luminosity of L{sub r'} = 1.5x10{sup 8} L{sub Sun }. Overall, G1 is a faint, low-mass, low-metallicity Im/H II galaxy. We also report on the line flux limits of another source (G3) which is the most likely candidate for the absorber system at z = 0.8596. From the spectrum of the QSO itself, we report a previously undetected Mg II {lambda}{lambda}2796, 2803 absorption line system at z = 1.245.« less
NASA Astrophysics Data System (ADS)
Khaire, Vikram
2017-08-01
There exists a large void in our understanding of the intergalactic medium (IGM) at z=0.5-1.5, spanning a significant cosmic time of 4 Gyr. This hole resulted from a paucity of near-UV QSO spectra, which were historically very expensive to obtain. However, with the advent of COS and the HST UV initiative, sufficient STIS/COS NUV spectra have finally become available, enabling the first statistical analyses. We propose a comprehensive study of the z 1 IGM using the Ly-alpha forest of 26 archival QSO spectra. This analysis will: (1) measure the distribution of HI absorbers to several percent precision down to log NHI < 13 to test our model of the IGM, and determine the extragalactic UV background (UVB) at that epoch; (2) measure the Ly-alpha forest power spectrum to 12%, providing another precision test of LCDM and our theory of the IGM; (3) measure the thermal state of the IGM, which reflects the balance of heating (photoheating, HI/HeII reionization) and cooling (Hubble expansion) of cosmic baryons, and directly verify the predicted cooldown of IGM gas after reionization for the first time; (4) generate high-quality reductions, coadds, and continuum fits that will be released to the public to enable other science cases. These results, along with our state-of-the-art hydrodynamical simulations, and theoretical models of the UVB, will fill the 4 Gyr hole in our understanding of the IGM. When combined with existing HST and ground-based data from lower and higher z, they will lead to a complete, empirical description of the IGM from HI reionization to the present, spanning more than 10 Gyr of cosmic history, adding substantially to Hubble's legacy of discovery on the IGM.
NASA Technical Reports Server (NTRS)
Kriss, G. A.; Shull, J. M.; Oegerle, W.; Zheng, W.; Davidsen, A. F.; Songaila, A.; Tumlinson, J.; Cowie, L. L.; Dehavreng, J.-M.; Friedman, S. D.
2001-01-01
The neutral hydrogen and the ionized helium absorption in the spectra of high-redshift quasi-stellar objects (QSOs) are unique probes of structure in the universe at epochs intermediate between the earliest density fluctuations seen in the cosmic background radiation and the distribution of galaxies visible today. We present Far-Ultraviolet Spectroscopic Explorer (FUSE) observations of the line of sight to the QSO HE2347-4342 in the 1000-1187 angstrom band at a resolving power of 15,000. Above redshift z = 2.7, the IGM is largely opaque in He II Ly-alpha (304 angstroms). At lower redshifts, the optical depth gradually decreases to a mean value tau = 1 at z = 2.4. We resolve the He II Ly-alpha absorption as a discrete forest of absorption lines in the z = 2.3 - 2.7 redshift range. Approximately 50% of these spectral features have H I counterparts with column densities N(sub HI) > 10(exp 12.3)/sq cm visible in a Keck spectrum. These account for most of the observed opacity in He II Ly-alpha. The remainder have N(sub HI) < 10(exp 12.3)/sq cm, below the threshold for current observations. A short extrapolation of the power-law distribution of H I column densities to lower values can account for these new absorbers. The He II to H I column density ratio eta averages approximately 80, consistent with photoionization of the IGM by a hard ionizing spectrum resulting from the integrated light of quasars at high redshift, but there is considerable scatter. Values of eta > 100 in many locations indicate that there may be localized contributions from starbursts or heavily filtered QSO radiation.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ueda, Shutaro; Hayashida, Kiyoshi; Anabuki, Naohisa
We report the Suzaku/XIS and HXD and Chandra/ACIS-I results on the X-ray spectra of the Phoenix cluster at the redshift z = 0.596. The spectrum of the intracluster medium (ICM) is well reproduced with the emissions from low-temperature (∼3.0 keV and ∼0.76 solar) and high-temperature (∼11 keV and ∼0.33 solar) plasmas; the former is localized at the cluster core, while the latter distributes over the cluster. In addition to these ICM emissions, a strongly absorbed power-law component is found, which is due to an active galactic nucleus (AGN) in the cluster center. The absorption column density and unobscured luminosity ofmore » the AGN are ∼3.2 × 10{sup 23} cm{sup –2} and ∼4.7 × 10{sup 45} erg s{sup –1} (2-10 keV), respectively. Furthermore, a neutral iron (Fe I) K-shell line is discovered for the first time with the equivalent width (EW) of ∼150 eV at the rest frame. The column density and the EW of the Fe I line are exceptionally large for such a high-luminosity AGN, and hence the AGN is classified as a type 2 quasi-stellar object (QSO). We speculate that a significant fraction of the ICM cooled gas would be consumed to maintain the torus and to activate the type 2 QSO. The Phoenix cluster has a massive starburst in the central galaxy, indicating that suppression in the cooling flow is less effective. This may be because the onset of the latest AGN feedback has occurred recently and has not yet been effective. Alternatively, the AGN feedback is predominantly in radiative mode, not in kinetic mode, and the torus may work as a shield to reduce its effect.« less
Resolving Fe-rich Neutral ISM in a Massive Quiescent Galaxy at z 0.4
NASA Astrophysics Data System (ADS)
Zahedy, Fakhri
2016-10-01
Roughly 40% of elliptical galaxies are found to contain cool gas but exhibit no on-going star formation, indicating that some feedback mechanisms are at work. While AGN feedback is commonly thought to be responsible for quenching star formation in massive halos, recent work has reiterated the importance of feedback from old stellar populations, including Type Ia supernovae (SNe Ia). In Zahedy et al. (2016), we reported detections of ultra-strong MgII absorption (>3.6 Ang) at 1-2 effective radii of a massive quiescent lensing galaxy at z=0.408. Strong MgII, FeII, MgI, and CaII absorption are found at the lens redshift along two lensed QSO sightlines separated by 8 kpc. The absorbers are resolved into 15 components with line-of-sight velocity spread of 600 km/s. The large observed ionic column densities, N>1e14 cm^-2 suggest large neutral hydrogen column densities N(HI)>1e18 cm^-2 and a significant neutral gas fraction. The most striking feature is the uniformly large Fe/Mg ratio across the full 600 km/s velocity range, suggesting a large contribution in chemical enrichment from SNe Ia (>20%). Here we propose QSO absorption-line spectroscopy of this unique system using STIS and the G140L grating with the slit oriented along the two lensed QSOs. The goal is to determine N(HI) from observations of the full Lyman absorption series and gas-phase metallicity of the interstellar medium at two locations separated by 8 kpc in an elliptical galaxy beyond the local universe. With a modest investment of HST time, we will be able to examine the extent SNe Ia-driven feedback in a distant quiescent galaxy using this unique double-lens system.
NASA Astrophysics Data System (ADS)
Stanley, F.; Alexander, D. M.; Harrison, C. M.; Rosario, D. J.; Wang, L.; Aird, J. A.; Bourne, N.; Dunne, L.; Dye, S.; Eales, S.; Knudsen, K. K.; Michałowski, M. J.; Valiante, E.; De Zotti, G.; Furlanetto, C.; Ivison, R.; Maddox, S.; Smith, M. W. L.
2017-12-01
We investigate the mean star formation rates (SFRs) in the host galaxies of ∼3000 optically selected quasi-stellar objects (QSOs) from the Sloan Digital Sky Survey within the Herschel-ATLAS fields, and a radio-luminous subsample covering the redshift range of z = 0.2-2.5. Using Wide-field Infrared Survey Explorer (WISE) and Herschel photometry (12-500 μm) we construct composite spectral energy distributions (SEDs) in bins of redshift and active galactic nucleus (AGN) luminosity. We perform SED fitting to measure the mean infrared luminosity due to star formation, removing the contamination from AGN emission. We find that the mean SFRs show a weak positive trend with increasing AGN luminosity. However, we demonstrate that the observed trend could be due to an increase in black hole (BH) mass (and a consequent increase of inferred stellar mass) with increasing AGN luminosity. We compare to a sample of X-ray selected AGN and find that the two populations have consistent mean SFRs when matched in AGN luminosity and redshift. On the basis of the available virial BH masses, and the evolving BH mass to stellar mass relationship, we find that the mean SFRs of our QSO sample are consistent with those of main sequence star-forming galaxies. Similarly the radio-luminous QSOs have mean SFRs that are consistent with both the overall QSO sample and with star-forming galaxies on the main sequence. In conclusion, on average QSOs reside on the main sequence of star-forming galaxies, and the observed positive trend between the mean SFRs and AGN luminosity can be attributed to BH mass and redshift dependencies.
QSO Emission Lines and the Black Hole-Galaxy Bulge Relation
NASA Astrophysics Data System (ADS)
Shields, G. A.; Gebhardt, K.; Salviander, S.; Wills, B. J.; Yuan, M.; Xie, B.; Dietrich, M.
2002-05-01
Supermassive black holes in galactic nuclei have masses closely related to the properties of the host galaxy bulge. In particular, MBH varies as the fourth power of σ , the stellar velocity dispersion (Tremaine et al. 2002, ApJ in press, and references therein). The origin of the black hole-bulge relation is unknown, although theoretical suggestions abound. An important clue would be provided by knowledge of how the relation has evolved over cosmic time. This requires measurement of black hole masses and galactic potentials at large look-back times, which is difficult to do directly. However, black hole masses may be derived from the continuum luminosity and the widths of the broad Balmer lines of QSOs (e.g., Kaspi et al. 2000, ApJ 533, 631), and σ may be derived from the widths of the narrow [O III] lines (Nelson 2000, ApJ, 544, L91). We have carried out this program for a set of published and unpublished observations of Seyfert galaxies and QSOs. Results for low redshift objects support the use of this method to derive MBH and σ . The few available measurements of high redshift QSOs are consistent little or no change in the MBH-σ relation between the present and redshifts up to z = 3.3, when the universe was only two billion years old. This material is based in part upon work supported by the Texas Advanced Research Program under Grant No. 003658-0177-2001.
NASA Astrophysics Data System (ADS)
Klitsch, A.; Péroux, C.; Zwaan, M. A.; Smail, I.; Oteo, I.; Biggs, A. D.; Popping, G.; Swinbank, A. M.
2018-03-01
Studying the flow of baryons into and out of galaxies is an important part of understanding the evolution of galaxies over time. We present a detailed case study of the environment around an intervening Ly α absorption line system at zabs = 0.633, seen towards the quasar J0423-0130 (zQSO = 0.915). We detect with ALMA the 12CO(2-1), 12CO(3-2), and 1.2 mm continuum emission from a galaxy at the redshift of the Ly α absorber at a projected distance of 135 kpc. From the ALMA detections, we infer interstellar medium conditions similar to those in low-redshift luminous infrared galaxies. Director's Discretionary Time (DDT) Multi-Unit Spectroscopic Explorer (MUSE) integral field unit observations reveal the optical counterpart of the 12CO emission line source and three additional emission line galaxies at the absorber redshift, which together form a galaxy group. The 12CO emission line detections originate from the most massive galaxy in this group. While we cannot exclude that we miss a fainter host, we reach a dust-uncorrected star formation rate (SFR) limit of >0.3 M⊙yr-1 within 100 kpc from the sightline to the background quasar. We measure the dust-corrected SFR (ranging from 3 to 50 M⊙ yr-1), the morpho-kinematics and the metallicities of the four group galaxies to understand the relation between the group and the neutral gas probed in absorption. We find that the Ly α absorber traces either an outflow from the most massive galaxy or intragroup gas. This case study illustrates the power of combining ALMA and MUSE to obtain a census of the cool baryons in a bounded structure at intermediate redshift.
Chemesthesis and taste: evidence of independent processing of sensation intensity.
Green, Barry G; Alvarez-Reeves, Marty; George, Pravin; Akirav, Carol
2005-11-15
The ability to perceive taste from temperature alone ("thermal taste") was recently shown to predict higher perceptual responsiveness to gustatory and olfactory stimuli. This relationship was hypothesized to be due in part to individual differences in CNS processes involved in flavor perception. Here we report three experiments that tested whether subjects who differ in responsiveness to thermal taste and/or chemical taste also differ in responsiveness to oral chemesthesis. In experiment 1, subjects identified as 'thermal tasters' (TTs) or 'thermal non-tasters' (TnTs) used the general Labeled Magnitude Scale to rate the intensity of sensations produced on the tongue tip by capsaicin, menthol, sucrose, NaCl, citric acid, and QSO4. TTs rated all four taste stimuli higher than did TnTs, whereas sensations of burning/stinging/pricking and temperature from capsaicin and menthol did not differ significantly between groups. In experiment 2, testing with capsaicin on both the front and back of the tongue confirmed there was no difference in ratings of burning/stinging/pricking when subjects were grouped according to the ability to perceive thermal taste. In experiment 3, subjects were classified as high- or low-tasters according to their ratings of sucrose sweetness rather than thermal taste. No group difference was found for perception of capsaicin even when presented in mixture with sucrose or NaCl. The results are discussed in the context of previous evidence of an association between chemesthesis and sensitivity to the bitter tastant PROP, and in terms of the various peripheral and central neural processes that may underlie intensity perception in taste and chemesthesis.
SNR-based queue observations at CFHT
NASA Astrophysics Data System (ADS)
Devost, Daniel; Moutou, Claire; Manset, Nadine; Mahoney, Billy; Burdullis, Todd; Cuillandre, Jean-Charles; Racine, René
2016-07-01
In an effort to optimize the night time utilizing the exquisite weather on Maunakea, CFHT has equipped its dome with vents and is now moving its Queued Scheduled Observing (QSO)1 based operations toward Signal to Noise Ratio (SNR) observing. In this new mode, individual exposure times for a science program are estimated using a model that uses measurements of the weather conditions as input and the science program is considered completed when the depth required by the scientific requirements are reached. These changes allow CFHT to make better use of the excellent seeing conditions provided by Maunakea, allowing us to complete programs in a shorter time than allocated to the science programs.
NASA Astrophysics Data System (ADS)
Reimers, D.; Kohler, S.; Wisotzki, L.; Groote, D.; Rodriguez-Pascual, P.; Wamsteker, W.
1997-11-01
We report on observations of redshifted Heii303.8 Angstroms absorption in the high-redshift QSO HE2347-4342 (z=2.885, V=16.1) with the Goddard High Resolution Spectrograph on board HST in its low resolution mode (bigtriangleup lambda = 0.7 Angstroms). With f_λ=3.6\\ 10(-15) ergcm(-2) s(-1) Angstroms(-1) at the expected position of Heii304 Angstroms absorption it is the most UV-bright high redshift QSO discovered so far. We show that the Heii opacity as a function of redshift is patchy showing spectral regions with low Heii opacity (``voids'') and regions with high Heii opacity (blacked-out ``troughs'') and no detectable flux. Combination with high-resolution optical spectra of the Lyalpha forest using CASPEC at the 3.6m telescope shows that the voids can be explained either exclusively by Lyalpha forest cloud absorption with a moderate N_{subs {He{sc ii}}}/N_{subs {H{sc i}}} ratio eta <=100 and turbulent line broadening or by a combination of Lyalpha forest with eta = 45 and thermal broadening plus a diffuse medium with tau_ {subs {GP}}({subs {He{sc ) ii}}} ~ 0.3. Since the latter is a minimum assumption for the Lyalpha forest, a strict upper limit to a diffuse medium is Omega_ {subs {diff}}<0.02 h50(-1.5) at z=2.8. In the troughs in addition to the Lyalpha forest opacity a continuous Heii 304 Angstroms opacity tau = 4.8(+infty }_{-2) is required. In case of photoionization, the troughs would require a diffuse component with a density close to Omega =~ 0.077(eta /45)(-0.5) h50(-1.5) , i.e. all baryons in the universe, which is inconsistent, however, with the observed absence of such a component in the voids. A tentative interpretation is that we observe the epoch of partial Heii reionization of the universe with patches not yet reionized. In that case a diffuse component with Omega_ {subs {diff}}>= 1.3\\ 10(-4) h(-1}_{50) would be sufficient to explain the ``trough'' opacity. The size of the 1163--1172 Angstroms trough is ~ 6 h50(-1) Mpc or ~ 2300 kms(-1) , respectively. We also discuss partially resolved Heii absorption of a high-ionization associated absorption system. Despite its high luminosity HE2347-4342 does not show a Heii proximity effect. A possible reason is that the strong associated system shields the Heii ionizing continuum. Based on observations collected at the European Southern Observatory, La Silla, Chile (ESO No.\\ 58.B--0116). Based on IUE observations collected at the ESA VILSPA ground station near Madrid, Spain. Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by Aura, Inc., under NASA contract NAS 5--26\\,555.
Discovery of a new quasar: SDSS J022155.26-064916.6
DOE Office of Scientific and Technical Information (OSTI.GOV)
Robertson, J. M.; Tucker, D. L.; Smith, J. A.
Here, we report the discovery of a new quasar: SDSS J022155.26-064916.6. This object was discovered while reducing the spectra of a sample of stars being considered as spectrophotometric standards for the Dark Energy Survey. The flux- and wavelength-calibrated spectrum is presented with four spectral lines identified. From these lines, the redshift is determined to be z≈0.806. In addition, the rest-frame u-, g-, and r-band luminosity, determined using a k-correction obtained with synthetic photometry of a proxy quasi stellar object (QSO), are reported as 7.496×10 13 L ⊙, 2.049×10 13 L ⊙, and 1.896×10 13 L ⊙, respectively.
Discovery of a new quasar: SDSS J022155.26-064916.6
Robertson, J. M.; Tucker, D. L.; Smith, J. A.; ...
2017-06-14
Here, we report the discovery of a new quasar: SDSS J022155.26-064916.6. This object was discovered while reducing the spectra of a sample of stars being considered as spectrophotometric standards for the Dark Energy Survey. The flux- and wavelength-calibrated spectrum is presented with four spectral lines identified. From these lines, the redshift is determined to be z≈0.806. In addition, the rest-frame u-, g-, and r-band luminosity, determined using a k-correction obtained with synthetic photometry of a proxy quasi stellar object (QSO), are reported as 7.496×10 13 L ⊙, 2.049×10 13 L ⊙, and 1.896×10 13 L ⊙, respectively.
Spitzer Imaging of Planck-Herschel Dusty Proto-Clusters at z=2-3
NASA Astrophysics Data System (ADS)
Cooray, Asantha; Ma, Jingzhe; Greenslade, Joshua; Kubo, Mariko; Nayyeri, Hooshang; Clements, David; Cheng, Tai-An
2018-05-01
We have recently introduced a new proto-cluster selection technique by combing Herschel/SPIRE imaging data and Planck/HFIk all-sky survey point source catalog. These sources are identified as Planck point sources with clumps of Herschel source over-densities with far-IR colors comparable to z=0 ULIRGS redshifted to z=2 to 3. The selection is sensitive to dusty starbursts and obscured QSOs and we have recovered couple of the known proto-clusters and close to 30 new proto-clusters. The candidate proto-clusters selected from this technique have far-IR flux densities several times higher than those that are optically selected, such as using LBG selection, implying that the member galaxies are in a special phase of heightened dusty starburst and dusty QSO activity. This far-IR luminous phase may be short but likely to be necessary piece to understand the whole stellar mass assembly history of clusters. Moreover, our photo-clusters are missed in optical selections, suggesting that optically selected proto-clusters alone do not provide adequate statistics and a comparison of the far-IR and optical selected clusters may reveal the importance of the dusty stellar mass assembly. Here, we propose IRAC observations of six of the highest priority new proto-clusters, to establish the validity of the technique and to determine the total stellar mass through SED models. For a modest observing time the science program will have a substantial impact on an upcoming science topic in cosmology with implications for observations with JWST and WFIRST to understand the mass assembly in the universe.
NASA Astrophysics Data System (ADS)
Martens, Sarah Katherine; Wilcots, Eric M.
2017-01-01
We investigate the redshift distribution and environmental conditions of quasar AGNs. The importance of studying these relationships is to use the evolutionary patterns of QSOs (features with many quantifiable characteristics) to gain insight into the evolutionary paths and environmental dependencies of their host super massive black holes (SMBHs), which are more difficult to study directly. We employ specific redshift bins within Data Release 13 of the Sloan Digital Sky Survey's (SDSS) Extended Baryonic Oscillation Spectroscopic Survey (eBOSS) and begin with a sample of 595,025 QSOs. We then incorporate overlapping data sets: The Very Large Array Faint Images of the Radio Sky at Twenty-Centimeters (FIRST) which provides the HI detected QSOs in our sample, along with the galaxy group and cluster sample from Tempel, Tago, Liivamägi 2012 which we cross referenced with our QSO sample to see which of them exist in group environments. The addition of these data sets allows us to create a more holistic view of the processes at work within our sample of QSOs. Understanding the HI presence in different evolutionary phases will allow us to draw conclusions on potential star formation rates or quenching, and by understanding the populations of QSOs in galaxy groups we can determine if QSOs exist overwhelmingly in one particular environment and how environmental conditions effect the other characteristics of QSOs. Overall we provide a multi-faceted analysis of some of the evolutionary patterns and cycles of the eBOSS Data Release 13 QSOs and their implications on the evolutionary paths of SMBHs. This work was supported by the SDSS Research Experience for Undergraduates program, which is funded by a grant from Sloan Foundation to the Astrophysical Research Consortium.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Álvarez Crespo, N.; Massaro, F.; Masetti, N.
The extragalactic γ-ray sky is dominated by emission from blazars, a peculiar class of active galactic nuclei. Many of the γ-ray sources included in the Fermi-Large Area Telescope Third Source catalog (3FGL) are classified as blazar candidates of uncertain type (BCUs) because there are no optical spectra available in the literature to confirm their nature. In 2013, we started a spectroscopic campaign to look for the optical counterparts of the BCUs and of the unidentified γ-ray sources to confirm their blazar nature. Whenever possible we also determine their redshifts. Here, we present the results of the observations carried out inmore » the northern hemisphere in 2013 and 2014 at the Telescopio Nazionale Galileo, Kitt Peak National Observatory, and Observatorio Astronómico Nacional in San Pedro Mártir. In this paper, we describe the optical spectra of 25 sources. We confirmed that all of the 15 BCUs observed in our campaign and included in our sample are blazars and we estimated the redshifts for three of them. In addition, we present the spectra for three sources classified as BL Lacs in the literature but with no optical spectra available to date. We found that one of them is a quasar (QSO) at a redshift of z = 0.208 and the other two are BL Lacs. Moreover, we also present seven new spectra for known blazars listed in the Roma-BZCAT that have an uncertain redshift or are classified as BL Lac candidates. We found that one of them, 5BZB J0724+2621, is a “changing look” blazar. According to the spectrum available in the literature, it was classified as a BL Lac, but in our observation we clearly detected a broad emission line that led us to classify this source as a QSO at z = 1.17.« less
The Starburst-AGN connection: quenching the fire and feeding the monster
NASA Astrophysics Data System (ADS)
Melnick, Jorge; Telles, Eduardo; De Propris, Roberto; Chu, Zhang-Hu
2015-10-01
The merger of two spiral galaxies is believed to be one of the main channels for the production of elliptical and early-type galaxies. In the process, the system becomes an (ultra) luminous infrared galaxy, or (U)LIRG, that morphs to a quasar, to a K+A galaxy, and finally to an early-type galaxy. The time scales for this metamorphosis are only loosely constrained by observations. In particular, the K+A phase should follow immediately after the quasi stellar object (QSO) phase during which the dust and gas remaining from the (U)LIRG phase are expelled by the active galactic nucleus (AGN). An intermediate class of QSOs with K+A spectral signatures, the post-starburst QSOs (PSQ), may represent the transitional phase between QSOs and K+As. We have compiled a sample of 72 bona fide z < 0.5 PSQ from the SDSS DR7 QSO catalogue. We find the intermediate age populations in this sample to be on average significantly weaker and metal poorer than their putative descendants, the K+A galaxies. The typical spectral energy distribution of PSQ is well fitted by three components: starlight; an obscured power-law; and a hot dust component required to reproduce the mid-IR fluxes. From the slope and bolometric luminosity of the power-law component we estimate typical masses and accretion rates of the AGN, but we find little evidence of powerful radio-loud or strong X-ray emitters in our sample. This may indicate that the power-law component originates in a nuclear starburst rather than in an AGN, as expected if the bulk of their young stars are still being formed, or that the AGN is still heavily enshrouded in dust and gas. We find that both alternatives are problematic and that more and better optical, X-ray, and mm-wave observations are needed to elucidate the evolutionary history of PSQ.
NASA Astrophysics Data System (ADS)
Glikman, Eilat; Djorgovski, S. G.; Stern, Daniel; Dey, Arjun; Jannuzi, Buell T.; Lee, Kyoung-Soo
2011-02-01
We present an updated determination of the z ~ 4 QSO luminosity function (QLF), improving the quality of the determination of the faint end of the QLF presented by Glikman et al. (2010). We have observed an additional 43 candidates from our survey sample, yielding one additional QSO at z = 4.23 and increasing the completeness of our spectroscopic follow-up to 48% for candidates brighter than R = 24 over our survey area of 3.76 deg2. We study the effect of using K-corrections to compute the rest-frame absolute magnitude at 1450 Å compared with measuring M 1450 directly from the object spectra. We find a luminosity-dependent bias: template-based K-corrections overestimate the luminosity of low-luminosity QSOs, likely due to their reliance on templates derived from higher luminosity QSOs. Combining our sample with bright quasars from the Sloan Digital Sky Survey and using spectrum-based M 1450 for all the quasars, we fit a double power law to the binned QLF. Our best fit has a bright-end slope, α = 3.3 ± 0.2, and faint-end slope, β = 1.6+0.8 -0.6. Our new data revise the faint-end slope of the QLF down to flatter values similar to those measured at z ~ 3. The break luminosity, though poorly constrained, is at M* = -24.1+0.7 -1.9, approximately 1-1.5 mag fainter than at z ~ 3. This QLF implies that QSOs account for about half the radiation needed to ionize the intergalactic medium at these redshifts. The data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation.
The Impact of Starbursts on the Gaseous Halos of Galaxies
NASA Astrophysics Data System (ADS)
Heckman, Timothy
2009-07-01
Perhaps the most important {yet uncertain} aspects of galaxy evolution are the processes by which galaxies accrete gas and by which the resulting star formation and black hole growth affects this accreting gas. It is believed that both the form of the accretion and the nature of the feedback change as a function of the galaxy mass. At low mass the gas comes in cold and the feedback is provided by massive stars. At high mass, the gas comes in hot, and the feedback is from an AGN. The changeover occurs near the mass where the galaxy population transitions from star-forming galaxies to red and dead ones. The population of red and dead galaxies is building with cosmic time, and it is believed that feedback plays an imporant role in this process: shutting down star formation by heating and/or expelling the reservoir of cold halo gas. To investigate these ideas, we propose to use COS far-UV spectra of background QSOs to measure the properties of the halo gas in a sample of galaxies near the transition mass that have undergone starbursts within the past 100 Myr to 1 Gyr. The galactic wind associated with the starburst is predicted to have affected the properties of the gaseous halo. To test this, we will compare the properties of the halos of the post-starburst galaxies to those of a control sample of galaxies matched in mass and QSO impact parameter. Do the halos of the post-starburst galaxies show a higher incidence rate of Ly-Alpha and metal absorption-lines? Are the kinematics of the halo gas more disturbed in the post-starbursts? Has the wind affected the ionization state and/or the metallicity of the halo? These data will provide fresh new insights into the role of feedback from massive stars on the evolution of galaxies, and may also offer clues about the properties of the QSO metal absorption-line systems at high-redshift.
NuSTARUnveils a Compton-Thick Type 2 Quasar in MrK 34
Gandhi, P.; Lansbury, G. B.; Alexander, D. M.; ...
2014-08-22
We present Nuclear Spectroscopic Telescope Array ( NuSTAR) 3-40 keV observations of the optically selected Type 2 quasar (QSO2) SDSS J1034+6001 or Mrk 34. The high-quality hard X-ray spectrum and archival XMM- Newton data can be fitted self-consistently with a reflection-dominated continuum and a strong Fe Kα fluorescence line with equivalent width >1 keV. Prior X-ray spectral fitting below 10 keV showed the source to be consistent with being obscured by Compton-thin column densities of gas along the line of sight, despite evidence for much higher columns from multiwavelength data. NuSTAR now enables a direct measurement of this column andmore » shows that N H lies in the Compton-thick (CT) regime. The new data also show a high intrinsic 2-10 keV luminosity of L 2-10 ~ 10 44 erg s –1, in contrast to previous low-energy X-ray measurements where L 2-10 ≲ 10 43 erg s –1 (i.e., X-ray selection below 10 keV does not pick up this source as an intrinsically luminous obscured quasar). Both the obscuring column and the intrinsic power are about an order of magnitude (or more) larger than inferred from pre- NuSTAR X-ray spectral fitting. Mrk 34 is thus a "gold standard" CT QSO2 and is the nearest non-merging system in this class, in contrast to the other local CT quasar NGC 6240, which is currently undergoing a major merger coupled with strong star formation. For typical X-ray bolometric correction factors, the accretion luminosity of Mrk 34 is high enough to potentially power the total infrared luminosity. In conclusion, X-ray spectral fitting also shows that thermal emission related to star formation is unlikely to drive the observed bright soft component below ~3 keV, favoring photoionization instead.« less
NASA Astrophysics Data System (ADS)
Jin, Chichuan; Done, Chris; Ward, Martin; Gardner, Emma
2017-10-01
We present a detailed multiwavelength study of an unobscured, highly super-Eddington Type-1 QSO RX J0439.6-5311. We combine the latest XMM-Newton observation with all archival data from infrared to hard X-rays. The optical spectrum is very similar to that of 1H 0707-495 in having extremely weak [O III] and strong Fe II emission lines, although the black hole mass is probably slightly higher at 5-10 × 106 M⊙. The broad-band spectral energy distribution is uniquely well defined due to the extremely low Galactic and intrinsic absorption, so the bolometric luminosity is tightly constrained. The optical/UV accretion disc continuum is seen down to 900 Å, showing that there is a standard thin disc structure down to R ≥ 190-380 Rg and determining the mass accretion rate through the outer disc. This predicts a much higher bolometric luminosity than observed, indicating that there must be strong wind and/or advective energy losses from the inner disc, as expected for a highly super-Eddington accretion flow. Significant outflows are detected in both the narrow-line region (NLR) and broad-line region (BLR) emission lines, confirming the presence of a wind. We propose a global picture for the structure of a super-Eddington accretion flow where the inner disc puffs up, shielding much of the potential NLR material, and show how inclination angle with respect to this and the wind can explain very different X-ray properties of RX J0439.6-5311 and 1H 0707-495. Therefore, this source provides strong supporting evidence that 'simple' and 'complex' super-Eddington NLS1s can be unified within the same accretion flow scenario but with different inclination angles. We also propose that these extreme NLS1s could be the low-redshift analogues of weak emission-line quasars.
Hubble’s cross-section of the cosmos
2014-04-17
This new Hubble image showcases a remarkable variety of objects at different distances from us, extending back over halfway to the edge of the observable Universe. The galaxies in this image mostly lie about five billion light-years from Earth but the field also contains other objects, both significantly closer and far more distant. Studies of this region of the sky have shown that many of the objects that appear to lie close together may actually be billions of light-years apart. This is because several groups of galaxies lie along our line of sight, creating something of an optical illusion. Hubble’s cross-section of the Universe is completed by distorted images of galaxies in the very distant background. These objects are sometimes distorted due to a process called gravitational lensing, an extremely valuable technique in astronomy for studying very distant objects [1]. This lensing is caused by the bending of the space-time continuum by massive galaxies lying close to our line of sight to distant objects. One of the lens systems visible here is called CLASS B1608+656, which appears as a small loop in the centre of the image. It features two foreground galaxies distorting and amplifying the light of a distant quasar the known as QSO-160913+653228. The light from this bright disc of matter, which is currently falling into a black hole, has taken nine billion years to reach us — two thirds of the age of the Universe. As well as CLASS B1608+656, astronomers have identified two other gravitational lenses within this image. Two galaxies, dubbed Fred and Ginger by the researchers who studied them, contain enough mass to visibly distort the light from objects behind them. Fred, also known more prosaically as [FMK2006] ACS J160919+6532, lies near the lens galaxies in CLASS B1608+656, while Ginger ([FMK2006] ACS J160910+6532) is markedly closer to us. Despite their different distances from us, both can be seen near to CLASS B1608+656 in the central region of this Hubble image. To capture distant and dim objects like these, Hubble required a long exposure. The image is made up of visible and infrared observations with a total exposure time of 14 hours. More info: www.spacetelescope.org/news/heic1408/ Credit: NASA/ESA/Hubble NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram
Wide Field Imaging of the Hubble Deep Field-South Region III: Catalog
NASA Technical Reports Server (NTRS)
Palunas, Povilas; Collins, Nicholas R.; Gardner, Jonathan P.; Hill, Robert S.; Malumuth, Eliot M.; Rhodes, Jason; Teplitz, Harry I.; Woodgate, Bruce E.
2002-01-01
We present 1/2 square degree uBVRI imaging around the Hubble Deep Field - South. These data have been used in earlier papers to examine the QSO population and the evolution of the correlation function in the region around the HDF-S. The images were obtained with the Big Throughput Camera at CTIO in September 1998. The images reach 5 sigma limits of u approx. 24.4, B approx. 25.6, V approx. 25.3, R approx. 24.9 and I approx. 23.9. We present a catalog of approx. 22,000 galaxies. We also present number-magnitude counts and a comparison with other observations of the same field. The data presented here are available over the world wide web.
Search for correlated UV and x ray absorption of NGC 3516
NASA Technical Reports Server (NTRS)
Martin, Christopher; Halpern, Jules P.; Kolman, Michiel
1991-01-01
NGC 3516, a low-luminosity Seyfert galaxy, is one of a small fraction of Seyfert galaxies that exhibit broad absorption in a resonance line. In order to determine whether the UV and x ray absorption in NGC 3516 are related, 5 IUE observations were obtained, quasi-simultaneously with 4 Ginga observations. The results are presented and discussed. The following subject areas are covered: short-term UV variability; emission lines; galactic absorption lines; the C IV, N V, and Si IV absorption features; lower limit on the carbon column density; estimate of the distance from the absorber to the continuum source; variability in the continuum and absorption; a comparison with BAL QSO's; and the x ray-UV connection.
The Co-evolution of QSOs and Galaxies
NASA Astrophysics Data System (ADS)
Coziol, R.; Torres-Papaqui, J. P.; Andernach, H.
2015-07-01
Using two large samples of QSOs detected in the mid-infrared (MIR) with WISE, we find that the change of W2-W3 colors with redshift suggests that star formation in their host galaxies increases by a factor of 3 from z = 0 to 2.7, then stays constant up to z = 4, and decreases above z=4. This behavior is slightly different from the best fits for the star formation history of field galaxies as deduced from the Optical-UV and IR, but is consistent with what is observed for sub-mm galaxies at high z. Our results constitute the clearest evidence, so far, that QSO host galaxies form their stars before field galaxies, and are in good agreement with the hierarchical biased structure formation paradigm.
Element abundances at high redshift
NASA Technical Reports Server (NTRS)
Meyer, David M.; Welty, D. E.; York, D. G.
1989-01-01
Abundances of Si(+), S(+), Cr(+), Mn(+), Fe(_), and Zn(+) are considered for two absorption-line systems in the spectrum of the QSO PKS 0528 - 250. Zinc and sulfur are underabundant, relative to H, by a factor of 10 compared to their solar and Galactic interstellar abundances. The silicon-, chromium-, iron-, and nickel-to-hydrogen ratios are less than the solar values and comparable to the local interstellar ratios. A straightforward interpretation is that nucleosynthesis in these high-redshift systems has led to only about one-tenth as much heavy production as in the gas clouds around the sun, and that the amount of the observed underabundances attributable to grain depletion is small. The dust-to-gas ratio in these clouds is less than 8 percent of the Galactic value.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Jenkins, Edward B.; Wallerstein, George, E-mail: ebj@astro.princeton.edu, E-mail: walleg@u.washington.edu
We present data on the gas-phase abundances for 9 different elements in the interstellar medium of the Small Magellanic Cloud (SMC), based on the strengths of ultraviolet absorption features over relevant velocities in the spectra of 18 stars within the SMC. From this information and the total abundances defined by the element fractions in young stars in the SMC, we construct a general interpretation on how these elements condense into solid form onto dust grains. As a group, the elements Si, S, Cr, Fe, Ni, and Zn exhibit depletion sequences similar to those in the local part of our Galaxymore » defined by Jenkins. The elements Mg and Ti deplete less rapidly in the SMC than in the Milky Way, and Mn depletes more rapidly. We speculate that these differences might be explained by the different chemical affinities to different existing grain substrates. For instance, there is evidence that the mass fractions of polycyclic aromatic hydrocarbons in the SMC are significantly lower than those in the Milky Way. We propose that the depletion sequences that we observed for the SMC may provide a better model for interpreting the element abundances in low-metallicity Damped Lyman Alpha (DLA) and sub-DLA absorption systems that are recorded in the spectra of distant quasars and gamma-ray burst afterglows.« less
[The backgroud sky subtraction around [OIII] line in LAMOST QSO spectra].
Shi, Zhi-Xin; Comte, Georges; Luo, A-Li; Tu, Liang-Ping; Zhao, Yong-Heng; Wu, Fu-Chao
2014-11-01
At present, most sky-subtraction methods focus on the full spectrum, not the particular location, especially for the backgroud sky around [OIII] line which is very important to low redshift quasars. A new method to precisely subtract sky lines in local region is proposed in the present paper, which sloves the problem that the width of Hβ-[OIII] line is effected by the backgroud sky subtraction. The exprimental results show that, for different redshift quasars, the spectral quality has been significantly improved using our method relative to the original batch program by LAMOST. It provides a complementary solution for the small part of LAMOST spectra which are not well handled by LAMOST 2D pipeline. Meanwhile, This method has been used in searching for candidates of double-peaked Active Galactic Nuclei.
The theory of QSO absorption line systems and their relationship to the galaxies
NASA Technical Reports Server (NTRS)
Charlton, Jane
1993-01-01
The fundamental goal of this effort is to paint a picture of what the Ly-alpha forest clouds are and how they are distributed in space. Progress during the first phase of this program involved development of the 'Cheshire Cat Model' of Ly-alpha clouds in which systems over a large range of column densities are produced by disks with somewhat smaller column densities than those of normal galaxies. A prediction of the slab model of Ly-alpha clouds was confirmed by a new observational result, and the comparison of models to the new data allowed an estimate of the pressure of the intergalactic medium. This result should be forthcoming in pre-print form within the next month. The various results will now be described in more detail.
VizieR Online Data Catalog: Milky Way L/T/M-dwarfs identified in BoRG survey (Holwerda+, 2014)
NASA Astrophysics Data System (ADS)
Holwerda, B. W.; Trenti, M.; Clarkson, W.; Sahu, K.; Bradley, L.; Stiavelli, M.; Pirzkal, N.; de Marchi, G.; Andersen, M.; Bouwens, R.; Ryan, R.
2017-07-01
Our principal data set is the WFC3 data from the BoRG (HST GO/PAR-11700; Trenti et al. 2011ApJ...727L..39T; Bradley et al. 2012ApJ...760..108B) survey to identify Milky Way dwarf stars from their morphology and color. The BoRG observations are undithered HST/WFC3 conducted in pure-parallel with the telescope pointing to a primary spectroscopic target with the Cosmic Origin Spectrograph (COS; typically a high-z QSO at high Galactic latitude). The limitations for such observations are primarily that no dithering strategy can be used (final images are at WFC3 native pixel scale) and total exposure times are dictated by the primary program. (5 data files).
Investigating the physical and geometrical properties of the dusty torus in QSO
NASA Astrophysics Data System (ADS)
Martínez-Paredes, M.; González-Martín, O.; Aretxaga, I.; Alonso-Herrero, A.
2017-07-01
Usining mid-IR high angular resolution (0.3 arcsec) data from CanariCam on the 10.4m Gran Telescopio CANARIAS we study the mid-IR nuclear emission of a nearby (z<0.1) sample of QSOs. The QSOs are selected with N-band flux (fN>0.02 Jy) and hard X-ray flux (fX(2-10 keV)>1043 erg s-1). From the analysis of this data we find that the mid-IR emission is unresolved at scales of a few hundred of pc. We use unresolved emission at H-band (e.g., Veilleux et al. 2009b) and the IRS-Spitzer spectrum (e.g., Schweitzer et al. 2006) to build near- to mid-IR unresolved spectral energy distribution (SEDs).
Probing the dark energy with quasar clustering.
Calvão, M O; de Mello Neto, J R T; Waga, I
2002-03-04
We show through Monte Carlo simulations that the Alcock-Paczyński test, as applied to quasar clustering, is a powerful tool to probe the cosmological density and equation of state parameters Omega(m0), Omega(x0), and w. By taking into account the effect of peculiar velocities upon the correlation function we obtain for the Two-Degree Field QSO Redshift Survey the predicted confidence contours for the cosmological constant (w = -1) and spatially flat (Omega(m0)+Omega(x0) = 1) cases. For w = -1, the test is especially sensitive to the difference Omega(m0)-Omega(Lambda0), thus being ideal to combine with cosmic microwave background results. For the flat case, it is competitive with future supernova and galaxy number count tests, besides being complementary to them.
NASA Astrophysics Data System (ADS)
Duari, Debiprosad; Gupta, Patrick D.; Narlikar, Jayant V.
1992-01-01
An overview of statistical tests of peaks and periodicities in the redshift distribution of quasi-stellar objects is presented. The tests include the power-spectrum analysis carried out by Burbidge and O'Dell (1972), the generalized Rayleigh test, the Kolmogorov-Smirnov test, and the 'comb-tooth' test. The tests reveal moderate to strong evidence for periodicities of 0.0565 and 0.0127-0.0129. The confidence level of the periodicity of 0.0565 in fact marginally increases when redshifts are transformed to the Galactocentric frame. The same periodicity, first noticed in 1968, persists to date with a QSO population that has since grown about 30 times its original size. The prima facie evidence for periodicities in 1n(1 + z) is found to be of no great significance.
Mobile phones and social structures: an exploration of a closed user group in rural Ghana
2013-01-01
Background In the Millennium Villages Project site of Bonsaaso, Ghana, the Health Team is using a mobile phone closed user group to place calls amongst one another at no cost. Methods In order to determine the utilization and acceptability of the closed user group amongst users, social network analysis and qualitative methods were used. Key informants were identified and interviewed. The key informants also kept prospective call journals. Billing statements and de-identified call data from the closed user group were used to generate data for analyzing the social structure revealed by the network traffic. Results The majority of communication within the closed user group was personal and not for professional purposes. The members of the CUG felt that the group improved their efficiency at work. Conclusions The methods used present an interesting way to investigate the social structure surrounding communication via mobile phones. In addition, the benefits identified from the exploration of this closed user group make a case for supporting mobile phone closed user groups amongst professional groups. PMID:24007331
First Results from the ISO-IRAS Faint Galaxy Survey
NASA Astrophysics Data System (ADS)
Levine, Deborah A.; Lonsdale, Carol J.; Hurt, Robert L.; Smith, Harding E.; Helou, George; Beichman, Charles; Cesarsky, Catherine; Elbaz, David; Klaas, Ulrich; Laureijs, Rene; Lemke, Detrich; Lord, Steven; McMahon, Richard; Moshir, Mehrdad; Neugebauer, Gerry; Soifer, B. T.; Van Buren, Dave; Wehrle, Ann; Wolstencroft, Ray
1998-09-01
We present the first results from the ISO-IRAS Faint Galaxy Survey (IIFGS), a program designed to obtain ISO observations of the most distant and luminous galaxies in the IRAS Faint Source Survey by filling short gaps in the ISO observing schedule with pairs of 12 μm ISOCAM and 90 μm ISOPHOT observations. As of 1997 October, over 500 sources have been observed, with an ISOCAM detection rate over 80%, covering over 1.25 deg2 of sky to an 11.5 μm point-source completeness limit of approximately 1.0 mJy (corresponding to a ~10 σ detection sensitivity). Observations are presented for nine sources detected by ISOPHOT and ISOCAM early in the survey for which we have ground-based G- and I-band images and optical spectroscopy. The ground-based data confirm that the IIFGS strategy efficiently detects moderate-redshift (z = 0.11-0.38 for this small sample) strong emission line galaxies with L60 μm >~ 1011 L⊙ one of our sample has L60 μm > 1012 L⊙ (H0 = 75 km s-1 Mpc-1, Ω = 1). The infrared-optical spectral energy distributions are comparable to those of nearby luminous infrared galaxies, which span the range from pure starburst (e.g., Arp 220) to infrared QSO (Mrk 231). Two of the systems show signs of strong interaction, and four show active galactic nucleus (AGN)-like excitation; one of the AGNs, F15390+6038, which shows a high excitation Seyfert 2 spectrum, has an unusually warm far- to mid-infrared color and may be an obscured QSO. The IIFGS sample is one of the largest and deepest samples of infrared-luminous galaxies available, promising to be a rich sample for studying infrared-luminous galaxies up to z ~ 1 and for understanding the evolution of infrared galaxies and the star formation rate in the universe. ISO is an ESA project with instruments funded by ESA member states (especially the PI countries: France, Germany, the Netherlands, and the United Kingdom) and with the participation of ISAS and NASA.
Intervening O vi Quasar Absorption Systems at Low Redshift: A Significant Baryon Reservoir.
