Jan 22, 2011 ... The column density distribution function at high redshift steepens for the highest column density HI absorbers, though the contribution to ...

Jun 9, 2011 ... The logarithm of the H I column density, in H atoms cm-2, ... the absorbing column and the spectral shape of the emitting plasma. ...

of the shocked gas, and the column density. Nri of foreground absorbing gas. Here, ne is the electron density of the shell, and t is the time since the ...

other high column density iron K-shell absorbers, with similar absorber parameters, have recently been observed in XMM-Newton and Chandru observations of ...

In the last Chandra cycle, we were awarded a joint Chandra/HST proposal to study the warm absorber in NGC 5548 and to obtain a definitive answer about the connection between the warm absorber and the UV absorber in this object. We are confident that the deep Chandra observation {500 ksec} will allow for an unprecedented determination ...

The propagation of electron surface waves can be used to sustain long plasma columns. The relation between the axial distribution of the electron density observed along the plasma column and the corresponding power distribution of the surface wave that produces it is investigated. It is found that the electron ...

The resonant fluorescent scattering equations for a diatomic molecule are developed as a function of temperature, column density, and optical thickness of absorbing rotation lines. The equations are solved numerically for absorption of solar vacuum UV radiation by the carbon monoxide fourth positive band system. Saturation ...

We report the discovery of a threshold in the H I column density of Galactic gas clouds below which the formation of the cold phase of H I is inhibited. This threshold is at N H I = 2 � 1020 cm�2 sight lines with lower H I column densities have high spin temperatures (median Ts ~ 1800 K), indicating low ...

We report sensitive Chandra X-ray non-detections of two unusual, luminous Iron Low-Ionization Broad Absorption Line Quasars (FeLoBALs). The observations do detect a non-BAL, wide-binary companion quasar to one of the FeLoBAL quasars. We combine X-ray-derived column density lower limits (assuming solar metallicity) with column ...

An atmospheric-pressure argon discharge plasma column is generated by making use of a single-electrode configuration with the power supply operating at a frequency of 45 kHz. It is observed that corona, glowlike plume, and filamentary discharges evolve individually with increasing applied voltage. It is in the filamentary state with average electron ...

An atmospheric-pressure argon discharge plasma column is generated by making use of a single-electrode configuration with the power supply operating at a frequency of 45 kHz. It is observed that corona, glowlike plume, and filamentary discharges evolve individually with increasing applied voltage. It is in the filamentary state with average electron ...

We present a wide grid of models for the structure and transmission properties of warm absorbers in active galactic nuclei (AGN). Contrary to commonly used constant density models, our absorbing cloud is assumed to be under constant total (gas plus radiation) pressure. This assumption implies the coexistence of material at different ...

... Title : THE DENSITY-GRADIENT COLUMN AS A TOOL FOR MEASURING SEA WATER DENSITY. Descriptive Note : Interim rept.,. ...

This report describes the analysis of streak spectra from the 1956 Redwing-Navajo chord experiment and the 1952 Ivy-King experiment. Column densities of O/sub 3/, HNO/sub 2/, NO/sub 2/, and vibrationally excited O/sub 2/ are inferred from the spectra and related to computed column densities of gamma ray and neutron ...

The observed intergalactic OVI absorbers have been regarded as a significant reservoir of the ``missing baryons''. This interpretation is subject to the assumption of collisional ionization origin of these absorbers. We present a pilot study of searching for the corresponding intergalactic X-ray absorption lines by referencing the dynamically complex OVI ...

models of the absorbers based on solar abundances severely overpredict the 0 VI columns previously obtained with the Far Ultraviolet Spectrograph, ...

We present a 63 ks FUSE observation of the narrow-line Seyfert 1 galaxy Arakelian 564. The spectrum is dominated by the strong emission in the O VI ??1032, 1038 resonance doublet. Strong, heavily saturated absorption troughs due to Lyman series of hydrogen, O VI, and C III ?977 at velocities near the systemic redshift of Ark 564 are also observed. We used the column ...

Gas-phase multicomponent transfer under conditions of high mass flux is analyzed theoretically by solving the phenomenological equations. The results are compared with experimental results on the simultaneous absorption of ammonia and methylamine in a wetted-wall column. Diffusive interaction between individual species to be absorbed becomes more ...

We present simultaneous X-ray, far-ultraviolet, and near-ultraviolet spectra of the Seyfert 1 galaxy NGC 7469 obtained with the Chandra X-Ray Observatory, the Far Ultraviolet Spectroscopic Explorer, and the Space Telescope Imaging Spectrograph on the Hubble Space Telescope. Previous non-simultaneous observations of this galaxy found two distinct UV absorption components, at -560 and -1900 km/s, ...

We present an investigation into the absorber in front of the z = 2.63 radio galaxy MRC 2025-218, using integral field spectroscopy obtained at the Very Large Telescope, and long-slit spectroscopy obtained at the Keck II telescope. The properties of MRC 2025-218 are particularly conducive to study the nature of the absorbing gas, i.e. this galaxy shows ...

Detecting HI using redshifted Ly? absorption lines is ~106 times more sensitive than using the 21 cm emission line. We review recent discoveries of HI Ly? absorbers made with the Hubble Space Telescope (HST) which have allowed us a first glimpse at gas in local intergalactic space between us and the ``Great Wall.'' Despite its mere 2.4 m aperture, HST can detect ...