Tripp; Savage; Jenkins
2000-05-01
Far-UV echelle spectroscopy of the radio-quiet QSO H1821+643 (zem=0.297), obtained with the Space Telescope Imaging Spectrograph (STIS) at approximately 7 km s-1 resolution, reveals four definite O vi absorption-line systems and one probable O vi absorber at 0.15
Auston, Darryl A; Meiss, Jordan; Serrano, Rafael; Sellers, Thomas; Carlson, Gregory; Hoggard, Timothy; Beebe, Michael; Quade, Jonathan; Watson, David; Simpson, Robert Bruce; Kistler, Brian; Shah, Anjan; Sanders, Roy; Mir, Hassan R
2017-04-01
To compare the incidence of complications (wound, infection, and nonunion) among those patients treated with closed, percutaneous, and open intramedullary nailing for closed tibial shaft fractures. Retrospective review. Multiple trauma centers. Skeletally mature patients with closed tibia fractures amenable to treatment with an intramedullary device. Intramedullary fixation with closed, percutaneous, or open reduction. Superficial wound complication, deep infection, nonunion. A total of 317 tibial shaft fractures in 315 patients were included in the study. Two-hundred fractures in 198 patients were treated with closed reduction, 61 fractures in 61 patients were treated with percutaneous reduction, and 56 fractures in 56 patients were treated with formal open reduction. The superficial wound complication rate was 1% (2/200) for the closed group, 1.6% (1/61) for the percutaneous group, and 3.6% (2/56) for the open group with no statistical difference between the groups (P = 0.179). The deep infection rate was 2% (4/200) for the closed group, 1.6% (1/61) for the percutaneous group, and 7.1% (4/56) for the open group with no significant difference between the groups (P = 0.133). Nonunion rate was 5.0% (10/200) for the closed group, 4.9% (3/61) for the percutaneous group, and 7.1% (4/56) for the open group, with no statistical difference between the groups (P = 0.492). This is the largest reported series of closed tibial shaft fractures nailed with percutaneous and open reduction. Percutaneous or open reduction did not result in increased wound complications, infection, or nonunion rates. Carefully performed percutaneous or open approaches can be safely used in obtaining reduction of difficult tibial shaft fractures treated with intramedullary devices. Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.
Zhang, Xuena; Wu, Anshi; Yao, Shanglong; Xue, Zhanggang; Yue, Yun
2015-01-01
Background The CONCERT-CL closed-loop infusion system designed by VERYARK Technology Co., Ltd. (Guangxi, China) is an innovation using TCI combined with closed-loop controlled intravenous anesthesia under the guide of BIS. In this study we performed a randomized, controlled, multicenter study to compare closed-loop control and open-loop control of propofol by using the CONCERT-CL closed-loop infusion system. Methods 180 surgical patients from three medical centers undergone TCI intravenous anesthesia with propofol and remifentanil were randomly assigned to propofol closed-loop group and propofol opened-loop groups. Primary outcome was global score (GS, GS = (MDAPE+Wobble)/% of time of bispectral index (BIS) 40-60). Secondary outcomes were doses of the anesthetics and emergence time from anesthesia, such as, time to tracheal extubation. Results There were 89 and 86 patients in the closed-loop and opened-loop groups, respectively. GS in the closed-loop groups (22.21±8.50) were lower than that in the opened-loop group (27.19±15.26) (p=0.009). The higher proportion of time of BIS between 40 and 60 was also observed in the closed-loop group (84.11±9.50%), while that was 79.92±13.17% in the opened-loop group, (p=0.016). No significant differences in propofol dose and time of tracheal extubation were observed. The frequency of propofol regulation in the closed-loop group (31.55±9.46 times/hr) was obverse higher than that in the opened-loop group (6.84±6.21 times/hr) (p=0.000). Conclusion The CONCERT-CL closed-loop infusion system can automatically regulate the TCI of propofol, maintain the BIS value in an adequate range and reduce the workload of anesthesiologists better than open-loop system. Trial Registration ChiCTR ChiCTR-OOR-14005551 PMID:25886041
A Unique Sample of Extreme-BCG Clusters at 0.2 < z < 0.5
NASA Astrophysics Data System (ADS)
Garmire, Gordon
2017-09-01
The recently-discovered Phoenix cluster harbors the most extreme BCG in the known universe. Despite the cluster's high mass and X-ray luminosity, it was consistently identified by surveys as an isolated AGN, due to the bright central point source and the compact cool core. Armed with hindsight, we have undertaken an all-sky survey based on archival X-ray, OIR, and radio data to identify other similarly-extreme systems that were likewise missed. A pilot study demonstrated that this strategy works, leading to the discovery of a new, massive cluster at z 0.2 which was missed by previous X-ray surveys due to the presence of a bright central QSO. We propose here to observe 6 new clusters from our complete northern-sky survey, which harbor some of the most extreme central galaxies known.
Grist : grid-based data mining for astronomy
NASA Technical Reports Server (NTRS)
Jacob, Joseph C.; Katz, Daniel S.; Miller, Craig D.; Walia, Harshpreet; Williams, Roy; Djorgovski, S. George; Graham, Matthew J.; Mahabal, Ashish; Babu, Jogesh; Berk, Daniel E. Vanden;
2004-01-01
The Grist project is developing a grid-technology based system as a research environment for astronomy with massive and complex datasets. This knowledge extraction system will consist of a library of distributed grid services controlled by a workflow system, compliant with standards emerging from the grid computing, web services, and virtual observatory communities. This new technology is being used to find high redshift quasars, study peculiar variable objects, search for transients in real time, and fit SDSS QSO spectra to measure black hole masses. Grist services are also a component of the 'hyperatlas' project to serve high-resolution multi-wavelength imagery over the Internet. In support of these science and outreach objectives, the Grist framework will provide the enabling fabric to tie together distributed grid services in the areas of data access, federation, mining, subsetting, source extraction, image mosaicking, statistics, and visualization.
Grist: Grid-based Data Mining for Astronomy
NASA Astrophysics Data System (ADS)
Jacob, J. C.; Katz, D. S.; Miller, C. D.; Walia, H.; Williams, R. D.; Djorgovski, S. G.; Graham, M. J.; Mahabal, A. A.; Babu, G. J.; vanden Berk, D. E.; Nichol, R.
2005-12-01
The Grist project is developing a grid-technology based system as a research environment for astronomy with massive and complex datasets. This knowledge extraction system will consist of a library of distributed grid services controlled by a workflow system, compliant with standards emerging from the grid computing, web services, and virtual observatory communities. This new technology is being used to find high redshift quasars, study peculiar variable objects, search for transients in real time, and fit SDSS QSO spectra to measure black hole masses. Grist services are also a component of the ``hyperatlas'' project to serve high-resolution multi-wavelength imagery over the Internet. In support of these science and outreach objectives, the Grist framework will provide the enabling fabric to tie together distributed grid services in the areas of data access, federation, mining, subsetting, source extraction, image mosaicking, statistics, and visualization.
Broad absorption-line time variability in the QSO CSO 203
NASA Technical Reports Server (NTRS)
Barlow, Thomas A.; Junkkarinen, Vesa T.; Burbidge, E. M.; Weymann, Ray J.; Morris, Simon L.; Korista, Kirk T.
1992-01-01
We present spectroscopy of the BALQSO CSO 203 during four epochs over a 17-month time span. These data show three distinct levels in the broad absorption lines (BALs) of Si IV 1397A and C IV 1549A. We also note possible variations in the N V 1240A and Al III 1857A absorption troughs. A broad-band monitoring effort during this period shows that the continuum level remained constant to within 10 percent. We argue that the triggering mechanism for the absorption-line changes is most likely synchronous with the continuum source photons; however, no correlation with the central source has yet been found. The observed variations are consistent with changes in the ionization level in the broad absorption-line region (BALR). We discuss possible mechanisms for these changes and the implications for the structure of the BALR.
Outskirts of Distant Galaxies in Absorption
NASA Astrophysics Data System (ADS)
Chen, Hsiao-Wen
QSO absorption spectroscopy provides a sensitive probe of both the neutral medium and diffuse ionized gas in the distant Universe. It extends 21 cm maps of gaseous structures around low-redshift galaxies both to lower gas column densities and to higher redshifts. Combining galaxy surveys with absorption-line observations of gas around galaxies enables comprehensive studies of baryon cycles in galaxy outskirts over cosmic time. This chapter presents a review of the empirical understanding of the cosmic neutral gas reservoir from studies of damped Lyα absorbers (DLAs). It describes the constraints on the star formation relation and chemical enrichment history in the outskirts of distant galaxies from DLA studies. A brief discussion of available constraints on the ionized circumgalactic gas from studies of lower column density Lyα absorbers and associated ionic absorption transitions is presented at the end.
Low-redshift Lyman-alpha absorption lines and the dark matter halos of disk galaxies
NASA Technical Reports Server (NTRS)
Maloney, Philip
1992-01-01
Ultraviolet observations of the low-redshift quasar 3C 273 using the Hubble Space Telescope have revealed many more Lyman-alpha absorption lines than would be expected from extrapolation of the absorption systems seen toward QSOs at z about 2. It is shown here that these absorption lines can plausibly be produced by gas at large radii in the disks of spiral and irregular galaxies; the gas is confined by the dark matter halos and ionized and heated by the extragalactic radiation field. This scenario does not require the extragalactic ionizing radiation field to decline as rapidly with decreasing z as the QSO emissivity. Observations of Ly-alpha absorption through the halos of known galaxies at low redshift will constrain both the extragalactic background and the properties of galactic halos.
High-resolution observations of the QSO 3C 345 at 1.3 centimeters
NASA Technical Reports Server (NTRS)
Baath, L. B.; Ronnang, B. O.; Pauliny-Toth, I. I. K.; Preuss, E.; Witzel, A.; Matveenko, L. I.; Kogan, L. R.; Kostenko, V. I.; Shaffer, D. B.
1981-01-01
High-resolution VLBI observations made at a frequency of 22.235 GHz of the quasar 3C 345 are discussed. Antennas located at the Crimean Astrophysical Observatory, USSR; Onsala, Sweden; Effelsberg, West Germany; and the Haystack Observatory, Massachusetts were employed at 4-min integration times to provide baselines ranging up to 5.5 x 10 to the 8th wavelengths. About 40% of the total flux density of 7.85 Jy, observed in November 1977, and 8.05 Jy, observed in October 1978, is found to originate in an unresolved component of the quasar core in a region less than 0.1 milliarcsec in diameter. The elongated jet-like component of the quasar is observed to contain several peaks of emission extending up to 6 milliarsec from the core which decreased in extent between the two observations.
Dark Galaxies and Lost Baryons (IAU S244)
NASA Astrophysics Data System (ADS)
Davies, Jonathan I.; Disney, Michael J.
2008-05-01
Preface; Conference prelims; The HI that barked in the night M. J. Disney; The detection of dark galaxies in blind HI surveys J. I. Davies; Red haloes of galaxies - reservoirs of baryonic dark matter? E. Zackrisson, N. Bergvall, C. Flynn, G. Ostlin, G. Micheva and B. Baldwell; Constraints on dark and visible mass in galaxies from strong gravitational lensing S. Dye and S. Warren; Lost baryons at low redshift S. Mathur, F. Nicastro and R. Williams; Observed properties of dark matter on small spatial scales R. Wyse and G. Gilmore; The mass distribution in spiral galaxies P. Salucci; Connecting lost baryons and dark galaxies via QSO absorption lines T. Tripp; ALFALFA: HI cosmology in the local universe R. Giovanelli; The ALFALFA search for (almost) dark galaxies across the HI mass function M. Haynes; HI clouds detected towards Virgo with the Arecibo Legacy Fast ALFA Survey B. Kent; Cosmic variance in the HI mass function S. Schneider; The Arecibo Galaxy Environments Survey - potential for finding dark galaxies and results so far R. Minchin et al.; Free-floating HI clouds in the M81 group E. Brinks, F. Walter and E. Skillman; Where are the stars in dark galaxies J. Rosenberg, J. Salzer and J. Cannon; The halo by halo missing baryon problem S. McGaugh; The local void is really empty R. Tully; Voids in the local volume: a limit on appearance of a galaxy in a dark matter halo A. Tikhonov and A. Klypin; Dim baryons in the cosmic web C. Impey; A census of baryons in galaxy clusters and groups A. Gonzalez, D. Zaritsky and A. Zabludo; Statistical properties of the intercluster light from SDSS image stacking S. Zibetti; QSO strong gravitational lensing and the detection of dark halos A. Maccio; Strong gravitational lensing: bright galaxies and lost dark-matter L. Koopmans; Mapping the distribution of luminous and dark matter in strong lensing galaxies I. Ferreras, P. Saha, L. Williams and S. Burles; Tidal debris posing as dark galaxies P. Duc, F. Bournaud and E. Brinks; Numerical simulation of the dwarf companions of giant galaxies A. Nelson and P. Williams; Delayed galaxies C. Struck, M. Hancock, B. Smith, P. Appleton, V. Charmandaris and M. Giroux; Probe of dark galaxies via disturbed/lopsided isolated galaxies I. Karachentsev, V. Karachentseva, W. Huchtmeier, D. Makarov and S. Kaisin; Star formation thresholds J. Schaye; Scaling relations of dwarf galaxies without supernova-driven winds K. Tassis, A. Kravtsov and N. Gnedin; Star formation in massive low surface brightness galaxies K. O'Neil; Linking clustering properties and the evolution of low surface brightness galaxies D. Bomans and S. Rosenbaum; Too small to form a galaxy: how the UV background determines the baryon fraction M. Hoeft, G. Yepes and S. Gottlober; Star formation in damped Lyman selected galaxies L. Christensen; Dark-matter content of early-type galaxies with planetary nebulae N. Napolitano et al.; Hunting for ghosts: low surface brightnesses from pixels R. Scaramella and S. Sabatini; Baryonic properties of the darkest galaxies E. Grebel; The dwarf low surface brightness population in different environments of the local universe S. Sabatini, J. Davies, S. Roberts and R. Scaramella; Mass modelling of dwarf spheroidal galaxies J. Klimentowski et al.; Evolution of dwarf galaxies in the Centaurus A Group L. Makarova and D. Makarov; A flat faint end of the Fornax cluster galaxy luminosity function S. Mieske, M. Hilker, L. Infante and C. Mendes de Oliveira; Can massive dark halos destroy the discs of dwarf galaxies? B. Fuchs and O. Esquivel; 'Dark galaxies' and local very metal-poor gas-rich galaxies: possible interrelations S. Pustilnik; Morphology and environment of dwarf galaxies in the local universe H. Ann; Arecibo survey of HI emission from disk galaxies at redshift z 0.2 B. Catinella, M. Haynes, J. Gardner, A. Connolly and R. Giovanelli; AGES observations of
Jacobson, Nicholas C.; Newman, Michelle G.
2016-01-01
Background Previous research has demonstrated that anxiety reliably predicts later depression, but little has been uncovered about the mechanism underlying this connection. Interpersonal relationships appear to be a viable mechanism of the association as anxiety has been shown to predict later deficits in both close (e.g., “best friendships”) and group relationships (e.g., classroom peer groups), and deficits in both close and group relationships have been linked to later depressive symptoms. The current study examined close and group relationships as potential mediators between anxiety and depression 12–14 years later. Methods In a nationally representative sample of adolescents (N = 6,504), anxiety was measured at baseline, perceptions of close relationships (i.e., feeling loved) and perceptions of group relationships (i.e., feeling part of a group) were measured 6 months later, and depression levels and diagnosis were measured 12–14 years later. Results Using structural equation models, the results showed that adolescent perceptions of both close and group relationships significantly mediated the relationship between adolescent anxiety and adult levels of depression. Furthermore, perceptions of not being accepted/loved in close relationships significantly mediated the relationship between adolescent anxiety and clinical depression in adulthood. Conclusions These results suggest that a perception of not being accepted in group relationships may be a mechanism by which heightened anxiety in adolescents leads to heightened nonclinical depression in adulthood. On the other hand, adolescent perceptions of not feeling loved or accepted in close relationships may be a mechanism by which heightened anxiety in adolescence leads to clinical depression—in adulthood. PMID:26290461
Jacobson, Nicholas C; Newman, Michelle G
2016-01-01
Previous research has demonstrated that anxiety reliably predicts later depression, but little has been uncovered about the mechanism underlying this connection. Interpersonal relationships appear to be a viable mechanism of the association as anxiety has been shown to predict later deficits in both close (e.g., "best friendships") and group relationships (e.g., classroom peer groups), and deficits in both close and group relationships have been linked to later depressive symptoms. The current study examined close and group relationships as potential mediators between anxiety and depression 12-14 years later. In a nationally representative sample of adolescents (N = 6,504), anxiety was measured at baseline, perceptions of close relationships (i.e., feeling loved) and perceptions of group relationships (i.e., feeling part of a group) were measured 6 months later, and depression levels and diagnosis were measured 12-14 years later. Using structural equation models, the results showed that adolescent perceptions of both close and group relationships significantly mediated the relationship between adolescent anxiety and adult levels of depression. Furthermore, perceptions of not being accepted/loved in close relationships significantly mediated the relationship between adolescent anxiety and clinical depression in adulthood. These results suggest that a perception of not being accepted in group relationships may be a mechanism by which heightened anxiety in adolescents leads to heightened nonclinical depression in adulthood. On the other hand, adolescent perceptions of not feeling loved or accepted in close relationships may be a mechanism by which heightened anxiety in adolescence leads to clinical depression--in adulthood. © 2015 Wiley Periodicals, Inc.
Vadai, Yishay; Poznanski, Dovi; Baron, Dalya; ...
2017-08-14
In recent years, the autocorrelation of the hydrogen Lyman α forest has been used to observe the baryon acoustic peak at redshift 2 < z < 3.5 using tens of thousands of QSO spectra from the BOSS survey. However, the interstellar medium of the Milky Way introduces absorption lines into the spectrum of any extragalactic source. These lines, while weak and undetectable in a single BOSS spectrum, could potentially bias the cosmological signal. In order to examine this, we generate absorption line maps by stacking over a million spectra of galaxies and QSOs. Here, we find that the systematics introducedmore » are too small to affect the current accuracy of the baryon acoustic peak, but might be relevant to future surveys such as the Dark Energy Spectroscopic Instrument (DESI). We outline a method to account for this with future data sets.« less
EGRET sources at intermediate galactic latitude
NASA Technical Reports Server (NTRS)
Halpern, Jules P. (Principal Investigator)
1996-01-01
This paper presents the abstracts of four papers (using ROSAT data) that are submitted to refereed journals during the current reporting period. The papers are: (1) Extreme x-ray variability in the narrow-line QSO PHL 1092; (2) The Geminga pulsar (soft x-ray variability and an EUVE observation); (3) a broad-band x-ray study of the geminga pulsar; and (4) Classification of IRAS-selected x-ray galaxies in the ROSAT all-sky survey. The abstracts of these papers are given in the next four sections of this report, and their status is given in the Appendix. Finally, two new projects (De-identifying a non-AGN and EGRET sources at intermediate galactic latitude) for which ROSAT data were recently received are currently being studied under this grant. A summary of work in progress on these new projects is given in the last two sections of this report.
Quasars at the Cosmic Dawn: effects on Reionization properties in cosmological simulations
NASA Astrophysics Data System (ADS)
Garaldi, Enrico; Compostella, Michele; Porciani, Cristiano
2018-05-01
We study a model of cosmic reionization where quasars (QSOs) are the dominant source of ionizing photons at all relevant epochs. We employ a suite of adaptive hydrodynamical simulations post-processed with a multi-wavelength Monte Carlo radiative-transfer code and calibrate them in order to accurately reproduce the observed quasar luminosity function and emissivity evolution. Our results show that the QSO-only model fails in reproducing key observables linked to the Helium reionization, as the temperature evolution of the inter-galactic medium (IGM) and the HeII effective optical depth in synthetic Lyα spectra. Nevertheless, we find hints that an increased quasar contribution can explain recent measurements of a large inhomogeneity in the IGM at redshift z ~ 5. Finally, we devise a method capable of constraining the QSOs contribution to the reionization from the properties of the HeII Lyα forest at z ~ 3.5.
Optical monitoring of QSO in the framework of the Gaia space mission
NASA Astrophysics Data System (ADS)
Taris, F.; Damljanovic, G.; Andrei, A.; Klotz, A.; Vachier, F.
2015-08-01
The Gaia astrometric mission of the European Space Agency has been launched the 19th December 2013. It will provide an astrometric catalogue of 500 000 extragalactic sources that could be the basis of a new optical reference frame. On the other hand, the current International Celestial Reference Frame (ICRF) is based on the observations of extragalactic sources at radio wavelength. The astrometric coordinates of sources in these two reference systems will have roughly the same uncertainty. It is then mandatory to observe a set of common targets at both optical and radio wavelength to link the ICRF with what could be called the GCRF (Gaia Celestial Reference Frame). We will show in this paper some results obtained with the TJO, Telescopi Juan Oro, from Observatori Astronomic del Montsec in Spain. It also presents some results obtained with the Lomb-Scargle and CLEAN algorithm methods applied to optical magnitude obtained with the TAROT telescopes.
Gravitational lensing effects of vacuum strings - Exact solutions
NASA Technical Reports Server (NTRS)
Gott, J. R., III
1985-01-01
Exact interior and exterior solutions to Einstein's field equations are derived for vacuum strings. The exterior solution for a uniform density vacuum string corresponds to a conical space while the interior solution is that of a spherical cap. For Mu equals 0-1/4 the external metric is ds-squared = -dt-squared + dr-squared + (1-4 Mu)-squared r-squared dphi-squared + dz-squared, where Mu is the mass per unit length in the string in Planck masses per Planck length. A maximum mass per unit length for a string is 6.73 x 10 to the 27th g/cm. It is shown that strings cause temperature fluctuations in the cosmic microwave background and produce equal brightness double QSO images separated by up to several minutes of arc. Formulae for lensing probabilities, image splittings, and time delays are derived for strings in a realistic cosmological setting. String searches using ST, the VLA, and the COBE satellite are discussed.
The distant red galaxy neighbour population of 1
NASA Astrophysics Data System (ADS)
Bornancini, C.; García Lambas, D.
We study the Distant Red Galaxy (DRG, J-Ks > 2.3) neighbour population of Quasi Stellar Objects (QSOs) selected from the Sloan Digital Sky Survey (SDSS) in the redshift range 1 < z < 2. We perform a similar analysis for optically obscured AGNs (i.e. with a limiting magnitude I > 24) detected in the mid-infrared (24 microns) with the Spitzer Space Telescope and a mean redshift z~2.2 in the Flamingos Extragalactic Survey (FLAMEX). We present results on the cross-correlation function of DRGs around QSOs and optically faint mid-infrared sources. The corresponding correlation length obtained for the QSO sample targets is r_0=5.4+/-1.6 Mpc. For the optically obscured galaxy sample we find r_0=8.9+/-1.4 Mpc. These results indicate that optically faint obscured sources are located in denser environment of evolved red galaxies compare to QSOs.
Far-ultraviolet absorption spectra of quasars: How to find missing hot gas and metals
NASA Technical Reports Server (NTRS)
Verner, D. A.; Tytler, David; Barthel, P. D.
1994-01-01
We show that some high-redshift QSO absorption systems that reveal only the H I Lyman series lines at wavelengths visible from the ground maybe a new class of ultra-high-ionization metal line systems, with metal lines in the far-UV region which is now being explored with satellites. At high temperatures or in intense radiation fields metal systems will not show the usual C IV absorption, and O VI will become the most prominent metal absorber. At still higher ionization, O IV also becomes weak and the strongest metal lines are from Ne VIII, Mg X and Si XII, which have doublets in the rangs 500-800 A. Hence very high ionization metal systems will not show metal lines in existing spectra. Recent X-ray observations show that galaxy halos contain hot gas, so we predict that far-UV spectra of QSOs will also show this gas.
Modeling MgII Absorbers from SDSS Spectroscopic and Imaging Catalogs
NASA Astrophysics Data System (ADS)
Rimoldini, L. G.; Menard, B.; Nestor, D. B.; Rao, S. M.; Sheth, R. K.; Turnshek, D. A.; Zibetti, S.; Feather, S.; Quider, A.
2005-12-01
The detection of more than 14,000 MgII absorption doublets along the sight-lines to SDSS DR4 QSOs (pursued by Turnshek, Nestor, Rao, and collaborators) has produced the largest sample of MgII absorbers to date in the redshift interval 0.37 < z < 2.30. The statistical relation between galaxies and MgII systems is investigated by cross-correlating the spectroscopic MgII catalog with the SDSS imaging catalog of galaxies in the neighborhood of QSO sight-lines. A model for MgII absorbers is derived to account for the measured MgII rest equivalent width distribution and the absorbing galaxy properties (e.g., luminosity, impact parameter, and morphological type). Some preliminary results of our analysis are presented. This work was supported in part by the National Science Foundation. L.G.R. acknowledges further support from the Z. Daniel's Predoctoral Fellowship.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Vadai, Yishay; Poznanski, Dovi; Baron, Dalya
In recent years, the autocorrelation of the hydrogen Lyman α forest has been used to observe the baryon acoustic peak at redshift 2 < z < 3.5 using tens of thousands of QSO spectra from the BOSS survey. However, the interstellar medium of the Milky Way introduces absorption lines into the spectrum of any extragalactic source. These lines, while weak and undetectable in a single BOSS spectrum, could potentially bias the cosmological signal. In order to examine this, we generate absorption line maps by stacking over a million spectra of galaxies and QSOs. Here, we find that the systematics introducedmore » are too small to affect the current accuracy of the baryon acoustic peak, but might be relevant to future surveys such as the Dark Energy Spectroscopic Instrument (DESI). We outline a method to account for this with future data sets.« less
Fixing the reference frame for PPMXL proper motions using extragalactic sources
Grabowski, Kathleen; Carlin, Jeffrey L.; Newberg, Heidi Jo; ...
2015-05-27
In this study, we quantify and correct systematic errors in PPMXL proper motions using extragalactic sources from the first two LAMOST data releases and the Vèron-Cetty & Vèron Catalog of Quasars. Although the majority of the sources are from the Vèron catalog, LAMOST makes important contributions in regions that are not well-sampled by previous catalogs, particularly at low Galactic latitudes and in the south Galactic cap. We show that quasars in PPMXL have measurable and significant proper motions, which reflect the systematic zero-point offsets present in the catalog. We confirm the global proper motion shifts seen by Wu et al.,more » and additionally find smaller-scale fluctuations of the QSO-derived corrections to an absolute frame. Finally, we average the proper motions of 158 106 extragalactic objects in bins of 3° × 3° and present a table of proper motion corrections.« less
Observation of high-energy gamma rays from the quasi-stellar object CTA 102
NASA Technical Reports Server (NTRS)
Nolan, P. L.; Bertsch, D. L.; Fichtel, C. E.; Hartman, R. C.; Hunter, S. D.; Kanbach, G.; Kniffen, D. A.; Lin, Y. C.; Mattox, J. R.; Mayer-Hasselwander, H. A.
1993-01-01
The quasar CTA 102 (QSO 2230 + 114) was observed four times in 1991-1992 by the EGRET high-energy gamma-ray telescope on the Compton GRO satellite. In the 1992 January 23-February 6 observation, emission was detected at the level (2.4 +/- 0.5) x 10 exp 7 photons/sq cm s (E is greater than 100 MeV). The other observations produced upper limits or detections with lower significance which are consistent with the same flux. The photon spectrum can be represented by a power law with a number index of 2.6 +/- 0.2, the softest so far observed by EGRET. The emitted gamma-ray luminosity, if isotropic, is 5 x 10 exp 47 ergs/s (H(0) = 75 km/s Mpc , q(0) = 0.5), although there are good reasons to believe that the gamma emission is strongly beamed.
Possible nutrient limiting factor in long term operation of closed aquatic ecosystem
NASA Astrophysics Data System (ADS)
Hao, Zongjie; Li, Yanhui; Cai, Wenkai; Wu, Peipei; Liu, Yongding; Wang, Gaohong
2012-03-01
To investigate nutrient limitation effect on the community metabolism of closed aquatic ecosystem and possible nutrient limiting factors in the experimental food chains, depletion of inorganic chemicals including carbon, nitrogen and phosphorous was tested. A closed aquatic ecosystem lab module consisting of Chlorella pyrenoidosa and Chlamydomonas reinhardtii, Daphnia magna and associated unidentified microbes was established. Closed ecological systems receive no carbon dioxide; therefore, we presumed carbon as a first limiting factor. The results showed that the algae population in the nutrient saturated group was statistically higher than that in the nutrient limited groups, and that the chlorophyll a content of algae in the phosphorus limited group was the highest among the limited groups. However, the nitrogen limited group supported the most Daphnia, followed by the carbon limited group, the nutrient saturated group and the phosphorus limited group. Redundancy analysis showed that the total phosphorus contents were correlated significantly with the population of algae, and that the amount of soluble carbohydrate as feedback of nutrient depletion was correlated with the number of Daphnia. Thus, these findings suggest that phosphorus is the limiting factor in the operation of closed aquatic ecosystem. The results presented herein have important indications for the future construction of long term closed ecological system.
Building the Foundation for Close Reading with Developing Readers
ERIC Educational Resources Information Center
Baker, Sheila F.; McEnery, Lillian
2017-01-01
Close Reading utilizes several strategies to help readers think more critically about a text. Close reading can be performed within the context of shared readings, read-alouds by the teacher, literature discussion groups, and guided reading groups. Students attempting to more closely read difficult texts may benefit from technologies and platforms…
[A Feasibility Study of closing the small bowel with high-frequency welding device].
Zhou, Huabin; Han, Shuai; Chen, Jun; Huang, Dequn; Peng, Liang; Ning, Jingxuan; Li, Zhou
2014-12-01
This study aimed to evaluate the feasibility and effectiveness of closing the small bowel in an ex vivo porcine model with high-frequency welding device. A total of 100 porcine small bowels were divided into two groups, and then were closed with two different methods. The fifty small bowels in experimental group were closed by the high-frequency welding device, and the other fifty small bowels in comparison group were hand-sutured. All the small bowels were subjected to leak pressure testing later on. The speed of closure and bursting pressure were compared. The 50 porcine small bowels closed by the high-frequency welding device showed a success rate of 100%. Compared with the hand-sutured group, the bursting pressures of the former were significantly lower (P<0.01) and the closing process was significantly shorter (P<0.01). The pathological changes of the closed ends mainly presented as acute thermal and pressure induced injury. Experimental results show that the high-frequency welding device has higher feasibility in closing the small bowel.
Desai, A; Wu, H; Sun, L; Sesterhenn, I A; Mostofi, F K; McLeod, D; Amling, C; Kusuda, L; Lance, R; Herring, J; Foley, J; Baldwin, D; Bishoff, J T; Soderdahl, D; Moul, J W
2002-01-01
The objectives of this work were to evaluate the efficacy of controlled close step-sectioned and whole-mounted radical prostatectomy specimen processing in prediction of clinical outcome as compared to the traditional processing techniques. Two-hundred and forty nine radical prostatectomy (RP) specimens were whole-mounted and close step-sectioned at caliper-measured 2.2-2.3 mm intervals. A group of 682 radical prostatectomy specimens were partially sampled as control. The RPs were performed during 1993-1999 with a mean follow-up of 29.3 months, pretreatment PSA of 0.1-40, and biopsy Gleason sums of 5-8. Disease-free survival based on biochemical or clinical recurrence and secondary intervention were computed using a Kaplan-Meier analysis. There were no significant differences in age at diagnosis, age at surgery, PSA at diagnosis, or biopsy Gleason between the two groups (P<0.05). Compared with the non-close step-sectioned group, the close step-sectioned group showed higher detection rates of extra-prostatic extension (215 (34.1%) vs, 128 (55.4%), P<0.01), and seminal vesicle invasion (50 (7.6%) vs 35 (14.7%), P<0.01). The close step-sectioned group correlated with greater 3-y disease-free survival in organ-confined (P<0.01) and specimen-confined (P<0.01) cases, over the non-uniform group. The close step-sectioned group showed significantly higher disease-free survival for cases with seminal vesicle invasion (P=0.046). No significant difference in disease-free survival was found for the positive margin group (P=0.39) between the close step-sectioned and non-uniform groups. The close step-sectioned technique correlates with increased disease-free survival rates for organ and specimen confined cases, possibly due to higher detection rates of extra-prostatic extension and seminal vesicle invasion. Close step-sectioning provides better assurance of organ-confined disease, resulting in enhanced prediction of outcome by pathological (TNM) stage.
Discovery of a Dwarf Poststarburst Galaxy near a High Column Density Local Lyα Absorber
NASA Astrophysics Data System (ADS)
Stocke, John T.; Keeney, Brian A.; McLin, Kevin M.; Rosenberg, Jessica L.; Weymann, R. J.; Giroux, Mark L.
2004-07-01
We report the discovery of a dwarf (MB=-13.9) poststarburst galaxy coincident in recession velocity (within uncertainties) with the highest column density absorber (NHI=1015.85 cm-2 at cz=1586 km s- 1) in the 3C 273 sight line. This galaxy is by far the closest galaxy to this absorber, projected just 71h-170 kpc on the sky from the sight line. The mean properties of the stellar populations in this galaxy are consistent with a massive starburst ~3.5 Gyr ago, whose attendant supernovae, we argue, could have driven sufficient gas from this galaxy to explain the nearby absorber. Beyond its proximity on the sky and in recession velocity, the further evidence in favor of this conclusion includes both a match in the metallicities of absorber and galaxy and the fact that the absorber has an overabundance of Si/C, suggesting recent Type II supernova enrichment. Thus, this galaxy and its ejecta are in the expected intermediate stage in the fading dwarf evolutionary sequence envisioned by Babul & Rees to explain the abundance of faint blue galaxies at intermediate redshifts. While this one instance of a QSO metal-line absorber and a nearby dwarf galaxy is not proof of a trend, a similar dwarf galaxy would be too faint to be observed by galaxy surveys around more distant metal-line absorbers. Thus, we cannot exclude the possibility that dwarf galaxies are primarily responsible for weak (NHI=1014-1017 cm-2) metal-line absorption systems in general. If a large fraction of the dwarf galaxies expected to exist at high redshift had a similar history (i.e., they had a massive starburst that removed all or most of their gas), these galaxies could account for at least several hundred high-z metal-line absorbers along the line of sight to a high-z QSO. The volume-filling factor for this gas, however, would be less than 1%. ID="FN1"> 1Based on observations made with the Apache Point 3.5 m telescope, operated by the Astronomical Research Consortium, and the 2.6 m du Pont telescope of the Las Campanas Observatory, operated by the Carnegie Institution of Washington, DC, and Pasadena, CA.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Christopher Martin, D.; Chang, Daphne; Matuszewski, Matt
The intergalactic medium (IGM) is the dominant reservoir of baryons, delineates the large-scale structure of the universe at low to moderate overdensities, and provides gas from which galaxies form and evolve. Simulations of a cold-dark-matter- (CDM-) dominated universe predict that the IGM is distributed in a cosmic web of filaments and that galaxies should form along and at the intersections of these filaments. While observations of QSO absorption lines and the large-scale distribution of galaxies have confirmed the CDM paradigm, the cosmic web of IGM has never been confirmed by direct imaging. Here we report our observation of the Lyαmore » blob 2 (LAB2) in SSA22 with the Cosmic Web Imager (CWI). This is an integral field spectrograph optimized for low surface brightness, extended emission. With 22 hr of total on- and off-source exposure, CWI has revealed that LAB2 has extended Lyα emission that is organized into azimuthal zones consistent with filaments. We perform numerous tests with simulations and the data to secure the robustness of this result, which relies on data with modest signal-to-noise ratios. We have developed a smoothing algorithm that permits visualization of data cube slices along image or spectral image planes. With both raw and smoothed data cubes we demonstrate that the filaments are kinematically associated with LAB2 and display double-peaked profiles characteristic of optically thick Lyα emission. The flux is 10-20 times brighter than expected for the average emission from the IGM but is consistent with boosted fluorescence from a buried QSO or gravitation cooling radiation. Using simple emission models, we infer a baryon mass in the filaments of at least 1-4 × 10{sup 11} M {sub ☉}, and the dark halo mass is at least 2 × 10{sup 12} M {sub ☉}. The spatial-kinematic morphology is more consistent with inflow from the cosmic web than outflow from LAB2, although an outflow feature maybe present at one azimuth. LAB2 and the surrounding gas have significant and coaligned angular momentum, strengthening the case for their association.« less
NASA Astrophysics Data System (ADS)
Moser, Lydia; Krips, Melanie; Busch, Gerold; Scharwächter, Julia; König, Sabine; Eckart, Andreas; Smajić, Semir; García-Marin, Macarena; Valencia-S., Mónica; Fischer, Sebastian; Dierkes, Jens
2016-03-01
We present a pilot study of ~3'' resolution observations of low CO transitions with the Submillimeter Array in three nearby Seyfert galaxies, which are part of the low-luminosity quasi-stellar object (LLQSOs) sample consisting of 99 nearby (z = 0.06) type-1 active galactic nuclei (AGN) taken from the Hamburg/ESO quasi-stellar object (QSO) survey. Two sources were observed in 12CO(2-1) and 13CO(2-1) and the third in 12CO(3-2) and HCO+(4-3). None of the sources is detected in continuum emission. More than 80% of the 12CO detected molecular gas is concentrated within a diameter (FWHM) < 1.8 kpc. 13CO is tentatively detected, while HCO+ emission could not be detected. All three objects show indications of a kinematically decoupled central unresolved molecular gas component. The molecular gas masses of the three galaxies are in the range Mmol = (0.7-8.7) × 109M⊙. We give lower limits for the dynamical masses of Mdyn> 1.5 × 109M⊙ and for the dust masses of Mdust> 1.6 × 106M⊙. The R21 = 12CO/13CO(2-1) line luminosity ratios show Galactic values of R21 ~ 5-7 in the outskirts and R21 ≳ 20 in the central region, similar to starbursts and (ultra)luminous infrared galaxies ((U)LIRGs; I.e. LIRGs and ULIRGs), implying higher temperatures and stronger turbulence. All three sources show indications of 12CO(2-1)/12CO(1-0) ratios of ~0.5, suggesting a cold or diffuse gas phase. Strikingly, the 12CO(3-2)/(1-0) ratio of ~1 also indicates a higher excited phase. Since these galaxies have high infrared luminosities of LIR ≥ 1011L⊙ and seem to contain a circumnuclear starburst with minimum surface densities of gas and star formation rate (SFR) around Σmol = 50-550 M⊙pc-2 and ΣSFR = 1.1-3.1 M⊙ kpc-2 yr-1, we conclude that the interstellar medium in the centers of these LIRG Seyferts is strongly affected by violent star formation and better described by the ULIRG mass conversion factor.
Studies of effects of closed microbial ecology. Report of 180-day test period
NASA Technical Reports Server (NTRS)
Kenyon, A. J.
1972-01-01
Experiments were performed to determine the influence closed microbial ecologies have on modification or simplification of natural intestinal flora of ferrets in a closed environmental system. On the basis of previous tests in which certain species (Salmonella and Bacteroides) were decreased at 90 days of enclosure, a second trial was constructed for 180-day tests. In this trial there was little difference in the 8 major classes of intestinal flora between animals in the Open and Closed environmental groups except for the level of Lactobacillus. It is of extreme importance to note that when both Open and Closed groups contracted hemorrhagic gastritis, the interrelationship of this agent with other intestinal flora produced a more profound effect on animals from the Closed Group, particularly with reference to Lactobacillus levels.
Comparison of open versus closed group interventions for sexually abused adolescent girls.
Tourigny, Marc; Hébert, Martine
2007-01-01
A first aim of this study is to evaluate the efficacy of an open group therapy for sexually abused teenagers using a quasi-experimental pretest/posttest treatment design. A second aim was to explore whether differential gains were linked to an open versus a closed group format. Results indicate that sexually abused girls involved in an open group therapy showed significant gains relative to teenagers of the control group girls for the majority of the variables considered. Analyses contrasting the two formats of group therapy fail to identify statistical differences suggesting that both open and closed group formats are likely to be associated with the same significant gains for sexually abused teenagers.
Tatli, Ersan; Vatan, Mehmet Bulent; Agac, Mustafa Tarik; Gunduz, Huseyin; Akdemir, Ramazan; Kilic, Harun
2017-01-01
Introduction Carotid artery stenting (CAS) is a promising alternative to surgery in high-risk patients. However, the impact of stent cell design on outcomes in CAS is a matter of continued debate. Aim To compare the periprocedural and clinical outcomes of different stent designs for CAS with distal protection devices. Material and methods All CAS procedures with both closed- and hybrid-cell stents performed at our institution between February 2010 and December 2015 were analyzed retrospectively. Adverse events were defined as death, major stroke, minor stroke, transient ischemic attack and myocardial infarction. Periprocedural and 30-day adverse events and internal carotid artery (ICA) vasospasm rates were compared between the closed-cell and hybrid-cell stent groups. Results The study included 234 patients comprising 146 patients with a closed-cell stent (Xact stent, Abbott Vascular) (mean age: 68.5 ±8.6; 67.1% male) and 88 patients with a hybrid-cell stent (Cristallo Ideale, Medtronic) (mean age: 67.2 ±12.8; 68.2% male). There was no significant difference between the groups with respect to periprocedural or 30-day adverse event rates. While there was no difference in terms of tortuosity index between the groups, there was a higher procedural ICA vasospasm rate in the closed-cell stent group (35 patients, 23%) compared with the hybrid-cell stent group (10 patients, 11%) (p = 0.017). Conclusions The results of this study showed no significant difference in the clinical adverse event rates after CAS between the closed-cell stent group and the hybrid-cell stent group. However, procedural ICA vasospasm was more common in the closed-cell stent group. PMID:28798784
Sullivan, Lauren A; Campbell, Vicki L; Onuma, Serene C
2010-07-15
To determine whether use of a closed urine collection system would decrease the incidence of nosocomial bacteriuria in hospitalized dogs, compared with use of an open urine collection system (used, sterile IV bags). Randomized controlled trial. 51 hospitalized dogs requiring indwelling urinary catheterization for >or= 24 hours. Dogs were randomly assigned to an open or closed urine collection system group. A standardized protocol for catheter placement and maintenance was followed for all dogs. A baseline urine sample was collected via cystocentesis for aerobic bacterial culture, with additional urine samples obtained daily from the urine collection reservoir. 27 dogs were assigned to the open urine collection system group, and 24 were assigned to the closed urine collection system group. The incidence of nosocomial bacteriuria in dogs with open urine collection systems (3/27 [11.1%]) was not significantly different from incidence in dogs with closed urine collection systems (2/24 [8.3%]). Median duration of catheterization was 2 days for dogs in both groups; the range was 1 to 7 days for dogs in the open group and 1 to 5 days for dogs in the closed group. Results suggested that for dogs requiring short-term indwelling urinary catheterization, the type of urine collection system (open vs closed) was not associated with likelihood of developing nosocomial bacteriuria. Use of a strict protocol for urinary catheter placement and maintenance was likely key in the low incidence of nosocomial bacteriuria in the present study.
Federal Register 2010, 2011, 2012, 2013, 2014
2012-05-01
..., Command and Control, Science and Technology, Missile Defense. Meeting Accessibility: Pursuant to 5 U.S.C... DEPARTMENT OF DEFENSE Notice of Advisory Committee Closed Meeting; U.S. Strategic Command Strategic Advisory Group AGENCY: Department of Defense. ACTION: Notice of Advisory Committee closed meeting...
Comparison of closed and open methods of pneumoperitonium in laparoscopic cholecystectomy.
Akbar, Mohammad; Khan, Ishtiaq Ali; Naveed, Danish; Khattak, Irfanuddin; Zafar, Arshad; Wazir, Muhammad Salim; Khan, Asif Nawaz; Zia-ur-Rehman
2008-01-01
Pneumoperitonium is the first step in laparoscopic surgery including cholecystectomy. Two commonly used methods to create pneumoperitonium are closed and open technique. Both have advantages and disadvantages. The current study was designed to compare these two techniques in terms of safety and time required to complete the procedure. This was a randomized controlled prospective study conducted at Department of Surgery, Ayub Hospital Complex Abbottabad, from 1st June 2007 to 31st May 2008. Randomization was done into two groups randomly using sealed envelopes containing the questionnaire. Seventy envelopes were kept in the cupboard, containing 35 proformas for group A and 35 for group B. An envelope was randomly fetched and opened upon selection of the patient after taking the informed consent. Pneumoperitonium was created by closed technique in group A, and by open technique in group B. Time required for successful pneumoperitonium was calculated in each group. Failure to induce pneumoperitonium was determined for each technique. Time required to close the wounds at completion, total operating time and injuries sustained during induction of pneumoperitonium were compared in both techniques. Out of the total 70 patients included in study, 35 were in group A and 35 in group B. Mean time required for successful pneumoperitonium was 9.17 minutes in group A and 8.11 minutes in group B. Total operating time ranged from 55 minutes to 130 minutes in group A and from 45 minutes to 110 minutes in group B. Mean of total operating time was 78.34 and 67 minutes in group A and B respectively. Mean time needed to close the wound was 9.88 minutes in group A and 4.97 minutes in group B. Failure of technique was noted in three patients in group A while no failure was experienced in group B. In two cases in group A minor complications during creation of pneumoperitonium were observed while in group B no complication occurred. No patient died in the study. We concluded from this study that open technique of pneumoperitonium was, less time consuming and safer than the closed technique.
Lilot, Marc; Bellon, Amandine; Gueugnon, Marine; Laplace, Marie-Christine; Baffeleuf, Bruno; Hacquard, Pauline; Barthomeuf, Felicie; Parent, Camille; Tran, Thomas; Soubirou, Jean-Luc; Robinson, Philip; Bouvet, Lionel; Vassal, Olivia; Lehot, Jean-Jacques; Piriou, Vincent
2018-01-27
An intraoperative automated closed-loop system for goal-directed fluid therapy has been successfully tested in silico, in vivo and in a clinical case-control matching. This trial compared intraoperative cardiac output (CO) in patients managed with this closed-loop system versus usual practice in an academic medical center. The closed-loop system was connected to a CO monitoring system and delivered automated colloid fluid boluses. Moderate to high-risk abdominal surgical patients were randomized either to the closed-loop or the manual group. Intraoperative final CO was the primary endpoint. Secondary endpoints were intraoperative overall mean cardiac index (CI), increase from initial to final CI, intraoperative fluid volume and postoperative outcomes. From January 2014 to November 2015, 46 patients were randomized. There was a lower initial CI (2.06 vs. 2.51 l min -1 m -2 , p = 0.042) in the closed-loop compared to the control group. No difference in final CO and in overall mean intraoperative CI was observed between groups. A significant relative increase from initial to final CI values was observed in the closed-loop but not the control group (+ 28.6%, p = 0.006 vs. + 1.2%, p = 0.843). No difference was found for intraoperative fluid management and postoperative outcomes between groups. There was no significant impact on the primary study endpoint, but this was found in a context of unexpected lower initial CI in the closed-loop group.Trial registry number ID-RCB/EudraCT: 2013-A00770-45. ClinicalTrials.gov Identifier NCT01950845, date of registration: 17 September 2013.
Farahani, T Amirabadi; Amanlou, H; Kazemi-Bonchenari, M
2017-08-01
This experiment was conducted to compare conventional (CON; 21 d) and shortened (SH; 10 d) close-up period, and evaluate the effect of shortened close-up period combined with feeding different metabolizable protein (MP) levels on dry matter (DM) intake, metabolic status, and performance of dairy cows. Forty-eight multiparous Holstein cows with similar parity, body weight (BW), and previous lactation milk yield were divided into 2 groups. The first group (n = 24) received the far-off diet from -60 to -21 d (CON), and the second group (n = 24) received same far-off diet from -60 to -10 d (SH) relative to expected parturition. Cows were then moved to individual stalls and randomly allocated to 1 of 3 close-up diets: low MP diet (LMP; MP = 79 g/kg of DM), medium MP diet (MMP; MP = 101 g/kg of DM), or high MP diet (HMP; MP = 118 g/kg of DM). Treatments were used in a 2 × 3 factorial arrangement with 2 lengths of close-up period (CON and SH) and 3 levels of MP (LMP, MMP, and HMP). All diets were fed for ad libitum intake during the close-up period. After calving, all cows received the same fresh cow diet. We found no interaction between close-up period length and MP levels for traits, except for postpartum serum fatty acids and β-hydroxybutyrate (BHB). The concentrations of postpartum serum fatty acids and BHB were higher on LMP than MMP and HMP diets in SH group. The cows of the SH group tended to produce less colostrum in the first milking than cows in CON group. The length of close-up period did not affect pre- and postpartum DM intake or energy balance of cows during the last week of prepartum, but cows of the CON group had greater BW changes during the last 3 wk before parturition than cows in SH group. Cows fed MMP and HMP diets consumed 1.2 and 1 kg more DM than for those fed LMP prepartum, respectively. The concentrations of prepartum BHB and Ca were higher for SH cows than CON group cows. Except for blood urea N concentration, no other blood metabolite in prepartum was affected by dietary MP. We found no effects of close-up period length or MP levels in the close-up diet on urinary pH, purine derivative excretion, and microbial N flow. Postpartum, milk yield was not affected by close-up period length, but cows in CON group tended to have higher 4% fat-corrected milk yield, had higher milk fat content and yield, had greater BW and body condition score loss, and higher energy negative balance than cows in the SH group. Cows fed MMP diet ate 1.8 kg more DM and yielded 3.37 kg more milk than those fed the LMP diet. Milk fat, protein, and lactose content, milk urea N, and somatic cell count were not affected by MP levels, but the yield of milk protein and lactose were higher on MMP diet than on LMP diet. Concentrations of postpartum serum fatty acids and BHB were decreased by shortening the close-up period length, but glucose, cholesterol, and triglyceride were similar between close-up groups. During the postpartum period, serum fatty acids, BHB, aminotransferase, and Ca concentrations were decreased by increasing the MP levels in the close-up diet. It appears from this data set that multiparous cows will benefit from a shortened close-up period, and feeding a moderate MP diet could improve DM intake, milk yield, and metabolic status of periparturient dairy cows. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.
Hadad, Bat-Sheva; Kimchi, Ruth
2006-11-01
In two experiments, visual search was used to study the grouping of shape on the basis of perceptual closure among participants 5-23 years of age. We first showed that young children, like adults, demonstrate an efficient search for a concave target among convex distractors for closed connected stimuli but an inefficient search for open stimuli. Reliable developmental differences, however, were observed in search for fragmented stimuli as a function of spatial proximity and collinearity between the closure-inducing fragments. When only closure was available, search for all the age groups was equally efficient for spatially close fragments and equally inefficient for spatially distant fragments. When closure and collinearity were available, search for spatially close fragments was equally efficient for all the age groups, but search for spatially distant fragments was inefficient for younger children and improved significantly between ages 5 and 10. These findings suggest that young children can utilize closure as efficiently as can adults for the grouping of shape for closed or nearly closed stimuli. When the closure-inducing fragments are spatially distant, only older children and adults, but not 5-year-olds, can utilize collinearity to enhance closure for the perceptual grouping of shape.
De Paulis, R; De Matteis, G M; Nardi, P; Scaffa, R; Buratta, M M; Chiariello, L
2001-08-01
The durability of aortic valve-sparing procedures is negatively affected by increased leaflet stress in the absence of normally shaped sinuses of Valsalva. We compared valve motion after remodeling procedures using a standard conduit and a specifically designed aortic root conduit. Echocardiographic studies of the aortic valve dynamics were performed in 14 patients after remodeling of the aortic root (7 standard conduits, group A; 7 new conduits, group B) and in 7 controls (group C). Opening and closing leaflet velocities and percent of slow closing leaflet displacement were measured. Root distensibility and the pressure strain of the elastic modulus were measured at all root levels. Root distensibility and the pressure strain of the elastic modulus were different in group A and B only at the sinuses (p < 0.001). Opening and closing leaflet velocities were not different among groups. Slow closing leaflet displacement was markedly more evident in group B patients (24.2%+/-1.9% versus 2.5%+/-1.9% in group A, p < 0.001) and similar to controls (22.1%+/-7.9%). The new conduit guarantees dynamic features of the aortic valve leaflets superior to those obtained with standard conduits and more similar to normal subjects.
White Dwarfs in the GALEX Survey
NASA Technical Reports Server (NTRS)
Kawka, Adela; Vennes, Stephane
2007-01-01
We have cross-correlated the 2dF QSO Redshift Survey (2QZ) white dwarf catalog with the GALEX 2nd Data Release and the Sloan Digital Sky Survey (SDSS) data release 5 to obtain ultraviolet photometry (FUV, NUV) for approximately 700 objects and optical photometry (ugriz) for approximately 800 objects. We have compared the optical-ultraviolet colors to synthetic white dwarf colors to obtain temperature estimates for approximately 250 of these objects. These white dwarfs have effective temperatures ranging from 10 000 K (cooling age of about 1Gyr) up to about 40000 K (cooling age of about 3 Myrs), with a few that have even higher temperatures. We found that to distinguish white dwarfs from other stellar luminosity classes both optical and ultraviolet colors are necessary, in particular for the hotter objects where there is contamination from B and 0 main-sequence stars. Using this sample we build a luminosity function for the DA white dwarfs with Mv < 12 mag.
Lick slit spectra of thirty-eight objective prism quasar candidates and low metallicity halo stars
NASA Technical Reports Server (NTRS)
Tytler, David; Fan, Xiao-Ming; Junkkarinen, Vesa T.; Cohen, Ross D.
1993-01-01
Lick Observatory slit spectra of 38 objects which were claimed to have pronounced UV excess and emission lines are presented. Eleven QSOs, four galaxies at z of about 0.1, 22 stars, and one unidentified object with a low S/N spectrum were found. Of 11 objects which Zhan and Chen (1987, 1989) suggested were QSO with z(prism) not greater than 2.8; eight are QSOs. Six of the QSOs show absorption systems, including Q0000+027A with a relatively strong associated C IV absorption system, and Q0008+008 with a damped Ly-alpha system with an H I column density of 10 exp 21/sq cm. The equivalent widths of the Ca II K line, the G band, and the Balmer lines in 10 stars with the best spectra are measured, and metallicities are derived. Seven of them are in the range -2.5 to -1.7, while the others are less metal-poor.
Distance determination to Broad Line Absorbers in AGN
NASA Astrophysics Data System (ADS)
Bautista, Manuel; Arav, N.; Dunn, J.; Edmonds, D.; Korista, K. T.; Moe, M.; Benn, C.; Ignacio, G.
2009-01-01
We present various techniques for the determination of the physical conditions (density, temperature, total hydrogen column density, and ionization structure), chemical composition, and distances of Broad Line Absorbers (BAL) to the central engine in AGN. We start by discussing various density diagnostics from absorption lines from species such as C II, Si II, and Fe III. On the other hand, lines from metastable levels Fe II are often affected by Bowen fluorescence by scattered C IV photons. Lines from metastable levels of Ni II are usually excited by continuum fluorescence and mostly sensitive to the strength of the radiation field shortward of the Lyman continuum and as such they cam be used as direct distance indicators. Further, we show how the total hydrogen density of the absorber, its ionization parameter and distance can be determined through photoionization modeling of the absorber. Finally, we present our results for outflows of three different quasars: QSO 2359-1241 and SDSS J0318-0600.
NASA Astrophysics Data System (ADS)
Cook, David O.; Kasliwal, Mansi; Van Sistine, Anglea; Kaplan, David; iPTF
2018-01-01
In this talk I introduce the Census of the Local Universe (CLU) galaxy survey. The survey uses 4 wavelength-adjacent, narrowband filters to search for emission-line (Hα) sources across ~3π (26,470 deg2) of the sky and out to distance of 200 Mpc. I will present an analysis of galaxy candidates in 14 preliminary fields (out of 3626) to assess the limits of the survey and the potential for finding new galaxies in the local Universe. We anticipate finding tens-of-thousands of new galaxies in the full ~3π survey. In addition, I present some interesting galaxies found in these fields, which include: newly discovered blue compact dwarfs (e.g., blueberries), 1 new green pea, 1 new QSO, and a known planetary nebula. The majority of the CLU galaxies show properties similar to normal star-forming galaxies; however, the newly discovered blueberries tend to have high star formation rates for their given stellar mass.
VizieR Online Data Catalog: LAMOST DR2 catalogs (Luo+, 2016)
NASA Astrophysics Data System (ADS)
Luo, A.-L.; Zhao, Y.-H.; Zhao, G.; Deng, L.-C.; Liu, X.-W.; Jing, Y.-P.; Wang, G.; Zhang, H.-T.; Shi, J.-R.; Cui, X.-Q.; Chu, Y.-Q.; Li, G.-P.; Bai, Z.-R.; Wu, Y.; Cai, Y.; Cao, S.-Y.; Cao, Z.-H.; Carlin, J. L.; Chen, H.-Y.; Chen, J.-J.; Chen, K.-X.; Chen, L.; Chen, X.-L.; Chen, X.-Y.; Chen, Y.; Christlieb, N.; Chu, J.-R.; Cui, C.-Z.; Dong, Y.-Q.; Du, B.; Fan, D.-W.; Feng, L.; Fu, J.-N.; Gao, P.; Gong, X.-F.; Gu, B.-Z.; Guo, Y.-X.; Han, Z.-W.; He, B.-L.; Hou, J.-L.; Hou, Y.-H.; Hou, W.; Hu, H.-Z.; Hu, N.-S.; Hu, Z.-W.; Huo, Z.-Y.; Jia, L.; Jiang, F.-H.; Jiang, X.; Jiang, Z.-B.; Jin, G.; Kong, X.; Kong, X.; Lei, Y.-J.; Li, A.-H.; Li, C.-H.; Li, G.-W.; Li, H.-N.; Li, J.; Li, Q.; Li, S.; Li, S.-S.; Li, X.-N.; Li, Y.; Li, Y.-B.; Li, Y.-P.; Liang, Y.; Lin, C.-C.; Liu, C.; Liu, G.-R.; Liu, G.-Q.; Liu, Z.-G.; Lu, W.-Z.; Luo, Y.; Mao, Y.-D.; Newberg, H.; Ni, J.-J.; Qi, Z.-X.; Qi, Y.-J.; Shen, S.-Y.; Shi, H.-M.; Song, J.; Song, Y.-H.; Su, D.-Q.; Su, H.-J.; Tang, Z.-H.; Tao, Q.-S.; Tian, Y.; Wang, D.; Wang, D.-Q.; Wang, F.-F.; Wang, G.-M.; Wang, H.; Wang, H.-C.; Wang, J.; Wang, J.-N.; Wang, J.-L.; Wang, J.-P.; Wang, J.-X.; Wang, L.; Wang, M.-X.; Wang, S.-G.; Wang, S.-Q.; Wang, X.; Wang, Y.-N.; Wang, Y.; Wang, Y.-F.; Wang, Y.-F.; Wei, P.; Wei, M.-Z.; Wu, H.; Wu, K.-F.; Wu, X.-B.; Wu, Y.-Z.; Xing, X.-Z.; Xu, L.-Z.; Xu, X.-Q.; Xu, Y.; Yan, T.-S.; Yang, D.-H.; Yang, H.-F.; Yang, H.-Q.; Yang, M.; Yao, Z.-Q.; Yu, Y.; Yuan, H.; Yuan, H.-B.; Yuan, H.-L.; Yuan, W.-M.; Zhai, C.; Zhang, E.-P.; Zhang, H.-W.; Zhang, J.-N.; Zhang, L.-P.; Zhang, W.; Zhang, Y.; Zhang, Y.-X.; Zhang, Z.-C.; Zhao, M.; Zhou, F.; Zhou, X.; Zhu, J.; Zhu, Y.-T.; Zou, S.-C.; Zuo, F.
2016-11-01
There are a couple of corrections been made in this releasing: Recalculated all the errors of Teff, Logg, Fe/H and rv in the AFGK catalog. Refer to the DR2 paper (in preparation) for details. Compare to the previous internal releasing, some extra spectra has been added into this version of releasing: STAR from 3,779,597 to 3,843,597, increased 63,923; GALAXY from 37,665 to 47,036, increased 9,371; QSO from 8,633 to 13,262, increased 4,629. The major contribution to this increasing is that we applied a new method to reduce the data which previously was abandoned due to lack of standard stars with high enough S/N. Refer to the paper 'LAMOST Spectrograph Response Curves: Stability and Application to flux calibration' (in preparation) for details. There are also a small amount of increasing is due to the correction of fiber flag, and to the eye check work, etc. (5 data files).
Imaging of the gravitational lens system PG 1115+080 with the Hubble Space Telescope
NASA Technical Reports Server (NTRS)
Kristian, Jerome; Groth, Edward J.; Shaya, Edward J.; Schneider, Donald P.; Holtzman, Jon A.; Baum, William A.; Campbell, Bel; Code, Arthur; Currie, Douglas G.; Danielson, G. E.
1993-01-01
This paper is the first of a series presenting observations of gravitational lenses and lens candidates, taken with the Wide Field/Planetary Camera of the HST. We have resolved the gravitational lens system PG 1115+080 into four point sources and a red, extended object that is presumably the lens galaxy; we present accurate relative intensities, colors, and positions of the four images, and lower accuracy intensity and position of the lens galaxy, all at the epoch 1991.2. Comparison with earlier data shows no compelling evidence for relative intensity variations between the QSO components having so far been observed. The new data agree with earlier conclusions that the system is rather simple, and can be produced by the single observed galaxy. The absence of asymmetry in the HST images implies that the emitting region of the quasar itself has an angular radius smaller than about 10 milliarcsec (100 pc for H0 = 50, q0 = 0.5).
Gamma-Ray Bursts: Lighting Up the High-Redshift Universe
NASA Astrophysics Data System (ADS)
Toy, Vicki Louise
Gamma-ray bursts (GRBs) are the most luminous events in the Universe with Egamma,iso ˜ 1048-54 erg. Leading models hypothesize that GRBs are created from inter- nal collisions within collimated and ultrarelativistic jets. The jets then shock-heat the surrounding material (e.g. interstellar medium) to create GRB afterglows. These afterglows are extremely useful probes of the Universe because long GRBs are (1) bright events that can be used as backlights for absorption studies, (2) able to probe at all redshifts massive stars exist, and (3) transient events that allow us to follow- up on the host galaxies at late times. In this thesis we study the environments of GRBs. We first explore the relationship between GRB and supernova (SN) using a nearby GRB-SN (GRB 130702A/SN 2013dx) at z = 0.145. There are only nine other GRB-SNe that were close enough to have extensive spectroscopic and photometric follow-up of the SN at late times. We create a quasi-bolometic light curve of SN 2013dx and fit an analytical equation to the quasi-bolometric light curve combined with measurements of the photospheric velocity to determine SN parameters: mass of 56Ni, kinetic energy, and ejecta mass. We examine the relationship between SN parameters and E gamma,iso for the 10 well-studied GRB-SNe, but find no correlations despite numerical simulation predictions that the mass of 56Ni should correlate with the degree of asymmetry. We then move to larger distance scales and use GRB afterglows as bright back- lights to study distant galaxies. We examine the galactic environments of Damped Lyman-alpha systems (DLAs; NHI ≥ 1020.3 cm-2 ) identified with GRB afterglows at z ˜ 2 - 6. We use late-time photometry after the GRB afterglow has faded to determine star formation rates (SFRs) from rest-frame ultraviolet measurements or spectral energy distribution (SED) models from multiband photometry. We com- pare our sample's SFRs to a sample of quasars (QSOs) DLA host galaxies. Despite the overlapping NHI and redshift ranges, our GRB-DLA galaxies have much larger SFRs than the QSO-DLA host galaxy sample; this may suggest that the QSO-DLA and GRB-DLA galaxy populations are different. We also compare star formation efficiencies to the local Universe and simulations at z = 3. A large portion of this thesis has focused on the development of a new ground- based GRB afterglow follow-up instrument, the Rapid infrared IMAger-Spectrometer (RIMAS), that will target high-redshift GRB afterglows to study early galaxy envi- ronments. RIMAS covers 0.97-2.37 mum and can simultaneously observe two band-passes in any observing mode: photometry, low-resolution spectroscopy (R ˜ 30), or high-resolution spectroscopy (R ˜ 4000). In particular, this thesis focuses on RIMAS's three detectors: two science grade Teledyne HgCdTe Astronomy Wide Area Infrared Imager with 2K x 2K, Reference Pixels and Guide Mode (H2RG) and a slit-viewer Spitzer Legacy Indium-Antimonide (InSb) array. We describe the detector hardware and characterization in detail and discuss general infrared detector troubleshooting methods at both cryogenic and room temperatures. Several software packages have been developed for RIMAS throughout this thesis work. We introduce RIMAS's quick reduction pipeline that takes raw images from a single acquisition and returns a single result frame. We then present a generalized data reduction pipeline that we have tested on two currently operational photometers. We also describe our detailed and realistic RIMAS throughput models for all three observing modes as well as our online observer calculators with these throughput models. All of our data products are open source and are publicly available on Github repositories with detailed documentation.
75 FR 8310 - Federal Advisory Committee; Transformation Advisory Group; Closed Meeting
Federal Register 2010, 2011, 2012, 2013, 2014
2010-02-24
... DEPARTMENT OF DEFENSE Office of the Secretary Federal Advisory Committee; Transformation Advisory... announces that the Transformation Advisory Group will hold a closed meeting on March 11, 2010. DATES: The... written statements to the membership of the Transformation Advisory Group at any time or in response to...
Being Close and Being Social: Peer Ratings of Distinct Aspects of Young Adult Social Competence
Larson, Justine J.; Whitton, Sarah W.; Hauser, Stuart T.; Allen, Joseph P.
2012-01-01
The present study had three main objectives: (1) to develop and validate scales of young adult social competence in two domains, close relationships and social groups, using peer ratings of California Q-sort (Block, 1974; Kremen & Block, 2002) items; (2) to test the hypothesis that social competence is associated with young adult well-being and ego development; (3) to test the hypothesis that close relationship competence aligns more closely than social group competence with young adult functioning. Psychometric data on peer ratings of social competence are presented. For 133 young adults, peer ratings of social competence were correlated in expected directions with indices of functioning (e.g., self-worth, education, psychological distress, criminal behavior, and ego development). Associations were generally stronger for competence in close relationships than in social groups. PMID:17764391
Sit-to-stand ground reaction force characteristics in blind and sighted female children.
Faraji Aylar, Mozhgan; Jafarnezhadgero, Amir Ali; Salari Esker, Fatemeh
2018-03-05
The association between visual sensory and sit-to-stand ground reaction force characteristics is not clear. Impulse is the amount of force applied over a period of time. Also, free moment represents the vertical moment applied in the center of pressure (COP). How the ground reaction force components, vertical loading rate, impulses and free moment respond to long and short term restricted visual information? Fifteen female children with congenital blindness and 45 healthy girls with no visual impairments participated in this study. The girls with congenital blindness were placed in one group and the 45 girls with no visual impairments were randomly divided into three groups of 15; eyes open, permanently eyes closed, and temporary eyes closed. The participants in the permanently eyes closed group closed their eyes for 20 min before the test, whereas temporary eyes closed group did tests with their eyes closed throughout, and those in the eyes open group kept their eyes open. Congenital blindness was associated with increased vertical loading rate, range of motion of knee and hip in the medio-lateral plane. Also, medio-lateral and vertical ground reaction force impulses. Similar peak negative and positive free moments were observed in three groups. In conclusion, the results reveal that sit-to-stand ground reaction force components in blind children may have clinical importance for improvement of balance control of these individuals. Copyright © 2018 Elsevier B.V. All rights reserved.
Cosmological Evolution of QSO Absorption Systems
NASA Astrophysics Data System (ADS)
Stengler-Larrea, Erik
1995-08-01
First, the evolution with cosmic time of the hydrogen clouds which produce the Lyman-alpha absorption lines is studied in dependence on the strength of these lines. From the analysis it is concluded that the results show no evidence of a dependence in the sense of stronger lines evolving faster, although for the resolution at which the used observations were done, it can not be ruled out. Within the same analysis, a distribution of the Doppler parameter of the lines was obtained, with large values and a wide spread. This parameter being an indicator of the gas temperature, this result is in accordance with high temperatures and, consequently, large ionised fractions and a large fraction of the baryonic matter of the universe being associated with these clouds. However, recent high resolution studies seem to reveal that much lower temperatures are characteristic of the clouds. The main content of this thesis, however, focuses on the redshift evolution of the absorbing systems producing absorption at the Lyman limit and of the amount of CIV producing CIV absorption lines. Regarding the CIV absorbers, previous predictions on the effects underlying their redshift distribution pointed to an increase with redshift of the absorbing column densities. In this thesis the first direct measurements of such column densities by profile fitting of a large number of absorption systems (73) are presented, confirming the predictions of a decrease of at least a factor of 3 between z=1.5 and z=3.0. The study on the evolution of Lyman limit absorption systems (LLSs) puts an end to previous discrepancies between the results of different groups. Both a smooth single power law dependence of the LLS number density on redshift indicating no evolution in number density for 0.4 <= z <= 4.1, and a broken power law with a rapid increase above z ~ 2.5 had been obtained with different data sets. A detailed analysis reveals here the reasons for these discrepancies and obtains the most reliable result to date, which is consistent with no cosmological evolution of these absorbers, allowing for, at most, a mild evolutionary rate, depending on the cosmology chosen to interpret the redshifts. Taken together, the results on these two classes of absorbers allow to conclude on the effects underlying the evolution of the intervening objects: This is due mostly to an increase of the chemical abundance of C and not to changes in the ionisation conditions of the absorbers, which may be present to a small extent. Given these constraints on the changes in the ionisation conditions of the absorbers, it was possible to set limits on the evolution of the ionising metagalactic UV background radiation. These limits are compared with a thorough compilation of variously determined results and theoretical predictions on the evolutionary behaviour of this metagalactic radiation from the literature, and are in agreement with those favouring mild or no decrease above z=2.5. To prepare the observations of many QSOs with the HST by the Team of the HST Key Project on QSO absorption lines, and in particular to estimate the necessary exposure times, the magnitudes of several of these objects had to be re-measured. The acquisition of their images and the results of the photometric calculations performed on them are also described in a separate chapter. (SECTION: Dissertation Summaries)
ERIC Educational Resources Information Center
Quan-McGimpsey, Sharon; Marziliano, Sarah Carmen; Hassen, Trevor Gregory; Brown, Allison Sandra; Kuczynski, Leon
2015-01-01
This study investigated teachers' experiences of closeness during interactions with the group of children in child care. Structured interviews were conducted with 24 female teachers who were teaching children between the ages of three and five (mean age = 3.9) regarding their perceptions of closeness with the group of children in the class.…
Adult meerkats modify close call rate in the presence of pups.
Wyman, Megan T; Rivers, Pearl R; Muller, Coline; Toni, Pauline; Manser, Marta B
2017-06-01
In animals, signaling behavior is often context-dependent, with variation in the probability of emitting certain signals dependent on fitness advantages. Senders may adjust signaling rate depending on receiver identity, presence of audiences, or noise masking the signal, all of which can affect the benefits and costs of signal production. In the cooperative breeding meerkat Suricata suricatta , group members emit soft contact calls, termed as "close calls", while foraging in order to maintain group cohesion. Here, we investigated how the close calling rate during foraging was affected by the presence of pups, that produce continuous, noisy begging calls as they follow older group members. Adults decreased their overall close call rate substantially when pups were foraging with the group in comparison to periods when no pups were present. We suggest this decrease was likely due to a masking effect of the loud begging calls, which makes the close call function of maintaining group cohesion partly redundant as the centrally located begging calls can be used instead to maintain cohesion. There was some support that adults use close calls strategically to attract specific pups based on fitness advantages, that is, as the philopatric sex, females should call more than males and more to female pups than male pups. Dominant females called more than dominant males when a pup was in close proximity, while subordinates showed no sex-based differences. The sex of the nearest pup did not affect the calling rate of adults. The study shows that meerkats modify their close call production depending on benefits gained from calling and provides an example of the flexible use of one calling system in the presence of another, here contact calls versus begging calls, within the same species.
Rinehart, Joseph; Chung, Elena; Canales, Cecilia; Cannesson, Maxime
2012-10-01
The authors compared the performance of a group of anesthesia providers to closed-loop (Learning Intravenous Resuscitator [LIR]) management in a simulated hemorrhage scenario using cardiac output monitoring. A prospective cohort study. In silico simulation. University hospital anesthesiologists and the LIR closed-loop fluid administration system. Using a patient simulator, a 90-minute simulated hemorrhage protocol was run, which included a 1,200-mL blood loss over 30 minutes. Twenty practicing anesthesiology providers were asked to manage this scenario by providing fluids and vasopressor medication at their discretion. The simulation program was also run 20 times with the LIR closed-loop algorithm managing fluids and an additional 20 times with no intervention. Simulated patient weight, height, heart rate, mean arterial pressure, and cardiac output (CO) were similar at baseline. The mean stroke volume, the mean arterial pressure, CO, and the final CO were higher in the closed-loop group than in the practitioners group, and the coefficient of variance was lower. The closed-loop group received slightly more fluid (2.1 v 1.9 L, p < 0.05) than the anesthesiologist group. Despite the roughly similar volumes of fluid given, the closed-loop maintained more stable hemodynamics than the practitioners primarily because the fluid was given earlier in the protocol and CO optimized before the hemorrhage began, whereas practitioners tended to resuscitate well but only after significant hemodynamic change indicated the need. Overall, these data support the potential usefulness of this closed-loop algorithm in clinical settings in which dynamic predictors are not available or applicable. Published by Elsevier Inc.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Alparslan, Burcu, E-mail: burcu.alparslan@gmail.com; Nas, Omer Fatih, E-mail: omerfatihnas@gmail.com; Eritmen, Ulku Turpcu, E-mail: drulkutur@hotmail.com.tr
PurposeThe aim of this study was to investigate the effect of stent cell geometry on midterm results of carotid artery stenting (CAS).Materials and MethodOne hundred fifty-five patients underwent CAS between February 2010 and December 2012. Ninety-one open- and 84 closed-cell stents were used in this non-randomized, retrospective study. Periprocedural complications were defined as the ones happened during the procedure or within 30 days afterwards. Starting from the 6th month after the procedure, in-stent restenosis was detected with multidetector computed tomography angiography and classified into four groups from focal restenosis to occlusion.ResultsEleven complications were encountered in the periprocedural period (four on themore » open- and seven on the closed-cell group). Total complication rate was 6.3 % (11/175). No significant difference was detected in terms of periprocedural complications between two groups (p = 0.643). There was statistically significant difference between stent design groups in regard to radiological findings (p = 0.002). Sixteen of open-cell stents and three of closed-cell stents had focal restenosis. One closed-cell stent had diffuse proliferative restenosis and one open-cell stent had total occlusion.ConclusionIn-stent restenosis was more common in open-cell stent group, which have larger free cell area than closed-cell stents. Although our radiologic findings promote us to use closed-cell design if ‘possible’, no difference was detected in terms of clinical outcomes.« less
Open Versus Closed Septorhinoplasty Approaches for Postoperative Edema and Ecchymosis.
Sakallioğlu, Öner; Cingi, Cemal; Polat, Cahit; Soylu, Erkan; Akyigit, Abdulvahap; Soken, Hakan
2015-06-01
The aim of this study was to compare periorbital edema and ecchymosis seen after closed (endonasal) and open (external) septorhinoplasty (SRP). In total, 50 patients undergoing hump extraction and osteotomies were allocated to 2 groups. Group 1 consisted of 25 patients who underwent closed SRP. Group 2 consisted of 25 patients who underwent open SRP. Operation time, amount of intraoperative bleeding, and complications were recorded. Scoring of eyelid edema and periorbital ecchymosis was evaluated on the first, third, and seventh postoperative days using a scale of 0 to 4 by the first author. There was no statistically significant difference between the groups in terms of age, sex, or operation time. No significant difference was observed clinically or statistically in the scores of periorbital edema or ecchymosis between groups 1 and 2 on the first, third, and seventh postoperative days (P > 0.05). The authors observed no clinically or statistically significant difference in comparing periorbital edema and ecchymosis seen after closed and open SRP.
Imaging the host galaxies of high-redshift radio-quiet QSOs
NASA Technical Reports Server (NTRS)
Lowenthal, James D.; Heckman, Timothy M.; Lehnert, Matthew, D.; Elias, J. H.
1995-01-01
We present new deep K-band and optical images of four radio-quiet QSOs at z approximately = 1 and six radio-quiet QSOs at z approximately = 2.5, as well as optical images only of six more at z approximately = 2.5. We have examined the images carefully for evidence of extended 'fuzz' from any putative QSO host galaxy. None of the z approximately = 2.5 QSOs shows any extended emission, and only two of the z approximately = 1 QSOs show marginal evidence for extended emission. Our 3 sigma detection limits in the K images, m(sub K) approximately = 21 for an isolated source, would correspond approximately to an unevolved L(sup star) elliptical galaxy at z = 2.5 or 2-3 mag fainter than an L(sup star) elliptical at z = 1, although our limits on host galaxy light are weaker than this due to the difficulty of separating galaxy light from QSO light. We simulate simple models of disk and elliptical host galaxies, and find that the marginal emission around the two z approximately = 1 QSOs can be explained by disks or bulges that are approximately 1-2 mag brighter than an unevolved L(sup star) galaxy in one case and approximately 1.5-2.5 mag brighter than L(sub star) in the other. For two other z approximately = 1 QSOs, we have only upper limits (L approximately = L(sup star)). The hosts of the high-redshift sample must be no brighter than about 3 mag above an unevolved L(sup star) galaxy, and are at least 1 magnitude fainter than the hosts of radio-loud QSOs at the same redshift. If the easily detected K-band light surrounding a previous sample of otherwise similar but radio-loud QSOs is starlight, then it must evolve on timescales of greater than or approximately equal to 10(exp 8) yr (e.g., Chambers & Charlot 1990); therefore our non-detection of host galaxy fuzz around radio-quiet QSOs supports the view that high-redshift radio-quiet and radio-loud QSOs inhabit different host objects, rather than being single types of objects that turn their radio emission on and off over short timescales. This is consistent with the general trend at low redshifts that radio-loud QSOs are found in giant elliptical galaxies while radio-quiet QSOs are found in less luminous disk galaxies. It also suggests that the processes responsible for the spectacular properties of radio-loud AGNs at high redshifts might not be generally relevent to the (far more numerous) radio-quiet population.
Hasegawa, Junichi; Kawabata, Ikuno; Takeda, Yoshiharu; Aoki, Hiroaki; Fukami, Takehiko; Tajima, Atsushi; Miyakoshi, Kei; Otsuki, Katsufumi; Shinozuka, Norio; Matsuda, Yoshio; Iwashita, Mitsutoshi; Okai, Takashi; Nakai, Akihito
2017-01-01
To clarify whether distinguishing between the uterine isthmus and cervix can improve the accuracy of diagnosing placenta previa at term. A multicenter prospective observational study was conducted among pregnant women with suspected placenta previa at 20-24 weeks' gestation. Subjects were divided into the open isthmus group and closed isthmus group. The accuracy of diagnosing placenta previa at term was compared between the 2 groups. We screened 9,341 patients, and 53 (0.6%) met the inclusion criteria. Nineteen cases with an open isthmus and 34 with a closed isthmus were followed. The accuracy for diagnosing placenta previa or a low-lying placenta at term was 94.7% in the open isthmus group and 26.5% in the closed isthmus group (p < 0.001). Elective or emergency Cesarean section was required in 100% of cases in the open isthmus group and 20.6% in the closed isthmus group (p < 0.001). A high prediction rate of placenta previa was obtained by using transvaginal ultrasound at 20-24 weeks' gestation after the isthmus opened by carefully distinguishing between the cervix and isthmus. © 2016 S. Karger AG, Basel.
Implementing Tuberculosis Close-contact Investigation in a Tertiary Hospital in Iran.
Shamaei, Masoud; Esmaeili, Shahrbanoo; Marjani, Majid; Tabarsi, Payam
2018-01-01
Close contact investigation is the essential key in tuberculosis (TB) case finding and an effective strategy for TB control program within any society. In this prospective study, 1186 close family contacts of hospitalized TB patients (index) in a referral TB hospital in Tehran-Iran were passively studied. These people were studied to rollout TB infection and disease. Demographic characteristics, clinical and laboratory data of these individuals were reviewed and summarized for analysis. A total of 886 (74.4%) close-family contacts completed their investigation. The index TB patients of these individuals were sputum smear negative for acid-fast bacilli in 137 cases (11.6%) and the rest were smear positive. A total of 610 (68.8%) close-family contact ruled out for TB infection or disease (Group I). A total of 244 cases (27.5%) had latent TB infection (Group II) and active TB (Group III) was confirmed in 32 cases (3.6%). A significant difference was shown for female gender, signs and symptoms, family size, and positive radiological finding between Group I and Group II. The study of index parameter including positive sputum smear/culture did not reveal any significant difference, but positive cavitary lesion significantly more has seen in active TB group ( P = 0.004). This study emphasizes on sign and symptoms and radiological finding in TB contact investigation, where index parameters including positive smear/culture, does not implicate any priority. Although cavitary lesions in index patient have more accompanied by active TB, close contact study should include all of TB indexes. This investigation should include chest radiography for these individuals.
Closed dressings after laser skin resurfacing.
Newman, J P; Koch, R J; Goode, R L
1998-07-01
To evaluate the safety, efficacy, and patient acceptance of closed dressings after full facial resurfacing with the carbon dioxide laser. Prospective cohort of men and women undergoing full facial carbon dioxide laser resurfacing. Ambulatory surgical center at a university hospital. Forty consecutive patients randomized to 1 of 4 dressing groups. All patients underwent full facial resurfacing with a carbon dioxide laser system. One of 5 closed dressings (single- or 3-layer composite foam, plastic mesh, hydrogel, or polymer film) was placed immediately after the procedure. Closed dressings were changed on postoperative day 2 and removed on postoperative day 4. Objective postoperative criteria of erythema, scarring, reepithelialization, and surface irregularities were recorded and photodocumented. Comparisons were made among the closed dressing groups as well as with a group of historical control subjects treated with open dressings. The ease of application, office time for preparation and application, and cost of the individual dressings were collected. Patient characteristics of overall acceptance, comfort, and ease of maintenance were recorded with a visual analog scale. There were no complications of scarring, surface irregularities, or contact dermatitis from the application or maintenance of the closed dressings. There were no significant differences in the number of days of postoperative erythema or in the rate of facial reepithelialization among the groups. Most patients preferred not to continue with the closed dressings past 2 days. Positive features from the use of closed dressings included reduction in crust formation, decreased pruritus, decreased erythema, and decreased postoperative pain, compared with historical controls. Negative features included time in preparation and application of the dressings. Costs ranged from $9.79 to $50 per dressing change. Closed dressings are safe and offer benefits noted during the first 4 postoperative days. Patients can be expected to maintain a closed dressing for at least 24 hours but no longer than 4 days. The positive features of closed dressings and patient acceptance outweigh the cost and office time involved with their application and maintenance.
NASA Astrophysics Data System (ADS)
Burchett, Joseph N.; Tripp, Todd M.; Wang, Q. Daniel; Willmer, Christopher N. A.; Bowen, David V.; Jenkins, Edward B.
2018-04-01
We analyse the intracluster medium (ICM) and circumgalactic medium (CGM) in seven X-ray-detected galaxy clusters using spectra of background quasi-stellar objects (QSOs) (HST-COS/STIS), optical spectroscopy of the cluster galaxies (MMT/Hectospec and SDSS), and X-ray imaging/spectroscopy (XMM-Newton and Chandra). First, we report a very low covering fraction of H I absorption in the CGM of these cluster galaxies, f_c = 25^{+25}_{-15} {per cent}, to stringent detection limits (N(H I) <1013 cm-2). As field galaxies have an H I covering fraction of ˜ 100 per cent at similar radii, the dearth of CGM H I in our data indicates that the cluster environment has effectively stripped or overionized the gaseous haloes of these cluster galaxies. Secondly, we assess the contribution of warm-hot (105-106 K) gas to the ICM as traced by O VI and broad Ly α (BLA) absorption. Despite the high signal-to-noise ratio of our data, we do not detect O VI in any cluster, and we only detect BLA features in the QSO spectrum probing one cluster. We estimate that the total column density of warm-hot gas along this line of sight totals to ˜ 3 per cent of that contained in the hot T > 107 K X-ray emitting phase. Residing at high relative velocities, these features may trace pre-shocked material outside the cluster. Comparing gaseous galaxy haloes from the low-density `field' to galaxy groups and high-density clusters, we find that the CGM is progressively depleted of H I with increasing environmental density, and the CGM is most severely transformed in galaxy clusters. This CGM transformation may play a key role in environmental galaxy quenching.
NASA Astrophysics Data System (ADS)
Jenkins, Edward B.; Wallerstein, George
2017-04-01
We present data on the gas-phase abundances for 9 different elements in the interstellar medium of the Small Magellanic Cloud (SMC), based on the strengths of ultraviolet absorption features over relevant velocities in the spectra of 18 stars within the SMC. From this information and the total abundances defined by the element fractions in young stars in the SMC, we construct a general interpretation on how these elements condense into solid form onto dust grains. As a group, the elements Si, S, Cr, Fe, Ni, and Zn exhibit depletion sequences similar to those in the local part of our Galaxy defined by Jenkins. The elements Mg and Ti deplete less rapidly in the SMC than in the Milky Way, and Mn depletes more rapidly. We speculate that these differences might be explained by the different chemical affinities to different existing grain substrates. For instance, there is evidence that the mass fractions of polycyclic aromatic hydrocarbons in the SMC are significantly lower than those in the Milky Way. We propose that the depletion sequences that we observed for the SMC may provide a better model for interpreting the element abundances in low-metallicity Damped Lyman Alpha (DLA) and sub-DLA absorption systems that are recorded in the spectra of distant quasars and gamma-ray burst afterglows. Based on observations with the NASA/ESA Hubble Space Telescope and additional data obtained from the Data Archive at the Space Telescope Science Institute, which is operated by the Associations of Universities for Research in Astronomy, Incorporated, under NASA contract NAS5-26555. These observations are associated with program nr. 13778.
Han, Jae Hwi; Yang, Jae-Hyuk; Bhandare, Nikhl N; Suh, Dong Won; Lee, Jong Seong; Chang, Yong Suk; Yeom, Ji Woong; Nha, Kyung Wook
2016-08-01
Medial opening wedge high tibial osteotomy (HTO) has become increasingly popular as an alternative to lateral closing wedge osteotomy for the treatment of medial compartment knee osteoarthritis with varus deformity. The present systematic review was conducted to provide an objective analysis of total knee arthroplasty (TKA) outcomes following previous knee osteotomy (medial opening wedge vs. lateral closing wedge). A literature search of online databases (MEDLINE, EMBASE, Cochrane Library database) was made, in addition to manual search of major orthopaedic journals. The methodological quality of each of the studies was assessed on the Newcastle-Ottawa Scale and Effective Practice and Organization of Care. A total of ten studies were included in the review. There were eight studies with Level IV and two studies with Level III evidence. Eight studies reported clinical and radiologic scores. Comparative studies between TKA following medial opening and lateral closing wedge HTO did not demonstrate statistically significant clinical and radiologic differences. The revision rates were similar. However, more technical issues during TKA surgery after lateral closing wedge HTO were mentioned than the medial open wedge group. The quadriceps snip, tibial tubercle osteotomy, and lateral soft tissue release were more frequently needed in the lateral closing wedge HTO group. In addition, because of loss of proximal tibia bone geometry in the lateral closing wedge HTO group, concerns such as tibia stem impingement in the lateral tibial cortex was noted. The present systematic review suggests that TKA after medial opening and lateral closing wedge HTO showed similar performance. Clinical and radiologic outcome including revision rates did not statistically differ from included studies. However, there are more surgical technical concerns in TKA conversion from lateral closing wedge HTO than from the medial opening wedge HTO group. IV.
Federal Register 2010, 2011, 2012, 2013, 2014
2011-09-30
... DEPARTMENT OF DEFENSE Notice of Advisory Committee Closed Meeting; U.S. Strategic Command Strategic Advisory Group; Correction AGENCY: Department of Defense. ACTION: Notice of Advisory Committee... Command Strategic Advisory Group gave notice of a meeting to be held on November 1, 2011, from 8 a.m. to 5...
Closed and Open Systems: The Tavistock Group from a General System Perspective.
ERIC Educational Resources Information Center
Rugel, Robert P.
1991-01-01
Describes phases in the life of a Tavistock group composed of college students using concepts from Von Bertalanffy's general systems theory, MacKenzie's role theory, and Kantor's family theory. Discusses early, middle, and late phases of typical 16-session group as it moves from a closed to an open system. (Author/NB)
Top management and management science: An exploratory study in 15 Federal civilian agencies
NASA Technical Reports Server (NTRS)
White, M. J.
1971-01-01
A study of the relation between top managers in Federal agencies and the operations research and management science (OR/MS) group is reported. Sixteen managers were questioned about the following characteristics: closeness of top managers to OR/MS groups; top managers' attitudes toward the OR/MS activities; relation between closeness and these attitudes; and top managers' use of OR/MS groups. It is concluded that OR/MS is relevant to many top managers and that OR/MS has begun to play a role in decisions. Top management attitudes and actions are not related in obvious ways. The consequences to top management's use of and closeness to an OR/MS group need not be the success of the group as a professional, innovative, research-oriented unit.
23 CFR 1340.6 - Assignment of observation times.
Code of Federal Regulations, 2012 CFR
2012-04-01
... Highways NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION UNIFORM CRITERIA FOR... sites. (c) Grouping of observation sites in close geographic proximity. Observations sites in close geographic proximity may be grouped to reduce data collection burdens if: (1) The first assignment of an...
23 CFR 1340.6 - Assignment of observation times.
Code of Federal Regulations, 2014 CFR
2014-04-01
... Highways NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION UNIFORM CRITERIA FOR... sites. (c) Grouping of observation sites in close geographic proximity. Observations sites in close geographic proximity may be grouped to reduce data collection burdens if: (1) The first assignment of an...
23 CFR 1340.6 - Assignment of observation times.
Code of Federal Regulations, 2013 CFR
2013-04-01
... Highways NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION UNIFORM CRITERIA FOR... sites. (c) Grouping of observation sites in close geographic proximity. Observations sites in close geographic proximity may be grouped to reduce data collection burdens if: (1) The first assignment of an...
Russia's [open quotes]red-brown[close quotes] hawks
DOE Office of Scientific and Technical Information (OSTI.GOV)
Goldanskii, V.I.
1993-06-01
Since the beginning of the [open quotes]Gorbachev years,[close quotes] there has been a remarkable democratization in Russia, but there has also been a sharpening of internal contradictions. These years have led to a coalition of [open quotes]red-brown[close quotes] groups -- the most reactionary elements of society -- Stalinists, extremely aggressive members of the military-industrial complex, self-styled [open quotes]protectors of the Russian Empire,[close quotes] national patriotic unions, and groups with their own storm troops. These have also been years of economic decline and the withering of research in the fundamental sciences. This article describes the anger of Soviet nuclear specialists atmore » vanishing funds and prestige. The desire of the neo-fascist groups for arms and power is addressed. The development of these groups is reviewed. Implications of political unrest for nuclear proliferation and the future of Russian nuclear specialists are discussed. Possibilities for government reorganization are proposed. 8 refs.« less
Effects of friendship closeness in an adolescent group HIV prevention intervention.