Context. In about half of the Seyfert galaxies, the X-ray emission is absorbed by an optically thin, ionized medium, the so-called "warm absorber", whose origin and location is still a matter of debate. Aims: The aim of this paper is to constrain the warm absorber further by studying its variability. Methods: We analyzed the X-ray ...

We present new UV spectra of the nucleus of the Seyfert 1 galaxy NGC 5548, which we obtained with the Space Telescope Imaging Spectrograph at high spectral resolution, in conjunction with simultaneous Chandra X-Ray Observatory spectra. Taking advantage of the low UV continuum and broad emission-line fluxes, we have determined that the deepest UV absorption component covers at least a portion of ...

We present new UV spectra of the nucleus of the Seyfert 1 galaxy NGC 5548, obtained with the Space Telescope Imaging Spectrograph at high spectral resolution (? /? ? = 30,000 - 46,000), simultaneously with Chandra X-ray Observatory spectra. Taking advantage of the low UV continuum and broad emission-line fluxes, we have determined that the deepest UV absorption component covers at least a portion ...

Jun 17, 2009 ... HI Column Density Map. ... HI Column Density Map. The sky maps are generated using the HEALPix sky pixelization scheme. ...

We present a study of the evolution of the column density distribution, f(N, z), and total neutral hydrogen mass in high column density quasar absorbers using candidates from a recent high-redshift survey for damped Lyman ? (DLA) and Lyman-limit system (LLS) absorbers. The ...

We describe recent discoveries of low column density (NHI = 1012.5-16.0 cm-2) H I Ly? absorbers made with the Hubble Space Telescope (HST) which have allowed us a first look at gas in local intergalactic space; i.e., between us and the "Great Wall". These absorbing clouds account for 29 � 4% of all baryons at z=0 ...

The structure of Triton's lower atmosphere is examined using Voyager 2 spectrometer occultation observations. The results reveal two constituents of the troposphere: CH4, and another absorber visible below 20 km altitude between 1400 and 1600 A. Although the density scale height and the wavelength dependence of the second absorber are ...

... Title : NUMERICAL TREATMENT OF THE POSITIVE COLUMN ... positive column of a gas discharge is ... densities a straightforward approach will lead ...

We report on the detection of a population of weak metal-line absorbers in the halo or nearby intergalactic environment of the Milky Way. Using high-resolution ultraviolet absorption-line spectra of bright quasars (QSO) obtained with the Space Telescope Imaging Spectrograph (STIS), along six sight lines we have observed unsaturated, narrow absorption in O I and Si II, together ...

Recently, convincing evidence was found for extremely large X-ray absorption by column densities greater than 10^23 cm^-2 in broad absorption line quasars. One consequence of this is that any soft X-ray emission from these QSOs would be the scattered light or leaked light from partially covering absorbing material. A detection of the ...

Absorption lines in the Ly(alpha) forest can be thought of as peaks in neutral hydrogen density along lines of sight. The column density distribution (the number density of absorption lines as a function of column density) is then a statistic of density ...

We present a systematic study of weak intervening Ca ii absorbers at low redshift (z < 0.5), based on the analysis of archival high-resolution (R ? 45 000) optical spectra of 304 quasars and active galactic nuclei observed with VLT/UVES. Along a total redshift path of ?z ? 100 we detected 23 intervening Ca ii absorbers in both the Ca ii H & K lines, ...

As a stellar X-ray source DG Tau shows two rather unusual features: A resolved X-ray jet [2] and an X-ray spectrum best described by two thermal components with different absorbing column densities, a so called �two-absorber X-ray (TAX)� morphology [1, 2]. In an effort to understand the properties of the ...

The diffuse interstellar bands (DIBs) probably arise from complex organic molecules whose strength in local galaxies correlates with neutral hydrogen column density, N(HI), and dust reddening, E(B - V). Because CaII absorbers in quasar (QSO) spectra are posited to have high N(HI) and significant E(B - V), they represent promising sites ...

A magnetohydromagnetic (MHD) wind from a clumpy molecular accretion disk is invoked to explain observations of warm absorbing gas at UV and X-ray energies in Seyfert 1 galaxies. This paper focuses on two important issues: (1) compatibility of kinematics and dynamics of an MHD wind with the observed properties of warm absorbers, and (2) the relationship ...

Having conducted a search for the ? 1.3 cm (22 GHz) water vapor line towards galaxies with nuclear activity, large nuclear column densities or high infrared luminosities, we present H2O spectra for NGC 2273, UGC 5101, and NGC 3393 with isotropic luminosities of 7, 1500, and 400 L?. The H2O maser in UGC 5101 is by far the most luminous yet found in an ...

Five studies are reported in this final report. The recently discovered 5.3 ms pulsar J1012+5307 at a distance of 520 pc is in an area of the sky which is particularly deficient in absorbing gas. The column density along the line of sight is less than 7.5...

We compare the kinematics and absorption properties of a sample of 30 strong MgII absorbers at z<1 to their host galaxy impact parameters and luminosities. The MgII absorption properties are derived from high resolution quasar spectra from the HIRES/Keck and UVES/VLT public archives. The host galaxy properties come from the larger imaging survey of Rao et al. (2010), which ...