Morrison, Diane M; Casey, Erin A; Beadnell, Blair A; Hoppe, Marilyn J; Gillmore, Mary Rogers; Wilsdon, Anthony; Higa, Darrel; Carlisle, Shauna; Wells, Elizabeth A
2007-12-01
Although many interventions for youth rely, explicitly or implicitly, on group effects, sparse theoretical or empirical attention has been paid to the rationale for choosing a small-group design. The present study assesses the role of friendship closeness among youth in prevention intervention groups in shaping their HIV risk-related attitudes, intentions, perceived self-efficacy and perceived norms. Data from an experimental test of a group HIV prevention intervention are used to assess the relationship of friendship on cognitive outcomes at posttest and 6-month follow-up, in a multilevel regression design. Friendship among group members was assessed at baseline and post-intervention, for youth in the experimental intervention and in a control, career exploration, condition. Level of friendship within the group was positively related to attendance and enjoyment of the intervention in the control group only. Most cognitive outcomes were unaffected by individual or group levels of friendship closeness, but those effects observed were opposite to those desired. Friendly groups were no more likely to converge in their cognitions over time than were less-friendly groups. The need for more research on the effects of friendship on intervention outcomes, and for multilevel analyses of group effects, are discussed.
Xiao, H; Sorofman, B; Manasse, H R
2000-03-01
The objectives of this study were 2-fold: (1) to examine the association of pharmacy closures with prescription drug use by Medicaid recipients in Iowa; and (2) to evaluate how drug utilization patterns differ between patients whose pharmacies closed and patients whose pharmacies remained open. A 2-group pretest-posttest study of Medicaid enrollees who may have been affected by pharmacy closures. Prescription medication use during the periods preceding and after pharmacy closures was compared. A comparison group was used to account for extraneous factors. Sixteen community pharmacies were selected from a pool of pharmacies that closed during 1994; 1092 patients were identified as the main users of these pharmacies, and a comparison group of 3491 patients whose main pharmacies had not closed also was identified. The average number of each patient's prescription claims for the 6 months preceding closing and the 6 months after closing was computed. Multiple regression analysis was conducted to determine whether any association existed between pharmacy closures and the use of prescription drugs. Patients whose pharmacies closed during 1994 had fewer prescription claims after the closings than before the closings. In contrast, patients whose pharmacies remained open had more prescription claims. This difference remains statistically significant after controlling for other factors, such as patient demographics and health status. A decrease in prescription drug use was associated with pharmacy closures. Attention should be directed to patient access to prescription medications in rural areas, as relatively more pharmacies close in rural areas.
A novel system for automated propofol sedation: hybrid sedation system (HSS).
Zaouter, Cedrick; Taddei, Riccardo; Wehbe, Mohamad; Arbeid, Erik; Cyr, Shantale; Giunta, Francesco; Hemmerling, Thomas M
2017-04-01
Closed-loop systems for propofol have been demonstrated to be safe and reliable for general anesthesia. However, no study has been conducted using a closed-loop system specifically designed for sedation in patients under spinal anesthesia. We developed an automatic anesthesia sedation system that allows for closed-loop delivery of propofol for sedation integrating a decision support system, called the hybrid sedation system (HSS). The objective of this study is to compare this system with standard practice. One hundred fifty patients were enrolled and randomly assigned to two groups: HSS-Group (N = 75), in which propofol was administered using a closed-loop system; Control Group (N = 75), in which propofol was delivered manually. The clinical performance of the propofol sedation control is defined as efficacy to maintain bispectral index (BIS) near 65. The clinical control was called 'Excellent', 'Good', 'Poor' and 'Inadequate' with BIS values within 10 %, from 11 to 20 %, 21 to 30 %, or greater than 30 % of the BIS target of 65, respectively. The controller performance was evaluated using Varvel's parameters. Data are presented as mean ± standard deviation, groups were compared using t test or Chi square test, P < 0.05. Clinical performance of sedation showed 'Excellent' control in the HSS-group for a significantly longer period of time (49 vs. 26 % in the control group, P < 0.0001). 'Poor' and 'Inadequate' sedation was significantly shorter in the HSS Group compared to the Control Group (11 and 10 % vs. 20 and 18 %, respectively, P < 0.0001). The novel, closed-loop system for propofol sedation showed better maintenance of the target BIS value compared to manual administration.
Fernandes, Ângela; Rocha, Nuno; Santos, Rubim; Tavares, João Manuel R S
2015-01-01
The aim of this study was to analyze the efficacy of cognitive-motor dual-task training compared with single-task training on balance and executive functions in individuals with Parkinson's disease. Fifteen subjects, aged between 39 and 75 years old, were randomly assigned to the dual-task training group (n = 8) and single-task training group (n = 7). The training was run twice a week for 6 weeks. The single-task group received balance training and the dual-task group performed cognitive tasks simultaneously with the balance training. There were no significant differences between the two groups at baseline. After the intervention, the results for mediolateral sway with eyes closed were significantly better for the dual-task group and anteroposterior sway with eyes closed was significantly better for the single-task group. The results suggest superior outcomes for the dual-task training compared to the single-task training for static postural control, except in anteroposterior sway with eyes closed.
Tartakovsky, Eugene; Abu Kheit, Ayat
2017-01-01
The present study investigates the connection between personal value preferences, group identifications, and cultural practices among Palestinian Israelis working in close contact with the Jewish population in Israel. One hundred twenty-two Palestinian Israelis participated in the study. The participants were employed in different professional positions in the Tel Aviv Metropolitan area and were recruited to the study using the snowball technique. A stronger national identification was associated with a higher preference for the security and conformity values, and a lower preference for the humility values. A stronger ethnic identification was associated with a lower preference for the security, power, and stimulation values. Group identifications mediated the connection between personal value preferences and cultural practices. A longer time working in close contact with the majority group and less frequent visits home were associated with a greater adherence to the majority group's cultural practices but not with adherence to the ethnic group's practices and not with the group identifications.
Split marketing as a risk factor for Salmonella enterica infection in swine.
Rostagno, Marcos H; Hurd, H Scott; McKean, James D
2009-09-01
On-farm reduction of Salmonella carriage prevalence in pigs requires the identification of risk factors to direct interventions development. This study was designed to determine if split marketing of finishing pigs constitutes a risk factor for Salmonella infections, by comparing Salmonella prevalence in the first group of pigs selected for harvest ("first pull") versus the prevalence in the last group of pigs selected for harvest ("close out") from multiple commercial finishing lots. Nine paired samplings were conducted consisting in matched groups of pigs from individual barns as the first pull and the close out with a 4-week interval between groups. From each group, fecal and meat samples were collected, on-farm and at harvest, respectively. Fecal samples were selectively enriched, and analyzed for the presence of Salmonella, whereas meat juice samples were analyzed for the presence of antibodies against Salmonella. In 7/9 (77.8%) of the studied barns, an increase in Salmonella prevalence was observed, based on both bacteriologic and serologic analysis. Overall, there was an increase of 9.2% (p < 0.05) in bacteriologic prevalence, and 31.3% (p < 0.05) in serologic prevalence from first pull to close out groups. This study demonstrates that a significant increase in Salmonella prevalence occurs between the first and the last group of pigs harvested from finishing lots, with close out groups of market pigs posing a higher risk for Salmonella contaminations.
Wang, Cheng; Li, Ying; Huang, Lei; Wang, Manyi
2010-10-01
To compare the results of two-staged open reduction and internal fixation (ORIF) and limited internal fixation with external fixator (LIFEF) for closed tibial plafond fractures. From January 2005 to June 2007, 56 patients with closed type B3 or C Pilon fractures were randomly allocated into groups I and II. Two-staged ORIF was performed in group I and LIFEF in group II. The outcome measures included bone union, nonunion, malunion, pin-tract infection, wound infection, osteomyelitis, ankle joint function, etc. These postoperative data were analyzed with Statistical Package for Social Sciences (SPSS) 13.0. Incidence of superficial soft tissue infection (involved in wound infection or pin-tract infection) in group I was lower than that in group II (P < 0.05), with significant difference. Group I has significantly less radiation exposure (P < 0.001). Group II had higher rates of malunion, delayed union, and arthritis symptoms, with no statistical significance. Both groups resulted similar ankle joint function. Logistic regression analysis indicated that smoking and fracture pattern were the two factors significantly influencing the final outcomes. In the treatment of closed tibial plafond fractures, both two-staged ORIF and LIFEF offer similar results. Patients undergo LIFEF carry significantly greater radiation exposure and higher superficial soft tissue infection rate (usually occurs on pin tract and does not affect the final outcomes).
Jeyaram, Kumaraswamy; Romi, Wahengbam; Singh, Thangjam Anand; Adewumi, Gbenga Adedeji; Basanti, Khundrakpam; Oguntoyinbo, Folarin Anthony
2011-11-01
PCR amplification of 16S rRNA gene by universal primers followed by restriction fragment length polymorphism analysis using RsaI, CfoI and HinfI endonucleases, distinctly differentiated closely related Bacillus amyloliquefaciens, Bacillus licheniformis and Bacillus pumilus from Bacillus subtilis sensu stricto. This simple, economical, rapid and reliable protocol could be an alternative to misleading phenotype-based grouping of these closely related species. Copyright © 2011 Elsevier B.V. All rights reserved.
STS-109 Crew Return Ceremony at Ellington Field
2002-03-13
Photographic documentation of the STS-109 Crew Return Ceremony. The events take place at Hangar 990 at Ellington Field. Views include: Overall view of crewmembers [09319]; View of crewmembers standing on stage talking to group [09320]; Unidentified crewmember waving to crowd [09321]; Unidentified crewmember autographing photo [09322]; Mission Specialist Michael J. Massimino holding crew photo as he talks to child in group [09323]; Pilot Duane G. Carey signing a crew photo for a visitor [09324]; Unidentified crewmember signing a photo for visitor [09325]; Commander Scott D. Altman talking to child in group [09326]; Unidentified crewmember giving a photo to visitor [09327]; Crewmembers exiting plane [09328]; Duane G. Carey shaking hands with visitor. Astronaut Scott Altman smiling in the background [09329); Astronaut Jim Newman kissing his child [09330]; Jim Newman holding his daughter as his son grabs at his pant leg [09331]; Close-up view of Payload Commander John Grunsfeld holding his daughter [09332]; Duane G. Carey standing with family members [09333]; Close-up view of Duane G. Carey placing his hand on a child's head as he is talking to him [09334]; Overall view of spectator watching ceremony [09335]; Close-up view of speaker during ceremony [09336]; Close-up view of Scott Altman speaking to crowd [09337]; Close-up view of a young spectator at ceremony [09338]; Close-up view of Duane G. Carey speaking to the crowd [09339]; Close-up view of Mission Specialist Nancy J. Currie speaking to the crowd [09340]; Close-up view of John M. Grunsfield speaking to the crowd [09341]; Close-up view of Mission Specialist Richard M. Linnehan speaking to the crowd [09342]; Close-up view of James H. Newman speaking to the crowd [09343]; Close-up view of Michael J. Massimino speaking to the crowd [09344
Development and assessment of sterility of a closed-system pediatric peritoneal dialysis.
Biazi, Ana Paula Pereira; Croti, Ulisses Alexandre; Braile, Domingo Marcolino; Oliveira, Marcos Aurélio Barboza de; Costa, Jane Gonçalves Soares; Cardoso, Lucas Monteiro
2009-01-01
To develop an easy-handling totally closed pediatric peritoneal dialysis system and assess the sterility assurance level. From February to December 2008 was designed and developed a closed-system pediatric peritoneal dialysis at the Bioengineering Division of Braile Biomédica Indústria, Comércio e Representações S/A. Twenty systems were manufactured and submitted to sterility assurance level testing, and were divided into Group A (10)--using the sterility test--and B (10)--ethylene oxide gas penetration. In Group A, the sterility test was negative for bacteria and fungi proliferation within 14 days in all systems. In Group B, the gas penetration test showed that there was gas penetration in all points assessed. It was possible to develop a new easy-handling closed-system pediatric peritoneal dialysis and ensure its sterility.
Stahl, Joachim S; Wang, Song
2008-03-01
Many natural and man-made structures have a boundary that shows a certain level of bilateral symmetry, a property that plays an important role in both human and computer vision. In this paper, we present a new grouping method for detecting closed boundaries with symmetry. We first construct a new type of grouping token in the form of symmetric trapezoids by pairing line segments detected from the image. A closed boundary can then be achieved by connecting some trapezoids with a sequence of gap-filling quadrilaterals. For such a closed boundary, we define a unified grouping cost function in a ratio form: the numerator reflects the boundary information of proximity and symmetry and the denominator reflects the region information of the enclosed area. The introduction of the region-area information in the denominator is able to avoid a bias toward shorter boundaries. We then develop a new graph model to represent the grouping tokens. In this new graph model, the grouping cost function can be encoded by carefully designed edge weights and the desired optimal boundary corresponds to a special cycle with a minimum ratio-form cost. We finally show that such a cycle can be found in polynomial time using a previous graph algorithm. We implement this symmetry-grouping method and test it on a set of synthetic data and real images. The performance is compared to two previous grouping methods that do not consider symmetry in their grouping cost functions.
Skalická, Věra; Belsky, Jay; Stenseng, Frode; Wichstrøm, Lars
2015-01-01
In this Norwegian study, bidirectional relations between children's behavior problems and child-teacher conflict and closeness were examined, and the possibility of moderation of these associations by child-care group size was tested. Eight hundred and nineteen 4-year-old children were followed up in first grade. Results revealed reciprocal effects linking child-teacher conflict and behavior problems. Effects of child-teacher closeness on later behavior problems were moderated by group size: For children in small groups only (i.e., ≤ 15 children), greater closeness predicted reduced behavior problems in first grade. In consequence, stability of behavior problems was greater in larger than in smaller groups. Results are discussed in light of regulatory mechanisms and social learning theory, with possible implications for organization of child care. © 2015 The Authors. Child Development © 2015 Society for Research in Child Development, Inc.
The HEMP QSO Monitoring Project
NASA Astrophysics Data System (ADS)
Welsh, William F.; Robinson, E. L.
2000-02-01
Many AGN are highly variable sources. Some of these show a pronounced time delay between variations seen in their optical continuum and in their emission lines. ``Echo mapping'' is a technique that uses these time delays to measure the geometry and kinematics of the gas inside the AGN, near the supermassive black hole. The technique is immensely powerful, but the results so far have been modest due to relatively low quality data. We have initiated a long--term project to echo map QSOs. We will examine nearby (but intrinsically faint) QSOs as well as QSOs at high redshift. The high--z QSOs present a problem: it is not known ahead of time which of these are variable sources. Thus we have started a campaign to monitor about 60 high-redshift QSOs for the purpose of determining their variability characteristics. We request SSTO time on the 0.9m telescope for long--term monitoring of high--redshift QSOs to: (i) test their suitability as viable echo mapping candidates; and (ii) measure (for the first time) their variability properties, which is of intrinsic value itself.
Color Variabilities of Spectrally Defined Red QSOs at z = 0.3–1.2
NASA Astrophysics Data System (ADS)
Chen, I.-Chenn; Hwang, Chorng-Yuan; Kaiser, Nick; Magnier, Eugene A.; Metcalfe, Nigel; Waters, Christopher
2018-03-01
We study the brightness and the color variabilities of 34 red and 122 typical quasi-stellar objects (QSOs) at z = 0.3–1.2 using data from the Pan-STARRS Medium Deep Survey. The red and the typical QSOs are selected based on the ratios of the flux densities at 3000 Å to those at 4000 Å in the rest frame. We find that 16 out of 34 red QSOs are identified as extended sources, which exhibit strong brightness and color variabilities at shorter wavelengths due to the contamination of the emission from their host galaxies. Some point-like QSOs with significant color variabilities are able to change their color classification according to our spectral definition. The timescales of the color variabilities for these point-like QSOs are within 4 years, suggesting that the size scales of the mechanisms producing the color variabilities are less than a few light years. The spectra of some extended and point-like red QSOs can be well fitted with the dust-reddened spectra of a typical QSO, while others are difficult to explain with dust reddening.
The light up and early evolution of high redshift Supermassive Black Holes
NASA Astrophysics Data System (ADS)
Comastri, Andrea; Brusa, Marcella; Aird, James; Lanzuisi, Giorgio
2016-07-01
The known AGN population at z > 6 is made by luminous optical QSO hosting Supermassive Black Holes (M > 10 ^{9}solar masses), likely to represent the tip of the iceberg of the luminosity and mass function. According to theoretical models for structure formation, Massive Black Holes (M _{BH} 10^{4-7} solar masses) are predicted to be abundant in the early Universe (z > 6). The majority of these lower luminosity objects are expected to be obscured and severely underepresented in current optical near-infrared surveys. The detection of such a population would provide unique constraints on the Massive Black Holes formation mechanism and subsequent growth and is within the capabilities of deep and large area ATHENA surveys. After a summary of the state of the art of present deep XMM and Chandra surveys, at z >3-6 also mentioning the expectations for the forthcoming eROSITA all sky survey; I will present the observational strategy of future multi-cone ATHENA Wide Field Imager (WFI) surveys and the expected breakthroughs in the determination of the luminosity function and its evolution at high (> 4) and very high (>6) redshifts.
Looking for early black holes signatures in the anisotropies of Cosmic backgrounds
NASA Astrophysics Data System (ADS)
Cappelluti, Nico
2016-04-01
We currently do not know how Super Massive Black Holes are seeded and grow to form the observed massive QSO at z~7. This is puzzling, because at that redshift the Universe was still too young to allow the growth of such massive black holes from stellar remnant black hole seeds. Theoretical models, taking into account the paucity of metals in the early Universe, explain this by invoking the formation of massive black holes seeds at z>10 as Direct Collapse Black holes of remnants of dead POPIII stars. As of today we cannot claim any detection of any high-z (z>7) black hole in their early stage of life. However, our recent measures of the arcminute scale joint fluctuations of the Cosmic X-ray Background and the Cosmic Infrared Background by Chandra and Spitzer can be explained by a population of highly absorbed z>10 Direct Collapse Black Holes.I will review the recent discoveries obtained with different instruments and by different teams and critically discuss these findings and the interpretations.
Initial Results of HamSCI Ham Radio 21 August 2017 Eclipse Ionospheric Experiments
NASA Astrophysics Data System (ADS)
Frissell, N. A.; Gerrard, A. J.; Vega, J. S.; Katz, J. D.; West, M. L.; Gunning, S. W.; Moses, M. L.; Miller, E. S.; Erickson, P. J.; Huba, J.; Silver, H. W.; Ceglia, F.; Smith, P.; Williams, R.; Shovkoplyas, A.; Earle, G. D.; Gerzoff, R.; Gladstone, P.; Reyer, S. E.; Ackermann, J. R.; Bern, D.; Rose, S. W.
2017-12-01
On 21 August 2017, a total solar eclipse will cause the shadow of the moon to traverse the United States from Oregon to South Carolina in just over 90 minutes. The sudden absence of sunlight due to the eclipse, especially solar UV and x-rays, provides an impulse function to the upper atmosphere that modifies the neutral dynamics, plasma concentrations, and related properties. Despite more than 60 years of research, questions remain regarding eclipse-induced ionospheric impacts. Ham radio operators' advanced technical skills and inherent interest in ionospheric science make the amateur radio community ideal for contributing to and and participating in large-scale ionospheric sounding experiments. We present initial results from three amateur radio experiments designed to study the 2017 total solar eclipse: the Solar Eclipse QSO Party (SEQP), the HF Wideband Recording Experiment, and the Eclipse Frequency Measurement Test (FMT). These experiments are coordinated by HamSCI, the Ham Radio Science Citizen Investigation, a citizen science organization that connects the amateur radio community to the professional space science research community for mutual benefit.
Discovery of the Most Ultra-Luminous QSO Using GAIA, SkyMapper, and WISE
NASA Astrophysics Data System (ADS)
Wolf, Christian; Bian, Fuyan; Onken, Christopher A.; Schmidt, Brian P.; Tisserand, Patrick; Alonzi, Noura; Hon, Wei Jeat; Tonry, John L.
2018-06-01
We report the discovery of the ultra-luminous quasi-stellar object SMSS J215728.21-360215.1 with magnitude z = 16.9 and W4 = 7.42 at redshift 4.75. Given absolute magnitudes of M145, AB = -29.3, M300, AB = -30.12, and logLbol/Lbol, ⊙ = 14.84, it is the quasi-stellar object with the highest unlensed UV-optical luminosity currently known in the Universe. It was found by combining proper-motion data from Gaia DR2 with photometry from SkyMapper DR1 and the Wide-field Infrared Survey Explorer. In the GAIA database, it is an isolated single source and thus unlikely to be strongly gravitationally lensed. It is also unlikely to be a beamed source as it is not discovered in the radio domain by either NRAO-VLA Sky Survey or Sydney University Molonglo Southern Survey. It is classed as a weak-emission-line quasi-stellar object and possesses broad absorption line features. A lightcurve from ATLAS spanning the time from 2015 October to 2017 December shows little sign of variability.
Conditions in the z = 0.692 absorber toward 3CR 286
NASA Technical Reports Server (NTRS)
Cohen, Ross D.; Barlow, Thomas A.; Beaver, E. A.; Junkkarinen, Vesa T.; Lyons, Ronald W.; Smith, Harding E.
1994-01-01
We present Hubble Space Telescope/Faint Object Spectrograph (HST/FOS) ultraviolet and ground-based optical spectra of the z = 0.692 21 cm absorption system in the quasi-stellar object (QSO) 3CR 286. The strength of the damped Lyman-alpha absorption implies an H I column density, N(H I) approximately 2 x 10(exp 21)/sq cm. We derive a high spin temperature for the H I gas, T(sub s) greater than or approximately equal to 10(exp 3) K, as has been found for other high-redshift 21 cm absorbing systems; at least 80% of the H I is hotter than 1200 K. Curve-of-growth analysis yields Mg(+) and Fe(+) abundances which are approximately 1-2 dex below solar values; the Ca(+) abundance is even lower implying some depletion onto dust grains. The H2 fraction is not high. We speculate that the high inferred T(sub s) for the gas may reflect continuing active star formation at the 5-8 Gyr look-back time to the absorbing galaxy.
NASA Technical Reports Server (NTRS)
Burks, Geoffrey S.; Bartko, Frank; Shull, J. Michael; Stocke, John T.; Sachs, Elise R.; Burbidge, E. Margaret; Cohen, Ross D.; Junkkarinen, Vesa T.; Harms, Richard J.; Massa, Derck
1994-01-01
The ultraviolet (1150 - 2850 A) spectra of a number of active galactic nuclei (AGNs) observed with the Hubble Space Telescope (HST) Faint Object Spectrograph (FOS) have been used to study the properties of the Galactic halo. The objects that served as probes are 3C 273, PKS 0454-220, Pg 1211+143, CSO 251, Ton 951, and PG 1351+640. The equivalent widths of certain interstellar ions have been measured, with special attention paid to the C IV/C II and Si IV/Si II ratios. These ratios have been intercompared, and the highest values are found in the direction of 3C 273, where C IV/C II = 1.2 and Si IV/Si II greater than 1. These high ratios may be due to a nearby supernova remnant, rather than to ionized gas higher up in the Galactic halo. Our data give some support to the notion that QSO metal-line systems may arise from intervening galaxies which contain high supernova rates, galactic fountains, and turbulent mixing layers.
Active galactic nuclei. III - Accretion flow in an externally supplied cluster of black holes
NASA Technical Reports Server (NTRS)
Pacholczyk, A. G.; Stoeger, W. R.; Stepinski, T. F.
1989-01-01
This third paper in the series modeling QSOs and AGNs as clusters of accreting black holes studies the accretion flow within an externally supplied cluster. Significant radiation will be emitted by the cluster core, but the black holes in the outer halo, where the flow is considered spherically symmetric, will not contribute much to the overall luminosity of the source because of their large velocities relative to the infalling gas and therefore their small accretion radii. As a result, the scenario discussed in Paper I will refer to the cluster cores, rather than to entire clusters. This will steepen the high-frequency region of the spectrum unless inverse Compton scattering is effective. In many cases accretion flow in the central part of the cluster will be optically thick to electron scattering, resulting in a spectrum featuring optically thick radiative component in addition to power-law regimes. The fitting of these spectra to QSO and AGN observations is discussed, and application to 3C 273 is worked out as an example.
Modeling Amateur Radio Soundings of the Ionospheric Response to the 2017 Great American Eclipse
NASA Astrophysics Data System (ADS)
Frissell, N. A.; Katz, J. D.; Gunning, S. W.; Vega, J. S.; Gerrard, A. J.; Earle, G. D.; Moses, M. L.; West, M. L.; Huba, J. D.; Erickson, P. J.; Miller, E. S.; Gerzoff, R. B.; Liles, W.; Silver, H. W.
2018-05-01
On 21 August 2017, a total solar eclipse traversed the continental United States and caused large-scale changes in ionospheric densities. These were detected as changes in medium- and high-frequency radio propagation by the Solar Eclipse QSO Party citizen science experiment organized by the Ham Radio Science Citizen Investigation (hamsci.org). This is the first eclipse-ionospheric study to make use of measurements from a citizen-operated, global-scale HF propagation network and develop tools for comparison to a physics-based model ionosphere. Eclipse effects were observed ±0.3 hr on 1.8 MHz, ±0.75 hr on 3.5 and 7 MHz, and ±1 hr on 14 MHz and are consistent with eclipse-induced ionospheric densities. Observations were simulated using the PHaRLAP raytracing toolkit in conjunction with the eclipsed SAMI3 ionospheric model. Model results suggest 1.8, 3.5, and 7 MHz refracted at h≥125 km altitude with elevation angles θ≥22°, while 14 MHz signals refracted at h < 125 km with elevation angles θ < 10°.
Radiation Pressure-Driven Magnetic Disk Winds in Broad Absorption Line Quasi-Stellar Objects
NASA Technical Reports Server (NTRS)
DeKool, Martin; Begelman, Mitchell C.
1995-01-01
We explore a model in which QSO broad absorption lines (BALS) are formed in a radiation pressure-driven wind emerging from a magnetized accretion disk. The magnetic field threading the disk material is dragged by the flow and is compressed by the radiation pressure until it is dynamically important and strong enough to contribute to the confinement of the BAL clouds. We construct a simple self-similar model for such radiatively driven magnetized disk winds, in order to explore their properties. It is found that solutions exist for which the entire magnetized flow is confined to a thin wedge over the surface of the disk. For reasonable values of the mass-loss rate, a typical magnetic field strength such that the magnetic pressure is comparable to the inferred gas pressure in BAL clouds, and a moderate amount of internal soft X-ray absorption, we find that the opening angle of the flow is approximately 0.1 rad, in good agreement with the observed covering factor of the broad absorption line region.
The Ionization History of The Intergalactic Medium:
NASA Technical Reports Server (NTRS)
Madau, Piero
2003-01-01
The funded project seeked a unified description of the ionization, physical structure, and evolution of the intergalactic medium (IGM) and quasar intervening absorption systems. We proposed to conduct theoretical studies of the IGM and QSO absorbers in the context of current theories of galaxy formation, developing and using numerical and analytical techniques aimed at a detailed modeling of cosmological radiative transfer, gas dynamics, and thermal and ionization evolution. The ionization history of the IGM has important implications for the metagalactic UV background, intergalactic helium absorption 21-cm tomography, metal absorption systems, fluctuations in the microwave background, and the cosmic rate of structure and star formation. All the original objectives of our program have been achieved, and the results widely used and quoted by the community. Indeed, they remain relevant as the level and complexity of research in this area has increased substantially since our proposal was submitted, due to new discoveries on galaxy formation and evolution, a flood of high-quality data on the distant universe, new theoretical ideas and direct numerical simulations of structure formation in hierarchical clustering theories.
Chu, Haikun; Xu, Yanbin; Chu, Haipeng; Xu, Yajun; Zhou, Fengji; Yu, Xin; Li, Hui; Ji, Xiaofeng
2012-06-01
To investigate the effectiveness of modified percutaneous suture in repairing acute closed Achilles tendon rupture by comparing with conventional open suture. Between January 2006 and October 2009, 50 patients with acute closed Achilles tendon rupture were treated with modified percutaneous suture by making 5 small incisions at both sides of Achilles tendon and zigzag suture (improved group, n=22) and with Kessler suture (conventional group, n=28), respectively. No significant difference was found in gender, age, time from injury to operation between 2 groups (P > 0.05). In improved group, the patients achieved healing of incisions by first intention after operation and no complication occurred; however, incision infection occurred in 1 case, Achilles tendon re-rupture in 1 case, and incision scar contracture in 2 cases in conventional group. The operation time of improved group [(38.7 +/- 6.6) minutes] was significantly shorter (t=-12.29, P=0.00) than that of conventional group [(52.3 +/- 6.9) minutes]; the blood loss of improved group [(4.9 +/- 2.0) mL] was significantly less (t=-25.20, P=0.00) than that of conventional group [(40.7 +/- 7.1) mL]. The patients were followed up 2-3 years (mean, 29.9 months). The American Orthopaedic Foot and Ankle Society (AOFAS) score was 99.6 +/- 1.0 in improved group and was 98.4 +/- 3.0 in conventional group, showing no significant difference between 2 groups (t=1.66, P=0.10). Comparison with conventional open suture, modified percutaneous suture has some advantages, such as easy operation, less complications, rapid recovery of limb function, and so on. Modified percutaneous suture is one of the best choices for the treatment of acute closed Achilles tendon rupture.
Rahal, Miguel Antônio; Alonso, Angélica Castilho; Andrusaitis, Felix Ricardo; Rodrigues, Thuam Silva; Speciali, Danielli Souza; Greve, Júlia Maria D′Andréa; Leme, Luiz Eugênio Garcez
2015-01-01
OBJECTIVE: To determine whether Tai Chi Chuan or ballroom dancing promotes better performance with respect to postural balance, gait, and postural transfer among elderly people. METHODS: We evaluated 76 elderly individuals who were divided into two groups: the Tai Chi Chuan Group and the Dance Group. The subjects were tested using the NeuroCom Balance Master® force platform system with the following protocols: static balance tests (the Modified Clinical Tests of Sensory Interaction on Balance and Unilateral Stance) and dynamic balance tests (the Walk Across Test and Sit-to-stand Transfer Test). RESULTS: In the Modified Clinical Test of Sensory Interaction on Balance, the Tai Chi Chuan Group presented a lower sway velocity on a firm surface with open and closed eyes, as well as on a foam surface with closed eyes. In the Modified Clinical Test of Sensory Interaction on Unilateral Stance, the Tai Chi Chuan Group presented a lower sway velocity with open eyes, whereas the Dance Group presented a lower sway velocity with closed eyes. In the Walk Across Test, the Tai Chi Chuan Group presented faster walking speeds than those of the Dance Group. In the Sit-to-stand Transfer Test, the Tai Chi Chuan Group presented shorter transfer times from the sitting to the standing position, with less sway in the final standing position. CONCLUSION: The elderly individuals who practiced Tai Chi Chuan had better bilateral balance with eyes open on both types of surfaces compared with the Dance Group. The Dance Group had better unilateral postural balance with eyes closed. The Tai Chi Chuan Group had faster walking speeds, shorter transfer times, and better postural balance in the final standing position during the Sit-to-stand Test. PMID:26017644
Rahal, Miguel Antônio; Alonso, Angélica Castilho; Andrusaitis, Felix Ricardo; Rodrigues, Thuam Silva; Speciali, Danielli Souza; Greve, Júlia Maria D Andréa; Leme, Luiz Eugênio Garcez
2015-03-01
To determine whether Tai Chi Chuan or ballroom dancing promotes better performance with respect to postural balance, gait, and postural transfer among elderly people. We evaluated 76 elderly individuals who were divided into two groups: the Tai Chi Chuan Group and the Dance Group. The subjects were tested using the NeuroCom Balance Master¯ force platform system with the following protocols: static balance tests (the Modified Clinical Tests of Sensory Interaction on Balance and Unilateral Stance) and dynamic balance tests (the Walk Across Test and Sit-to-stand Transfer Test). In the Modified Clinical Test of Sensory Interaction on Balance, the Tai Chi Chuan Group presented a lower sway velocity on a firm surface with open and closed eyes, as well as on a foam surface with closed eyes. In the Modified Clinical Test of Sensory Interaction on Unilateral Stance, the Tai Chi Chuan Group presented a lower sway velocity with open eyes, whereas the Dance Group presented a lower sway velocity with closed eyes. In the Walk Across Test, the Tai Chi Chuan Group presented faster walking speeds than those of the Dance Group. In the Sit-to-stand Transfer Test, the Tai Chi Chuan Group presented shorter transfer times from the sitting to the standing position, with less sway in the final standing position. The elderly individuals who practiced Tai Chi Chuan had better bilateral balance with eyes open on both types of surfaces compared with the Dance Group. The Dance Group had better unilateral postural balance with eyes closed. The Tai Chi Chuan Group had faster walking speeds, shorter transfer times, and better postural balance in the final standing position during the Sit-to-stand Test.
Hypnosis closed loop TCI systems in outpatient surgery.
Ramos-Luengo, A; Asensio-Merino, F
Determine the influence of general anaesthesia with closed-loop systems in the results of outpatient varicose vein surgery. Retrospective observational study including data from 270 outpatients between 2014 and 2015. The patients were divided into 2 groups according to the type of general anaesthesia used. The CL Group included patients who received propofol in closed-loop guided by BIS and remifentanil using TCI, and the C Group received non-closed-loop anaesthesia. Age, sex, surgical time, discharge time and failure of outpatient surgery were recorded. Quantitative data were checked for normal distribution by the method of Kolmogorov-Smirnov-Lilliefors. Differences between groups were analysed by a Student-t-test or Mann-Whitney-Wilcoxon test, depending on their distribution. Categorical data were analysed by a Chi-squared test. We used Kaplan-Meier estimator and the effect size (calculated by Cohen's d) to study the discharge time. Statistical analysis was performed using R 3.2.3 binary for Mac OS X 10.9. There were no significant differences in age, sex and surgical time and failure of outpatient surgery. Discharge time was different in both groups: 200 (100) vs. 180 (82.5) minutes, C Group and CL Group, respectively (data are median and interquartile rank); P=.005. The use of closed-loop devices for the hypnotic component of anaesthesia hastens discharge time. However, for this effect to be clinically significant, some improvements still need to be made in our outpatient surgery units. Copyright © 2016 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Publicado por Elsevier España, S.L.U. All rights reserved.
Randomized Effectiveness Study of Four Therapeutic Strategies for TMJ Closed Lock
Schiffman, E.L.; Look, J.O.; Hodges, J.S.; Swift, J.Q.; Decker, K.L.; Hathaway, K.M.; Templeton, R.B.; Fricton, J.R.
2008-01-01
For individuals with temporomandibular joint (TMJ) disc displacement without reduction with limited mouth opening (closed lock), interventions vary from minimal treatment to surgery. In a single-blind trial, 106 individuals with TMJ closed lock were randomized among medical management, rehabilitation, arthroscopic surgery with post-operative rehabilitation, or arthroplasty with post-operative rehabilitation. Evaluations at baseline, 3, 6, 12, 18, 24, and 60 months used the Craniomandibular Index (CMI) and Symptom Severity Index (SSI) for jaw function and TMJ pain respectively. Using an intention-to-treat analysis, we observed no between-group difference at any follow-up for CMI (p ≥ 0.33) or SSI (p ≥ 0.08). Both outcomes showed within-group improvement (p < 0.0001) for all groups. The findings of this study suggest that primary treatment for individuals with TMJ closed lock should consist of medical management or rehabilitation. The use of this approach will avoid unnecessary surgical procedures. PMID:17189464
A prospective evaluation of open face masks for head and neck radiation therapy.
Wiant, David; Squire, Sarah; Liu, Han; Maurer, Jacqueline; Lane Hayes, T; Sintay, Benjamin
Head and neck (HN) radiation therapy patients are typically immobilized with closed thermoplastic masks that cover the face and may cause discomfort. In this work, we examine the use of open masks for HN radiation therapy. Fifty HN patients were prospectively randomized into 2 groups (25 closed masks, 25 open masks). The open-mask group was monitored with surface imaging to evaluate intrafraction motion. Both groups underwent daily volumetric imaging. All daily images were rigidly registered to their respective planning images to evaluate spinal canal and mandible position as a check for interfraction posture change. Posture changes were determined by the amount the spinal canal and mandible contours from the planning images had to be expanded to cover the structures on each daily image set. The vector length (VL) of the intrafraction linear translations, spine, and mandible positions for each open-mask patient were checked for correlation with fraction number using the Pearson r value. All patients were given a weekly survey ranking anxiety and claustrophobia from 0 to 10 (0 = no issue, 10 = extreme issue). The mean VL for all open-mask patients was 0.9 ± 0.5 mm (1 standard deviation). Only 1 patient showed significant correlation between VL and fraction number. The mean contour expansions to cover the spine and mandible were 1.5 ± 0.9 mm and 1.8 ± 1.3 mm for the closed-mask group, and 1.6 ± 0.8 mm and 1.8 ± 1.1 mm for the open-mask group. Both groups showed similar behavior relative to fraction number. The mean anxiety and claustrophobia scores were 1.63 and 1.44 for the closed-mask group, and 0.81 and 0.63 for the open-mask group. The groups were not significantly different. Open masks provide comparable immobilization and posture preservation to closed masks for HN radiation therapy. Copyright © 2016 American Society for Radiation Oncology. Published by Elsevier Inc. All rights reserved.
NASA Astrophysics Data System (ADS)
Fengler, Felipe; Ribeiro, Admilson; Longo, Regina; Merides, Marcela; Soares, Herlon; Melo, Wanderley
2017-04-01
Although reclamation techniques for forest ecosystems recovery have been developed over the past decades, there is still a great difficulty in the establishment on environment assessment, especially when compared to the non-disturbed ecosystems. This work evaluated the results and limitations on cassiterite-mined areas in reclamation, at Brazilian Amazônia. Floristic variables from 29 plots located on 15-year-old native species reforestation sites and two plots from preserved open/closed canopy forests were analyzed in a chronosequece way (2010-2015). Regeneration density, species richness, average girth, and average height were evaluated every year, by means of cluster analysis (Euclidian distance, Ward method) and submitted to multiscale bootstrap resampling (a=5%). It was conduced the regression analysis for each identified group in 2015 in order to verify differences between the chronosequece development. The results showed the existence of two main groups in 2010, one witch all mined plots were allocated and other with open/closed canopy plots. After 2011 some mined areas became allocated in the open/closed canopy plots group. From 2013 and on open/closed canopy plots appeared shuffled in the formed groups, indicating the reclamation sites conditions became similar to natural areas. Finally, in 2015 three main groups were formed. The regression analysis showed that group three had a higher trend of development for regeneration density, with higher angular coefficient and higher values. For species richness all the groups had a similar trend, with values lower than open/closed canopy forest. In average girth higher trends were observed in group one and all values were near to open canopy forest in 2015. Average height showed better trends and higher values in group two. It was concluded that all mined sites had a forest recovery process. However, different responses to reclamation process were observed due to the differences in the degraded soils characteristics. Keywords: Recovery, Restoration, Forest, Chronosequece, Cassiterite.
Tang, Xin; Liu, Lei; Tu, Chong-qi; Li, Jian; Li, Qi; Pei, Fu-xing
2014-07-01
The timing of surgery for osteosynthesis of type C pilon (AO/OTA) fractures remains controversial. The aim of this study was to determine the outcome of early and delayed open reduction and internal fixation (ORIF) for treating closed type C pilon fractures. Forty-six patients with closed type C pilon fractures matched according to age, gender, soft tissue conditions, and fracture pattern were divided into group A (early group: underwent surgery within 36 hours of the injury) or group B (delayed group: underwent surgery 10 days to 3 weeks postinjury after the soft tissue swelling subsided). In the delayed group, 9 patients were treated first by temporary external fixation. All the closed fractures were managed by ORIF with locking plates. At follow-up, the clinical and radiographic results were retrospectively analyzed. The mean follow-up time was 25.8 months (range, 14 to 48 months) in group A and 26.0 months (range, 15 to 44 months) in group B. There was no significant difference (P > .05) between the 2 groups regarding the rate of soft tissue complication, the rate of fracture union, and the final functional score. The patients in group A had a significantly shorter mean time to fracture union (21.5 ± 4.0 weeks vs 23.3 ± 3.7 weeks, P < .05), operating time (84.3 ± 12.1 months vs 100.6 ± 13.7 months, P < .01), and hospital stay (7.6 ± 2.6 days vs 15.2 ± 4.2 days, P < .01). If soft tissue conditions are acceptable, early ORIF for treating closed type C pilon fractures can be safe and effective, with similar rates of wound complication, fracture union, and final good functional recovery but shorter operative time, union time, and hospital stay. These results favorably compare with delayed ORIF treatment. Level III, retrospective comparative study. © The Author(s) 2014.
Comparison of Fibrin Glue and Sutures for Conjunctival Wound Closure in Strabismus Surgery
Lee, Jae Hyung
2011-01-01
Purpose To evaluate and compare the efficacy and tolerance of fibrin glue and sutures for closing conjunctival wounds in strabismus surgery. Methods In a prospective trial, we performed strabismus surgery using limbal incisions. Conjunctival wounds were closed with fibrin glue in 20 eyes of 20 patients (fibrin group) and 8-0 polyglactin suture in 20 eyes of 20 patients (suture group). Postoperative pain, tearing, and inflammation were compared at 1 day, 1 week, 3 weeks, and 6 weeks after surgery. Conjunctival incision healing was also investigated. Results One day and one week post-operatively, pain and tearing scores were lower in the fibrin group (p = 0.000, respectively). Mean surgery time was significantly shorter in the fibrin (48 ± 5 minutes) than the suture group (63 ± 7 minutes) (p = 0.000). Inflammation was significantly more severe in the suture group until 3 weeks postoperative (p = 0.000, respectively), but conjunctival healing did not differ between the groups. Hyperemia appeared more prominent in the fibrin group 3 and 6 weeks after surgery (p = 0.087 and 0.000, respectively). Two eyes in the fibrin group showed conjunctival gaps of more than 2 mm, which closed spontaneously by three weeks after surgery. No allergic reactions or infections developed. Conclusions Fibrin glue proved to be as effective as sutures in closing conjunctival wounds. It provides more comfortable early postoperative courses and might be considered as an alternative to sutures in strabismus surgery. PMID:21655043
Nett, Michael; Avelar, Rui; Sheehan, Michael; Cushner, Fred
2011-03-01
Standard medial parapatellar arthrotomies of 10 cadaveric knees were closed with either conventional interrupted absorbable sutures (control group, mean of 19.4 sutures) or a single running knotless bidirectional barbed absorbable suture (experimental group). Water-tightness of the arthrotomy closure was compared by simulating a tense hemarthrosis and measuring arthrotomy leakage over 3 minutes. Mean total leakage was 356 mL and 89 mL in the control and experimental groups, respectively (p = 0.027). Using 8 of the 10 knees (4 closed with control sutures, 4 closed with an experimental suture), a tense hemarthrosis was again created, and iatrogenic suture rupture was performed: a proximal suture was cut at 1 minute; a distal suture was cut at 2 minutes. The impact of suture rupture was compared by measuring total arthrotomy leakage over 3 minutes. Mean total leakage was 601 mL and 174 mL in the control and experimental groups, respectively (p = 0.3). In summary, using a cadaveric model, arthrotomies closed with a single bidirectional barbed running suture were statistically significantly more water-tight than those closed using a standard interrupted technique. The sample size was insufficient to determine whether the two closure techniques differed in leakage volume after suture rupture.
Root canal penetration of a sodium hypochlorite mixture using sonic or ultrasonic activation.
Sáinz-Pardo, Marta; Estevez, Roberto; Pablo, Óliver Valencia de; Rossi-Fedele, Giampiero; Cisneros, Rafael
2014-01-01
The purpose of this ex vivo study was to determine, in "open" and "closed" systems, whether the design has an influence on the penetration length of sodium hypochlorite mixed with a radiopaque contrast medium, measured in millimeters, when delivered using positive pressure (PP) and using sonic (SI) or passive ultrasonic (PUI) activation. Sixty single-rooted teeth were divided into two groups: open and closed systems (n=30). Root canal shaping was performed to a working length of 17 mm. The samples were divided into three sub-groups (n=10) according to irrigant delivery and activation: PP, and SI or PUI activation. By using radiographs, penetration length was measured, and vapor lock was assessed. For the closed group, the penetration distance means were: PP 15.715 (±0.898) mm, SI 16.299 (±0.738) mm and PUI 16.813 (±0.465) mm, with vapor lock occurring in 53.3% of the specimens. In the open group, penetration to 17 mm occurred in 97.6% of the samples, and no vapor lock occurred. Irrigant penetration and distribution evaluation using open and closed systems provide significantly different results. For closed systems, PUI is the most effective in delivering the irrigant to working length, followed by SI.
Rom, Eldad; Mikulincer, Mario
2003-06-01
Four studies examined attachment-style differences in group-related cognitions and behaviors. In Studies 1-2, participants completed scales on group-related cognitions and emotions. In Studies 3-4, participants were divided into small groups, and their performance in group tasks as well as the cohesion of their group were assessed. Both attachment anxiety and avoidance in close relationships were associated with negative group-related cognitions and emotions. Anxiety was also related to the pursuit of closeness goals and impaired instrumental performance in group tasks. Avoidance was related to the pursuit of distance goals and deficits in socioemotional and instrumental performance. Group cohesion significantly moderated the effects of attachment anxiety. The discussion emphasizes the relevance of attachment theory within group contexts.