We analyze a 137 ks exposure X-ray spectrum of the Seyfert 1 galaxy NGC 5548 obtained with the XMM-Newton Reflection Grating Spectrometer. Due to the long exposure time, the spectrum is of higher statistical quality than the previous observations of this AGN. Therefore, we detect for the first time in NGC 5548 inner-shell transitions from O Iii to O Vi ions, and the Unresolved Transition Array of ...

We present Very Long Baseline Array (VLBA) H i absorption observations of the core region of the powerful radio galaxy Cygnus A. These data show both broad (FWHM = 231 � 21 km s-1) and narrow (FWHM < 30 km s-1) velocity width absorption components. The broad velocity absorption shows high opacity on the counter-jet, low opacity against the core and no absorption on the jet side. We argue that ...

We propose a 400 ks follow-up HETGS GTO observation of MCG--6-30-15 to supplement the previous 120ks GTO look to probe in detail the warm absorber in this source. The high statistics are necessary to construct the distribution functions of the ionic column densities (using weak high-order lines), systematic and turbulent velocities, ...

We present a Chandra monitoring campaign of the highly variable Seyfert galaxy UGC 4203 (the `Phoenix Galaxy') which revealed variations in the X-ray absorbing column density on time-scales of 2 weeks. This is the third, clear case, after NGC 1365 and NGC 7582, of dramatic NH variability on short time-scales observed in a `changing ...

In this paper, we analyze spectra of the Seyfert 1 galaxy NGC 4593 obtained with the Chandra Low Energy Transmission Grating Spectrometer (LETGS), the Reflection Grating Spectrometer (RGS) and the European Photon Imaging Camera's (EPIC) onboard of XMM-Newton. The two observations were separated by ~ 7 months. In the LETGS spectrum we detect a highly ionized warm absorber ...

We report sensitive Chandra X-ray non-detections of two unusual, luminous Iron Low-Ionization Broad Absorption Line Quasars (FeLoBALs). The observations do detect a non-BAL, wide-binary companion quasar to one of the FeLoBAL quasars. We combine X-ray-derived column density lower limits (assuming solar metallicity) with column ...

Microwave atmospheric pressure discharge in neon sustained by surface waves in a dielectric tube is considered. The plasma column length was measured versus absorbed microwave power for different discharge conditions. This gives a view on the wave propagation characteristics. The predicted dependence of discharge length on the total flux of wave power ...

We calculate the column density distribution of damped Ly? systems, modeled as spherical isothermal gaseous halos ionized by the external cosmic background. The effects of self-shielding introduce a hump in this distribution, at a column density of NHI~1.6�1017X-1 cm-2, where X is the neutral fraction at the ...

I present the results of spectral analysis and modeling of nine Chandra and XMM-Newton X-ray observations of NGC 4151, spanning the period 2000-2007. The complex and highly variable spectrum is characterized by attenuation of the intrinsic power-law continuum by nested absorption components, which contribute both broadband curvature in the 1-5 keV continuum, and individual line absorption. ...

Context. About ten persistently highly absorbed super-giant high-mass X-ray binaries (sgHMXB) have been discovered by INTEGRAL as bright hard X-ray sources lacking bright X-ray counterparts. Besides IGR J16318-4848, which has peculiar characteristics, the other members of this family share many properties with the classical wind-fed sgHMXB systems. Aims: Our goal is to ...

We present computations of the ionization structure and metal-absorption properties of thermally conductive interface layers that surround evaporating warm spherical clouds embedded in a hot medium. We rely on the analytical steady-state formalism of Dalton and Balbus to calculate the temperature profile in the evaporating gas, and we explicitly solve the time-dependent ionization equations for H, ...

We present computations of the ionization structure and metal-absorption properties of thermally conductive interface layers that surround evaporating warm spherical clouds embedded in a hot medium. We rely on the analytical steady-state formalism of Dalton and Balbus to calculate the temperature profile in the evaporating gas, and we explicitly solve the time-dependent ionization equations for H, ...

The interaction of thermal neutrons with a coin shaped detector is discussed in terms of the reaction rate in an infinite sheet of pure absorber irradiated in a void by an isotropic, Maxwell distribution of thermal neutrons. A coincidence method for the evaluation of the decay rate of the neutron induced activity in gold is examined in detail and utilized to measure ...

Results are presented from calculation of the absorption efficiency of the ordinary wave scattered from low-frequency density oscillations under the conditions in which electron-cyclotron resonance (ECR) heating of the plasma is carried out in the L-2 stellerator. The propagation and absorption of the electromagnetic waves in the plasma have been calculated in the ...

The key elements of the Muon Ionization Cooling Experiment (MICE) cooling channel are the absorbers that are a part of the MICE absorber focus coil modules (AFC modules). The boundaries of room temperature solid absorbers are well defined. The density of most solid absorber materials is also ...

The exquisite far-UV sensitivity of the Cosmic Origins Spectrograph has yielded moderate-resolution AGN spectra of unprecedented quality with signal to noise ratios (S/N) of 50 per resolution element in some cases. This high data quality allows us to detect some of the weakest (W 10 m�) absorption features ever found in far-UV spectra including weak photoionized Ly? forest ...

Context: Studying the spectral changes during the dips exhibited by almost edge-on, low-mass X-ray binaries (LMXBs) is a powerful means of probing the structure of accretion disks. The XMM-Newton, Chandra, or Suzaku discovery of absorption lines from Fe xxv and other highly-ionized species in many dippers has revealed a highly-ionized atmosphere above the disk. A highly (but less strongly) ionized ...

Density gradient columns are the most accurate type of equipment for determining unknown densities. Commercial equipment is designed for chemical engineering practice, where the typical sample size hardly exceeds a few grams. The accuracy of measurements crucially depends on the precision of height determination. Here we demonstrate ...

... II. Water Absorption ... weight. Density Densities of the cured epoxy specimens were measured in a density gradient column ...

The high-frequency-peaked BL Lac, MS 0205.7+3509 was observed twice with XMM-Newton. Both X-ray spectra are synchrotron-dominated, with mean 0.2-10 keV fluxes of 2.80�0.01 and 3.34�0.02�10-12 erg cm-2 s-1. The X-ray spectra are well fit by a power-law with absorption above the Galactic value, however no absorption edges are detected, implying a low metallicity absorber ...

The observed intergalactic O VI absorbers at z>0 have been regarded as a significant reservoir of the "missing baryons." However, to fully understand how these absorbers contribute to the baryon inventory, it is crucial to determine whether the systems are collisionally ionized or photoionized (or both). Using the identified intergalactic O VI ...

We present an analysis of the Ly? forest towards 3C 273 from the Space Telescope Imaging Spectrograph at ~7kms-1 resolution, along with reprocessed data from the Far Ultraviolet Spectroscopic Explorer. The high ultraviolet flux of 3C 273 allows us to probe the weak, low-z absorbers. The main sample consists of 21 HI absorbers that we could discriminate to ...

We present preliminary results of an ASCA observation of the Seyfert 1 galaxy, NGC 3227. The source exhibits rapid X-ray amplitude and spectral variability, the flux below 2 keV varying by a factor of approximately 3 in approximately 10,000 s while the flux in the 2-10 keV band varies by a factor of approximately 2 in the same interval. The spectrum below approximately 1 keV shows complex ...

Continuously Injected Plasma Columns Tom Pasquini, Joel Fajans Department of Physics, University of California, Berkeley, CA, 94720 Abstract. Electron plasma columns continuously injected into a Malmberg, the injections form cylinders of uniform density. As the density increases, the column s ...

We present preliminary results from a study of the stellar wind modulation of the X-ray spectrum of Vela X-1 using the broad-band (2-200 keV) data obtained in period 1988-1991 with the TTM and HEXE instruments on-board the MIR space station. We find that the hydrogen column density of the absorbing material varies from a negligible ...

We used the photometric database of the Sloan Digital Sky Survey (SDSS) to estimate the reddening of 13 SDSS quasars selected on the basis of the presence of zinc absorption lines in an intervening Damped Ly ? (DLA) system. In 5 of these quasars the reddening is detected at ?2? confidence level in two independent color indices of the SDSS ugriz photometric system. A detailed analysis of the data ...

In a previous study, Gilbert et al. derived the column density and total mass of solar prominences using a new technique, which measures how much coronal radiation in the Fe XII (195 �) spectral band is absorbed by prominence material, while considering the effects of both foreground and background radiation. In the present work, we ...

Ultraviolet spectra of the Earth's thermospheric dayglow are analyzed. The observations were made on August 10, 1982 from Poker Flats, Alaska, using a rocket-borne spectrometer that measured the wavelength range 1950 to 2170 A. This part of the spectrum is dominated by emissions from the gamma, delta, and epsilon bands of nitric oxide. Column ...

In recent years, an extremely successful method to observationally study early stages of galaxy formation has been provided by the study of quasar absorbers. Quasar absorption lines are systems intercepting our line-of-sight to a given quasar and thus produce a feature in the quasar spectrum. Damped Lyman-? systems (hereafter DLAs) have N (H I) > 2 � 1020 atoms cm-2, and ...

When chromatography is carried out with high-density carbon dioxide as the main component of the mobile phase (a method generally known as "supercritical fluid chromatography" or SFC), the required pressure gradient along the column is moderate. However, this mobile phase is highly compressible and, under certain experimental conditions, its ...

The Immobilized Cell Reactor-Separator (ICRS) consists of two column reactors: a cocurrent gas-liquid enricher followed by a countercurrent stripper. The columns are four-phase tubular reactors consisting of 1) an inert gas phase, 2) the liquid fermentation broth, 3) the solid column internal packing, and 4) the immobilized biological ...

. After passing through the absorption column, the transmitted light impinged on a sodium salycilate

In this first paper of a series, we report on the use of quasar spectra obtained with the high-resolution Ultraviolet-Visual Echelle Spectrograph (UVES) and available through the European Southern Observatory (ESO) Very Large Telescope (VLT) archive to build the first homogeneous and unbiased sample of sub-damped Lyman ? (sub-DLA) systems, absorbers with HI ...

Water sample is passed through a column containing macroreticular resin, which absorbs only nonionic

We present observations of the UV absorption lines in the Seyfert 1 galaxy NGC 3783, obtained with the medium resolution (?/??~40,000) echelle gratings of the Space Telescope Imaging Spectrograph (STIS) on the Hubble Space Telescope (HST). The spectra reveal the presence of three kinematic components of absorption in Ly?, C IV, and N V, at radial velocities of -1365, -548, and -724 km s-1 with ...

Aims: We study the properties of low-column density gas clumps in the halo of the Milky Way based on high-resolution 21-cm observations. Methods: Using interferometric data from the Westerbork Synthesis Radio Telescope (WSRT) and the Very Large Array (VLA), we studied H i emission at low-, intermediate- and high radial velocities along four lines of sight ...