Kim, Young-Hoon; Kim, Chae-Yong; Oh, Chang Wan
2013-01-01
Objective We performed this study to investigate whether the use of closed-suction drainage following microvascular decompression (MVD) causes cerebrospinal fluid (CSF) leakage. Methods Between 2004 and 2011, a total of 157 patients with neurovascular compression were treated with MVD. MVD was performed for hemifacial spasm in 150 (95.5%) cases and for trigeminal neuralgia in 7 (4.5%) cases. The mean age of the patients was 49.8±9.6 years (range, 20-69). Dural substitutes were used in 44 (28.0%) patients. Ninety-two patients (58.6%) were underwent a 4-5 cm craniotomy using drainage (drainage group), and 65 (41.4%) did a small 2-2.5 cm retromastoid craniectomy without closed-suction drainage (no-drainage group). Results Eleven (7.0%) patients experienced CSF leakage following MVD based on the criteria of this study; all of these patients were in the drainage group. In the unadjusted analyses, the incidence of CSF leakage was significantly related with the use of closed-suction drainage following MVD (12.0% in the drainage group vs. 0% in the no-drainage group, respectively; p=0.003; Fisher's exact test). Those who received dural substitutes and the elderly (cut-off value=60 years) exhibited a tendency to develop CSF leakage (p=0.075 and p=0.090, respectively; Fisher's exact test). In the multivariate analysis, only the use of closed-suction drainage was significantly and independently associated with the development of CSF leakage following MVD (odds ratio=9.900; 95% confidence interval, 1.418 to infinity; p=0.017). Conclusion The use of closed-suction drainage following MVD appears to be related to the development of CSF leakage. PMID:24175025
Familism and Psychological Health: The Intervening Role of Closeness and Social Support
Campos, Belinda; Ullman, Jodie B.; Aguilera, Adrian; Schetter, Christine Dunkel
2014-01-01
Familism, a cultural value that emphasizes warm, close, supportive family relationships and that family be prioritized over self, has been associated with psychological health. The goal of this work was to fill a gap in the literature on how familism contributes to psychological health. Drawing from conceptual links between familism and close relationship processes, we hypothesized that familism contributes to better psychological health by facilitating closeness and social support. A university sample of U.S. women and men of Latino (n = 173), European (n = 257), and Asian (n = 642) cultural backgrounds completed measures of familism, closeness to family members, general perceived social support, and psychological health as indexed by perceived stress, general mental health, and depressive symptoms. Structural equation multiple-group modeling analyses found direct effects of familism on closeness to family members and perceived social support and an indirect effect of familism on better psychological health via greater closeness to family members and greater perceived social support. These effects did not differ by cultural background. Consistent with previous research, however, Latinos reported the highest levels of familism of the three cultural groups, and women reported higher familism and support as well as poorer psychological health than men. Discussion is focused on the implications of these findings for understanding the association of familism with psychological health and the relevance of the familism construct for diverse U.S. groups. PMID:24773004
Facy, Olivier; Combier, Christophe; Poussier, Matthieu; Magnin, Guy; Ladoire, Sylvain; Ghiringhelli, François; Chauffert, B; Rat, Patrick; Ortega-Deballon, Pablo
2015-01-01
Heated intraperitoneal chemotherapy (HIPEC) treats residual microscopic disease after cytoreductive surgery. In experimental models, the open HIPEC technique has shown a higher and more homogenous concentration of platinum in the peritoneum than achieved using the closed technique. A 25-cm H2O pressure enhances the penetration of oxaliplatin. Because pressure is easier to set up with the closed technique, high pressure may counterbalance the drawbacks of this technique versus open HIPEC, and a higher pressure may induce a higher penetration. Because higher concentration does not mean deeper penetration, a study of tissues beneath the peritoneum is required. Finally, achieving a deeper penetration (and a higher concentration) raises the question of the passage of drugs through the surgical glove and the surgeon's safety. Four groups of pigs underwent HIPEC with oxaliplatin (150 mg/L) for 30 minutes in open isobaric pressure and pressure at 25 cm H2O, and closed pressure at 25 and 40 cm H2O. Systemic absorption and peritoneal mapping of the concentration of platinum were analyzed, as well as in the retroperitoneal tissue and the surgical gloves. Blood concentrations were higher in open groups. In the parietal surfaces, the concentrations were not different between the isobaric and the closed groups (47.08, 56.39, and 48.57 mg/kg, respectively), but were higher in the open high-pressure group (85.93 mg/kg). In the visceral surfaces, they were lower in the closed groups (3.2 and 3.05 mg/kg) than in the open groups (7.03 and 9.56 mg/kg). Platinum concentrations were similar in the deep retroperitoneal tissue when compared between isobaric and high-pressure procedures. No platin was detected in the internal aspect of the gloves. The use of high pressure during HIPEC does not counterbalance the drawbacks of closed techniques. The tissue concentration of oxaliplatin achieved with the open techniques is higher, even if high pressure is applied during a closed technique. Open 25 cm H2O HIPEC achieved the highest tissue penetration of oxaliplatin, but did not enhance the depth of oxaliplatin penetration. High pressure did not enhance the risk of HIPEC. Copyright © 2015 Elsevier Inc. All rights reserved.
Interpersonal Identity Formation in Conversations with Close Friends about Dating Relationships
ERIC Educational Resources Information Center
Morgan, Elizabeth M.; Korobov, Neill
2012-01-01
The present study explores how close same-sex friendship groups participate in the co-construction of identities in the interpersonal domain during young adulthood. Participants included 24 same-sex college student friendship triads (12 male and 12 female; 72 total participants) who took part in semi-structured group interviews that elicited…
ERIC Educational Resources Information Center
Libby, Roger W.; And Others
1978-01-01
Propositions concerned with reference group and role correlates of Ira Reiss' premarital sexual permissiveness theory were tested. Reiss' basic propositions are only partially supported. Closeness to mother's sexual standards is considerably more predictive of self-permissiveness than was obvious in Reiss' theory. Closeness to friends' and peers'…
78 FR 67370 - National Heart, Lung, and Blood Institute; Notice of Closed Meetings
Federal Register 2010, 2011, 2012, 2013, 2014
2013-11-12
... Group; Heart, Lung, and Blood Program Project Review Committee. Date: December 6, 2013. Time: 8:00 a.m...-0303, [email protected] . Name of Committee: Heart, Lung, and Blood Initial Review Group; NHLBI... Blood Institute; Notice of Closed Meetings Pursuant to section 10(d) of the Federal Advisory Committee...
Altered characteristics of balance control in obese older adults.
Melzer, Itshak; Oddsson, Lars I E
2016-01-01
Obesity is one of the most significant epidemiological trends of the last decades. Recently it was found that obese individuals show postural instability. Balance control mechanisms in obese older adults were less studied. Therefore we aimed to investigate the effect of obesity on balance control mechanisms in older adults. Parameters from Stabilogram-Diffusion Analysis (SDA) and measures from summary statistics of foot centre-of-pressure (COP) displacements along the anterior-posterior (AP) and mediolateral (ML) directions in eyes open and eyes closed conditions were used to characterize postural control in 22 obese (30-<35kg/m(2)), 26 overweight (25-<30kg/m(2)), and 18 normal weight subjects (18.5-<25kg/m(2)). Obese group subjects demonstrated significantly greater transition displacement, transition time interval, and short-term scaling exponent in the ML-direction compared with the normal weight group (eyes open and closed). In the AP-direction the obese group showed greater transition displacement (eyes open) and short-term scaling exponent (eyes open and closed). Average AP-COP and ML-COP ranges of COP sway were higher in the obese group compared with the normal weight group (eyes open and closed). This work indicates an altered postural control process in obese older adults. A greater sway displacement before closed-loop feedback mechanisms are called into play was seen in the ML direction that may lead to a higher risk of instability and fall events. Copyright © 2015 Asia Oceania Association for the Study of Obesity. Published by Elsevier Ltd. All rights reserved.
Microleakage of Four Dental Cements in Metal Ceramic Restorations With Open Margins.
Eftekhar Ashtiani, Reza; Farzaneh, Babak; Azarsina, Mohadese; Aghdashi, Farzad; Dehghani, Nima; Afshari, Aisooda; Mahshid, Minu
2015-11-01
Fixed prosthodontics is a routine dental treatment and microleakage is a major cause of its failure. The aim of this study was to assess the marginal microleakage of four cements in metal ceramic restorations with adapted and open margins. Sixty sound human premolars were selected for this experimental study performed in Tehran, Iran and prepared for full-crown restorations. Wax patterns were formed leaving a 300 µm gap on one of the proximal margins. The crowns were cast and the samples were randomly divided into four groups based on the cement used. Copings were cemented using zinc phosphate cement (Fleck), Fuji Plus resin-modified glass ionomer, Panavia F2.0 resin cement, or G-Cem resin cement, according to the manufacturers' instructions. Samples were immersed in 2% methylene blue solution. After 24 hours, dye penetration was assessed under a stereomicroscope and analyzed using the respective software. Data were analyzed using ANOVA, paired t-tests, and Kruskal-Wallis, Wilcoxon, and Mann-Whitney tests. The least microleakage occurred in the Panavia F2.0 group (closed margin, 0.18 mm; open margin, 0.64 mm) and the maximum was observed in the Fleck group (closed margin, 1.92 mm; open margin, 3.32 mm). The Fleck group displayed significantly more microleakage compared to the Fuji Plus and Panavia F2.0 groups (P < 0.001) in both closed and open margins. In open margins, differences in microleakage between the Fuji Plus and G-Cem as well as between the G-Cem and Panavia F2.0 groups were significant (P < 0.001). In closed margins, only the G-Cem group displayed significantly more microleakage as compared to the Panavia F2.0 group (P < 0.05). Paired t-test results showed significantly more microleakage in open margins compared to closed margins, except in the Fuji Plus group (P = 0.539). Fuji Plus cement exhibited better sealing ability in closed and open margins compared to G-Cem and Fleck cements. When using G-Cem and Fleck cements for full metal ceramic restorations, clinicians should try to minimize marginal gaps in order to reduce restoration failure. In situations where there are doubts about perfect marginal adaptation, the use of Fuji Plus cement may be helpful.
Soltani, Ghasem; Khorsand, Mahmood; Shamloo, Alireza Sepehri; Jarahi, Lida; Zirak, Nahid
2015-01-01
Background: Postoperative pain is a common side effect following surgery that can significantly reduce surgical quality and patient’s satisfaction. Treatment options are morphine and buprenorphine. We aimed to compare the efficacy of a single dose of intravenous morphine with sublingual buprenorphine in postoperative pain control following closed reduction surgery. Methods: This triple blind clinical trial was conducted on 90 patients referred for closed reduction orthopedic surgery. They were older than 18 years and in classes I and II of the American Society of Anesthesiologists (ASA) with an operation time of 30-90 minutes. Patients were divided into two groups of buprenorphine (4.5µg/kg sublingually) and morphine (0.2mg/kg intravenously). Baseline characteristics, vital signs, pain score, level of sedation and pharmacological side effects were recorded in the recovery room (at 0 and 30 minutes), and in the ward (at 3, 6 and 12 hours). SPSS version 19 software was used for data analysis and the significance level was set at P<0.05. Results: Ninety patients were studied, 60 males and 30 females with a mean age of 37.7±16.2 years. There was no significant difference between the two groups in terms of baseline characteristics. Pain score in the morphine group was significantly higher than the buprenorphine group with an average score of 2.5 (P<0.001). Postoperative mean heart rate in the buprenorphine group was four beats lower than the morphine group (P<0.001). Also, in the buprenorphine 48.6% and in the morphine group 86.7% of cases were conscious in recovery (P=0.001) with a higher rate of pruritus in the latter group (P=0.001). Conclusion: Sublingual buprenorphine administration before anesthesia induction in closed reduction surgery can lead to better postoperative pain control in comparison to intravenous morphine. Due to simple usage and longer postoperative sedation, sublingual buprenorphine is recommended as a suitable drug in closed reduction surgery. PMID:26550594
Soltani, Ghasem; Khorsand, Mahmood; Shamloo, Alireza Sepehri; Jarahi, Lida; Zirak, Nahid
2015-10-01
Postoperative pain is a common side effect following surgery that can significantly reduce surgical quality and patient's satisfaction. Treatment options are morphine and buprenorphine. We aimed to compare the efficacy of a single dose of intravenous morphine with sublingual buprenorphine in postoperative pain control following closed reduction surgery. This triple blind clinical trial was conducted on 90 patients referred for closed reduction orthopedic surgery. They were older than 18 years and in classes I and II of the American Society of Anesthesiologists (ASA) with an operation time of 30-90 minutes. Patients were divided into two groups of buprenorphine (4.5µg/kg sublingually) and morphine (0.2mg/kg intravenously). Baseline characteristics, vital signs, pain score, level of sedation and pharmacological side effects were recorded in the recovery room (at 0 and 30 minutes), and in the ward (at 3, 6 and 12 hours). SPSS version 19 software was used for data analysis and the significance level was set at P<0.05. Ninety patients were studied, 60 males and 30 females with a mean age of 37.7±16.2 years. There was no significant difference between the two groups in terms of baseline characteristics. Pain score in the morphine group was significantly higher than the buprenorphine group with an average score of 2.5 (P<0.001). Postoperative mean heart rate in the buprenorphine group was four beats lower than the morphine group (P<0.001). Also, in the buprenorphine 48.6% and in the morphine group 86.7% of cases were conscious in recovery (P=0.001) with a higher rate of pruritus in the latter group (P=0.001). Sublingual buprenorphine administration before anesthesia induction in closed reduction surgery can lead to better postoperative pain control in comparison to intravenous morphine. Due to simple usage and longer postoperative sedation, sublingual buprenorphine is recommended as a suitable drug in closed reduction surgery.
Lewine, Eliza; Kim, Jaehon M; Miller, Patricia E; Waters, Peter M; Mahan, Susan T; Snyder, Brian; Hedequist, Daniel; Bae, Donald S
2018-02-01
The purpose of this investigation was to compare the presentation and postoperative results of children treated for open and closed, completely displaced type III supracondylar humerus fractures (SCFs). Thirty patients with open and 66 patients with closed, completely displaced type III SCFs were evaluated. Open fractures underwent irrigation and debridement, and all patients were treated by open or closed reduction and pin fixation. Medical records were reviewed to obtain demographic information as well as preoperative and postoperative clinical data regarding mechanism of injury, neurovascular status, associated injuries, postoperative range of motion, infections, and pain. Radiographs were evaluated to quantify displacement, Baumann's angle, humeral capitellar angle, position of the anterior humeral line, and adequacy of reduction. Outcomes were assessed using Flynn criteria. Mean clinical follow-up for the open and closed fracture groups was 8.9 and 5.7 months, respectively. Both groups were similar with respect to age, sex distribution, weight and body mass index, laterality of involvement, and mechanism of injury. At presentation, 35% of closed SCFs and 23% of open SCFs presented with abnormal neurovascular status. There was a higher prevalence of diminished/absent pulses or distal limb ischemia in patients with open injuries (27%) compared with closed fractures (18%). Conversely, severely displaced closed fractures were more commonly associated with nerve injury/palsy at presentation (35%) than those with open fractures (23%). Spontaneous nerve recovery was seen in 87% within 3 to 6 months. Postoperative loss of reduction and malunion were more common in the closed fracture group. However, 84% of patients achieved good-to-excellent results by Flynn criteria, with no appreciable difference based upon open versus closed fractures. With timely wound and fracture treatment, the clinical and radiographic results of children treated for open SCFs is similar to those with closed type III injuries, with little increased risk for infection, malunion, or neurovascular compromise. Level III.
Taheri, Parvin; Asgari, Narges; Mohammadizadeh, Majid; Golchin, Mehri
2012-01-01
Aims: Mechanical ventilation is used for some infants in neonatal intensive care units (NICU) due to many physiological and clinical causes. Since these patients have endotracheal tubes, cleaning and keeping the airways open through suctioning should be done to increase oxygenation. This study aimed to evaluate effect of open and closed suctioning methods on respiratory parameters of infants undergoing mechanical ventilation. Materials and Methods: In this crossover clinical trial, 44 infants were selected among those undergone mechanical ventilation in NICU of Isfahan's Al-Zahra Hospital using convenience sampling method. The subjects were randomly divided into two groups. In the first group, open suctioning was carried out and after three hours of cleaning, closed suctioning was done. In the second group, closed suctioning was firstly done and following three hours of cleaning, open suctioning was implemented. Respiratory rate (RR) and percentage of arterial blood oxygen saturation was measured before, during and after each type of suctioning. Data were analyzed using repeated measures ANOVA and independent student's t-test. Findings: There was a significant difference between mean respiratory rate and arterial blood oxygen saturation in infants before, during and after the closed and open suctioning. The percentage of arterial blood oxygen saturation had a significant reduction in open method compared to closed method during suctioning and immediately after it. RR three minutes after suctioning showed a significant reduction in both steps in open method compared to closed method. Conclusions: Close method caused fewer changes in hemodynamic status of infants. Therefore, in order to prevent respiratory complications in infants, nurses are recommended to perform the endotracheal tube suctioning by closed method. PMID:23493041
Braga Goncalves, Ines; Heistermann, Michael; Ganswindt, André; Manser, Marta B.
2017-01-01
It is well established that animal vocalizations can encode information regarding a sender’s identity, sex, age, body size, social rank and group membership. However, the association between physiological parameters, particularly stress hormone levels, and vocal behavior is still not well understood. The cooperatively breeding African meerkats (Suricata suricatta) live in family groups with despotic social hierarchies. During foraging, individuals emit close calls that help maintain group cohesion. These contact calls are acoustically distinctive and variable in rate across individuals, yet, information on which factors influence close calling behavior is missing. The aim of this study was to identify proximate factors that influence variation in call rate and acoustic structure of meerkat close calls. Specifically, we investigated whether close calling behavior is associated with sex, age and rank, or stress hormone output (i.e., measured as fecal glucocorticoid metabolite (fGCM) concentrations) as individual traits of the caller, as well as with environmental conditions (weather) and reproductive seasonality. To disentangle the effects of these factors on vocal behavior, we analyzed sound recordings and assessed fGCM concentrations in 64 wild but habituated meerkats from 9 groups during the reproductive and non-reproductive seasons. Dominant females and one-year old males called at significantly higher rates compared to other social categories during the reproductive season. Additionally, dominant females produced close calls with the lowest mean fundamental frequencies (F0) and the longest mean pulse durations. Windy conditions were associated with significantly higher call rates during the non-reproductive season. Fecal GCM concentrations were unrelated to close calling behavior. Our findings suggest that meerkat close calling behavior conveys information regarding the sex and social category of the caller, but shows no association with fGCM concentrations. The change in call rate in response to variation in the social and ecological environments individuals experience indicates some degree of flexibility in vocal production. PMID:28467419
Using a Facebook Closed Group to Improve EFL Students' Writing
ERIC Educational Resources Information Center
Rodliyah, Rojab Siti
2016-01-01
This study investigates how social media, in this case Facebook, can be incorporated in ELT through e-dialogue journal writing shared in a Facebook closed group. Fifteen EFL students participated in this case study. They were second, third, and fourth year students of English Education Department of a university in Bandung, who voluntarily joined…
76 FR 14950 - Closed Meeting of the U.S. Strategic Command Strategic Advisory Group
Federal Register 2010, 2011, 2012, 2013, 2014
2011-03-18
... DEPARTMENT OF DEFENSE Office of the Secretary Closed Meeting of the U.S. Strategic Command.... Strategic Command Strategic Advisory Group. DATES: April 7, 2011, from 8 a.m. to 5 p.m. and April 8, 2011... policy-related issues to the Commander, U.S. Strategic Command, during the development of the Nation's...
Federal Register 2010, 2011, 2012, 2013, 2014
2011-08-23
... DEPARTMENT OF DEFENSE Notice of Advisory Committee Closed Meeting; U.S. Strategic Command.... Strategic Command Strategic Advisory Group. DATES: November 1, 2011, from 8 a.m. to 5 p.m. and November 2..., intelligence, and policy-related issues to the Commander, U.S. Strategic Command, during the development of the...
Effects of Elicitation Procedures on the Narratives of Normal and Closed Head-Injured Adults.
ERIC Educational Resources Information Center
Liles, Betty Z.; And Others
1989-01-01
Twenty-three normal adults and four closed head-injured (CHI) adults with a high level of language recovery retold and generated stories. The two tasks differentially influenced the performance of both groups. The two groups differed in measures of cohesiveness and story grammar only in the story generation task. (Author/JDD)
Referential Cohesion and Logical Coherence of Narration after Closed Head Injury
ERIC Educational Resources Information Center
Davis, G. Albyn; Coelho, Carl A.
2004-01-01
A group with closed head injury was compared to neurologically intact controls regarding the referential cohesion and logical coherence of narrative production. A sample of six stories was obtained with tasks of cartoon-elicited story-telling and auditory-oral retelling. We found deficits in the clinical group with respect to referential cohesion,…
Fracture of mandibular condyle—to open or not to open: an attempt to settle the controversy.
Rastogi, Sanjay; Sharma, Siddharth; Kumar, Sanjeev; Reddy, Mahendra P; Niranjanaprasad Indra, B
2015-06-01
To compare the outcome of the open method versus the closed method of treatment for mandibular condylar fracture. Fifty patients with fractures of the mandibular condylar processes were evaluated. All fractures were displaced, with a degree of deviation between the condylar fragment and the ascending ramus of 10 to 45 degrees (mediolaterally). The patients were randomly divided into two groups, with group 1 receiving open reduction internal fixation and group 2 receiving closed reduction. The follow-up was done over the period of 6 months. Statistically significant improvement was seen in group 1 compared with group 2 in terms of anatomic reduction of the condyle, shortening of the ascending ramus, occlusal status, and deviation on mouth opening. A statistically significant difference was seen in the patients treated with the open method, with improved temporomandibular joint functions and fewer short- and long-term complications compared with those treated with the closed method. Copyright © 2015 Elsevier Inc. All rights reserved.
Krishnamoorthy, Bhuvaneswari; Critchley, William R; Nair, Janesh; Malagon, Ignacio; Carey, John; Barnard, James B; Waterworth, Paul D; Venkateswaran, Rajamiyer V; Fildes, James E; Caress, Ann L; Yonan, Nizar
The aim of the study was to assess whether the use of carbon dioxide insufflation has any impact on integrity of long saphenous vein comparing 2 types of endoscopic vein harvesting and traditional open vein harvesting. A total of 301 patients were prospectively randomized into 3 groups. Group 1 control arm of open vein harvesting (n = 101), group 2 closed tunnel (carbon dioxide) endoscopic vein harvesting (n = 100) and Group 3 open tunnel (carbon dioxide) endoscopic vein harvesting (open tunnel endoscopic vein harvesting) (n = 100). Each group was assessed to determine the systemic level of partial arterial carbon dioxide, end-tidal carbon dioxide, and pH. Three blood samples were obtained at baseline, 10 minutes after start of endoscopic vein harvesting, and 10 minutes after the vein was retrieved. Vein samples were taken immediately after vein harvesting without further surgical handling to measure the histological level of endothelial damage. A modified validated endothelial scoring system was used to compare the extent of endothelial stretching and detachment. The level of end-tidal carbon dioxide was maintained in the open tunnel endoscopic vein harvesting and open vein harvesting groups but increased significantly in the closed tunnel endoscopic vein harvesting group (P = 0.451, P = 0.385, and P < 0.001). Interestingly, partial arterial carbon dioxide also did not differ over time in the open tunnel endoscopic vein harvesting group (P = 0.241), whereas partial arterial carbon dioxide reduced significantly over time in the open vein harvesting group (P = 0.001). A profound increase in partial arterial carbon dioxide was observed in the closed tunnel endoscopic vein harvesting group (P < 0.001). Consistent with these patterns, only the closed tunnel endoscopic vein harvesting group demonstrated a sudden drop in pH over time (P < 0.001), whereas pH remained stable for both open tunnel endoscopic vein harvesting and open vein harvesting groups (P = 0.105 and P = 0.869, respectively). Endothelial integrity was better preserved in the open vein harvesting group compared with open tunnel endoscopic vein harvesting or closed tunnel endoscopic vein harvesting groups (P = 0.012) and was not affected by changes in carbon dioxide or low pH. Significantly greater stretching of the endothelium was observed in the open tunnel endoscopic open tunnel endoscopic vein harvesting group compared with the other groups (P = 0.003). This study demonstrated that the different vein harvesting techniques impact on endothelial integrity; however, this does not seem to be related to the increase in systemic absorption of carbon dioxide or to the pressurized endoscopic tunnel. The open tunnel endoscopic harvesting technique vein had more endothelial stretching compared with the closed tunnel endoscopic technique; this may be due to manual dissection of the vein. Further research is required to evaluate the long-term clinical outcome of these vein grafts.
[Class III surgical patients facilitated by accelerated osteogenic orthodontic treatment].
Wu, Jia-qi; Xu, Li; Liang, Cheng; Zou, Wei; Bai, Yun-yang; Jiang, Jiu-hui
2013-10-01
To evaluate the treatment time and the anterior and posterior teeth movement pattern as closing extraction space for the Class III surgical patients facilitated by accelerated osteogenic orthodontic treatment. There were 10 skeletal Class III patients in accelerated osteogenic orthodontic group (AOO) and 10 patients in control group. Upper first premolars were extracted in all patients. After leveling and alignment (T2), corticotomy was performed in the area of maxillary anterior teeth to accelerate space closing.Study models of upper dentition were taken before orthodontic treatment (T1) and after space closing (T3). All the casts were laser scanned, and the distances of the movement of incisors and molars were digitally measured. The distances of tooth movement in two groups were recorded and analyzed. The alignment time between two groups was not statistically significant. The treatment time in AOO group from T2 to T3 was less than that in the control group (less than 9.1 ± 4.1 months). The treatment time in AOO group from T1 to T3 was less than that in the control group (less than 6.3 ± 4.8 months), and the differences were significant (P < 0.01). Average distances of upper incisor movement (D1) in AOO group and control group were (2.89 ± 1.48) and (3.10 ± 0.95) mm, respectively. Average distances of upper first molar movement (D2) in AOO group and control group were (2.17 ± 1.13) and (2.45 ± 1.04) mm, respectively.No statistically significant difference was found between the two groups (P > 0.05). Accelerated osteogenic orthodontic treatment could accelerate space closing in Class III surgical patients and shorten preoperative orthodontic time. There were no influence on the movement pattern of anterior and posterior teeth during pre-surgical orthodontic treatment.
Hajovsky, Daniel B; Mason, Benjamin A; McCune, Luke A
2017-08-01
Multiple group longitudinal cross-lagged panel models were implemented to understand the directional influences between teacher-student closeness and conflict and measured math and reading achievement across elementary grades and gender groups using the National Institute of Child Health and Human Development longitudinal sample (N=1133). Specifically, after testing multiple group longitudinal measurement invariance to ensure consistent measurement across genders and time, and tests of equivalence of the latent parameters, we were interested in whether longitudinal changes in teacher-rated closeness and conflict explained longitudinal changes in achievement, and vice versa, and whether those longitudinal influences varied by gender. Latent teacher-student closeness decreased for both genders over time (Cohen's d=-0.15 to -0.32), but latent conflict increased for males (Cohen's d=0.16). There was also increased heterogeneity in teacher-student relationship quality for males relative to females. Math and reading achievement had medium reciprocal effects (β=0.12 to 0.23), and previous math achievement had small to medium effects on subsequent teacher-student closeness (β=0.08 to 0.11) and conflict (β=-0.07 to -0.09). Teacher-student conflict and closeness did not influence subsequent levels of math or reading achievement once previous levels were controlled. Further, these influences were consistent across gender groups despite latent differences in teacher-student closeness and conflict with teachers reporting closer relationships with female students and more conflictual relationships with male students. Copyright © 2017 Society for the Study of School Psychology. Published by Elsevier Ltd. All rights reserved.
Xu, Xiaofeng; Shi, Jun; Xu, Bing; Dai, Jiewen; Zhang, Shilei
2015-03-01
To evaluate the treatment methods of mandibular symphyseal fracture combined with dislocated intracapsular condylar fractures (MSF&DICF) and to compare the effect of different treatment methods of condylar fractures. Twenty-eight patients with MSF&DICF were included in this study. Twenty-two sites were treated by open reduction, and all the medial condylar fragments were fixed with titanium screws; whereas the other 22 sites underwent close treatment. The surgical effect between these 2 groups was compared based on clinical examination and radiographic examination results. Seventeen of 22 condyle fractures were repositioned in the surgery group, whereas 4 of 22 condyle fractures were repositioned in the close treatment group. Statistical difference was observed between these 2 groups (P < 0.01). Functional outcomes of the patients treated in the surgical treatment group also were better than those in the close treatment group. The dislocated intracapsular condyle fractures should be treated by surgical reduction with the maintenance of the attachment of lateral pterygoid muscle, which is beneficial to repositioning the dislocated condyle to its original physiological position, to closure of the mandibular lingual gap, to restore the mandibular width.
Chimpanzees' responses to the dead body of a 9-year-old group member.
van Leeuwen, Edwin J C; Mulenga, Innocent Chitalu; Bodamer, Mark D; Cronin, Katherine A
2016-09-01
The social behavior of chimpanzees has been extensively studied, yet not much is known about how they behave in response to the death of a group member. Here, we provide a detailed report of the reactions of a group of chimpanzees to finding the dead body of a 9-year-old male group member. The behavior of the group was characterized by quiet attendance and close inspections punctuated by rare displays. Moreover, the body was continuously attended and closely inspected by several adults and juveniles, including an adult male who formed a close social bond with the deceased individual after the deceased individual's mother died 4 years earlier. When considered with observations of how chimpanzees respond to dead infants and adults in this group and in others, these observations suggest that chimpanzees' responses to death may be mediated by social bonds with the deceased individual. The results are discussed in light of recent reports on chimpanzees' reactions to dead community members and more general primate thanatology. Am. J. Primatol. 78:914-922, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.
Yuenyong, Siriwan; O'Brien, Beverley; Jirapeet, Veena
2012-01-01
To evaluate the efficacy of a close female relative providing emotional and physical support during active labor and birth. Randomized, two-group controlled clinical trial. Regional teaching hospital in the eastern part of Thailand with 782 beds. Primiparous women (N = 120) whose gestational ages were ≥ 36 weeks and who had uncomplicated pregnancies. Participants were randomly assigned to receive usual care and support from a chosen close female relative from admission until 2 hours after birth or usual care only. Within 24 hours of birth, labor outcomes (length of labor & type of birth) and levels of maternal satisfaction were assessed. Those in the experimental group had a significantly shorter duration of active labor and were more satisfied with their childbirth experiences than those in the control group. Differences between groups with respect to incidence of spontaneous delivery were not found. A close female relative was effective in providing supportive care during labor and delivery. The integration of this nursing intervention for women and their families at public hospitals in Thailand is supported. © 2012 AWHONN, the Association of Women's Health, Obstetric and Neonatal Nurses.
Reaction to the sensory integration therapy in children with postural stability deficits.
Maciaszek, Janusz; Kilan, Natalia; Bronikowski, Michal
2016-10-05
The goal was to examine the influence of sensory integration therapy (SIT) on one leg standing in children with deficits of the postural stability. 28 children 4 - 6 year old that could not stand on one leg for more than 20 seconds were randomly divided into control "C" and experimental "E" groups. Group "C" participated in standard classes in the kindergarten. Group "E" participated in sensory integration therapy (SIT) for 2 weeks, 5 times a week (additionally to the standard classes). Results of the experiment show that the skill of standing on one leg has significantly improved (p<0.01) in the group that underwent additional therapy. The change in time of standing on the right leg with eyes open in the E group was statistically and significantly higher than the changes observed in the same time in group C (F = 22.5, p = 0.001' η2 = 0.44). Similarly, significant changes in time of standing on the right leg with eyes closed were observed in group E. The foregoing changes were bigger in group E than in group C (F = 16. 1 , p = 0.004, η2 = 0.36). The analysis post hoc revealed that while there were no significant differences between the two groups on the pretest (p>0.05), there were significant differences between groups in right leg standing test with eyes open or closed on posttest. (p<0.05). Similar results were observed during on the one, left leg standing. The time of one leg standing with both eyes open and closed improved more significantly in group E than in group C (F = 20.4, p = 0.001, η2 = 0.42 respectively for the test with eyes open and F = 7.4, p = 0.010, η2 = 0.21 for the test with eyes closed). The analysis post hoc revealed that while there were no significant differences between the two groups on the pretest (p>0.05), there were significant differences between groups in left leg standing test with eyes open or closed on posttest. (p<0.05). Research conducted show that there is a positive influence of SIT on children with low level of postural stability. Its significant improvement in children with low levels of postural stability is important not only for the current functioning of those children but for their future - by protecting them from falling down and from injuries.
Tracheal tube biofilm removal through a novel closed-suctioning system: an experimental study.
Aguilera Xiol, E; Li Bassi, G; Wyncoll, D; Ntoumenopoulos, G; Fernandez-Barat, L; Marti, J D; Comaru, T; De Rosa, F; Rigol, M; Rinaudo, M; Ferrer, M; Torres, A
2015-11-01
Tracheal tube biofilm develops during mechanical ventilation. We compared a novel closed-suctioning system vs standard closed-suctioning system in the prevention of tracheal tube biofilm. Eighteen pigs, on mechanical ventilation for 76 h, with P. aeruginosa pneumonia were randomized to be tracheally suctioned via the KIMVENT* closed-suctioning system (control group) or a novel closed-suctioning system (treatment group), designed to remove tracheal tube biofilm through saline jets and an inflatable balloon. Upon autopsy, two tracheal tube hemi-sections were dissected for confocal and scanning electron microscopy. Biofilm area, maximal and minimal thickness were computed. Biofilm stage was assessed. Sixteen animals were included in the final analysis. In the treatment and control group, the mean (sd) pulmonary burden was 3.34 (1.28) and 4.17 (1.09) log cfu gr(-1), respectively (P=0.18). Tracheal tube P. aeruginosa colonization was 5.6 (4.9-6.3) and 6.2 (5.6-6.9) cfu ml(-1) (median and interquartile range) in the treatment and control group, respectively (P=0.23). In the treatment group, median biofilm area was 3.65 (3.22-4.21) log10 μm2 compared with 4.49 (4.27-4.52) log10 μm2 in the control group (P=0.031). In the treatment and control groups, the maximal biofilm thickness was 48.3 (26.7-71.2) µm (median and interquartile range) and 88.8 (43.8-125.7) µm, respectively. The minimal thickness in the treatment and control group was 0.6 (0-4.0) µm and 23.7 (5.3-27.8) µm (P=0.040) (P=0.017). Earlier stages of biofilm development were found in the treatment group (P<0.001). The novel CSS reduces biofilm accumulation within the tracheal tube. A clinical trial is required to confirm these findings and the impact on major outcomes. © The Author 2015. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
SU-E-T-65: A Prospective Trial of Open Face Masks for Head and Neck Radiotherapy
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wiant, D; Squire, S; Maurer, J
Purpose: Open face head and neck masks allow for active patient monitoring during treatment and may reduced claustrophobia and anxiety compared to closed masks. The ability of open masks to limit intrafraction motion and to preserve the patient shape/position from simulation over protracted treatments should be considered. Methods: Thirty-two head and neck patients were prospectively randomized to treatment in a closed mask or a novel open face mask. All patients received daily volumetric imaging. The daily images were automatically rigidly registered to the planning CT’s offline using a commercial image processing tool. The shifts needed to optimize the registration, themore » mutual information coefficient (MI), and the Pearson correlation (PC) coefficients were recorded to evaluate shape preservation. The open group was set-up and monitored with surface imaging at treatment. The real time surface imaging information was recorded to evaluate intrafraction motion. Results: Sixteen patients were included in each group. Evaluations were made over a total of 984 fractions. The mean MI and PC showed significantly higher shape preservation for the open group than for the closed group (p = 0). The mean rotations for the open group were smaller or < 0.15° larger versus the closed group. The mean intrafraction motion for the open group was 0.93 +/−0.99 mm (2 SD). The maximum single fraction displacement was 3.2 mm. Fourteen of 16 patients showed no significant correlation of motion with fraction number (p > 0.05). Conclusion: The open masks preserved shape as well as the closed masks, and they limited motion to < 2 mm for 95% of the treated fractions. These results are consistent over treatment courses of up to 35 fractions. The open mask is suitable for treatment with or without active monitoring. This work was partially supported by Qfix.« less
Hua, Wen-Bin; Zhang, Yu-Kun; Gao, Yong; Liu, Xian-Zhe; Yang, Shu-Hua; Wu, Xing-Huo; Wang, Jing; Yang, Cao
2017-07-15
Retrospective analysis of clinical records. To assess and compare the improvement in sagittal balance after one- or two-level closing wedge osteotomy for correcting thoracolumbar kyphosis secondary to ankylosing spondylitis (AS). Closing wedge osteotomy represents a common approach to correct kyphosis in AS. Although several reports have described the outcomes of one- or two-level closing wedge osteotomy in terms of sagittal parameters, data comparing the outcomes of these procedures are scarce. Between January 2010 and December 2014, 22 patients with AS underwent closing wedge osteotomy (one-level, 12 patients; two-level, 10 patients) for correcting thoracolumbar kyphosis (mean follow-up, 24.8 months; range, 12-60 months). Preoperative and postoperative chin-brow vertical angle, and the sagittal parameters of the vertebral osteotomy segment were documented and compared. Perioperative and postoperative complications were also recorded. The chin-brow vertical angle improved significantly, from 55.0° ± 27.3° to 4.7° ± 4.9° and from 38.2° ± 14.9° to 3.2° ± 5.4° in the one-level and two-level groups, respectively. The total correction (thoracic kyphosis and lumbar lordosis) was 32.8° ± 18.2° and 53.7° ± 9.4° in the one-level and two-level groups, respectively. No death, complete paralysis, or vascular complications occurred during the procedure, but cerebrospinal fluid leak was noted in one and two patients from the one-level and two-level groups, respectively. A distal pedicle screw adjacent to the osteotomy segment became loose during surgery in one patient (one-level group). Postoperatively, no transient neurological deficit, infection, delay union, or loosening or breaking of the internal fixation devices was observed. Osteotomy site fusion was achieved in all patients, and the Oswestry Disability Index scores improved significantly. Closing wedge osteotomy is effective and safe for correcting thoracolumbar kyphosis in patients with AS. Significant correction and improvement in all sagittal parameters were noted in both groups, but two-level closing wedge osteotomy provided better correction. 3.
Is the recurrence rate of chronic subdural hematomas dependent on the duration of drainage?
Kale, Aydemir; Öz, İbrahim İlker; Gün, Eren Görkem; Kalaycı, Murat; Gül, Şanser
2017-05-01
Chronic subdural hematoma (CSDH) is the most frequent type of intracranial hemorrhage which especially affects the elderly. Various surgical techniques have been reported for CSDH treatment; optimal treatment methods are still controversial. In this study, the effects of long drainage durations on results and recurrences were investigated in patients on whom closed system drainage with burr hole craniotomy was applied due to CSDH. 90 patients with 105 CSDH were operated between 2008 and 2016. Patients were divided into two groups based on the duration of drainage. Group A (n = 40) was determined as 2-4 days of closed-system drainage, while Group B (n = 50) was recorded as 5-7 days of closed-system drainage. Recurrence was defined as accumulation of blood in the operation area and recurrence of symptoms within the monitoring period of six months. Recurrence was observed in 7 (15.6) of the Group A patients and 2 (3.3%) of the Group B patients. There was a statistically significant difference between groups in terms of recurrence rate (p = 0.04). Postoperative thickness of hematoma was measured in the first month follow-up computerized tomography. There was a statistically significant difference between groups in terms of postoperative thickness of residual hematoma (p = 0.05). 2-4 days of closed system drainage following burr hole craniotomy is an effective and reliable choice of treatment in CSDH. Nevertheless, increasing the duration of drainage to 5-7 days provided better results without increasing the risk of complication.
Jadhav, Siddharth P; More, Snehal R; Shenava, Vinitha; Zhang, Wei; Kan, J Herman
2018-04-25
Magnetic resonance imaging (MRI) of the hips is being increasingly used to confirm hip reduction after surgery and spica cast placement for developmental dysplasia of the hip (DDH). To review a single institutional experience with post-spica MRI in children undergoing closed or open hip reduction and describe the utility of MRI in directing the need for re-intervention. Seventy-four patients (52 female, 22 male) who underwent post-spica hip MRI over a 6-year period were retrospectively reviewed. One hundred and seven hips were included. Data reviewed included age at intervention, gender, type of intervention performed, MRI findings, the need for re-intervention and the interval between interventions. Gender was compared between the closed and open reduction groups via the Fisher exact test. Age at the first procedure was compared via the Wilcoxon rank test. Rates of re-intervention after closed and open reduction were calculated and the reasons for re-intervention were reviewed. The mean age at the time of the first intervention was 16.4 months (range: 4 to 63 months). Mean age for the closed reduction group was 10.5 months (range: 4-24 months) and for the open reduction group was 23.7 months (range: 5-63 months), which was significant (P-value <0.0001). Of the 52 hips that underwent closed reduction, 16 (31%) needed re-intervention. Of the 55 hips that underwent open reduction, MRI was useful in deciding re-intervention in only 1 (2%). This patient had prior multiple failed closed and open reductions at an outside institute. Post intervention hip spica MRI is useful in determining the need for re-intervention after closed hip reduction, but its role after open reduction is questionable.
Group cohesion in foraging meerkats: follow the moving 'vocal hot spot'.
Gall, Gabriella E C; Manser, Marta B
2017-04-01
Group coordination, when 'on the move' or when visibility is low, is a challenge faced by many social living animals. While some animals manage to maintain cohesion solely through visual contact, the mechanism of group cohesion through other modes of communication, a necessity when visual contact is reduced, is not yet understood. Meerkats ( Suricata suricatta ), a small, social carnivore, forage as a cohesive group while moving continuously. While foraging, they frequently emit 'close calls', soft close-range contact calls. Variations in their call rates based on their local environment, coupled with individual movement, produce a dynamic acoustic landscape with a moving 'vocal hotspot' of the highest calling activity. We investigated whether meerkats follow such a vocal hotspot by playing back close calls of multiple individuals to foraging meerkats from the front and back edge of the group simultaneously. These two artificially induced vocal hotspots caused the group to spatially elongate and split into two subgroups. We conclude that meerkats use the emergent dynamic call pattern of the group to adjust their movement direction and maintain cohesion. Our study describes a highly flexible mechanism for the maintenance of group cohesion through vocal communication, for mobile species in habitats with low visibility and where movement decisions need to be adjusted continuously to changing environmental conditions.
Li, Chi; Kuo, Shuenn-Wen; Hsu, Hsao-Hsun; Lin, Mong-Wei; Chen, Jin-Shing
2018-03-01
To evaluate whether main tumor resection improves survival compared with pleural biopsy alone in patients with lung adenocarcinoma with intraoperatively diagnosed pleural seeding. Forty-three patients with lung adenocarcinoma with pleural seeding diagnosed unexpectedly during surgery performed between January 2006 and December 2014 were included in this retrospective study using a prospectively collected lung cancer database. Each surgeon decided whether to perform main tumor resection or pleural biopsy alone. Main tumor and visible pleural nodule resection was performed in 30 patients (tumor resection group). The remaining 13 patients underwent pleural nodule biopsy alone (open-close group). The clinical T stage was higher in the open-close group than in the tumor resection group (P = .02). The tumor resection group had longer operative times compared with the open-close group (mean, 141.8 vs 80.3 minutes). There were no other statistically significant differences in perioperative parameters. The surgical method was the sole statistically significant prognostic factor. Patients in the tumor resection group had better progression-free survival (3-year survival: 44.5% vs 0%; P = .009) and overall survival (3-year survival: 82.9% vs 38.5%; P = .013) than did the open-close group. There was no significant survival difference between sublobar resection and lobectomy for the main tumor resection. Our study demonstrated improved progression-free and overall survival after main tumor and visible pleural nodule resection in patients with lung adenocarcinoma with intraoperatively diagnosed pleural seeding. Further randomized trials are needed to define the role of main tumor resection in these patients. Copyright © 2017 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.
Sadek, Ahmed F; Osman, Mohammed K; Laklok, Mohamed A
2016-10-01
The aim of this study was to assess the effect of degree of anterior translation of the distal tibial fragment after lateral closing wedge high tibial osteotomy in patients having combined knee medial compartmental and patellofemoral osteoarthritis. A retrospective study was conducted on 64 patients who were operated on for combined knee medial compartmental and patellofemoral osteoarthritis, by lateral closing wedge high tibial osteotomy with anterior translation of the distal tibial fragment. They were divided into two groups; Group I comprising 32 patients (34 knees, mean age of 51.4±7years) whose degree of anterior translation was <1cm and Group II comprising 32 patients (33 knees, mean age of 52.2±8.3years) whose degree of anterior translation was >1.5cm. The final assessment was performed via: visual analog scale, postoperative Knee Society clinical rating system function score, active range of motion, time to union, degree of correction of mechanical axis, posterior tibial slope, and Insall-Salvati ratio. Group II patients exhibited statistically superior mean postoperative score and better return to their work than Group I (P=0.013, 0.076, respectively). Both groups showed statistically significant differences between the preoperative and postoperative evaluation parameters (P<0.001). The posterior tibial slope was decreased in both groups but with no significant difference (P=0.527). Lateral closing wedge high tibial osteotomy combined with anterior translation of the distal tibial fragment more than 1.5cm achieved significantly better postoperative functional knee score. Both groups exhibited comparatively decreased posterior tibial slope. Copyright © 2016 Elsevier B.V. All rights reserved.