A process for separation of carbon dioxide and sulfur containing compounds from a gas stream including the step of feeding the liquid physical solvent absorbent containing dissolved carbon dioxide and sulfur containing gases into the central region of a fractionating column and introducing liquid physical solvent absorbent ...

... in the following column present # < in columns 88, 94, 101 or 107 means that the upper limit of the flux density is presented in the following column. ...

How common are the building blocks of life in the Universe? We hope to further our knowledge in this field by searching QSO absorption line systems for organic molecules in extragalactic sources. Within the Milky Way, complex organic molecules are thought to be the cause of 300 absorption features known as the diffuse interstellar bands (DIBs) found mostly within the visible part of the ...

We present Suzaku observations of three iron low-ionization broad absorption line quasars (FeLoBALs). We detect J1723+5553 (3?) in the observed 2-10 keV band, and constrain its intrinsic N H column density to N H > 6 � 1023 cm�2 by modeling its X-ray hardness ratio. We study the broadband spectral index, ?ox, between the X-ray and UV bands by ...

The objective of this proposal was to measure variations in the 1/4 keV emission from the galactic halo, using ROSAT (x-ray astronomy satellite) Position Sensitive Proportional Counters (PSPC) observations toward known enhancements in the absorbing column density along the line-of-sight out of the Galaxy. Target directions were ...

The axial variation of the electron density and the neutral gas density along a mercury plasma column were measured. The electron density was determined from measurements of the shift of the resonance frequency of a cylindrical microwave cavity operating ...

We present the analysis and interpretation of a sample of nine ASCA/SAX observations of Broad Absorption Line Quasi-Stellar Objects (BALQSOs). This is the first moderate-size sample of sensitive BALQSO observations from 2--10 keV, and the BALQSOs in our sample are among the optically brightest known. Despite the ability of 2--10 keV X-rays to penetrate large column ...

The presence of Satellite Absorption Components (SACs) in the N IV spectral lines of 20 Oe stars of different spectral subtypes were analyzed and the physical parameters which characterize the corresponding N IV density regions were studied. We found that the N IV spectral lines consist of one or two Satellite Absorption Components. We calculate the values of the apparent ...

Design and analysis effort is required to initiate development of the Hydraulically Supported Absorber Ball ISS for advanced LMFBR's. Therefore, parametric evaluations are necessary through testing in a realistic hydraulic environment and physical envelop...

We analyze the Chandra High Energy Transmission Grating Spectrometer observation of the Seyfert 2 AGN IRAS 18325-5926. We detect a v = -360+41 -66 km s-1 blueshifted ionized absorber in the X-ray spectrum, with photoionization parameter log ? = 2.0+0.1 -0.1 and hydrogen column density N H = 1.55+0.75 -0.38 � 1021 cm-2. The ...

... is $50, but the high column density required for ... latter, consistent with its lower energy level being at ... The derived OH column densities will be lower ...

Slant Column Densities (SCDs). II. Subtract estimate of stratospheric SCD. III. Convert remaining tropospheric SCD to. tropospheric Vertical Column Density ...

The simultaneous separation of volatile fermentation products from product inhibited fermentations can increase the productivity of a bioreactor by reducing the product concentration in the bioreactor. In this work, a simultaneous tubular reactor separator is developed in which the volatile product is removed from the reacting broth by an inert gas phase. The immobilized cell reactor separator ...

We have studied a sample of 809 MgII absorption systems with 1.0 <=zabs<= 1.86 in the spectra of Sloan Digital Sky Survey quasi-stellar objects (QSOs), with the aim of understanding the nature and abundance of the dust and the chemical abundances in the intervening absorbers. Normalized, composite spectra were derived, for abundance measurements, for the full sample and ...

The existence of large quantities of gas that have cooled and dropped out of the hot phase in massive elliptical galaxies, groups, and clusters is the key prediction of the inhomogeneous cooling flow scenario. Using spatially resolved, deprojected ROSAT Position Sensitive Proportional Counter (PSPC) spectra of 10 of the brightest cooling flow galaxies and groups with low Galactic ...

We present results for Ly-alpha forest from 7km/s resolution data from HST+STIS for 3C 273 (z=0.158), and use complementary re-processed FUSE data to constrain higher order Lyman lines. The main sample has 38 Ly-alpha absorbers at 4.0 sigma significance with column density logNHI>12.5 over 0.020

Experimental data were taken to determine the acoustic absorbing properties of uniform low density and layered variable density samples using a bulk absober with a perforated plate facing to hold the material in place. In the layered variable density case...

We report discovery of the first metastable HeI* broad absorption line quasar using SpeX on IRTF. The blue-shifted absorption profile extends in velocity space from about -1,000 to -11,000 km/s, and it shows considerable velocity structure of the order of 1,000 km/s. The maximum apparent optical depth is 0.6. Integration over the 10830 apparent optical depth profile yields a lower limit on the ...

Results of a careful analysis of the highly ionized absorption systems, observed over the redshift range 2.198-2.2215 in the zem = 2.24 HDFS-QSO J 2233-606, are presented. The strength and covering factor of the O VI and Ne VIII absorption lines suggest that the gas is closely associated with the AGN. In addition, most of the lines show signature of partial coverage and the covering factor varies ...