75 FR 64734 - National Cancer Institute; Notice of Closed Meeting
Federal Register 2010, 2011, 2012, 2013, 2014
2010-10-20
...--Clinical Groups, NCI-H Cooperative Groups. Date: November 1, 2010. Time: 12 p.m. to 4 p.m. Agenda: To....S.C. App.), notice is hereby given of the following meeting. The meeting will be closed to the public in accordance with the provisions set forth in sections 552b(c)(4) and 552b(c)(6), Title 5 U.S.C...
Guo, J J; Tang, N; Yang, H L; Tang, T S
2010-07-01
We compared the outcome of closed intramedullary nailing with minimally invasive plate osteosynthesis using a percutaneous locked compression plate in patients with a distal metaphyseal fracture in a prospective study. A total of 85 patients were randomised to operative stabilisation either by a closed intramedullary nail (44) or by minimally invasive osteosynthesis with a compression plate (41). Pre-operative variables included the patients' age and the side and pattern of the fracture. Peri-operative variables were the operating time and the radiation time. Postoperative variables were wound problems, the time to union of the fracture, the functional American Orthopaedic Foot and Ankle surgery score and removal of hardware. We found no significant difference in the pre-operative variables or in the time to union in the two groups. However, the mean radiation time and operating time were significantly longer in the locked compression plate group (3.0 vs 2.12 minutes, p < 0.001, and 97.9 vs 81.2 minutes, p < 0.001, respectively).After one year, all the fractures had united. Patients who had intramedullary nailing had a higher mean pain score (40 = no pain, 0 = severe pain), [corrected] but better function, alignment and total American Orthopaedic Foot and Ankle surgery scores, although the differences were not statistically significant (p = 0.234, p = 0.157, p = 0.897, p = 0.177 respectively). Three (6.8%) patients in the intramedullary nailing group and six (14.6%) in the locked compression plate group showed delayed wound healing, and 37 (84.1%) in the former group and 38 (92.7%) in the latter group expressed a wish to have the implant removed. We conclude that both closed intramedullary nailing and a percutaneous locked compression plate can be used safely to treat Orthopaedic Trauma Association type-43A distal metaphyseal fractures of the tibia. However, closed intramedullary nailing has the advantage of a shorter operating and radiation time and easier removal of the implant. We therefore prefer closed intramedullary nailing for patients with these fractures.
ERIC Educational Resources Information Center
Sawyer, Keith
2015-01-01
Keith Sawyer views the spontaneous collaboration of group creativity and improvisation actions as "group flow," which organizations can use to function at optimum levels. Sawyer establishes ideal conditions for group flow: group goals, close listening, complete concentration, being in control, blending egos, equal participation, knowing…
Akosah, Eric; Ohemeng-Dapaah, Seth; Sakyi Baah, Joseph; Kanter, Andrew S
2013-01-01
Background The network structure of an organization influences how well or poorly an organization communicates and manages its resources. In the Millennium Villages Project site in Bonsaaso, Ghana, a mobile phone closed user group has been introduced for use by the Bonsaaso Millennium Villages Project Health Team and other key individuals. No assessment on the benefits or barriers of the use of the closed user group had been carried out. Objective The purpose of this research was to make the case for the use of social network analysis methods to be applied in health systems research—specifically related to mobile health. Methods This study used mobile phone voice records of, conducted interviews with, and reviewed call journals kept by a mobile phone closed user group consisting of the Bonsaaso Millennium Villages Project Health Team. Social network analysis methodology complemented by a qualitative component was used. Monthly voice data of the closed user group from Airtel Bharti Ghana were analyzed using UCINET and visual depictions of the network were created using NetDraw. Interviews and call journals kept by informants were analyzed using NVivo. Results The methodology was successful in helping identify effective organizational structure. Members of the Health Management Team were the more central players in the network, rather than the Community Health Nurses (who might have been expected to be central). Conclusions Social network analysis methodology can be used to determine the most productive structure for an organization or team, identify gaps in communication, identify key actors with greatest influence, and more. In conclusion, this methodology can be a useful analytical tool, especially in the context of mobile health, health services, and operational and managerial research. PMID:23552721
Kaonga, Nadi Nina; Labrique, Alain; Mechael, Patricia; Akosah, Eric; Ohemeng-Dapaah, Seth; Sakyi Baah, Joseph; Kodie, Richmond; Kanter, Andrew S; Levine, Orin
2013-04-03
The network structure of an organization influences how well or poorly an organization communicates and manages its resources. In the Millennium Villages Project site in Bonsaaso, Ghana, a mobile phone closed user group has been introduced for use by the Bonsaaso Millennium Villages Project Health Team and other key individuals. No assessment on the benefits or barriers of the use of the closed user group had been carried out. The purpose of this research was to make the case for the use of social network analysis methods to be applied in health systems research--specifically related to mobile health. This study used mobile phone voice records of, conducted interviews with, and reviewed call journals kept by a mobile phone closed user group consisting of the Bonsaaso Millennium Villages Project Health Team. Social network analysis methodology complemented by a qualitative component was used. Monthly voice data of the closed user group from Airtel Bharti Ghana were analyzed using UCINET and visual depictions of the network were created using NetDraw. Interviews and call journals kept by informants were analyzed using NVivo. The methodology was successful in helping identify effective organizational structure. Members of the Health Management Team were the more central players in the network, rather than the Community Health Nurses (who might have been expected to be central). Social network analysis methodology can be used to determine the most productive structure for an organization or team, identify gaps in communication, identify key actors with greatest influence, and more. In conclusion, this methodology can be a useful analytical tool, especially in the context of mobile health, health services, and operational and managerial research.
Phylogeny of the Celastraceae inferred from phytochrome B gene sequence and morphology.
Simmons, M P; Clevinger, C C; Savolainen, V; Archer, R H; Mathews, S; Doyle, J J
2001-02-01
Phylogenetic relationships within Celastraceae were inferred using a simultaneous analysis of 61 morphological characters and 1123 base pairs of phytochrome B exon 1 from the nuclear genome. No gaps were inferred, and the gene tree topology suggests that the primers were specific to a single locus that did not duplicate among the lineages sampled. This region of phytochrome B was most useful for examining relationships among closely related genera. Fifty-one species from 38 genera of Celastraceae were sampled. The Celastraceae sensu lato (including Hippocrateaceae) were resolved as a monophyletic group. Loesener's subfamilies and tribes of Celastraceae were not supported. The Hippocrateaceae were resolved as a monophyletic group nested within a paraphyletic Celastraceae sensu stricto. Goupia was resolved as more closely related to Euphorbiaceae, Corynocarpaceae, and Linaceae than to Celastraceae. Plagiopteron (Flacourtiaceae) was resolved as the sister group of Hippocrateoideae. Brexia (Brexiaceae) was resolved as closely related to Elaeodendron and Pleurostylia. Canotia was resolved as the sister group of Acanthothamnus within Celastraceae. Perrottetia and Mortonia were resolved as the sister group of the rest of the Celastraceae. Siphonodon was resolved as a derived member of Celastraceae. Maytenus was resolved as three disparate groups, suggesting that this large genus needs to be recircumscribed.
Tsai, Chia-Liang; Pan, Chien-Yu; Chen, Fu-Chen; Tseng, Yu-Ting
2017-01-01
This study aimed to explore the effects of open- and closed-skill exercise interventions on the neurocognitive performance of executive functions in the elderly. Sixty-four healthy elderly males were randomly assigned to either a closed-skill (bike riding or brisk walking/jogging, n = 22), open-skill (table tennis, n = 21), or control (n = 21) group. Various neuropsychological [e.g., accuracy rates (AR) and reaction time (RT)] and electrophysiological [e.g., event-related potential (ERP) P3 component] measures were assessed during a variant of the task-switching paradigm, as well as an N-back task at baseline and after either a 6-month exercise intervention or control period. The results showed that, when performing the task-switching paradigm, the two exercise groups relative to control group showed significantly faster RTs in the switch trials after the exercise intervention. However, the RT facilitation in the non-switch and switch trials post-exercise relative to pre-exercise only emerged in the open-skill group. In terms of the N-back task, the two exercise groups significantly increased ARs in the 1-back condition after the exercise intervention, and the beneficial AR effect on the 2-back condition only emerged in the closed-skill group. In addition, the two exercise groups exhibited significantly larger P3 amplitudes on the frontal-to-parietal cortex areas after the exercise intervention relative to the baseline when performing the two cognitive tasks. These neurocognitive results still remained unchanged even when the confounding factors (e.g., cardiorespiratory fitness, social participation, and BMI) were controlled for. The present study concluded that, although 6-month open- and closed-skill exercise interventions facilitate overall electrophysiological effects (i.e., increased ERP P3 amplitudes) on the frontal-to-parietal cortices in the elderly, the two exercise modes produced different levels of neuropsychologically beneficial effects on RTs of the task-switching paradigm (i.e., lessened RTs) and ARs of the N-back task (i.e., enhanced ARs). The distinctive neurocognitive changes induced by open- and closed-skill exercise have implications for task switching and working memory in elderly individuals, especially with such cognitive functioning impairments. PMID:28959200
Sports training enhances visuo-spatial cognition regardless of open-closed typology
Hsieh, Shu-Shih; Chen, Kuan-Fu; Chang, Yu-Kai
2017-01-01
The aim of this study was to investigate the effects of open and closed sport participation on visuo-spatial attention and memory performance among young adults. Forty-eight young adults—16 open-skill athletes, 16 closed-skill athletes, and 16 non-athletes controls—were recruited for the study. Both behavioral performance and event-related potential (ERP) measurement were assessed when participants performed non-delayed and delayed match-to-sample task that tested visuo-spatial attention and memory processing. Results demonstrated that regardless of training typology, the athlete groups exhibited shorter reaction times in both the visuo-spatial attention and memory conditions than the control group with no existence of speed-accuracy trade-off. Similarly, a larger P3 amplitudes were observed in both athlete groups than in the control group for the visuo-spatial memory condition. These findings suggest that sports training, regardless of typology, are associated with superior visuo-spatial attention and memory performance, and more efficient neural resource allocation in memory processing. PMID:28560098
O'Gorman, Rick; Roberts, Ruth
2017-09-01
Kinship and friendship are key human relationships. Increasingly, data suggest that people are not less altruistic toward friends than close kin. Some accounts suggest that psychologically we do not distinguish between them; countering this is evidence that kinship provides a unique explanatory factor. Using the Implicit Association Test, we examined how people implicitly think about close friends versus close kin in three contexts. In Experiment 1, we examined generic attitudinal dispositions toward friends and family. In Experiment 2, attitude similarity as a marker of family and friends was examined, and in Experiments 3 and 4, strength of in-group membership for family and friends was examined. Findings show that differences exist in implicit cognitive associations toward family and friends. There is some evidence that people hold more positive general dispositions toward friends, associate attitude similarity more with friends, consider family as more representative of the in-group than friends, but see friends as more in-group than distant kin.
Recalculating the quasar luminosity function of the extended Baryon Oscillation Spectroscopic Survey
NASA Astrophysics Data System (ADS)
Caditz, David M.
2017-12-01
Aims: The extended Baryon Oscillation Spectroscopic Survey (eBOSS) of the Sloan Digital Sky Survey provides a uniform sample of over 13 000 variability selected quasi-stellar objects (QSOs) in the redshift range 0.68
A Statistical Study of the Southern Fermi Bubble in UV Absorption Spectra
NASA Astrophysics Data System (ADS)
Karim, Md. Tanveer; Fox, Andrew; Jenkins, Edward; Bordoloi, Rongmon; Wakker, Bart; Savage, Blair D.; Lockman, Felix; Crawford, Steve; Bland-Hawthorn, Joss; Jorgenson, Regina A.
2018-01-01
The Fermi Bubbles are two giant lobes of plasma situated at the center of the Milky Way, extending 55° above and below the Galactic Midplane. Although the Bubbles have been widely studied in multiple wavelengths, few studies have been done in UV absorption. Here we present a statistical study of the Southern Fermi Bubble using 17 QSO sightlines — 6 inside the Bubble, 11 outside — using UV absorption spectra from the Hubble Space Telescope Cosmic Origins Spectrograph (HST/COS). We searched for high-velocity clouds (HVCs) in 11 metal lines from ions of Aluminium, Carbon and Silicon. We detected HVCs in 83% of the sightlines inside the Bubble and 64% outside the Bubble, showing an enhancement in the covering fraction of HVCs in the Southern Bubble region. We also observed a decrease in vLSR of the HVCs as a function of the galactic latitude, consistent with a scenario where the identified HVCs trace the Galactic nuclear outflow, as sightlines closer to the central engine are expected to show a higher velocity. Combined with previous studies, our analysis indicates that the Southern Fermi Bubble is a dynamic environment giving rise to complex absorption features.
Starburst or AGN Dominance in Submillimetre-Luminous Candidate AGN?
NASA Astrophysics Data System (ADS)
Coppin, Kristen; Pope, Alexandra; Menéndez-Delmestre, Karín; Alexander, David M.; Dunlop, James
2010-06-01
It is widely believed that ultraluminous infrared (IR) galaxies and active galactic nuclei (AGN) activity are triggered by galaxy interactions and merging, with the peak of activity occurring at z~2, where submillimetre galaxies are thousands of times more numerous than local ULIRGs. In this evolutionary picture, submillimetre galaxies (SMGs) would host an AGN, which would eventually grow a black hole (BH) strong enough to blow off all of the gas and dust leaving an optically luminous QSO. To probe this evolutionary sequence we have focussed on the `missing link' sources, which demonstrate both strong starburst (SB) and AGN signatures, in order to determine if the SB is the main power source even in SMGs when we have evidence that an AGN is present from their IRAC colours. The best way to determine if a dominant AGN is present is to look for their signatures in the mid-infrared with the Spitzer IRS, since often even deep X-ray observations miss identifying the presence of AGN in heavily dust-obscured SMGs. We present the results of our audit of the energy balance between star-formation and AGN within this special sub-population of SMGs-where the BH has grown appreciably to begin heating the dust emission.
The AGN Impact on the Circumgalactic Medium of Cen A
NASA Astrophysics Data System (ADS)
Lehner, Nicolas
2017-08-01
There seems to be broad agreement that feedback from AGN plays a critical role in transforming massive star forming galaxies to quiescent ones and keeping them quenched thereafter. Through the emission of copious amounts of radiation emitted in the active QSO/AGN phase and the deposition of thermal and mechanical energy on scales of hundreds of kpc during the radio phase, AGN feedback shifts the temperatures and ionization states of the gas in the circumgalactic medium (CGM) of these galaxies to higher energies, suppressing cooling that might otherwise provide fuel for new star formation. We propose to observe absorption lines from the CGM of the nearby, very well-studied giant radio-lobe galaxy Cen A to search directly for the signal of AGN feedback impacting the CGM of a galaxy. We will target 4 background QSOs projected 270-340 kpc from the galaxy at a range of azimuthal angles relative to the 300 kpc-long jets and 1 control sight line well away from the jets. These spectra will provide probes of the ionization balance and kinematic structure of the cool/warm CGM. This will be the first attempt to dissect the cool/warm gas in a CGM undergoing interactions with an active AGN.
The X-ray Absorber in the X-ray Transient NLS1 WPVS 007
NASA Astrophysics Data System (ADS)
Grupe, Dirk
This proposal is for a funding request for an approved XMM-Newton observations of the X-ray transient Narrow-Line Seyfert 1 galaxy WPVS 007. The request is for 4 month of salary for the PI for one year in order to do the data analysis, publish the results, and attend an international AGN meeting. XMM will observe WPVS 007 in June 2010 simultaneously with HST, Chandra, and Swift. The goal is to establish a tight connection between the UV broad absorption line troughs found in FUSE observations and the strong partial covering absorber feature found by Swift. WPVS 007 showed a dramatic transformation into a Broad Absorption line QSO like AGN between a 1996 HST observation and a 2003 FUSE observation. Several Swift monitoring observations have suggested that the absorber may have started to disappear. Therefore it is crucial for our HST COS UV spectroscopy to know what the status of the X-ray absorber is. The XMM observation will provide a well-exposed X-ray spectrum even if WPVS 007 will be in a low flux state. This spectrum will enable us to put constraints on the absorption column density and covering fraction of the partial covering absorber.
Gravitational microlensing - The effect of random motion of individual stars in the lensing galaxy
NASA Technical Reports Server (NTRS)
Kundic, Tomislav; Wambsganss, Joachim
1993-01-01
We investigate the influence of random motion of individual stars in the lensing galaxy on the light curve of a gravitationally lensed background quasar. We compare this with the effects of the transverse motion of the galaxy. We find that three-dimensional random motion of stars with a velocity dispersion sigma in each dimension is more effective in producing 'peaks' in a microlensed light curve by a factor a about 1.3 than motion of the galaxy with a transverse velocity v(t) = sigma. This effectiveness parameter a seems to depend only weakly on the surface mass density. With an assumed transverse velocity of v(t) = 600 km/s of the galaxy lensing the QSO 2237+0305 and a measured velocity dispersion of sigma = 215 km/s, the expected rate of maxima in the light curves calculated for bulk motion alone has to be increased by about 10 percent due to the random motion of stars. As a consequence, the average time interval Delta t between two high-magnification events is smaller than the time interval Delta(t) bulk, calculated for bulk motion alone, Delta t about 0.9 Delta(t) bulk.
NASA Astrophysics Data System (ADS)
Dong, X. Y.; Wu, Xue-Bing; Ai, Y. L.; Yang, J. Y.; Yang, Q.; Wang, F.; Zhang, Y. X.; Luo, A. L.; Xu, H.; Yuan, H. L.; Zhang, J. N.; Wang, M. X.; Wang, L. L.; Li, Y. B.; Zuo, F.; Hou, W.; Guo, Y. X.; Kong, X.; Chen, X. Y.; Wu, Y.; Yang, H. F.; Yang, M.
2018-05-01
This is the second installment for the Large Sky Area Multi-Object Fibre Spectroscopic Telescope (LAMOST) Quasar Survey, which includes quasars observed from 2013 September to 2015 June. There are 9024 confirmed quasars in DR2 and 10911 in DR3. After cross-match with the Sloan Digital Sky Survey (SDSS) quasar catalogs and NED, 12126 quasars are discovered independently. Among them, 2225 quasars were released by SDSS DR12 QSO catalog in 2014 after we finalized the survey candidates. 1801 sources were identified by SDSS DR14 as QSOs. The remaining 8100 quasars are considered as newly founded, and among them, 6887 quasars can be given reliable emission line measurements and the estimated black hole masses. Quasars found in LAMOST are mostly located at low-to-moderate redshifts, with a mean value of 1.5. The highest redshift observed in DR2 and DR3 is 5. We applied emission line measurements to Hα, Hβ, Mg II, and C IV. We deduced the monochromatic continuum luminosities using photometry data, and estimated the virial black hole masses for the newly discovered quasars. Results are compiled into a quasar catalog, which will be available online.
Being me and being us in a family living close to death at home.
Carlander, Ida; Ternestedt, Britt-Marie; Sahlberg-Blom, Eva; Hellström, Ingrid; Sandberg, Jonas
2011-05-01
We used interpretive description to describe how everyday life close to death was experienced and dealt with in families with one member who had a life-threatening illness. We performed 28 individual, couple, and group interviews with five families. We found two patterns, namely, "being me in a family living close to death" and "being us in a family living close to death." "Being me" meant that every individual in the family had to deal with the impending death, regardless of whether or not he or she was the person with the life-threatening illness. This was linked to ways of promoting the individual's self-image, or "me-ness." This pattern was present at the same time as the pattern of "being us," or in other words, being a family, and dealing with impending death and a new "we-ness" as a group. "Striving for the optimal way of living close to death" was the core theme.
Vividness and transformation of mental images in karate and ballet.
Di Corrado, Donatella; Guarnera, Maria; Quartiroli, Alessandro
2014-12-01
While imagery research has become popular in recent years, little research has specifically investigated differences in imagery ability between open- and closed-skill sport activities. The purpose of this study was to investigate whether the type of task, open or closed, affects vividness and controllability differently. Thirty female classic dancers (closed skill), 30 female karate athletes (open skill), and 30 female non-athlete students, between 14 and 20 years of age (M = 17.0, SD = 1.6), participated. They completed the Vividness of Visual Imagery Questionnaire, the Vividness of Movement Imagery Questionnaire, and the Subtraction of Parts Task. There was no difference in imagery ability between open- and closed-skill sport groups. Furthermore, dancers and karatekas had higher mean scores on imagery ability than the non-athlete group. A positive correlation was observed between the two questionnaires, supporting findings on the componential basis of imagery. This study contributed to increase the research in the specific area of open- and closed-skill sports and imagery ability.
Gravitational lensing in quasar samples
NASA Astrophysics Data System (ADS)
Claeskens, Jean-François; Surdej, Jean
The first cosmic mirage was discovered approximately 20 years ago as the double optical counterpart of a radio source. This phenomenon had been predicted some 70 years earlier as a consequence of General Relativity. We present here a summary of what we have learnt since. The applications are so numerous that we had to concentrate on a few selected aspects of this new field of research. This review is focused on strong gravitational lensing, i.e. the formation of multiple images, in QSO samples. It is intended to give the reader an up-to-date status of the observations and to present an overview of its most interesting potential applications in cosmology and astrophysics, as well as numerous important results achieved so far. The first section follows an intuitive approach to the basics of gravitational lensing and is developed in view of our interest in multiply imaged quasars. The astrophysical and cosmological applications of gravitational lensing are outlined in Sect. 2 and the most important results are presented in Sect. 5. Sections 3 and 4 are devoted to the observations. Finally, conclusions are summarized in the last section. We have tried to avoid duplication with existing (and excellent) introductions to the field of gravitational lensing. For this reason, we did not concentrate on the individual properties of specific lens models, as these are already well presented in Narayan and Bartelmann (1996) and on a more intuitive ground in Refsdal and Surdej (1994). Wambsganss (1998) proposes a broad view on gravitational lensing in astronomy; the reviews by Fort and Mellier (1994) and Hattori et al. (1999) deal with lensing by galaxy clusters; microlensing in the Galaxy and the local group is reviewed by Paczynski (1996) and a general panorama on weak lensing is given by Bartelmann and Schneider (1999) and Mellier (1999). The monograph on the theory of gravitational lensing by Schneider, Ehlers and Falco (1992) also remains a reference in the field.
NASA Astrophysics Data System (ADS)
Burchett, Joseph N.; Tripp, Todd M.; Bordoloi, Rongmon; Werk, Jessica K.; Prochaska, J. Xavier; Tumlinson, Jason; Willmer, C. N. A.; O'Meara, John; Katz, Neal
2016-12-01
Using Hubble Space Telescope Cosmic Origins Spectrograph observations of 89 QSO sightlines through the Sloan Digital Sky Survey footprint, we study the relationships between C IV absorption systems and the properties of nearby galaxies, as well as the large-scale environment. To maintain sensitivity to very faint galaxies, we restrict our sample to 0.0015\\lt z\\lt 0.015, which defines a complete galaxy survey to L≳ 0.01 L\\ast or stellar mass {M}* ≳ {10}8 {M}⊙ . We report two principal findings. First, for galaxies with impact parameter ρ \\lt 1 {r}{vir}, C IV detection strongly depends on the luminosity/stellar mass of the nearby galaxy. C IV is preferentially associated with galaxies with {M}* \\gt {10}9.5 {M}⊙ ; lower-mass galaxies rarely exhibit significant C IV absorption (covering fraction {f}C={9}-6+12 % for 11 galaxies with {M}* \\lt {10}9.5 {M}⊙ ). Second, C IV detection within the {M}* \\gt {10}9.5 {M}⊙ population depends on environment. Using a fixed-aperture environmental density metric for galaxies with ρ < 160 kpc at z\\lt 0.055, we find that {57}-13+12 % (8/14) of galaxies in low-density regions (regions with fewer than seven L\\gt 0.15 L\\ast galaxies within 1.5 Mpc) have affiliated C IV absorption; however, none (0/7) of the galaxies in denser regions show C IV. Similarly, the C IV detection rate is lower for galaxies residing in groups with dark matter halo masses of {M}{halo}\\gt {10}12.5 {M}⊙ . In contrast to C IV, H I is pervasive in the circumgalactic medium without regard to mass or environment. These results indicate that C IV absorbers with {log} N({{C}} {{IV}})≳ 13.5 {{cm}}-2 trace the halos of {M}* \\gt {10}9.5 {M}⊙ galaxies but also reflect larger-scale environmental conditions.
Environments of strong/ultrastrong, ultraviolet Fe II emitting quasars
NASA Astrophysics Data System (ADS)
Clowes, Roger G.; Raghunathan, Srinivasan; Söchting, Ilona K.; Graham, Matthew J.; Campusano, Luis E.
2013-08-01
We have investigated the strength of ultraviolet (UV) Fe II emission from quasars within the environments of large quasar groups (LQGs) in comparison with quasars elsewhere, for 1.1 ≤
Seeing Red and Shooting Blanks: A Study of Red Quasars and Blank Field X-Ray Sources
NASA Technical Reports Server (NTRS)
Elvis, Martin; Oliversen, Ronald J. (Technical Monitor)
2002-01-01
We have identified a population of 'blank field sources' (or 'blanks') among the ROSAT (Roentgen Satellite) bright unidentified X-ray sources with faint optical counterparts. The extreme X-ray over optical flux ratio of blank field sources is not compatible with the main classes of X-ray emitters except for extreme BL Lacertae objects at fx/fv is equal to or less than 35. From the analysis of ROSAT archival data we found evidence for only three sources, out of 16, needing absorption in excess of the Galactic value and no indication of variability. We also found evidence for an extended nature for only one of the five blanks with a serendipitous HRI (High Resolution Imager) detection; this source (1WGA J1226.9+3332) was confirmed as a z=0.89 cluster of galaxies. Palomar images reveal the presence of a red (O - E is equal to or greater than 2) counterpart in the X-ray error circle for six blanks. The identification process brought to the discovery of another high z cluster of galaxies, one (possibly extreme) BL Lac and two apparently normal type 1 AGNs (Active Galactic Nuclei). These AGNs, together with four more AGN-like objects seem to form a well defined group: they present type 1 X-ray spectra but red Palomar counterparts. We discuss the possible explanations for the discrepancy between the X-ray and optical data, among which: a suppressed big blue bump emission, an extreme dust to gas (approximately 40 - 60 the Galactic ratio) ratio value and a high redshift (z is greater than or equal to 3.5) QSO (Quasi-Stellar Object) nature. These AGN-like blanks seem to be the bright (and easier to study) analogs of the sources which are being found in deep Chandra observations. Five more blanks have a still an unknown nature.
Tamaru, Yuzuru; Oka, Shiro; Tanaka, Shinji; Hiraga, Yuko; Kunihiro, Masaki; Nagata, Shinji; Furudoi, Akira; Ninomiya, Yuki; Asayama, Naoki; Shigita, Kenjiro; Nishiyama, Soki; Hayashi, Nana; Chayama, Kazuaki
2016-10-01
The lower rectum close to the dentate line has distinct characteristics, making endoscopic submucosal dissection (ESD) of tumors challenging. We assessed clinical outcomes of ESD for such patients with hemorrhoids. Sixty-four patients (mean age, 68 years) underwent ESD for anorectal tumors close to the dentate line. We divided patients into those with (Group A, 45 patients) and without hemorrhoids (Group B, 19 patients). We examined en bloc and histological en bloc resection rates, procedure time, complication rates, and postoperative prognosis after ESD. The mean tumor size was 43 mm. Histologic diagnoses were adenoma (42 %, 27/64), carcinoma in situ (44 %, 28/64), and T1 carcinoma (14 %, 9/64). There was no significant difference in en bloc resection (93 %, 42/45 vs. 95 %, 18/19) or postoperative bleeding rates (16 %, 7/45 vs. 11 %, 2/19) between Groups A and B, respectively. The mean procedural durations were 120 and 124 min, respectively, in Groups A and B. No perforations occurred. There was no significant difference in postoperative anal pain rate between Groups A (18 %, 8/45) and B (16 %, 3/19), and it resolved within a few days in all cases. There was one case of stricture in Group B. Two patients with T1 carcinoma underwent additional surgery, one underwent chemotherapy, and five had no additional treatment. No recurrence occurred during the follow-up period of 38 months. ESD is safe and effective for anorectal tumors close to the dentate line in patients with hemorrhoids.
Kasari, Connie; Dean, Michelle; Kretzmann, Mark; Shih, Wendy; Orlich, Felice; Whitney, Rondalyn; Landa, Rebecca; Lord, Catherine; King, Bryan
2016-02-01
Peer relationships improve for children with autism spectrum disorder (ASD) in clinic-based social skills groups but rarely generalize to real world contexts. This study compares child outcomes of two social skills interventions conducted in schools with children in Kindergarten through fifth grade. Children with ASD were randomized to one of two interventions that varied on group composition (mixed typical and ASD vs. all ASD or social difficulties) and intervention approach (didactic SKILLS based vs. activity-based ENGAGE groups). Interventions were implemented at school for 8 weeks (16 sessions) with an 8-week follow-up. Innovative measures of peer nomination and playground peer engagement, as well as teacher reports of child behavior problems and teacher-child relationship were analyzed for 137 children with ASD across four sites. On the primary outcome of social network connections from the peer nomination measure, there was no main effect of treatment, but there were moderator effects. Children with low teacher-child closeness or high conflict improved more in their social connections if they received the SKILLS intervention, whereas children with higher teacher-child closeness improved more if they received the ENGAGE intervention. Only two secondary outcome measures yielded significant effects of treatment. Children in the SKILLS groups increased peer engagement and decreased isolation during recess. Child behavior problems and teacher-child closeness moderated peer engagement such that children with higher behavior problems and lower closeness benefitted more from SKILLS groups. These findings suggest that social skills groups conducted at school can affect both peer engagement during recess as well as peer acceptability. Child characteristics and teacher-child relationship prior to intervention yield important information on who might benefit from a specific social skills intervention. © 2015 Association for Child and Adolescent Mental Health.
Effect of complete and partial removable dentures on chewing movements.
Gonçalves, T M S V; Vilanova, L S R; Gonçalves, L M; Rodrigues Garcia, R C M
2014-03-01
Partial or complete edentulism impairs mastication. However, it is unclear how the chewing cycle is affected by prosthetics. We evaluated the chewing movements of patients fitted with complete (CD) or removable partial denture (RPD). A total of 29 subjects were kinesiographically evaluated during chewing of peanuts and Optocal portions in a random sequence. The subjects were divided into two groups according to prosthesis type. Group RPD was composed of 14 partially edentulous patients using a lower distal extension RPD (mean age 61 ± 8 years), and group CD contained 15 completely edentulous patients using CD (mean age 65·9 ± 7·9 years) in both jaws. Opening, closing, occlusal and masticatory cycle times, movement angle (opening and closing), maximum velocity (opening and closing), total area and chewing cycle amplitudes were evaluated. The results were subjected to anova and Tukey's HSD test at a significance level of 5%. The RPD group exhibited shorter opening and closing phases and masticatory cycle time (P < 0·05). Maximum velocities were also higher in the RPD group, irrespective of the test material (P < 0·05). The area and amplitude of the chewing envelope was smaller in the CD group (P < 0·0001). The test material did not influence chewing cycles in any of the parameters evaluated (P > 0·05). RPD wearers use a faster chewing sequence with greater vertical and lateral jaw excursions compared with CD wearers. © 2013 John Wiley & Sons Ltd.
76 FR 53686 - Center For Scientific Review; Notice of Closed Meetings
Federal Register 2010, 2011, 2012, 2013, 2014
2011-08-29
... Group, Oral, Dental and Craniofacial Sciences Study Section. Date: October 4-5, 2011. Time: 8 a.m. to 5...; Notice of Closed Meetings Pursuant to section 10(d) of the Federal Advisory Committee Act, as amended (5 U.S.C. App.), notice is hereby given of the following meetings. The meetings will be closed to the...
DNA homology among diverse spiroplasma strains representing several serological groups.
Lee, I M; Davis, R E
1980-11-01
Deoxyribonucleic acid (DNA) homology among 10 strains of spiroplasma associated with plants and insects was assessed by analysis of DNA-DNA hybrids with single strand specific S1 nuclease. Based on DNA homology, the spiroplasmas could be divided into three genetically distinct groups (designated I, II, and III), corresponding to three separate serogroups described previously. DNA sequence homology between the three groups was less than or equal to 5%. Based on DNA homology, group I could be divided into three subgroups (A, B, and C) that corresponded to three serological subgroups of serogroup I. Subgroup A contained Spiroplasma citri strains Maroc R8A2 and C 189; subgroup B contained strains AS 576 from honey bee and G 1 from flowers; subgroup C contained corn stunt spiroplasma strains I-747 and PU 8-17. There was 27-54% DNA sequence homology among these three subgroups. Group II contained strains 23-6 and 27-31 isolated from flowers of tulip tree (Liriodendron tulipifera L.). Group III contained strains SR 3 and SR 9, other isolates from flowers of tulip tree. Based on thermal denaturation, guanine plus cytosine contents of DNA from five type strains representing all groups and subgroups were estimated to be close to 26 mol% for group I strains, close to 25 mol% for group II strains, and close to 29 mol% for group III strains. The genome molecular weights of these five type strains were all estimated to bae about 10(9).
Gauchard, Gérome C; Gangloff, Pierre; Jeandel, Claude; Perrin, Philippe P
2003-09-01
Balance disorders increase considerably with age due to a decrease in posture regulation quality, and are accompanied by a higher risk of falling. Conversely, physical activities have been shown to improve the quality of postural control in elderly individuals and decrease the number of falls. The aim of this study was to evaluate the impact of two types of exercise on the visual afferent and on the different parameters of static balance regulation. Static postural control was evaluated in 44 healthy women aged over 60 years. Among them, 15 regularly practiced proprioceptive physical activities (Group I), 12 regularly practiced bioenergetic physical activities (Group II), and 18 controls walked on a regular basis (Group III). Group I participants displayed lower sway path and area values, whereas Group III participants displayed the highest, both in eyes-open and eyes-closed conditions. Group II participants displayed intermediate values, close to those of Group I in the eyes-open condition and those of Group III in the eyes-closed condition. Visual afferent contribution was more pronounced for Group II and III participants than for Group I participants. Proprioceptive exercise appears to have the best impact on balance regulation and precision. Besides, even if bioenergetic activity improves postural control in simple postural tasks, more difficult postural tasks show that this type of activity does not develop a neurosensorial proprioceptive input threshold as well, probably on account of the higher contribution of visual afferent.
Xu, Songao; Yu, Huijie; Sun, Hui; Zhu, Xiangyun; Xu, Xiaoqin; Xu, Jun; Cao, Weizhong
2017-01-01
To investigate the efficiency of closed tracheal suction system (CTSS) using novel splash-proof ventilator circuit component on ventilator-associated pneumonia (VAP) and the colonization of multiple-drug resistant bacteria (MDR) in patients undergoing mechanical ventilation (MV) prevention. A prospective single-blinded randomized parallel controlled intervention study was conducted. 330 severe patients admitted to the intensive care unit (ICU) of the First Hospital of Jiaxing from January 2014 to May 2016 were enrolled, and they were divided into open tracheal suction group, closed tracheal suction group, and splash-proof suction group on average by random number table. The patients in the three groups used conventional ventilator circuit component, conventional CTSS, and CTSS with a novel splash-proof ventilator circuit component for MV and sputum suction, respectively. The incidence of VAP, airway bacterial colonization rate, MDR and fungi colonization rate, duration of MV, length of ICU and hospitalization stay, and financial expenditure during hospitalization, as well as the in-hospital prognosis were recorded. After excluding patients who did not meet the inclusion criteria, incomplete data, backed out and so on, 318 patients were enrolled in the analysis finally. Compared with the open tracheal suction group, the total incidence of VAP was decreased in the closed tracheal suction group and splash-proof suction group [20.95% (22/105), 21.90% (23/105) vs. 29.63% (32/108)], but no statistical difference was found (both P > 0.05), and the incidence of VAP infections/1 000 MV days showed the same change tendency (cases: 14.56, 17.35 vs. 23.07). The rate of airway bacterial colonization and the rate of MDR colonization in the open tracheal suction group and splash-proof suction group were remarkably lower than those of closed tracheal suction group [32.41% (35/108), 28.57% (30/105) vs. 46.67% (49/105), 20.37% (22/108), 15.24% (16/105) vs. 39.05% (41/105)] with significantly statistical differences (all P < 0.05). Besides, no significantly statistical difference was found in the fungi colonization rate among open tracheal group, closed tracheal group, and splash-proof suction group (4.63%, 3.81% and 6.67%, respectively, P > 0.05). Compared with the closed tracheal suction group, the duration of MV, the length of ICU and hospitalization stay were shortened in the open tracheal suction group and splash-proof suction group [duration of MV (days): 8.00 (4.00, 13.75), 8.00 (5.00, 13.00) vs. 9.00 (5.00, 16.00); the length of ICU stay (days): 10.00 (6.00, 16.00), 11.00 (7.00, 19.00) vs. 13.00 (7.50, 22.00); the length of hospitalization stay (days): 16.50 (9.25, 32.00), 19.00 (10.50, 32.50) vs. 21.00 (10.00, 36.00)], and financial expenditure during hospitalization was lowered [10 thousand Yuan: 4.95 (3.13, 8.62), 5.47 (3.84, 9.41) vs. 6.52 (3.99, 11.02)] without significantly statistical differences (all P > 0.05). Moreover, no significantly statistical difference was found in the in-hospital prognosis among the three groups. CTSS performed using novel splash-proof ventilator circuit component shared similar advantages in preventing VAP with the conventional CTSS. Meanwhile, it is superior because it prevented the colonization of MDR and high price in the conventional CTSS.Clinical Trail Registration Chinese Clinical Trial Registry, ChiCTR-IOR-16009694.
NASA Technical Reports Server (NTRS)
Zardetto-Smith, Andrea M.; Johnson, Alan Kim
1995-01-01
This study examined efferent output from the median preoptic nucleus (MNPO) to pontine noradrenergic and serotonergic cell groups using an anterograde tracing technique (Phaseolus vulgaris leucoagglutinin, PHA-L) combined with glucose oxidase immunocytochemistry to serotonin (5-HT) or to dopamine-beta-hydroxylase (DBH). Injections of PHA-L into the ventral MNPO resulted in moderate axonal labeling within the region of the B7 and B8 serotonergic groups in the dorsal raphe. PHA-L labeled fibers and punctate processes were observed in close apposition to many of the 5-HT immunoreactive neurons in these regions. In contrast, sparse terminal labeling was found within the B5 group in the raphe pontis nucleus, and only trace fiber labeling observed in the B3 and B6 groups. Efferents from the MNPO also provided moderate innervation to the A6 and A7 noradrenergic groups. PHA-L labeled punctate processes were found most frequently in close apposition to DBH-immunoreactive neurons at mid- to caudal levels of the locus coeruleus. Some labeled axons were also present within the A7 and A5 groups. Additionally, a close apposition between labeled MNPO efferents and 5-HT fibers within the lateral parabrachial nucleus was observed. The results indicate the MNPO provides a topographic innervation of monoaminergic groups in the upper brainstem.
NASA Technical Reports Server (NTRS)
Zardetto-Smith, Andrea M.; Johnson, Alan Kim
1995-01-01
This study examined efferent output from the median preoptic nucleus (MnPO) to pontine noradrenergic and serotonergic cell groups using an anterograde tracing technique (Phaseolus vulgaris leucoagglutinin, PHA-L) combined with glucose oxidase immunocytochemistry to scrotonin (5-HT) or to dopamine-(beta)-hydroxylase (DBH). Injections of PHA-L into the ventral MNPO resulted in moderate axonal labeling within the region of the B7 and B8 serotonergic groups in the dorsal raphe. PHA-L labeled fibers and punctate processes were observed in close apposition to many of the 5-HT immunoreactive neurons in these regions, In contrast, sparse terminal labeling was found within the B5 group in the raphe pontis nucleus, and only trace fiber labeling observed in the B3 and B6 groups. Efferents from the MNPO also provided moderate innervation to the A6 and A7 noradrenergic groups. PHA-L labeled punctate processes were found most frequently in close apposition to DBH-immunorcactive neurons at mid- to caudal levels of the locus coeruleus. Some labeled axons were also present within the A7 and A5 groups. Additionally, a close apposition between labeled MNPO efferents and 5-HT fibers within the lateral parabrachial nucleus was observed, The results indicate the MNPO provides a topographic innerva- tion of monoaminergic groups in the upper brainstem.
Arayasantiparb, Raweewan; Tsuchimochi, Makoto
2010-02-01
Many measures have been developed to determine the extent of disc displacement in internal derangements of the temporomandibular joint (TMJ) using magnetic resonance imaging. The purpose of this study was to develop a quantitative method of analyzing disc position and to evaluate the positions of the disc in internal derangements of the TMJ (group 1, with reduction; group 2, without reduction). Magnetic resonance images of 150 TMJs in 20 healthy volunteers and 55 patients with internal derangements were evaluated. The anatomical points of interest of the TMJ, including the anterior (DA) and posterior (DP) points of the disc, were marked on parasagittal magnetic resonance images of the TMJ disc taken in both the closed- and the open-mouth positions. All points were recorded using an x-y coordinate system, with reference to a referral line. In the closed-mouth position, the DP in patients in group 1 was situated in a more-anterior direction than the DP in volunteers. The DP in group 2 was located further anterior and inferior than the DP in group 1. However, the position of the DA did not differ between group 1 and group 2. In the open-mouth position, the DP was displaced anteroinferiorly to a greater extent in group 2 than in group 1 (one-way ANOVA, followed by Scheffe's test; P < 0.0001). The distance between the disc points in the closed- and open-mouth positions was also evaluated. Comparison of the disc point position in the closed- and open-mouth positions in symptomatic and asymptomatic displaced TMJ discs revealed no significant difference. In conclusion, most of our results quantitatively support previously reported findings in imaging, surgical, and histopathological studies of TMJ internal derangement. We suggest that our measure of disc position of the TMJ would be useful to assess the status and response to treatment of internal derangements of the TMJ.
A prospective study of two methods of closing surgical scalp wounds.
Adeolu, A A; Olabanji, J K; Komolafe, E O; Ademuyiwa, A O; Awe, A O; Oladele, A O
2012-02-01
Scalp wounds are commonly closed in two layers, although single layer closure is feasible. This study prospectively compared the two methods of closing scalp wounds. Patients with non-traumatic scalp wounds were allocated to either the single layer closure group or the multilayer closure group. We obtained relevant data from the patients. The primary outcome measures were wound edge related complications, rate of suturing and cost of sutures used for suturing. Thirty-one wounds were in the single layer closure group and 30 were in the multilayer closure group. Age range was 1-80 years. The most common indication for making a scalp incision was subdural hematoma, representing 27.8% of all the indications. The most common surgery was burr hole drainage of subdural hematoma. Polyglactin acid suture was used for the inner layer and polyamide -00- for the final layer in the multilayer closure group. Only the latter suture was used for the single layer closure method. Total cost of suturing per wound in the single layer closure group was N= 100 (0.70USD) and N= 800 (5.30USD) in the multilayer group. The mean rate of closure was 0.39 ± 1.89 mm/sec for single layer closure and 0.23 ± 0.89 mm/sec in multilayer closure. The difference was statistically significant. Wound edge related complication rate was 19.35% in the single layer closure group and 16.67% in the multilayer closure method group. The difference was not statistically significant (z: 0.00, p value: 1.000; Pearson chi-squared (DF = 1)= 0.0075, p = 0.0785). The study shows that closing the scalp in one layer is much faster and more cost effective compared to the multilayer closure method. We did not observe significant difference in the complication rates in the two methods of closure. Long-term outcome, especially cosmetic outcome, remains to be determined in this preliminary study.
75 FR 4047 - Materials Technical Advisory Committee; Notice of Partially Closed Meeting
Federal Register 2010, 2011, 2012, 2013, 2014
2010-01-26
... the Bureau of Industry and Security Management. 3. Industry Presentation on Composite Technology. 4. Report of Composite Working group and ECCN review subgroup. 5. New business. Closed Session 6. Discussion...
Emergence of topological semimetals in gap closing in semiconductors without inversion symmetry.
Murakami, Shuichi; Hirayama, Motoaki; Okugawa, Ryo; Miyake, Takashi
2017-05-01
A band gap for electronic states in crystals governs various properties of solids, such as transport, optical, and magnetic properties. Its estimation and control have been an important issue in solid-state physics. The band gap can be controlled externally by various parameters, such as pressure, atomic compositions, and external field. Sometimes, the gap even collapses by tuning some parameter. In the field of topological insulators, this closing of the gap at a time-reversal invariant momentum indicates a band inversion, that is, it leads to a topological phase transition from a normal insulator to a topological insulator. We show, through an exhaustive study on possible space groups, that the gap closing in inversion-asymmetric crystals is universal, in the sense that the gap closing always leads either to a Weyl semimetal or to a nodal-line semimetal. We consider three-dimensional spinful systems with time-reversal symmetry. The space group of the system and the wave vector at the gap closing uniquely determine which possibility occurs and where the gap-closing points or lines lie in the wave vector space after the closing of the gap. In particular, we show that an insulator-to-insulator transition never happens, which is in sharp contrast to inversion-symmetric systems.