A method for making density measurements in a compressible flow by using off resonance laser induced

Soft X-rays high resolution spectroscopy of obscured AGNs shows the existence of a complex soft $X$-ray spectrum dominated by emission lines of He and H-like transitions of elements from Carbon to Neon, as well as L-shell transitions due to iron ions. In this paper we characterize the XMM-Newton RGS spectrum of the Seyfert 1 galaxy NGC 4051 observed during a low flux state and infer the physical ...

Context. Soft X-ray high resolution spectroscopy of obscured AGNs shows a complex soft X-ray spectrum dominated by emission lines of He and H-like transitions of elements from carbon to neon, as well as L-shell transitions due to iron ions. Aims: In this paper we characterize the XMM-Newton RGS spectrum of the Seyfert 1 galaxy NGC 4051 observed during a low flux state and infer the physical ...

An oscillating water column (OWC) wave power absorber is one of the most promising devices, as well as the Salter Duck and the Clam. This paper presents a simple prediction method, in which the equivalent floating body approximation is used, for absorbing wave power characteristics of an oscillating water column ...

Recent results from the ROSAT All-Sky Survey have shown that broad absorption line (BAL) QSOs are either highly absorbed or underluminous in the soft X-ray bandpass. Here we extend this work by analyzing all known bona fide BAL QSOs observed within the inner 20' of the ROSAT Position Sensitive Proportional Counter. This sample includes both targeted and serendipitous exposures ...

We present a detailed analysis of the Chandra High Energy Transmission Grating Spectrometer (HETGS) and XMM-Newton high-resolution spectra of the bright Seyfert 1 galaxy, Mrk 290. The Chandra HETGS spectra reveal complex absorption features that can be best described by a combination of three ionized absorbers. The outflow velocities of these warm ...

Observations of interstellar absorptions superposed on the chromospheric Mg II emissions of nearby cool stars have been used to explore the structure of the local interstellar medium along many lines of sight. The interstellar cloud in which the sun is immersed (the local cloud, hereafter LC) has not previously been detected using this technique. These Mg II data, taken from observations and from ...

The redshifted 21-cm and Mg II absorption lines observed in the QSO 3C 286 and the BL Lacertae object 0735+178, respectively, are analyzed to determine the location of the absorbing gas. We first describe evidence which supports the presence of neutral hydrogen intrinsic to QSOs, and then examine excitation conditions influencing the formation of 21-cm absorption ...

Resonantly enhanced scattering from the iodine molecule is studied experimentally for the purpose of

We present a detailed model for the ionized absorbing gas evident in the 900 ks Chandra HETGS spectrum of NGC 3783. The analysis was carried out with PHASE, a new tool designed to model X-ray and UV absorption features in ionized plasmas. The 0.5-10 keV intrinsic continuum of the source is well represented by a single power law (?=1.53) and a soft blackbody component (kT~0.1 ...

The aim of this paper is to investigate the properties of the intervening absorbers lying along the line of sight of GRB080319B through the analysis of its optical absorption features. For this purpose, we analyse Ultraviolet and Visual Echelle Spectrograph (UVES)/Very Large Telescope multi-epoch, high-resolution spectroscopic observations (R = 40000, corresponding to 7.5 ...

Recent observations of Broad Absorption Line (BAL) quasars demonstrated that the soft X-ray emission of these objects is extremely weak, and convincing evidence for very strong absorption by a high column density (~1023.5 cm-2) was obtained for PG 1411+442, even though it is one of the few BAL QSOs strongly detected in soft X-rays. This paper examines the ...

When ozone is depleted in the stratosphere during ozone-hole period, UV-B radiation, which is normally absorbed in this region, penetrates into the troposphere. As a result, the behavior of several species in the troposphere, which interact with UV-B radiation, is likely to change. Sulfur dioxide is predominantly found in the troposphere. To study the behavior of sulfur ...

The flat spectrum compact radio source PKS 1830-211 has been suggested to be a gravitational lens candidate based on the observed double structure of the source with a separation of 1 arcsec together with an elliptical ring-like structure connecting the two components. The redshifts of the radio source PKS 1830-211 and the lens have yet to be measured since searches in the optical and IR have ...

Context. X-ray observations of unabsorbed active galactic nuclei provide an opportunity to explore the innermost regions of supermassive black hole accretion discs. Aims: Our goal in this paper is to investigate the central environment of a Seyfert 1.5 galaxy IRAS 05078+1626. Methods: We studied the time-averaged spectrum obtained with the EPIC and RGS instruments onboard XMM-Newton. Results: A ...

We have measured the two-dimensional two-point correlation function, ?AG, between low-column-density Ly? absorbers and galaxies at a redshift z ~ 1. We measured Ly? absorbers between redshifts z = 0.68 and 1.51 over a total redshift path length of ?z = 1.08 from Hubble Space Telescope Space Telescope Imaging Spectrograph E230M ...

The meaning of this quantity and the normalization can be better understood if we ... Obviously, the column density of the emitter is important also. ...

We report results from a deep search for redshifted HI 21cm absorption in 55 strong MgII?2796 absorbers (having W?27960 > 0.5�) at intermediate redshifts, 0.58 < zabs < 1.70, with the Green Bank Telescope (GBT) and the Giant Metrewave Radio Telescope (GMRT). Nine detections of HI 21cm absorption were obtained, all at 1.17 < zabs < 1.68, including three systems ...