Galaxy Clusters and Their Central Supermassive Black Holes: Case of M87
NASA Astrophysics Data System (ADS)
Churazov, Eugene; Sazonov, Sergey; Sunyaev, Rashid; Forman, William; Jones, Christine; Böhringer, Hans
Observations suggest that AGN activity regulates the thermal state of the gas by injecting energy into the intra-cluster medium in the cores of relaxed clusters, where radiative cooling time is often as short as few 108 years. Bubbles of relativistic plasma are inflated by a supermassive black hole and rise buoyantly through the gaseous atmosphere, leading to a number of spectacular phenomena like expanding shocks, X-ray dim and radio bright cavities, X-ray dim and radio dim "ghost" cavities (aged version of "normal" cavities), filaments in the wakes of the rising bubbles formed by the entrained low entropy gas, etc. Simple estimates of the energetics involved (based on the estimates of the energy content of bubbles/cavities and their life-time) suggest that amount of mechanical energy supplied by AGNs is sufficient to offset gas cooling losses in objects vastly different in size and luminosity. This hints on some form of self-regulation controlling the AGN power as the gas cools or gets heated. One can build a toy model where accretion rate (and therefore the amount of energy provided by the AGN) is sensitive to the gas properties, in particular to its entropy, thus closing the feedback loop. How the mechanical energy, provided by the AGN, is dissipated depends on the ICM microphysics (e.g. magnetic fields, viscosity, conduction etc). However it is easy to imagine the situation when close to 100% of mechanical energy is eventually dissipated in the cluster core, regardless of the particular physical process involved. Comparison of the gravitational potential profiles of the elliptical galaxies derived from X-ray and optical data suggests that the combined contribution of cosmic rays, magnetic fields and micro-turbulence to the gas pressure is of order 10-30%. This in turn suggests that the dissipation time scale of the energy deposited by the AGN is a similar 10-30% fraction of the gas cooling time. The same process of AGN-ICM interaction, operating in nearby clusters, could be important at z = 2 - 3 when present day massive ellipticals were forming. The importance of this process depends critically on the physics of accretion. An analogy with the Galactic stellar mass black holes suggests that a black hole can switch from the radiation dominated mode to the mechanically dominated mode when the accretion rate drops below the fraction 10-2 - 10-1 of the Eddington value. Given that the coupling constant of these two forms of energy output with the ICM can differ by a factor of 104 - 105 this change in the accretion mode may explain the switch of a SMBH (and its parent galaxy) from the QSO-type behavior and an intense star formation to the radiatively inefficient AGN and essentially passive evolution of the parent galaxy.
Gamma-ray bursts, QSOs and active galaxies.
Burbidge, Geoffrey
2007-05-15
The similarity of the absorption spectra of gamma-ray burst (GRB) sources or afterglows with the absorption spectra of quasars (QSOs) suggests that QSOs and GRB sources are very closely related. Since most people believe that the redshifts of QSOs are of cosmological origin, it is natural to assume that GRBs or their afterglows also have cosmological redshifts. For some years a few of us have argued that there is much optical evidence suggesting a very different model for QSOs, in which their redshifts have a non-cosmological origin, and are ejected from low-redshift active galaxies. In this paper I extend these ideas to GRBs. In 2003, Burbidge (Burbidge 2003 Astrophys. J. 183, 112-120) showed that the redshift periodicity in the spectra of QSOs appears in the redshift of GRBs. This in turn means that both the QSOs and the GRB sources are similar objects ejected from comparatively low-redshift active galaxies. It is now clear that many of the GRBs of low redshift do appear in, or very near, active galaxies.A new and powerful result supporting this hypothesis has been produced by Prochter et al. (Prochter et al. 2006 Astrophys. J. Lett. 648, L93-L96). They show that in a survey for strong MgII absorption systems along the sightlines to long-duration GRBs, nearly every sightline shows at least one absorber. If the absorbers are intervening clouds or galaxies, only a small fraction should show absorption of this kind. The number found by Prochter et al. is four times higher than that normally found for the MgII absorption spectra of QSOs. They believe that this result is inconsistent with the intervening hypothesis and would require a statistical fluctuation greater than 99.1% probability. This is what we expect if the absorption is intrinsic to the GRBs and the redshifts are not associated with their distances. In this case, the absorption must be associated with gas ejected from the QSO. This in turn implies that the GRBs actually originate in comparatively low-redshift active galaxies and are ejected in the same way as are the QSOs. This relates these phenomena to a supernova origin for the GRBs. The current situation based on the latest observational data will be discussed.
NASA Technical Reports Server (NTRS)
Tripp, Todd M.; Giroux, Mark L.; Stocke, John T.; Tumlinson, Jason; Oegerle, William R.; Fisher, Richard R. (Technical Monitor)
2001-01-01
We use high-resolution UV (ultraviolet) spectra of the radio-quiet QSO (quasi-stellar object) H1821+643 (z(sub em) = 0.297), obtained with the Space Telescope Imaging Spectrograph (STIS) and the Far Ultraviolet Spectroscopic Explorer (FUSE), to study the ionization and metallicity of an intervening O VI absorption line system at z(sub abs) = 0.1212. This absorber has the following notable properties: (1) Several galaxies are close to the sight line at the absorber redshift, including an actively star-forming galaxy at a projected distance of 144 h(sub 75)(exp -1) kpc. (2) There is a complex cluster of H I Ly(alpha) absorption lines near the O VI redshift, including at least five components spread over a velocity range of approximately 700 km s(exp -1). (3) The strongest Ly(alpha) line in the cluster appears to be composed of a mildly saturated component with a typical b-value blended with a remarkably broad component with b approximately equals 85 km s(exp -1). (4) The O VI absorption is not aligned with the strongest (saturated) H I absorption, but instead is well-aligned with the very broad component. (5) The only detected species (at the 4(sigma) level) are O VI and H I despite coverage of strong transitions of abundant elements (e.g., C II, C III, and C IV). Based on these constraints, we find that the absorption line properties can be produced in collisionally ionized gas with 10(exp 5.3) is equal to or less than T is equal to or less than 10(exp 5.6) K and -1.8 is equal to or less than [O/H] is equal to or less than -0.6. However, we find that photoionization is also viable if the pathlength l through the absorbing gas is long enough; simple photoionization models require 85 is equal to or less than l is equal to or less than 1900 kpc and -1.1 is equal to or less than [O/H] is equal to or less than -0.3. We briefly discuss how observations of X-ray absorption lines due to O VII and O VIII could be used, in principle, to break the ionization mechanism degeneracy, and we conclude with some comments regarding the nature of O VI absorbers.
Brammer, Lee
2017-10-13
The role of the closing lecture in a Faraday Discussion is to summarise the contributions made to the Discussion over the course of the meeting and in so doing capture the main themes that have arisen. This article is based upon my Closing Remarks Lecture at the 203 rd Faraday Discussion meeting on Halogen Bonding in Supramolecular and Solid State Chemistry, held in Ottawa, Canada, on 10-12 th July, 2017. The Discussion included papers on fundamentals and applications of halogen bonding in the solid state and solution phase. Analogous interactions involving main group elements outside group 17 were also examined. In the closing lecture and in this article these contributions have been grouped into the four themes: (a) fundamentals, (b) beyond the halogen bond, (c) characterisation, and (d) applications. The lecture and paper also include a short reflection on past work that has a bearing on the Discussion.
Ayhan, Baris; Erikoglu, Mehmet; Tavli, Süleyman S; Toy, Hatice
2012-08-04
Anastomotic leaks constitute one of the most serious intraoperative complications and although many studies have been devoted to finding a solution for this problem, none of them has yet been able offer a decisive, successful method. In this study, the ability of fibrin glue and adhesive film to repair anastomotic leaks in an experimental model was compared. The sample comprised four groups of seven rats: Group 1 (Control): the distal colon was transected and anastomosis was performed. Group 2 (Primary repair): incomplete anastomosis produced a leak that was closed by primary repair on day 3. Group 3 (Fibrin glue): incomplete anastomosis produced a leak that was closed by primary repair and fibrin glue applied on day 3. Group 4 (Adhesive film): incomplete anastomosis produced a leak that was closed by primary repair and adhesive film was applied on day 3. The rats were sacrificed on day 6 following anastomosis. Anastomotic blast compressions were measured and fibroblast activation, inflammation, neovascularization and levels of collagen were evaluated. The results from Group 4 showed that blast compression values were high and statistically significantly increased over control values (p < 0.05). Inflammation in Group 2 was significantly higher than the other groups (p < 0.05). No significant differences were detected in the comparison of the groups regarding the other scoring criteria (p > 0.05). Adhesive film is more effective in reducing anastomotic leakage than fibrin glue.
78 FR 24160 - Information Systems Technical Advisory Committee; Notice of Partially Closed Meeting
Federal Register 2010, 2011, 2012, 2013, 2014
2013-04-24
... and Introductions. 2. Working Group Reports. 3. Industry presentation: Oscilloscopes Architectures. 4. Industry presentation: 5E1c1 Technology. 5. New business. Wednesday, May 8 Closed Session 6. Discussion of...
Gestalt grouping via closure degrades suprathreshold depth percepts.
Deas, Lesley M; Wilcox, Laurie M
2014-08-19
It is well known that the perception of depth is susceptible to changes in configuration. For example, stereoscopic precision for a pair of vertical lines can be dramatically reduced when these lines are connected to form a closed object. Here, we extend this paradigm to suprathreshold estimates of perceived depth. Using a touch-sensor, observers made quantitative estimates of depth between a vertical line pair presented in isolation or as edges of a closed rectangular object with different figural interpretations. First, we show that the amount of depth estimated within a closed rectangular object is consistently reduced relative to the vertical edges presented in isolation or when they form the edges of two segmented objects. We then demonstrate that the reduction in perceived depth for closed objects is modulated by manipulations that influence perceived closure of the central figure. Depth percepts were most disrupted when the horizontal connectors and vertical lines matched in color. Perceived depth increased slightly when the connectors had opposite contrast polarity, but increased dramatically when flankers were added. Thus, as grouping cues were added to counter the interpretation of a closed object, the depth degradation effect was systematically eliminated. The configurations tested here rule out explanations based on early, local interactions such as inhibition or cue conflict; instead, our results provide strong evidence of the impact of Gestalt grouping, via closure, on depth magnitude percepts from stereopsis. © 2014 ARVO.
The Development of Altruism with Special Reference to Human Relationships: A 10-Stage Theory.
Ma, Hing Keung
2017-01-01
All human relationships involve some form of cost and benefit and altruism forms the foundation upon which human relationships are built. In this paper, a taxonomy of human relationships in terms of altruism was constructed. In the proposed taxonomy, human relationships are categorized into three major groups: primary group, secondary group, and tertiary group. The primary group consists of members that are very closely related to each other either by genetic relatedness (e.g., parents, siblings, and cousins) or social relatedness (e.g., mate and close friends) or both. The secondary group consists of members that are socially related but also less closely related with each other (e.g., people of the same political or religious group, teachers, mentors, acquaintances, neighbors, working colleagues, and strangers). Lastly, the tertiary group consists of members of other species. A 10-stage theory of altruism with special reference to human relationships is proposed. The affective, cognitive, and relationship aspects of each stage are delineated in details. There are two developmental principles of altruism. The first principle states that the development of altruism follows the 10-stage theory and moves from Stage 1: Egoism toward the higher stages of altruism slowly. The second developmental principle states that the taxonomy of human relationships is valid at any stage of altruism development. In other words, people at any stage of altruism are more altruistic toward their kin and mate, and then close friends, extended family members, and so on. They are least altruistic toward enemies and members of non-human species. In summary, the proposed developmental principle of altruism and human relationships is logical and robust. It is formulated based on the major developmental and social psychological theories. The theory has the potential in providing a useful framework for future studies on the development and evolution of human relationships.
The Development of Altruism with Special Reference to Human Relationships: A 10-Stage Theory
Ma, Hing Keung
2017-01-01
All human relationships involve some form of cost and benefit and altruism forms the foundation upon which human relationships are built. In this paper, a taxonomy of human relationships in terms of altruism was constructed. In the proposed taxonomy, human relationships are categorized into three major groups: primary group, secondary group, and tertiary group. The primary group consists of members that are very closely related to each other either by genetic relatedness (e.g., parents, siblings, and cousins) or social relatedness (e.g., mate and close friends) or both. The secondary group consists of members that are socially related but also less closely related with each other (e.g., people of the same political or religious group, teachers, mentors, acquaintances, neighbors, working colleagues, and strangers). Lastly, the tertiary group consists of members of other species. A 10-stage theory of altruism with special reference to human relationships is proposed. The affective, cognitive, and relationship aspects of each stage are delineated in details. There are two developmental principles of altruism. The first principle states that the development of altruism follows the 10-stage theory and moves from Stage 1: Egoism toward the higher stages of altruism slowly. The second developmental principle states that the taxonomy of human relationships is valid at any stage of altruism development. In other words, people at any stage of altruism are more altruistic toward their kin and mate, and then close friends, extended family members, and so on. They are least altruistic toward enemies and members of non-human species. In summary, the proposed developmental principle of altruism and human relationships is logical and robust. It is formulated based on the major developmental and social psychological theories. The theory has the potential in providing a useful framework for future studies on the development and evolution of human relationships. PMID:29085818
Kricheldorf, Fabio; Bueno, Cleuber Rodrigo de Souza; Amaral, Wilson da Silva; Junior, Joel Ferreira Santiago; Filho, Hugo Nary
2018-01-01
The objective of this study is to compare the marginal adaptation of feldspathic porcelain crowns using two computer-aided design/computer-aided manufacturing systems, one of them is open and the other is closed. Twenty identical titanium abutments were divided into two groups: open system (OS), where ceramic crowns were created using varied equipment and software, and closed system (CS), where ceramic crowns were created using the CEREC system. Through optical microscopy analysis, we assess the marginal adaptation of the prosthetic interfaces. The data were subjected to the distribution of normality and variance. The t -test was used for the analysis of the comparison factor between the groups, and the one-way ANOVA was used to compare the variance of crown analysis regions within the group. A significance level of 5% was considered for the analyses. There was a significant difference between the systems ( P = 0.007), with the CS group having the higher mean (23.75 μm ± 3.05) of marginal discrepancy when compared to the open group (17.94 μm ± 4.77). Furthermore, there were no differences in marginal discrepancy between the different points between the groups ( P ≥ 0.05). The studied groups presented results within the requirements set out in the literature. However, the OS used presented better results in marginal adaptation.
Robinson, Hayley; Ravikulan, Abhimati; Nater, Urs M; Skoluda, Nadine; Jarrett, Paul; Broadbent, Elizabeth
2017-07-01
Social support is known to reduce the negative effects of stress on health, but there is mixed evidence for the effects of social support on wound healing. This study aimed to investigate whether undergoing a task designed to promote social closeness with a fellow participant and being paired with that person during a tape-stripping procedure could reduce stress and improve skin barrier recovery compared to going through tape stripping alone. Seventy-two healthy adults were randomized to either a social closeness condition where participants completed a relationship-building task and tape stripping in pairs or a control condition where they completed tape stripping alone. Skin barrier recovery was measured using transepidermal water loss. Salivary cortisol and alpha-amylase were collected at four time points as markers of the endocrine and autonomic stress response. Social closeness had a beneficial effect on skin barrier recovery compared to the control condition, t(54) = 2.86, p = .006, r = .36. Social closeness significantly reduced self-reported stress. The effects of the intervention on skin barrier recovery were moderated by self-reported stress reduction (p = .035). There were no significant differences in cortisol between groups, but alpha-amylase increased significantly more from baseline to after tape stripping in the control group compared to the intervention group. This is the first study to show that social closeness with a person going through a similar unfamiliar procedure can positively influence wound healing. Future research needs to replicate these findings in other wound types and in clinical settings. (PsycINFO Database Record (c) 2017 APA, all rights reserved).
Participants' Perception of Therapeutic Factors in Groups for Incest Survivors.
ERIC Educational Resources Information Center
Wheeler, Inese; And Others
1992-01-01
Investigated member-perceived curative factors in an incest-survivor group, comparing therapeutic factors reported in closed, time-limited incest survivor group to those in Bonney et al.'s open, long-term survivor group and to Yalom's therapy groups. Findings suggest that relative importance of curative factors may be related to group stages.…
Weatherly, Nic L; Gravina, Nicole E
2005-01-01
An informant functional assessment was used to evaluate closing-task completion by servers and dishwashers at a restaurant. Based on the functional assessment results, an intervention consisting of task clarification, posted graphic feedback, and verbal feedback was implemented and evaluated with a multiple baseline design across two groups of employees. Results showed an increase of 15% and 38% in task completion for the two groups. PMID:15898481
Pearce, Eiluned; Launay, Jacques; van Duijn, Max; Rotkirch, Anna; David-Barrett, Tamas; Dunbar, Robin I M
2016-01-01
Singing together seems to facilitate social bonding, but it is unclear whether this is true in all contexts. Here we examine the social bonding outcomes of naturalistic singing behaviour in a European university Fraternity composed of exclusive ‘Cliques’: recognised sub-groups of 5-20 friends who adopt a special name and identity. Singing occurs frequently in this Fraternity, both ‘competitively’ (contests between Cliques) and ‘cooperatively’ (multiple Cliques singing together). Both situations were re-created experimentally in order to explore how competitive and cooperative singing affects feelings of closeness towards others. Participants were assigned to teams of four and were asked to sing together with another team either from the same Clique or from a different Clique. Participants (N = 88) felt significantly closer to teams from different Cliques after singing with them compared to before, regardless of whether they cooperated with (singing loudly together) or competed against (trying to singing louder than) the other team. In contrast, participants reported reduced closeness with other teams from their own Clique after competing with them. These results indicate that group singing can increase closeness to less familiar individuals regardless of whether they share a common motivation, but that singing competitively may reduce closeness within a very tight-knit group. PMID:27777494
Trikha, V; Saini, P; Mathur, P; Agarwal, A; Kumar, S V; Choudhary, B
2016-04-01
To compare blade cultures in surgery for closed fracture using a single or double blade technique to determine whether the current practice of double blade technique is justified. 155 men and 29 women aged 20 to 60 (mean, 35) years who underwent surgery for closed fracture with healthy skin at the incision site were included. Patients were block randomised to the single (n=92) or double (n=92) blade technique. Blades were sent for bacteriological analysis. Outcome measures were early surgical site infection (SSI) within 30 days and cultures from the blades. The 2 groups were comparable in baseline characteristics. In the single blade group, 6 surgical blades and 2 control blades showed positive cultures; 4 patients developed SSI, but only one had a positive culture from the surgical blade (with different organism isolated from the wound culture). In the double blade group, 6 skin blades, 7 deep blades, and 0 control blade showed positive culture; only 2 patients had the same bacteria grown from both skin and deep blade. Five patients developed SSI, but only one patient had a positive culture from the deep blade (with different organism isolated from the wound culture). The difference in incidence of culture-positive blade or SSI between the 2 groups was not significant. The relative risk of SSI in the single blade group was 0.8. Positive blade culture was not associated with SSI in the single or double blade group. The practice of changing blade following skin incision has no effect on reducing early SSI in surgery for closed fracture in healthy patients with healthy skin.
Lazy orbits: An optimization problem on the sphere
NASA Astrophysics Data System (ADS)
Vincze, Csaba
2018-01-01
Non-transitive subgroups of the orthogonal group play an important role in the non-Euclidean geometry. If G is a closed subgroup in the orthogonal group such that the orbit of a single Euclidean unit vector does not cover the (Euclidean) unit sphere centered at the origin then there always exists a non-Euclidean Minkowski functional such that the elements of G preserve the Minkowskian length of vectors. In other words the Minkowski geometry is an alternative of the Euclidean geometry for the subgroup G. It is rich of isometries if G is "close enough" to the orthogonal group or at least to one of its transitive subgroups. The measure of non-transitivity is related to the Hausdorff distances of the orbits under the elements of G to the Euclidean sphere. Its maximum/minimum belongs to the so-called lazy/busy orbits, i.e. they are the solutions of an optimization problem on the Euclidean sphere. The extremal distances allow us to characterize the reducible/irreducible subgroups. We also formulate an upper and a lower bound for the ratio of the extremal distances. As another application of the analytic tools we introduce the rank of a closed non-transitive group G. We shall see that if G is of maximal rank then it is finite or reducible. Since the reducible and the finite subgroups form two natural prototypes of non-transitive subgroups, the rank seems to be a fundamental notion in their characterization. Closed, non-transitive groups of rank n - 1 will be also characterized. Using the general results we classify all their possible types in lower dimensional cases n = 2 , 3 and 4. Finally we present some applications of the results to the holonomy group of a metric linear connection on a connected Riemannian manifold.
Lee, Byung Moo
2017-12-29
Massive multiple-input multiple-output (MIMO) systems can be applied to support numerous internet of things (IoT) devices using its excessive amount of transmitter (TX) antennas. However, one of the big obstacles for the realization of the massive MIMO system is the overhead of reference signal (RS), because the number of RS is proportional to the number of TX antennas and/or related user equipments (UEs). It has been already reported that antenna group-based RS overhead reduction can be very effective to the efficient operation of massive MIMO, but the method of deciding the number of antennas needed in each group is at question. In this paper, we propose a simplified determination scheme of the number of antennas needed in each group for RS overhead reduced massive MIMO to support many IoT devices. Supporting many distributed IoT devices is a framework to configure wireless sensor networks. Our contribution can be divided into two parts. First, we derive simple closed-form approximations of the achievable spectral efficiency (SE) by using zero-forcing (ZF) and matched filtering (MF) precoding for the RS overhead reduced massive MIMO systems with channel estimation error. The closed-form approximations include a channel error factor that can be adjusted according to the method of the channel estimation. Second, based on the closed-form approximation, we present an efficient algorithm determining the number of antennas needed in each group for the group-based RS overhead reduction scheme. The algorithm depends on the exact inverse functions of the derived closed-form approximations of SE. It is verified with theoretical analysis and simulation that the proposed algorithm works well, and thus can be used as an important tool for massive MIMO systems to support many distributed IoT devices.
2017-01-01
Massive multiple-input multiple-output (MIMO) systems can be applied to support numerous internet of things (IoT) devices using its excessive amount of transmitter (TX) antennas. However, one of the big obstacles for the realization of the massive MIMO system is the overhead of reference signal (RS), because the number of RS is proportional to the number of TX antennas and/or related user equipments (UEs). It has been already reported that antenna group-based RS overhead reduction can be very effective to the efficient operation of massive MIMO, but the method of deciding the number of antennas needed in each group is at question. In this paper, we propose a simplified determination scheme of the number of antennas needed in each group for RS overhead reduced massive MIMO to support many IoT devices. Supporting many distributed IoT devices is a framework to configure wireless sensor networks. Our contribution can be divided into two parts. First, we derive simple closed-form approximations of the achievable spectral efficiency (SE) by using zero-forcing (ZF) and matched filtering (MF) precoding for the RS overhead reduced massive MIMO systems with channel estimation error. The closed-form approximations include a channel error factor that can be adjusted according to the method of the channel estimation. Second, based on the closed-form approximation, we present an efficient algorithm determining the number of antennas needed in each group for the group-based RS overhead reduction scheme. The algorithm depends on the exact inverse functions of the derived closed-form approximations of SE. It is verified with theoretical analysis and simulation that the proposed algorithm works well, and thus can be used as an important tool for massive MIMO systems to support many distributed IoT devices. PMID:29286339
Code of Federal Regulations, 2013 CFR
2013-01-01
... 7 Agriculture 2 2013-01-01 2013-01-01 false Group. 30.7 Section 30.7 Agriculture Regulations of... AND STANDARDS Classification of Leaf Tobacco Covering Classes, Types and Groups of Grades § 30.7 Group. A group of grades, or a division of a type covering several closely related grades, based on the...
Code of Federal Regulations, 2012 CFR
2012-01-01
... 7 Agriculture 2 2012-01-01 2012-01-01 false Group. 30.7 Section 30.7 Agriculture Regulations of... AND STANDARDS Classification of Leaf Tobacco Covering Classes, Types and Groups of Grades § 30.7 Group. A group of grades, or a division of a type covering several closely related grades, based on the...
Code of Federal Regulations, 2011 CFR
2011-01-01
... 7 Agriculture 2 2011-01-01 2011-01-01 false Group. 30.7 Section 30.7 Agriculture Regulations of... AND STANDARDS Classification of Leaf Tobacco Covering Classes, Types and Groups of Grades § 30.7 Group. A group of grades, or a division of a type covering several closely related grades, based on the...
Code of Federal Regulations, 2014 CFR
2014-01-01
... 7 Agriculture 2 2014-01-01 2014-01-01 false Group. 30.7 Section 30.7 Agriculture Regulations of... AND STANDARDS Classification of Leaf Tobacco Covering Classes, Types and Groups of Grades § 30.7 Group. A group of grades, or a division of a type covering several closely related grades, based on the...
Code of Federal Regulations, 2010 CFR
2010-01-01
... 7 Agriculture 2 2010-01-01 2010-01-01 false Group. 30.7 Section 30.7 Agriculture Regulations of... AND STANDARDS Classification of Leaf Tobacco Covering Classes, Types and Groups of Grades § 30.7 Group. A group of grades, or a division of a type covering several closely related grades, based on the...
Sawani, Shefali; Arora, Vipin; Jaiswal, Shikha; Nikhil, Vineeta
2014-01-01
Background: Evaluation of microleakage is important for assessing the success of new restorative materials and methods. Aim and Objectives: Comparative evaluation of microleakage in Class II restorations using open vs. closed centripetal build-up techniques with different lining materials. Materials and Methods: Standardized mesi-occlusal (MO) and distoocclusal (DO) Class II tooth preparations were preparedon 53 molars and samples were randomly divided into six experimental groups and one control group for restorations. Group 1: Open-Sandwich technique (OST) with flowable composite at the gingival seat. Group 2: OST with resin-modified glass ionomer cement (RMGIC) at the gingival seat. Group 3: Closed-Sandwich technique (CST) with flowable composite at the pulpal floor and axial wall. Group 4: CST with RMGIC at the pulpal floor and axial wall. Group 5: OST with flowable composite at the pulpal floor, axial wall, and gingival seat. Group 6: OST with RMGIC at the pulpal floor, axial wall, and gingival seat. Group 7: Control — no lining material, centripetal technique only. After restorations and thermocycling, apices were sealed and samples were immersed in 0.5% basic fuchsin dye. Sectioning was followed by stereomicroscopic evaluation. Results: Results were analyzed using Post Hoc Bonferroni test (statistics is not a form of tabulation). Cervical scores of control were more than the exprimental groups (P < 0.05). Less microleakage was observed in CST than OST in all experimental groups (P < 0.05). However, insignificant differences were observed among occlusal scores of different groups (P > 0.05). Conclusion: Class II composite restorations with centripetal build-up alone or when placed with CST reduces the cervical microleakage when compared to OST. PMID:25125847
77 FR 28886 - Center for Scientific Review; Notice of Closed Meetings
Federal Register 2010, 2011, 2012, 2013, 2014
2012-05-16
..., Functional and Cognitive Neuroscience Integrated Review Group; Sensorimotor Integration Study Section. Date... and Developmental Neuroscience Integrated Review Group; Neural Oxidative Metabolism and Death Study...: Molecular, Cellular and Developmental Neuroscience Integrated Review Group; Neurodifferentiation, Plasticity...
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Federal Register 2010, 2011, 2012, 2013, 2014
2013-01-28
.... Remarks from BIS senior management. 3. Presentation by DuPont on the impact of Australia Group and Wassenaar membership for Mexico in particular. 4. Report of Composite Working Group and other working groups...
Yamagishi, Norio; Ayukawa, Yu; Lee, Inhyung; Oboshi, Kenji; Naito, Yoshihisa
2005-06-01
To determine the effect of exogenous 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] combined with induced parturition on calcium (Ca) metabolism, cows received a single intramuscular injection of 1,25(OH)2D3 and prostaglandin F(2alpha) (PGF(2alpha)) closely before calving. Ten late-pregnant, multiparous Holstein cows were assigned to 1,25(OH)2D3 group (five treated with both 1,25(OH)2D3 and PGF(2alpha)) and control group (five treated with PGF(2alpha)). 1,25(OH)2D3 group showed an increase in plasma Ca concentration around parturition, whereas control group revealed a decrease in plasma Ca level. Plasma Ca concentration in 1,25(OH)2D3 group were significantly higher than that in control group during -0.5 to 3 days after parturition.
Roach, R P; Hatton, J F; Gillespie, M J
2001-11-01
Contamination of the root canal system by persistent, enteric bacteria via leakage through interim restorations has been well documented. This in vitro study evaluated the ability of interappointment medications to prevent contamination of the root canal system by Enterococcus faecalis. Coronally unsealed, medicated tooth roots fixed in a closed system were contaminated daily with a standardized, aerobic, broth culture of E. faecalis. Four medications were evaluated (n = 15): group A, calcium hydroxide/methylcellulose paste; group B, camphorated parachlorophenol/calcium hydroxide paste; group C, 1% chlorhexidine/methylcellulose gel; and group D, calcium hydroxide points. The mean number of days to contamination as indicated by turbidity in the closed system was the following: group A, 37; group B, 46; group C, 16; group D, 5; and a positive control (no medication), 3. A one-way analysis of variance with a Scheffe post hoc test (p = 0.05) detected significant differences in effectiveness with A and B superior to C and D, and C superior to D.
Ly, Trang T; Roy, Anirban; Grosman, Benyamin; Shin, John; Campbell, Alex; Monirabbasi, Salman; Liang, Bradley; von Eyben, Rie; Shanmugham, Satya; Clinton, Paula; Buckingham, Bruce A
2015-07-01
To evaluate the feasibility and efficacy of a fully integrated hybrid closed-loop (HCL) system (Medtronic MiniMed Inc., Northridge, CA), in day and night closed-loop control in subjects with type 1 diabetes, both in an inpatient setting and during 6 days at diabetes camp. The Medtronic MiniMed HCL system consists of a fourth generation (4S) glucose sensor, a sensor transmitter, and an insulin pump using a modified proportional-integral-derivative (PID) insulin feedback algorithm with safety constraints. Eight subjects were studied over 48 h in an inpatient setting. This was followed by a study of 21 subjects for 6 days at diabetes camp, randomized to either the closed-loop control group using the HCL system or to the group using the Medtronic MiniMed 530G with threshold suspend (control group). The overall mean sensor glucose percent time in range 70-180 mg/dL was similar between the groups (73.1% vs. 69.9%, control vs. HCL, respectively) (P = 0.580). Meter glucose values between 70 and 180 mg/dL were also similar between the groups (73.6% vs. 63.2%, control vs. HCL, respectively) (P = 0.086). The mean absolute relative difference of the 4S sensor was 10.8 ± 10.2%, when compared with plasma glucose values in the inpatient setting, and 12.6 ± 11.0% compared with capillary Bayer CONTOUR NEXT LINK glucose meter values during 6 days at camp. In the first clinical study of this fully integrated system using an investigational PID algorithm, the system did not demonstrate improved glucose control compared with sensor-augmented pump therapy alone. The system demonstrated good connectivity and improved sensor performance. © 2015 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.
The School of Hard Knocks: The Development of Close Air Support in Burma during the Second World War
2015-05-23
Group CAOC Combined Air Operations Center CAS Close Air Support CBI China-Burma-India EAC Eastern Air Command FM Field Manual JP Joint...Command ( EAC ) solved problems identified by the American Volunteer Group (AVG) in 1942. EAC’s doctrine, procedures, and techniques laid the foundation for...named the Eastern Air Command ( EAC ), and oversaw the air-land cooperation during the Allied counter-offensive into Burma throughout 1943 and 1944.8 The
Genetic Evidence for Recent Population Mixture in India
Moorjani, Priya; Thangaraj, Kumarasamy; Patterson, Nick; Lipson, Mark; Loh, Po-Ru; Govindaraj, Periyasamy; Berger, Bonnie; Reich, David; Singh, Lalji
2013-01-01
Most Indian groups descend from a mixture of two genetically divergent populations: Ancestral North Indians (ANI) related to Central Asians, Middle Easterners, Caucasians, and Europeans; and Ancestral South Indians (ASI) not closely related to groups outside the subcontinent. The date of mixture is unknown but has implications for understanding Indian history. We report genome-wide data from 73 groups from the Indian subcontinent and analyze linkage disequilibrium to estimate ANI-ASI mixture dates ranging from about 1,900 to 4,200 years ago. In a subset of groups, 100% of the mixture is consistent with having occurred during this period. These results show that India experienced a demographic transformation several thousand years ago, from a region in which major population mixture was common to one in which mixture even between closely related groups became rare because of a shift to endogamy. PMID:23932107
76 FR 24894 - Center for Scientific Review; Notice of Closed Meetings
Federal Register 2010, 2011, 2012, 2013, 2014
2011-05-03
... personal privacy. Name of Committee: Oncology 2--Translational Clinical Integrated Review Group; Chemo... . Name of Committee: Oncology 2--Translational Clinical Integrated Review Group; [email protected] . Name of Committee: Oncology 1--Basic Translational Integrated Review Group...
78 FR 54664 - Center for Scientific Review; Notice of Closed Meetings
Federal Register 2010, 2011, 2012, 2013, 2014
2013-09-05
..., Functional and Cognitive Neuroscience Integrated Review Group; Sensorimotor Integration Study Section. Date... Cognitive Neuroscience Integrated Review Group; Neuroendocrinology, Neuroimmunology, Rhythms and Sleep Study...
Captioning: New Tool for Inclusiveness.
ERIC Educational Resources Information Center
PTA Today, 1995
1995-01-01
Closed-captioned television is useful for various special-needs student groups, assisting students who are hard of hearing, taking remedial reading, and learning English as a Second Language. The article examines related research and provides examples of use of closed-captioned television in classrooms. (SM)
Zhang, Dawei; Ye, Xiangming; Zhang, Xiaofeng; Zhang, Wenjie
2017-03-12
To observe the differences of affected-side ankle plantar flexors function and clinical efficacy between contralateral acupuncture combined with rehabilitation training and rehabilitation training alone for patients with acute closed achilles tendon rupture. Seventy-four patients with acute closed achilles tendon rupture were randomly assigned to an observation group and a control group, 37 cases in each group. Patients in the both groups were treated with routine rehabilitation training after the operation for 12 weeks; besides, patients in the observation group were treated with contralateral acupuncture at Zusanli (ST 36), Yanglingquan (GB 34), Chengshan (BL 57), Taixi (KI 3) before rehabilitation training in the first 6 weeks. The treatment were given once a day, 5 times as 1 course with 2 d at the interval. The Biodex System 4 multi-joint dynamometers system was applied to test and compare affected-side plantar flexion peak torque (PFPT), peak torque/body weight (PT/BW) and total work (TW) after 6 weeks, 8 weeks and 12 weeks. The efficacy evaluation was conducted after 6 weeks and 12 weeks, and the follow-up visit was conducted 12 weeks after end of treatment. The PFPT, PT/BW, TW in the observation group were significantly superior to those in the control group after 8 weeks and 12 weeks of treatment (all P <0.05); compared with those after 6 weeks, the PFPT, PT/BW, TW were significantly increased after 8 weeks of treatment (all P <0.05); compared with those after 6 weeks and 8 weeks, the PFPT, PT/BW, TW were significantly increased after 12 weeks of treatment (all P <0.05). After 12 weeks of treatment and at follow-up visit, the clinical excellent and effective rates in the observation group were higher than those in the control group[89.2% (33/37) vs 70.3% (26/37), 94.6% (35/37) vs 75.7% (28/37), both P <0.05]. During the postoperative rehabilitation of acute closed achilles tendon rupture, the contralateral acupuncture combined with rehabilitation training could improve ankle plantar flexors function and clinical efficacy better than rehabilitation training only.
Pilot randomised controlled trial of face-down positioning following macular hole surgery.
Lange, C A K; Membrey, L; Ahmad, N; Wickham, L; Maclaren, R E; Solebo, L; Xing, W; Bunce, C; Ezra, E; Charteris, D; Aylward, B; Yorston, D; Gregor, Z; Zambarakji, H; Bainbridge, J W
2012-02-01
This was a pilot randomised controlled trial (RCT) to investigate the effect of post-operative face-down positioning on the outcome of macular hole surgery and to inform the design of a larger definitive study. In all, 30 phakic eyes of 30 subjects with idiopathic full-thickness macular holes underwent vitrectomy with dye-assisted peeling of the ILM and 14% perfluoropropane gas. Subjects were randomly allocated to posture face down for 10 days (posturing group) or to avoid a face-up position only (non-posturing group). The primary outcome was anatomical hole closure. Macular holes closed in 14 of 15 eyes (93.3%; 95% confidence interval (CI) 68-100%) in the posturing group and in 9 of 15 (60%; 95% CI 32-84%) in the non-posturing group. In a subgroup analysis of outcome according to macular hole size, all holes smaller than 400 μm closed regardless of posturing (100%). In contrast, holes larger than 400 μm closed in 10 of 11 eyes (91%; 95% CI 58-99%) in the posturing group and in only 4 of 10 eyes (40%; 95% CI 12-74%) in the non-posturing group (Fisher's exact test P=0.02). Post-operative face-down positioning may improve the likelihood of macular hole closure, particularly for holes larger than 400 μm. These results support the case for a RCT.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Han, C S; Xie, G; Challacombe, J F
The sequencing and analysis of two close relatives of Bacillus anthracis are reported. AFLP analysis of over 300 isolates of B. cereus, B. thuringiensis and B. anthracis identified two isolates as being very closely related to B. anthracis. One, a B. cereus, BcE33L, was isolated from a zebra carcass in Nambia; the second, a B. thuringiensis, 97-27, was isolated from a necrotic human wound. The B. cereus appears to be the closest anthracis relative sequenced to date. A core genome of over 3,900 genes was compiled for the Bacillus cereus group, including B anthracis. Comparative analysis of these two genomesmore » with other members of the B. cereus group provides insight into the evolutionary relationships among these organisms. Evidence is presented that differential regulation modulates virulence, rather than simple acquisition of virulence factors. These genome sequences provide insight into the molecular mechanisms contributing to the host range and virulence of this group of organisms.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Han, Cliff S.; Xie, Gary; Challacombe, Jean F.
The sequencing and analysis of two close relatives of Bacillus anthracis are reported. AFLP analysis of over 300 isolates of B.cereus, B. thuringiensis and B. anthracis identified two isolates as being very closely related to B. anthracis. One, a B. cereus, BcE33L, was isolated from a zebra carcass in Nambia; the second, a B. thuringiensis, 97-27, was isolated from a necrotic human wound. The B. cereus appears to be the closest anthracis relative sequenced to date. A core genome of over 3,900 genes was compiled for the Bacillus cereus group, including Banthracis. Comparative analysis of these two genomes with othermore » members of the B. cereus group provides insight into the evolutionary relationships among these organisms. Evidence is presented that differential regulation modulates virulence, rather than simple acquisition of virulence factors. These genome sequences provide insight into the molecular mechanisms contributing to the host range and virulence of this group of organisms.« less
Woodward, Matthew J; Eddinger, Jasmine; Henschel, Aisling V; Dodson, Thomas S; Tran, Han N; Beck, J Gayle
2015-10-01
Research has suggested that social support can shape posttraumatic cognitions and PTSD. However, research has yet to compare the influence of separate domains of support on posttraumatic cognitions. Multiple-group path analysis was used to examine a model in a sample of 170 victims of intimate partner violence and 208 motor vehicle accident victims in which support from friends, family, and a close other were each predicted to influence posttraumatic cognitions, which were in turn predicted to influence PTSD. Analyses revealed that support from family and friends were each negatively correlated with posttraumatic cognitions, which in turn were positively associated with PTSD. Social support from a close other was not associated with posttraumatic cognitions. No significant differences in the model were found between trauma groups. Findings identify which relationships are likely to influence posttraumatic cognitions and are discussed with regard to interpersonal processes in the development and maintenance of PTSD. Copyright © 2015 Elsevier Ltd. All rights reserved.
78 FR 29373 - Center For Scientific Review; Notice of Closed Meetings
Federal Register 2010, 2011, 2012, 2013, 2014
2013-05-20
... Committee: Oncology 2--Translational Clinical Integrated Review Group; Developmental Therapeutics [email protected] . Name of Committee: Oncology 1-Basic Translational Integrated Review Group; Cancer...
The effects of cognitive loading on balance control in patients with multiple sclerosis.
Negahban, Hossein; Mofateh, Razieh; Arastoo, Ali Asghar; Mazaheri, Masood; Yazdi, Mohammad Jafar Shaterzadeh; Salavati, Mahyar; Majdinasab, Nastaran
2011-10-01
The aim of this study was to compare the effects of concurrent cognitive task (silent backward counting) on balance performance between two groups of multiple sclerosis (MS) (n=23) and healthy (n=23) participates. Three levels of postural difficulty were studied on a force platform, i.e. rigid surface with eyes open, rigid surface with eyes closed, and foam surface with eyes closed. A mixed model analysis of variance showed that under difficult sensory condition of foam surface with eyes closed, execution of concurrent cognitive task caused a significant decrement in variability of sway velocity in anteroposterior direction for the patient group (P<0.01) while this was not the case for healthy participants (P=0.22). Also, the variability of sway velocity in mediolateral direction was significantly decreased during concurrent execution of cognitive task in patient group (P<0.01) and not in healthy participants (P=0.39). Furthermore, in contrast to single tasking, dual tasking had the ability to discriminate between the 2 groups in all conditions of postural difficulty. In conclusion, findings of variability in sway velocity seem to confirm the different response to cognitive loading between two groups of MS and healthy participants. Copyright © 2011 Elsevier B.V. All rights reserved.
Nielsen, Dennis S; Jakobsen, Mogens; Jespersen, Lene
2010-06-01
During an investigation of the microbiology of Ghanaian cocoa fermentations, a number of yeast isolates with unusual pheno- and genotypic properties representing three possible novel species were isolated. Members of Group A divided by multilateral budding and ascospores were not produced. Group B strains produced true hyphae and ascospores were not produced. Group C representatives divided by budding and formed chains and star-like aggregates. Ascospores were not produced. Sequence analysis of the 26S rRNA gene (D1/D2 region) revealed that the Group A isolates were phylogenetically most closely related to Saturnispora mendoncae (gene sequence similarity 92.4 %), Saturnispora besseyi (88.8 %), Saturnispora saitoi (88.8 %) and Saturnispora ahearnii (88.3 %). Members of Group B were most closely related to representatives of the genera Dipodascus and Galactomyces and the asporogenous genus Geotrichum, but in all cases with 26S rRNA gene (D1/D2 region) similarities below 87 %. For Group C, the most closely related species were Candida rugopelliculosa (92.4 %), Pichia occidentalis (91.6 %) and Pichia exigua (91.9 %). The very low gene sequence similarities obtained for the three groups of isolates clearly indicated that they represented novel species. Repetitive Palindromic PCR (Rep-PCR) of the isolates and their closest phylogenetic relatives confirmed that the new isolates belonged to previously undescribed species. In conclusion, based on the genetic and phenotypic results, the new isolates were considered to represent three novel species, for which the names Candida halmiae (group A, type strain G3(T)=CBS 11009(T)=CCUG 56721(T)); Geotrichum ghanense (group B, type strain G6(T)=CBS 11010(T)=CCUG 56722(T)) and Candida awuaii (group C, type strain G15(T)=CBS 11011(T)=CCUG 56723(T)) are proposed.
Weinstein, Daniel; Launay, Jacques; Pearce, Eiluned; Dunbar, Robin I. M.; Stewart, Lauren
2016-01-01
Over our evolutionary history, humans have faced the problem of how to create and maintain social bonds in progressively larger groups compared to those of our primate ancestors. Evidence from historical and anthropological records suggests that group music-making might act as a mechanism by which this large-scale social bonding could occur. While previous research has shown effects of music making on social bonds in small group contexts, the question of whether this effect ‘scales up’ to larger groups is particularly important when considering the potential role of music for large-scale social bonding. The current study recruited individuals from a community choir that met in both small (n = 20 – 80) and large (a ‘megachoir’ combining individuals from the smaller subchoirs n = 232) group contexts. Participants gave self-report measures (via a survey) of social bonding and had pain threshold measurements taken (as a proxy for endorphin release) before and after 90 minutes of singing. Results showed that feelings of inclusion, connectivity, positive affect, and measures of endorphin release all increased across singing rehearsals and that the influence of group singing was comparable for pain thresholds in the large versus small group context. Levels of social closeness were found to be greater at pre- and post-levels for the small choir condition. However, the large choir condition experienced a greater change in social closeness as compared to the small condition. The finding that singing together fosters social closeness – even in large contexts where individuals are not known to each other – is consistent with evolutionary accounts that emphasize the role of music in social bonding, particularly in the context of creating larger cohesive groups than other primates are able to manage. PMID:27158219
Code of Federal Regulations, 2014 CFR
2014-01-01
... 7 Agriculture 2 2014-01-01 2014-01-01 false Group. 29.1026 Section 29.1026 Agriculture Regulations... Type 92) § 29.1026 Group. A division of a type covering closely related grades based on certain characteristics which are related to stalk position, body, or the general quality of the tobacco. Groups in Flue...
Code of Federal Regulations, 2014 CFR
2014-01-01
... 7 Agriculture 2 2014-01-01 2014-01-01 false Group. 29.3523 Section 29.3523 Agriculture Regulations... Type 95) § 29.3523 Group. A division of a type covering closely related grades based on certain characteristics which are related to stalk position, body, or the general quality of the tobacco. Groups in Dark...
Code of Federal Regulations, 2012 CFR
2012-01-01
... 7 Agriculture 2 2012-01-01 2012-01-01 false Group. 29.3031 Section 29.3031 Agriculture Regulations... Group. A division of a type covering closely related grades based on certain characteristics which are related to stalk position or the general quality of the tobacco. Groups in Burley, Types 31 and 93, are as...