We have used the ROSAT (1)/(4) keV all-sky survey together with H I observations to derive the total column density of hydrogen nuclei, N(H), of the Draco nebula [= G91+38 (v_LSR = -21 km s(-1) )], which casts a deep shadow in the soft X-ray background. Adopting a two-component model for the X-ray plasma in which one component is located behind the Draco ...

Apparatus for separating sharp boiling point fractions from products of cracking petroleum oil comprises a fractional condenser; a condensate outlet from the fractional condenser; a first rectifying column connected to the condensate outlet; means for taking top, bottom and side cuts from the first rectifying column; a vapor outlet from the fractional ...

Observations have cumulatively revealed the presence of blueshifted absorption features from various astrophysical objects hosting central black holes (i.e. Seyferts, quasars, galactic black holes). These are thought to be the result of absorption by specific ionic species of a wind/outflow of relatively high column density in our line of sight (LoS). ...

Lyman limit systems {LLS} are a key for understanding the transfer of ionizing radiation in the universe, the interactions between the galaxies and their environments, and the distribution of metals in the universe. Yet, they are the least understood and studied class of QSO absorbers both observationally and theoretically. This is especially true at z<2 {i.e. looking back ...

We present the analysis and interpretation of a sample of eight ASCA observations of broad absorption line quasi-stellar objects (BALQSOs). This is the first moderate-sized sample of sensitive BALQSO observations above 2 keV, and the BALQSOs in our sample are among the optically brightest known (B=14.5-18.5). Despite the ability of 2-10 keV X-rays to penetrate large column ...

We have analyzed archival Chandra and XMM-Newton data for two nearly complete homogeneously selected samples of type 2 Seyfert galaxies (Sy2s). These samples were selected based on intrinsic active galactic nuclei (AGNs) flux proxies: a mid-infrared (MIR) sample from the original IRAS 12 ?m survey and an optical ([O III]? 5007 flux limited) sample from the Sloan Digital Sky Survey, providing a ...

It has been proposed that the radio spectra of radio-quiet quasars are produced by free-free emission in the optically thin part of an accretion disc wind. An important observational constraint on this model is the observed X-ray luminosity. We investigate this constraint using a sample of Palomar-Green (PG) radio-quiet quasars for which XMM-Newton European Photon Imaging Camera (EPIC) spectra are ...

The intergalactic medium (IGM) is predominantly studied through Ly? absorption lines in the spectra of quasars and AGN (the "Ly? Forest"). Most IGM research to date has been done at z>2 where the Ly? forest is shifted within range of optical telescopes. It is only with the advent of space-based UV observatories such as HST and FUSE that the same methods can be used to survey the IGM in the ...

We present sensitive Giant Metrewave Radio Telescope (GMRT) and high-resolution Arecibo HI 21-cm observations of the damped Lyman-alpha absorber (DLA) at z=0.2212 towards OI 363 (B2 0738+313). The GMRT and Arecibo spectra are in excellent agreement and yield a spin temperature Ts = 890 +/- 160 K, consistent with earlier lower sensitivity observations of the system. This value ...

We present FUSE and HST/STIS observations of the absorber near the emission redshift of the radio-quiet, X-ray bright quasar HE0226-4110 (z=0.495). The spectra cover the rest-frame wavelength range of 610-1140A, and we detect a wide range of ionization species in the ejection velocity range 300-700 km/s, including four adjacent stages of oxygen: OIII, OIV, OV, and OVI. Strong ...

Since the recognition during the seventies of the importance played by the minor atmospheric compounds in the climate system (gases and aerosols), the studies regarding the chemistry and dynamical processes of Ozone (O3) and of nitrogen dioxide (NO2) at high and mid-latitudes, became a fruitful field of research. This work deals mainly with the retrieval and analysis of O3 and NO2 total ...

We investigate the origin and physical properties of O VI absorbers at low redshift (z= 0.25) using a subset of cosmological, hydrodynamical simulations from the OverWhelmingly Large Simulations (OWLS) project. Intervening O VI absorbers are believed to trace shock-heated gas in the warm-hot intergalactic medium (WHIM) and may thus play a key role in the ...

The emphasis of this thesis is on the gas and dust in the diffuse neutral interstellar medium. This study was conducted in two parts each of which makes use of 3.5 km s-1 resolution spectroscopic data obtained with the Goddard High Resolution Spectrograph aboard the Hubble Space Telescope. The first chapter is a detailed analysis of the gas and dust properties of the neutral ...

We present a physically based absorption-line model for the spectroscopic study of the intergalactic medium (IGM). This model adopts results from Cloudy simulations and theoretical calculations by Gnat & Sternberg to examine the resulting observational signatures of the absorbing gas with the following ionization scenarios: collisional ionization equilibrium (CIE), ...

The baryonic content of the Universe is well known from Big Bang nucleosynthesis models, deuterium abundances, and the high-redshift Lyman-? forest. However, surveys of the nearby Universe reveal a dearth of baryons in stars, galaxies, and clusters. Recent cosmological simulations have placed the most likely reservoir of baryons at low redshift---upward of 40%---in moderately overdense (? ...

Development of robust protocols for use in mapping shallow water habitats using hyperspectral imagery requires knowledge of absorbing and scattering features present in the environment. These include, but are not limited to, water quality parameters, phytoplankton concentrations and species, submerged aquatic vegetation (SAV) species and densities, ...