Code of Federal Regulations, 2012 CFR
2012-01-01
... 7 Agriculture 2 2012-01-01 2012-01-01 false Group. 29.1026 Section 29.1026 Agriculture Regulations... Type 92) § 29.1026 Group. A division of a type covering closely related grades based on certain characteristics which are related to stalk position, body, or the general quality of the tobacco. Groups in Flue...
Code of Federal Regulations, 2011 CFR
2011-01-01
... 7 Agriculture 2 2011-01-01 2011-01-01 false Group. 29.3523 Section 29.3523 Agriculture Regulations... Type 95) § 29.3523 Group. A division of a type covering closely related grades based on certain characteristics which are related to stalk position, body, or the general quality of the tobacco. Groups in Dark...
Code of Federal Regulations, 2013 CFR
2013-01-01
... 7 Agriculture 2 2013-01-01 2013-01-01 false Group. 29.3031 Section 29.3031 Agriculture Regulations... Group. A division of a type covering closely related grades based on certain characteristics which are related to stalk position or the general quality of the tobacco. Groups in Burley, Types 31 and 93, are as...
Code of Federal Regulations, 2014 CFR
2014-01-01
... 7 Agriculture 2 2014-01-01 2014-01-01 false Group. 29.3031 Section 29.3031 Agriculture Regulations... Group. A division of a type covering closely related grades based on certain characteristics which are related to stalk position or the general quality of the tobacco. Groups in Burley, Types 31 and 93, are as...
Code of Federal Regulations, 2012 CFR
2012-01-01
... 7 Agriculture 2 2012-01-01 2012-01-01 false Group. 29.3523 Section 29.3523 Agriculture Regulations... Type 95) § 29.3523 Group. A division of a type covering closely related grades based on certain characteristics which are related to stalk position, body, or the general quality of the tobacco. Groups in Dark...
Code of Federal Regulations, 2013 CFR
2013-01-01
... 7 Agriculture 2 2013-01-01 2013-01-01 false Group. 29.3523 Section 29.3523 Agriculture Regulations... Type 95) § 29.3523 Group. A division of a type covering closely related grades based on certain characteristics which are related to stalk position, body, or the general quality of the tobacco. Groups in Dark...
Code of Federal Regulations, 2013 CFR
2013-01-01
... 7 Agriculture 2 2013-01-01 2013-01-01 false Group. 29.1026 Section 29.1026 Agriculture Regulations... Type 92) § 29.1026 Group. A division of a type covering closely related grades based on certain characteristics which are related to stalk position, body, or the general quality of the tobacco. Groups in Flue...
Code of Federal Regulations, 2010 CFR
2010-01-01
... 7 Agriculture 2 2010-01-01 2010-01-01 false Group. 29.3523 Section 29.3523 Agriculture Regulations... Type 95) § 29.3523 Group. A division of a type covering closely related grades based on certain characteristics which are related to stalk position, body, or the general quality of the tobacco. Groups in Dark...
NASA Astrophysics Data System (ADS)
Zeng, Liang; Smith, Chris; Poelzer, G. Herold; Rodriguez, Jennifer; Corpuz, Edgar; Yanev, George
2014-12-01
In our pilot studies, we found that many introductory physics textbook illustrations with supporting text for sound standing waves of air columns in open-open, open-closed, and closed-closed pipes inhibit student understanding of sound standing wave phenomena due to student misunderstanding of how air molecules move within these pipes. Based on the construct of meaningful learning from cognitive psychology and semiotics, a quasiexperimental study was conducted to investigate the comparative effectiveness of two alternative approaches to student understanding: a traditional textbook illustration approach versus a newly designed air molecule motion illustration approach. Thirty volunteer students from introductory physics classes were randomly assigned to two groups of 15 each. Both groups were administered a presurvey. Then, group A read the air molecule motion illustration handout, and group B read a traditional textbook illustration handout; both groups were administered postsurveys. Subsequently, the procedure was reversed: group B read the air molecule motion illustration handout and group A read the traditional textbook illustration handout. This was followed by a second postsurvey along with an exit research questionnaire. The study found that the majority of students experienced meaningful learning and stated that they understood sound standing wave phenomena significantly better using the air molecule motion illustration approach. This finding provides a method for physics education researchers to design illustrations for abstract sound standing wave concepts, for publishers to improve their illustrations with supporting text, and for instructors to facilitate deeper learning in their students on sound standing waves.
STUDIES ON THE BIOLOGY OF STREPTOCOCCUS
Stevens, Franklin A.; Dochez, A. R.
1926-01-01
1. Strains of hemolytic streptococci isolated from cases of erysipelas agglutinate in a high percentage of instances with erysipelas immune sera. When agglutination occurs with one serum, the strain usually agglutinates with all other erysipelas sera. 2. Erysipelas immune sera agglutinate strains from erysipelas in a higher percentage of instances than they agglutinate scarlatinal strains. 3. Strains from miscellaneous pyogenic infections may agglutinate in these sera, but the percentage of positive reactions is low and a strain usually agglutinates in but one or two of several sera. 4. Erysipelas strains which agglutinate in immune sera are not necessarily identical, although identical strains may occur. Similarly, identical strains may occur among scarlatinal strains agglutinated by scarlatinal immune sera. 5. Erysipelas strains form a closely related group of hemolytic streptococci. Scarlatinal strains form an equally compact group. The two groups are related antigenically but less closely related than the strains within the groups. These groups are related to pyogenic strains, but less closely than they are related to each other. 6. Erysipelas, scarlatinal, or pyogenic strains which agglutinate in erysipelas or scarlatinal sera are capable of absorbing the agglutinin for all other strains except the homologous strain and strains identical with it. Strains identical with the homologous strain absorb the agglutinin completely. 7. Erysipelas or scarlatinal strains may absorb the common group agglutinin from their respective sera, when they are incapable of agglutination in these sera. 8. The agglutinogen is probably of complex or composite nature, with characteristic variations in the scarlet fever and erysipelas groups. PMID:19869130
76 FR 55400 - Center for Scientific Review; Notice of Closed Meetings
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2011-09-07
...: Integrative, Functional and Cognitive Neuroscience Integrated Review Group; Auditory System Study Section... Neuroscience Integrated Review Group; Neurotoxicology and Alcohol Study Section. Date: October 13, 2011. Time... Disorders and Clinical Neuroscience Integrated Review Group; Developmental Brain Disorders Study Section...
77 FR 57571 - Center For Scientific Review; Notice of Closed Meetings
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2012-09-18
...: Genes, Genomes, and Genetics Integrated Review Group; Genomics, Computational Biology and Technology... Reproductive Sciences Integrated Review Group; Cellular, Molecular and Integrative Reproduction Study Section...: Immunology Integrated Review Group; Cellular and Molecular Immunology--B Study Section. [[Page 57572
76 FR 370 - Center for Scientific Review; Notice of Closed Meetings
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2011-01-04
... . Name of Committee: Genes, Genomes, and Genetics Integrated Review Group; Molecular Genetics B Study... Committee: Cardiovascular and Respiratory Sciences Integrated Review Group; Lung Cellular, Molecular, and... Committee: Population Sciences and Epidemiology Integrated Review Group; Behavioral Genetics and...
78 FR 26378 - Center for Scientific Review; Notice of Closed Meetings
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2013-05-06
..., Genomes, and Genetics Integrated Review Group; Prokaryotic Cell and Molecular Biology Study Section. Date..., Kidney and Urological Systems Integrated Review Group; Clinical, Integrative and Molecular... Respiratory Sciences Integrated Review Group; Lung Cellular, Molecular, and Immunobiology Study Section. Date...
Plattner, H; Sehring, I M; Mohamed, I K; Miranda, K; De Souza, W; Billington, R; Genazzani, A; Ladenburger, E-M
2012-05-01
The importance of Ca2+-signaling for many subcellular processes is well established in higher eukaryotes, whereas information about protozoa is restricted. Recent genome analyses have stimulated such work also with Alveolates, such as ciliates (Paramecium, Tetrahymena) and their pathogenic close relatives, the Apicomplexa (Plasmodium, Toxoplasma). Here we compare Ca2+ signaling in the two closely related groups. Acidic Ca2+ stores have been characterized in detail in Apicomplexa, but hardly in ciliates. Two-pore channels engaged in Ca2+-release from acidic stores in higher eukaryotes have not been stingently characterized in either group. Both groups are endowed with plasma membrane- and endoplasmic reticulum-type Ca2+-ATPases (PMCA, SERCA), respectively. Only recently was it possible to identify in Paramecium a number of homologs of ryanodine and inositol 1,3,4-trisphosphate receptors (RyR, IP3R) and to localize them to widely different organelles participating in vesicle trafficking. For Apicomplexa, physiological experiments suggest the presence of related channels although their identity remains elusive. In Paramecium, IP3Rs are constitutively active in the contractile vacuole complex; RyR-related channels in alveolar sacs are activated during exocytosis stimulation, whereas in the parasites the homologous structure (inner membrane complex) may no longer function as a Ca2+ store. Scrutinized comparison of the two closely related protozoan phyla may stimulate further work and elucidate adaptation to parasitic life. See also "Conclusions" section. Copyright © 2012 Elsevier Ltd. All rights reserved.
77 FR 54921 - Center for Scientific Review; Notice of Closed Meetings
Federal Register 2010, 2011, 2012, 2013, 2014
2012-09-06
... personal privacy. Name of Committee: Oncology 2--Translational Clinical Integrated Review Group; Radiation... Committee: Oncology 2--Translational Clinical Integrated Review Group; Basic Mechanisms of Cancer...
Howard, D M
1995-06-01
The derivation of larynx closed quotient (CQ) measures from the electrolarynogograph output is discussed and data are presented for a group of trained and untrained adult female singers (N = 26) for a sung two-octave G major scale. Statistically significant trends are observed between the trained and untrained groups that suggest for the trained group: (a) CQ tends to be lower for pitches below D4 and higher for pitches above B4, and (b) the gradient [CQ/log(F0)] tends to correlate positively with the number of years singing training/experience. These data are compared with those reported previously for an adult male group, and it is suggested that CQ could be a useful parameter to include in a real-time visual display for singing training.
Designing efficient photochromic dithienylethene dyads.
Fihey, Arnaud; Jacquemin, Denis
2015-06-01
Aiming at designing more efficient multiphotochromes, we investigate with the help of ab initio tools the impact of the substitution on a series of dimers constituted of two dithienylethene (DTE) moieties, strongly coupled to each other through an ethynyl linker. The electronic structure and the optical properties of a large panel of compounds, substituted on different positions by various types of electroactive groups, have been compared with the aim of designing a dyad in which the three possible isomers (open-open, closed-open, closed-closed) can be reached. We show that appending the reactive carbons atoms of the DTE core with electroactive groups on one of the two photochromes allows cyclisation to be induced on a specific moiety, which leads to the formation of the desired closed-open isomer. Substituting the lateral positions of the thiophene rings provides further control of the topology of the frontier molecular orbitals, so that the electronic transition inducing the second ring closure stands out in the spectrum of the intermediate isomer.
Ano-rectal physiological changes after rubber band ligation and closed haemorrhoidectomy.
Bursics, A; Weltner, J; Flautner, L E; Morvay, K
2004-01-01
The effect of treatment for haemorrhoids on ano-rectal physiology was studied in a prospective longitudinal follow-up study. Thirty-six consecutive patients having II-III degree (Group I, 18 patients) or IV degree (Group II, 18 patients) haemorrhoids were studied. Group I underwent rubber band ligation while Group II underwent closed scissors haemorrhoidectomy. Patients in Group I had significantly lower maximum basal pressure (P < 0.05) and also significantly lower maximum squeeze pressure (P < 0.05) compared to Group II before treatment. Both basal and squeeze pressures dropped after haemorrhoidectomy (P < 0.001) whereas they remained unchanged after rubber band ligation (P > 0.1). The volume of first sensation was higher in Group II before treatment (P < 0.001) and remained so after treatment. Rectal compliance was higher (P < 0.005) in Group I before treatment. It increased significantly in both groups (P < 0.05, Group I; P < 0.001, Group II) after treatment. The results show a significant increase in anal pressures in constantly prolapsing (IV degree) haemorrhoids. Most of the physiological differences observed between the two groups were abolished after treatment. This suggests that these may be a consequence rather than a cause of haemorrhoids.
Meerlo-Habing, Z E; Kosters-Boes, E A; Klip, H; Brand, P L P
2009-07-01
Mothers of preterm infants are more likely to discontinue breast feeding early than mothers of term infants. We evaluated the effect of early discharge with tube feeding of preterm infants under close supervision by paediatric nurse specialists on the duration of breast feeding. Case-control study. Medium/high-care neonatal unit of a large district general hospital. Preterm infants (<37 weeks' gestational age). Early discharge with tube feeding under close supervision by paediatric nurse specialists or regular follow-up of preterm infants discharged with oral feeding. Duration of breast feeding assessed by telephone interview 6 months after birth. There were 50 preterm infants in the early discharge group and 78 in the control group. Mothers in the early discharge group continued to breast feed longer than mothers in the control group (log rank test, p = 0.028). Four months after discharge, 63% of preterm infants in the control group were fed formula compared to 36% in the early discharge group (95% CI for difference 9% to 43%, p = 0.04). The relative risk of breast feeding cessation 6 months after birth in the early discharge group compared to the control group was 0.63 (95% CI 0.41 to 0.96). After adjustment for smoking, gestational age and birth weight, this relative risk was 0.67 (95% CI 0.43 to 1.05). Close supervision and follow-up by paediatric nurse specialists of preterm infants discharged early with tube feeding appears to increase duration of breast feeding. A randomised controlled trial to confirm these findings is warranted.
Muscle Activity Patterns Do Not Differ Between Push-Up and Bench Press Exercises.
Gottschall, Jinger S; Hastings, Bryce; Becker, Zachary
2018-05-29
Popular topics for upper body resistance training involve the differences between hand positions, open versus closed chain exercises, and movement variations for the novice to the advanced. We hypothesized that there will be no difference between closed (push-up) versus open (bench press) chain exercises for the primary muscle group activity nor would there be a difference between push-ups on the toes versus knees with respect to the percent contribution of each muscle. We measured surface muscle activity of 8 upper body and core muscles during a sequence of push-up and bench press variations with a normalized weight for twelve active men. Each participant completed push-ups and bench press exercises at each of three hand positions. Our results demonstrated that there were few differences between closed versus open chain exercises for the primary muscle groups with the exception of core activation. To add, in general, narrow hand positions yielded greater activation and there were no significant differences between push-ups on the toes versus knees with respect to the percent contribution for the primary muscle groups. To sum, closed chain exercises may be preferred for functional training and knee push-ups may be ideal as a novice push-up variation.
77 FR 28610 - Center For Scientific Review; Notice of Closed Meetings
Federal Register 2010, 2011, 2012, 2013, 2014
2012-05-15
... personal privacy. Name of Committee: Oncology 2--Translational Clinical Integrated Review Group; [email protected] . Name of Committee: Oncology 2--Translational Clinical Integrated Review Group; Chemo...
75 FR 1795 - Center for Scientific Review; Notice of Closed Meetings
Federal Register 2010, 2011, 2012, 2013, 2014
2010-01-13
... funding cycle. Name of Committee: Oncology 1--Basic Translational Integrated Review Group, Tumor... Committee: Oncology 2--Translational Clinical Integrated Review Group, Clinical Oncology Study Section. Date...
78 FR 737 - Center for Scientific Review; Notice of Closed Meetings
Federal Register 2010, 2011, 2012, 2013, 2014
2013-01-04
... Disorders and Clinical Neuroscience Integrated Review Group; Aging Systems and Geriatrics Study Section... Skin Sciences Integrated Review Group; Skeletal Muscle and Exercise Physiology Study Section. Date...
78 FR 5190 - Center for Scientific Review; Notice of Closed Meetings
Federal Register 2010, 2011, 2012, 2013, 2014
2013-01-24
....nih.gov . Name of Committee: Immunology Integrated Review Group; Vaccines against Microbial Diseases..., Genomes, and Genetics Integrated Review Group; Genetic Variation and Evolution Study Section. Date...
78 FR 54259 - Center for Scientific Review; Notice of Closed Meetings
Federal Register 2010, 2011, 2012, 2013, 2014
2013-09-03
... . Name of Committee: Genes, Genomes, and Genetics Integrated Review Group; Molecular Genetics B Study... . Name of Committee: Emerging Technologies and Training Neurosciences Integrated Review Group; Molecular...
77 FR 511 - Center for Scientific Review; Notice of Closed Meetings
Federal Register 2010, 2011, 2012, 2013, 2014
2012-01-05
... . Name of Committee: Genes, Genomes, and Genetics Integrated Review Group, Molecular Genetics B Study...: Digestive, Kidney and Urological Systems Integrated Review Group, Clinical, Integrative and Molecular...
Baughn, Anthony D; Malamy, Michael H
2002-04-02
Aconitase and isocitrate dehydrogenase (IDH) enzyme activities were detected in anaerobically prepared cell extracts of the obligate anaerobe Bacteroides fragilis. The aconitase gene was located upstream of the genes encoding the other two components of the oxidative branch of the Krebs cycle, IDH and citrate synthase. Mutational analysis indicates that these genes are cotranscribed. A nonpolar in-frame deletion of the acnA gene that encodes the aconitase prevented growth in glucose minimal medium unless heme or succinate was added to the medium. These results imply that B. fragilis has two pathways for alpha-ketoglutarate biosynthesis-one from isocitrate and the other from succinate. Homology searches indicated that the B. fragilis aconitase is most closely related to aconitases of two other Cytophaga-Flavobacterium-Bacteroides (CFB) group bacteria, Cytophaga hutchinsonii and Fibrobacter succinogenes. Phylogenetic analysis indicates that the CFB group aconitases are most closely related to mitochondrial aconitases. In addition, the IDH of C. hutchinsonii was found to be most closely related to the mitochondrial/cytosolic IDH-2 group of eukaryotic organisms. These data suggest a common origin for these Krebs cycle enzymes in mitochondria and CFB group bacteria.
Kim, So Young; Lee, Sanghoon; Seo, Jeong-Meen; Lim, So Young
2015-04-01
Surgical treatment of extensive cervicofacial lymphatic malformations is often challenging due to a high rate of postoperative fluid re-accumulation and lesion recurrence resulting from incomplete resection. This study suggests a combined treatment of surgical resection and postoperative adjuvant OK-432 sclerotherapy via closed suction drainage. Using comparative analysis, this study aims to evaluate the efficacy of adjuvant sclerotherapy. A retrospective chart review was performed on patients who underwent surgical resection of cervicofacial lymphatic malformations between January 2009 and July 2013. Patients were divided into two groups based on whether or not adjuvant OK-432 sclerotherapy was administered via closed suction drainage after surgery. Both surgery-related and adjuvant sclerotherapy-related complications were assessed, and treatment effectiveness was measured based on the change in Cologne Disease Score (CDS) or the need for further treatment. A total of 17 patients underwent surgical resection. Nine of these patients underwent surgical resection only, while the other eight underwent surgical resection with adjuvant OK-432 sclerotherapy. The increase in total Cologne Disease Score (CDS) and change of progression parameters were significantly higher for the adjuvant sclerotherapy group compared to the surgery-only group. Additionally, there were no cases of postoperative lymphatic fluid retention among the adjuvant sclerotherapy group. The two groups exhibited similar complication rates with no statistically significant difference. Adjuvant OK-432 sclerotherapy via closed suction drainage is a safe and effective treatment modality. The combination of surgical resection and post-operative adjuvant sclerotherapy via closed suction drainage should be integrated into the treatment algorithm of extensive cervicofacial lymphatic malformation. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
77 FR 27073 - Center for Scientific Review; Notice of Closed Meetings
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2012-05-08
... . Name of Committee: Oncology 1-Basic Translational Integrated Review Group; Tumor Progression [email protected] . Name of Committee: Oncology 2--Translational Clinical Integrated Review Group; Cancer....nih.gov . Name of Committee: Oncology 2--Translational Clinical Integrated Review Group; Cancer...
76 FR 573 - Center for Scientific Review; Notice of Closed Meetings
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2011-01-05
..., [email protected] . Name of Committee: Biology of Development and Aging Integrated Review Group... Committee: Biology of Development and Aging Integrated Review Group, Development--1 Study Section. Date..., Metabolism, Nutrition and Reproductive Sciences Integrated Review Group, Integrative Physiology of Obesity...
77 FR 2739 - Center for Scientific Review; Notice of Closed Meetings
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2012-01-19
... . Name of Committee: Genes, Genomes, and Genetics Integrated Review Group; Molecular Genetics A Study... Urological Systems Integrated Review Group; Kidney Molecular Biology and Genitourinary Organ Development... Sciences Integrated Review Group; Molecular and Cellular Endocrinology Study Section. Date: February 13...
78 FR 55752 - Center For Scientific Review; Notice of Closed Meetings
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2013-09-11
... Epidemiology Integrated Review Group, Behavioral Genetics and Epidemiology Study Section. Date: October 8, 2013... Committee: Oncology 1-Basic Translational Integrated Review Group, Cancer Genetics Study Section. Date... Biology Integrated Review Group, Molecular and Integrative Signal Transduction Study Section. Date...
75 FR 76994 - Center for Scientific Review; Notice of Closed Meetings
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2010-12-10
... Committee: Brain Disorders and Clinical Neuroscience Integrated Review Group Developmental Brain Disorders....gov . Name of Committee: Brain Disorders and Clinical Neuroscience Integrated Review Group, Cell [email protected] . Name of Committee: Brain Disorders and Clinical Neuroscience Integrated Review Group...
ALMA Detections of CO Emission in the Most Luminous, Heavily Dust-obscured Quasars at z > 3
NASA Astrophysics Data System (ADS)
Fan, Lulu; Knudsen, Kirsten K.; Fogasy, Judit; Drouart, Guillaume
2018-03-01
We report the results of a pilot study of CO(4 ‑ 3) emission line of three Wide-field Infrared Survey Explorer (WISE)-selected hyper-luminous, dust-obscured quasars (QSOs) with sensitive ALMA Band 3 observations. These obscured QSOs with L bol > 1014 L ⊙ are among the most luminous objects in the universe. All three QSO hosts are clearly detected both in continuum and in CO(4 ‑ 3) emission line. Based on CO(4 ‑ 3) emission line detection, we derive the molecular gas masses (∼1010‑11 M ⊙), suggesting that these QSOs are gas-rich systems. We find that the obscured QSOs in our sample follow the similar {L}CO}{\\prime }{--}{L}FIR} relation as unobscured QSOs at high redshifts. We also find the complex velocity structures of CO(4 ‑ 3) emission line, which provide the possible evidence for a gas-rich merger in W0149+2350 and possible molecular outflow in W0220+0137 and W0410‑0913. Massive molecular outflow can blow away the obscured interstellar medium and make obscured QSOs evolve toward the UV/optical bright, unobscured phase. Our result is consistent with the popular active galactic nucleus (AGN) feedback scenario involving the co-evolution between the supermassive black holes and host galaxy.
Explore Full Range of QSO/AGN Properties
NASA Technical Reports Server (NTRS)
Oliversen, Ronald (Technical Monitor); Wilkes, Belinda
2005-01-01
The goal of the proposal is to perform ISO spectroscopic studies, including data analysis and modeling, of star formation regions using an ensemble of archival space-based data from the Infrared Space Observatory s Long Wavelength Spectrometer and Short Wavelength Spectrometer, but including as well some other spectroscopic databases. Four kinds of regions are considered in the studies: (1) disks around more evolved objects; (2) young, low or high mass pre-main sequence stars in star formation regions; (3) star formation in external, bright IR galaxies; and (4) the galactic center. One prime focus of the program is the OH lines in the far infrared. The program had the following goals: 1) Refine the data analysis of IS0 observations to obtain deeper and better SNR results on selected sources. The IS0 data itself underwent "pipeline 10" reductions in early 2001, and additional "hands-on data reduction packages" were supplied by the IS0 teams in 2001. The Fabry-Perot database is particularly sensitive to noise and slight calibration errors. 2) Model the atomic and molecular line shapes, in particular the OH lines, using revised monte- carlo techniques developed by the SWAS team at the Center for Astrophysics; 3) Attend scientific meetings and workshops; 4) Do E&PO activities related to infrared astrophysics and/or spectroscopy.
Predicting the Quasar Photometric Reshift with the Sloan Digital Sky Survey Filter System
NASA Astrophysics Data System (ADS)
Laubacher, Emily M.; York, Donald G.
1999-10-01
Photometric data were obtained for a set of known quasars (QSOs) in five bands with the Sloan Digital Sky Survey (SDSS) filter system for the purpose of testing the ability of the SDSS system to accurately predict the photometric redshift of QSOs. The initial plot of the SDSS photometric redshift versus the measured redshift shows a good relationship, but a lot of scatter. A literature search was conducted on a selected sampling of 49 QSOs, 26 with redshift z <= 0.5 and 23 with 0.5 < z < 2.6, to confirm their accurate identifications as QSOs with their advertised redshifts. This search revealed 10 rejected QSOs which were not QSOs but rather Seyfert galaxies or Narrow Line Objects. Additionally, 11 QSOs were either Broad Absorption Line Systems or had spectra that were in some way incomplete, and therefore, their QSO identification could not be confirmed. The revised plot, with the rejected and unconfirmed QSOs removed, gives an excellent straight line with very little scatter. Although these results are preliminary and for only a small sampling of QSOs, they show that further study of the relationship is warranted and that eventually the SDSS method may be used to accurately predict the photometric redshift of QSOs.
Ahnen, M. L.; Ansoldi, S.; Antonelli, L. A.; ...
2015-12-15
The flat-spectrum radio quasar PKS 1441+25 at a redshift of z = 0.940 is detected between 40 and 250 GeV with a significance of 25.5σ using the MAGIC telescopes. Together with the gravitationally lensed blazar QSO B0218+357 (z = 0.944), PKS 1441+25 is the most distant very high energy (VHE) blazar detected to date. The observations were triggered by an outburst in 2015 April seen at GeV energies with the Large Area Telescope on board Fermi. Multi-wavelength observations suggest a subdivision of the high state into two distinct flux states. In the band covered by MAGIC, the variability timescale ismore » estimated to be 6.4 ± 1.9 days. Modeling the broadband spectral energy distribution with an external Compton model, the location of the emitting region is understood as originating in the jet outside the broad-line region (BLR) during the period of high activity, while being partially within the BLR during the period of low (typical) activity. In conclusion, the observed VHE spectrum during the highest activity is used to probe the extragalactic background light at an unprecedented distance scale for ground-based gamma-ray astronomy.« less
A "WISE BOSS": Finding The Cosmic Monsters in the Mid-Infrared Lochs
NASA Astrophysics Data System (ADS)
Ross, Nicholas; Hamann, F. W.; Alexandroff, R.; Brandt, W. N.; Strauss, M. A.; Dey, A.; Richards, G. T.; Worseck, G.; Zakamska, N. L.; Eisenstein, D.; Ge, J.; Glikman, E.; Greene, J. E.; Haggard, D.; Krolik, J. H.; Myers, A. D.; Petitjean, P.; Streblyanska, A.; Schawinski, K.; Shen, Y.; Villforth, C.; McMahon, R.
2013-01-01
Mid-infrared photometry of QSOs provide an important constraint on the presence of hot dust in the vicinity of the active nucleus. However, assembling large statistical MIR samples of quasars at the height of the ``quasar epoch'' ( 2.5) has, up until now, been challenging due to either wide but relatively shallow optical quasar surveys, or deep but narrow mid-IR data. The SDSS-III Baryon Oscillation Spectroscopic Survey (BOSS) is the state-of-the-art in optical wide-field spectroscopy, and has over 150,000 quasars confirmed, with the majority of the quasar data at z=2.2-3.5. We combine these data with the all-sky mid-infrared coverage from the Wide-Field Infrared Survey Explorer (WISE), and initially concentrate on BOSS quasars with ``extreme'' colors, e.g. r-[22]>14, and those detected only in the redder WISE bands, a.k.a. "the W1W2drops". We find that these selections identify a heterogeneous sample within the BOSS quasar data, but also provide a key tool for finding interesting populations including the 2.5 Type II QSO population. We relate these very red BOSS quasars to the recent discoveries of the ``hyper-LIRG" and ``Hot Dust Obscured Galaxy'' (or Hot DOG) population.
Identifying Luminous AGN in Deep Surveys: Revised IRAC Selection Criteria
NASA Astrophysics Data System (ADS)
Donley, Jennifer; Koekemoer, A. M.; Brusa, M.; Capak, P.; Cardamone, C. N.; Civano, F.; Ilbert, O.; Impey, C. D.; Kartaltepe, J.; Miyaji, T.; Salvato, M.; Sanders, D. B.; Trump, J. R.; Zamorani, G.
2012-01-01
Spitzer IRAC selection is a powerful tool for identifying luminous AGN. The AGN selection wedges currently in use, however, are heavily contaminated by star-forming galaxies, especially at high redshift. Using the large samples of luminous AGN and high-redshift star-forming galaxies in COSMOS, we redefine the AGN selection criteria for use in deep IRAC surveys. The new IRAC criteria are designed to be both highly complete and reliable, and incorporate the best aspects of the current AGN selection wedges and of infrared power-law selection while excluding high redshift star-forming galaxies selected via the BzK, DRG, LBG, and SMG criteria. At QSO-luminosities of log L(2-10 keV)>44, the new IRAC criteria recover 75% of the hard X-ray and IRAC-detected XMM-COSMOS sample, yet only 37% of the IRAC AGN candidates have X-ray counterparts, a fraction that rises to 51% in regions with Chandra exposures of 50-160 ks. X-ray stacking of the individually X-ray non-detected AGN candidates leads to a hard X-ray signal indicative of heavily obscured to mildly Compton-thick obscuration (log NH >= 23.7). While IRAC selection recovers a substantial fraction of luminous unobscured and obscured AGN, it is incomplete to low-luminosity and host-dominated AGN.
VizieR Online Data Catalog: Quasars narrow absorption lines from SDSS (Chen+, 2015)
NASA Astrophysics Data System (ADS)
Chen, Z.-F.; Gu, Q.-S.; Chen, Y.-M.; Cao, Y.
2017-11-01
The Baryon Oscillation Spectroscopic Survey (BOSS: Eisenstein et al. 2011AJ....142...72E; Paris et al. 2012, Cat. VII/269) is the main dark-time legacy survey of the third stage of the SDSS, which used the same 2.5-m telescope (Gunn et al. 2006AJ....131.2332G; Ross et al. 2012, J/ApJS/199/3) as the first and second stages of the SDSS (hereafter SDSS-I/II). SDSS-I/II spectra have a wavelength coverage from 3800-9200Å with a spectral resolution of 1800-2200 (e.g. York et al. 2000AJ....120.1579Y). BOSS spectra span a range from 3600-10500Å at a resolution of 1300-2500 (Paris et al. 2012, Cat. VII/269). During the first two years, BOSS detected 87822 quasars over an area of 3275 deg2, including 7932 quasars that were observed by SDSS-I/II as well. Quasars observed by both SDSS-I/II and BOSS provide a remarkable chance to study the variabilities of absorption lines in a large population. Throughout this work, we take the quasar emission redshifts provided by Hewett & Wild (2010, J/MNRAS/405/2302, http://das.sdss.org/va/HewettWilddr7qso_newz/) directly. (2 data files).
Properties of Spectrally Defined Red QSOs at z = 0.3–1.2
DOE Office of Scientific and Technical Information (OSTI.GOV)
Tsai, A.-L.; Hwang, C.-Y., E-mail: altsai@astro.ncu.edu.tw, E-mail: hwangcy@astro.ncu.edu.tw
We investigated the properties of a sample of red Quasi-stellar Objects (QSOs) using optical, radio, and infrared data. These QSOs were selected from the Sloan Digital Sky Survey Data Release 7 quasar catalog. We only selected sources with sky coverage in the Very Large Array Faint Images of the Radio Sky at Twenty-centimeters survey, and searched for sources with Wide-field Infrared Survey Explorer counterparts. We defined the spectral color of the QSOs based on the flux ratio of the rest-frame 4000 to 3000 Å continuum emission to select red QSOs and typical QSOs. In accordance with this criterion, only QSOsmore » with redshifts between 0.3 and 1.2 could be selected. We found that red QSOs have stronger infrared emission than typical QSOs. We noted that the number ratios of red QSOs to typical QSOs decrease with increasing redshifts, although the number of typical QSOs increase with redshifts. Furthermore, at high redshifts, the luminosity distributions of typical QSOs and red QSOs seem to have similar peaks; however, at low redshifts, the luminosities of red QSOs seem to be lower than those of typical QSOs. These findings suggest that there might be at least two types of red QSOs in our QSO samples.« less
NASA Astrophysics Data System (ADS)
Braibant, L.; Hutsemékers, D.; Sluse, D.; Anguita, T.
2016-07-01
We investigate the kinematics and ionization structure of the broad emission line region of the gravitationally lensed quasar QSO2237+0305 (the Einstein cross) using differential microlensing in the high- and low-ionization broad emission lines. We combine visible and near-infrared spectra of the four images of the lensed quasar and detect a large-amplitude microlensing effect distorting the high-ionization CIV and low-ionization Hα line profiles in image A. While microlensing only magnifies the red wing of the Balmer line, it symmetrically magnifies the wings of the CIV emission line. Given that the same microlensing pattern magnifies both the high- and low-ionization broad emission line regions, these dissimilar distortions of the line profiles suggest that the high- and low-ionization regions are governed by different kinematics. Since this quasar is likely viewed at intermediate inclination, we argue that the differential magnification of the blue and red wings of Hα favors a flattened, virialized, low-ionization region whereas the symmetric microlensing effect measured in CIV can be reproduced by an emission line formed in a polar wind, without the need of fine-tuned caustic configurations. Based on observations made with the ESO-VLT, Paranal, Chile; Proposals 076.B-0197 and 076.B-0607 (PI: Courbin).
Revisiting the incidence of Mg II absorbers along the blazar sightlines
NASA Astrophysics Data System (ADS)
Mishra, Sapna; Chand, Hum; Gopal-Krishna; Joshi, Ravi
2018-04-01
It is believed that the cool gas clouds traced by Mg II absorption, within a velocity offset of 5000 km/s from the background quasar, are associated with the quasar itself, whereas the absorbers seen at larger velocity offsets towards us are intervening systems and hence their existence is completely independent of the background quasar. Recent evidence by Bergeron et al. 2011 (hereafter BBM), however, seriously questions this canonical view, by showing that the number density of intervening Mg II absorbers along the sightlines towards 45 blazars is, on average, 2 times the expectation based on the Mg II absorption systems seen on the sightlines to normal QSOs. Given the serious implications of this finding, it becomes important to revisit this issue by enlarging the source sample and subjecting it to an independent analysis. Here, we first report our results based on a re-analysis of the spectroscopic data for the BBM sample; this has reproduced their factor 2 excess in dN/dz along blazar sightlines, vis-a-vis the normal QSOs. Next, we assemble a 6 times larger sample of blazar sightlines, albeit with lower SNR. Using this enlarged sample together with the BBM sample, our analysis shows that the dN/dz of Mg II absorbers statistically matches that known for normal QSO sightlines.
Mapping Gas Flows from the Disk to the Circumgalactic Medium
NASA Astrophysics Data System (ADS)
Zheng, Yong
2017-08-01
The feedback efficiency in galaxies remains a crucial component in simulations that is not well constrained by observations. To understand how effectively feedback drives metals into the circumgalactic medium (CGM), we propose to map the metal flows from the disk to the CGM of the nearby dwarf irregular galaxy IC 1613. This will be the first spatial and kinematic map of gas flows from the disk to the halo of a dwarf galaxy. In archival COS spectra of two IC 1613 stars we detect blue-shifted SiII, CII, and SiIV absorption lines, indicative of the existence of multiphase outflows from the disk. We propose to observe two more UV bright stars in IC 1613's disk to assess the covering fraction and strength of the outflow in relation to the galaxy's resolved star formation. We will also observe three QSO sightlines at 0.1, 0.3, and 0.5 Rvir to measure the ionization profile of the gas and the extent of the outflows. We will relate our measurements to the detailed observed star formation history of IC 1613 to directly determine the mass loading factor and feedback efficiency. The proposal will provide critical information on how galaxies evolve and how metals circulate between the disk and the CGM.
Code of Federal Regulations, 2014 CFR
2014-07-01
... such goods, or in any closely related process or occupation directly essential to the production... of such goods, 55 and include those whose work is closely related and directly essential thereto, 56... exclusively, this includes that large group of employees engaged in mines, oil fields, quarries, and...
Code of Federal Regulations, 2012 CFR
2012-07-01
... such goods, or in any closely related process or occupation directly essential to the production... of such goods, 55 and include those whose work is closely related and directly essential thereto, 56... exclusively, this includes that large group of employees engaged in mines, oil fields, quarries, and...
Code of Federal Regulations, 2013 CFR
2013-07-01
... such goods, or in any closely related process or occupation directly essential to the production... of such goods, 55 and include those whose work is closely related and directly essential thereto, 56... exclusively, this includes that large group of employees engaged in mines, oil fields, quarries, and...
75 FR 42450 - National Institute on Alcohol Abuse and Alcoholism; Notice of Closed Meeting
Federal Register 2010, 2011, 2012, 2013, 2014
2010-07-21
... Alcohol Abuse and Alcoholism; Notice of Closed Meeting Pursuant to section 10(d) of the Federal Advisory... and Alcoholism Initial Review Group; Epidemiology, Prevention and Behavior Research Review... Alcohol Abuse and Alcoholism, Office of Extramural Activities, Extramural Project Review Branch, 5635...
Randomized controlled trial of bipolar diathermy vs ultrasonic scalpel for closed hemorrhoidectomy
Tsunoda, Akira; Sada, Haruki; Sugimoto, Takuya; Kano, Nobuyasu; Kawana, Mariko; Sasaki, Tadanori; Hashimoto, Hideki
2011-01-01
AIM: To compare hemorrhoidectomy with a bipolar electrothermal device or hemorrhoidectomy using an ultrasonically activated scalpel. METHODS: Sixty patients with grade III or IV hemorrhoids were prospectively randomized to undergo closed hemorrhoidectomy assisted by bipolar diathermy (group 1) or hemorrhoidectomy with the ultrasonic scalpel (group 2). Operative data were recorded, and patients were followed at 1, 3, and 6 wk to evaluate complications. Independent assessors were assigned to obtain postoperative pain scores, oral analgesic requirement and satisfaction scores. RESULTS: Reduced intraoperative blood loss median 0.9 mL (95% CI: 0.8-3.7) vs 4.6 mL (95% CI: 3.8-7.0), P = 0.001 and a short operating time median 16 (95% CI: 14.6-18.2) min vs 31 (95% CI: 28.1-35.3) min, P < 0.0001 was observed in group 1 compared with group 2. There was a trend towards lower postoperative pain scores on day 1 group 1 median 2 (95% CI: 1.8-3.5) vs group 2 median 3 (95% CI: 2.6-4.2), P = 0.135. Reduced oral analgesic requirement during postoperative 24 h after operation median 1 (95% CI: 0.4-0.9) tablet vs 1 (95% CI: 0.9-1.3) tablet, P = 0.006 was observed in group 1 compared with group 2. There was no difference between the two groups in the degree of patient satisfaction or number of postoperative complications. CONCLUSION: Bipolar diathermy hemorrhoidectomy is quick and bloodless and, although as painful as closed hemorrhoidectomy with the ultrasonic scalpel, is associated with a reduced analgesic requirement immediately after operation. PMID:22110846
Ayatollahi, Vida; Vafaiyan, Maryam; Hatami, Maryam; Behdad, Shekoufeh
2016-06-01
Ketofol is a mixture of propofol and ketamine in various concentrations. It is accepted as a suitable combination in procedural sedation and analgesia. The mixture of propofol and ketamine with different respiratory and hemodynamic effects may result in fewer dose-related side effects and a probable synergistic effect. This study was designed to compare the adverse effects and quality of analgesia of 2 different intravenous concentrations of ketofol in patients undergoing closed reduction of the nose. This randomized double-blinded study was conducted on 100 patients who underwent closed reduction of nose. The patients were divided into 2 groups of 50, and received either a combination of propofol/ketamine (1:1) (Group I) or propofol/ketamine (3:1) (Group II). Hemodynamic changes, including systolic blood pressure, diastolic blood pressure, heart rate and O2sat, and side effects such as hallucination, vomiting, coughing and apnea, were recorded. Data analysis showed that the demographic characteristics (age, height, and weight) were similar in 2 groups, and there were no significant differences between the 2 groups. There was no significant hemodynamic change between both groups. However, there was a decrease in hallucination and vomiting in the group that received higher concentration of ketofol (ketamine/propofol of 1:3). There was no significant hemodynamic change between both groups that received concentrations of 1:1 and 3:1 propofol /ketamine. However, there was a reduction in hallucination, vomiting, and recovery duration in the group that received higher concentration of propofol. In conclusion, increasing the concentration of propofol can be useful with fewer side effects and lower duration of recovery.
76 FR 49779 - Center for Scientific Review; Notice of Closed Meetings
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2011-08-11
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75 FR 54159 - Center for Scientific Review; Notice of Closed Meetings
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2010-09-03
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75 FR 55591 - Center for Scientific Review; Notice of Closed Meetings
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2010-09-13
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76 FR 54240 - Center for Scientific Review; Notice of Closed Meetings
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2011-08-31
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Matching with Multiple Control Groups with Adjustment for Group Differences
ERIC Educational Resources Information Center
Stuart, Elizabeth A.; Rubin, Donald B.
2008-01-01
When estimating causal effects from observational data, it is desirable to approximate a randomized experiment as closely as possible. This goal can often be achieved by choosing a subsample from the original control group that matches the treatment group on the distribution of the observed covariates. However, sometimes the original control group…
2004-03-01
Historical Volatility Task Group Objectives Process Observations Recommendations...Next Steps WTI Nymex Mth1 Close Historical Volatility Chart 0% 20% 40% 60% 80% 100% 120% 140% 160% 180% 1/ 29 /8 8 1/ 29 /8 9 1/ 29 /9 0 1/ 29 /9 1 1...29 /9 2 1/ 29 /9 3 1/ 29 /9 4 1/ 29 /9 5 1/ 29 /9 6 1/ 29 /9 7 1/ 29 /9 8 1/ 29 /9 9 1/ 29 /0 0 1/ 29 /0 1 1/ 29 /0 2 WTI Nymex Mth1 Close
75 FR 54638 - Center for Scientific Review; Notice of Closed Meetings
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2010-09-08
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78 FR 56239 - Center for Scientific Review; Notice of Closed Meetings
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2013-09-12
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75 FR 25273 - Center for Scientific Review; Notice of Closed Meetings
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2010-05-07
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78 FR 738 - Center for Scientific Review; Notice of Closed Meetings
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2013-01-04
... Neuroscience Integrated Review Group Biophysics of Neural Systems Study Section. Date: February 1, 2013. Time...: Population Sciences and Epidemiology Integrated Review Group Kidney, Nutrition, Obesity and Diabetes Study... Review Group, Bioengineering, Technology and Surgical Sciences Study Section. Date: February 7-8, 2013...
Recurrence of primary spontaneous pneumothorax in young adults and children.
Noh, Dongsub; Lee, Sungsoo; Haam, Seok Jin; Paik, Hyo Chae; Lee, Doo Yun
2015-08-01
Although better nutritional support has improved the growth rates in children, the occurrence of primary spontaneous pneumothorax has also been increasing in children. The current study attempts to investigate the occurrence and recurrence of primary spontaneous pneumothorax and the efficacy of surgery for primary spontaneous pneumothorax in young adults and children. A total of 840 patients were treated for pneumothorax at our hospital from January 2006 to December 2010. Exclusion criteria for this study were age >25 or secondary, traumatic or iatrogenic pneumothorax, and a total of 517 patients were included. Patients were classified into three groups according to age at the first episode of primary spontaneous pneumothorax: Group A: ≤16 years; Group B: 17-18 years and Group C: ≥19 years. The study group was composed of 470 male and 47 female patients. There were 234 right-sided, 279 left-sided and 4 bilateral primary spontaneous pneumothoraces. Wedge resection by video-assisted thoracic surgery was performed in 285 patients, while 232 were managed by observation or closed thoracostomy. In the wedge resection group, 51 patients experienced recurrence. The recurrence rates after wedge resection were 27.9% in Group A, 16.5% in Group B and 13.2% in Group C (P = 0.038). The recurrence rates after observation or closed thoracostomy were 45.7% in Group A, 51.9% in Group B and 47.7% in Group C (P = 0.764). In the present study, postoperative recurrence rates were higher than those in the literature. Intense and long-term follow-up was probably one reason for the relatively high recurrence rate. The recurrence rate after wedge resection in patients aged ≤16 years was higher than that in older patients. There was no difference between the recurrence rates after observation or closed thoracostomy, regardless of age. These results suggest that wedge resection might be delayed in children. © The Author 2015. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.
78 FR 66369 - National Institute of General Medical Sciences; Notice of Closed Meetings
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2013-11-05
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75 FR 55805 - National Institute of General Medical Sciences; Notice of Closed Meeting
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2010-09-14
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78 FR 66367 - National Institute of General Medical Sciences; Notice of Closed Meetings
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2013-11-05
... General Medical Sciences; Notice of Closed Meetings Pursuant to section 10(d) of the Federal Advisory... Sciences Initial Review Group; Training and Workforce Development Subcommittee--A. Date: November 21, 2013... Review Officer, Office of Scientific Review, National Institute of General Medical Sciences, National...
49 CFR 172.102 - Special provisions.
Code of Federal Regulations, 2012 CFR
2012-10-01
... design type that has passed a leakproofness test at the Packing Group II level. Small inner packagings... packaging or transport unit is closed. Each packaging must correspond to a design type that has passed a... transport unit is closed. Each packaging must correspond to a design type that has passed a leakproofness...