We present far-ultraviolet (1245-1680 �), high-resolution ( R � 3 km s-1 ) spectroscopic observations of three early-type stars (HD 32630, HD 158427, and HD 175191) located within 75 pc of the Sun recorded with the recently refurbished HST-STIS instrument. These data have allowed an absorption study of the local interstellar gas to investigate some of its physical, chemical, and kinematic ...

Outflows in Active Galactic Nuclei (AGN) play an important role in the evolution of their host galaxy and on the enrichment of the intergalactic medium. In the X-ray range, the outflows appear as a warm absorber (WA) gas displaying high bulk velocities. The Absorption Measure Distribution (AMD) method provides a new handle on constraining the physics of the WA. Here, we ...

Results from BeppoSAX observations of Compton-thick Seyfert 2 galaxies are summarized and reviewed, and their general properties derived and discussed. In five out of the seven observed sources, the nucleus is directly visible at high X-ray energies, where the photons penetrate absorbers with column densities in the range ...

We present a study of 25 z < 0.4 intergalactic absorption systems with detections of three or more metal ions using spectra of 17 quasars from the Far Ultraviolet Spectroscopic Explorer and the E140M mode of the HST/Space Telescope Imaging Spectrograph. Previously, we characterized the component structure of the absorption in several ions, O VI, N V, C IV/C III/C II, Si IV/Si III/Si II, S IV/S ...

There has been a renewed interest in searching for diffuse interstellar bands (DIBs) due to their probable connection to organic molecules and, thus, their possible link to life in the Universe. Within the Milky Way there have been more than 300 DIBs discovered to date; most of the DIBs are seen in the visible part of the electromagnetic spectrum. Although abundant in the Milky Way, DIBs have only ...

We investigate the effect of two important, but of neglected, factors which can affect the detectability of HI 21-cm absorption in MgII absorption systems. The effect of line-of-sight geometry on the coverage of the background radio flux and any possible correlation between the 21-cm line strength and the rest-frame equivalent width of the MgII 2796 � line, as is seen in the case of damped Lyman ...

Seagrasses are ecologically important but extremely vulnerable to anthropogenic modifications of the coastal zone that affect light availability within these unique ecosystems. Strongly pigmented seagrass leaves can extend for more than 1 m above the substrate and biomass is distributed unevenly throughout the canopy. in this study, light attenuation in a 7 m water column that ...

... absorbing cell; Ne, X=594.5 nm. 217 Page 3. The density of absorbing atoms, calculated by References expression A = 0, 2T2 (A ...

Link between absorber and thermometer can be a fourth important component ... Thus the link between the absorber and the thermometer ...

the method to the epi-cadmium capture rates at various radii of uranium rods .... the correct capture rate C in an absorber of atom density N and volume V. ...

The behavior of the density profile behind a strong airblast and its scaling with yield in the form of approximate analytical formulae are summarized, and then are applied to obtain the time histories of air column densities out to various radii from the ...

Here we present the results of a Suzaku observation of the broad-line radio galaxy 3C 445. We confirm the results obtained with the previous X-ray observations which unveiled the presence of several soft X-ray emission lines and an overall X-ray emission which strongly resembles a typical type 2 Seyfert galaxy despite of the optical classification as an unobscured active galactic nucleus. The ...

We present an analysis of three strong, intervening Mg II absorption systems (zabs = 0.603, 0.656, 1.107) towards the optical afterglow of gamma-ray burst (GRB) 060418. From high-resolution Ultraviolet and Visual Echelle Spectrograph (UVES) spectra we measure metal column densities and find that the highest redshift absorber exhibits a ...

Aims: We present a 0.2-200 keV broadband study of absorbed Active Galactic Nuclei (AGN) observed with INTEGRAL, XMM-Newton, Chandra, and ASCA to investigate the continuum shape and the absorbing/reflecting medium properties. Methods: The sources are selected in the INTEGRAL AGN sample to have a 20-100 keV flux below 8� 10-11 erg cm-2 s-1 (5 mCrab), and ...

We present an H I 21 cm absorption survey with the Green Bank Telescope (GBT) of galaxy-quasar pairs selected by combining galaxy data from the Sloan Digital Sky Survey (SDSS) and radio sources from the Faint Images of the Radio Sky at Twenty-Centimeters (FIRST) survey. Our sample consists of 23 sight lines through 15 low-redshift foreground galaxy-background quasar pairs with impact parameters ...

... distances beyond 300 RE be- hind the Earth, the electron densities are uniform. We compute the average electron column density (TEC) in ...

ment density of the structural model on the mechanical and thermal ... first two stress columns represent the high element density areas ...

We present evidence for X-ray line emitting and absorbing gas in the nucleus of the broad-line radio galaxy 3C 445. A 200 ks Chandra Low Energy Transmission Grating observation of 3C 445 reveals the presence of several highly ionized emission lines in the soft X-ray spectrum, primarily from the He- and H-like ions of O, Ne, Mg, and Si. Radiative recombination emission is ...

We argue that most strong intervening metal absorption line systems, where the rest equivalent width of the Mg II ?2796 line is >0.5 �, are interstellar material in, and outflowing from, star-forming disks. We show that a version of the Kennicutt-Schmidt law is readily obtained if the Mg II equivalent widths are interpreted as kinematic broadening from absorbing gas in ...

We present Suzaku observations of three iron low-ionization broad absorption line quasars (FeLoBALs), SDSS J0943+5417, J1352+4239, and J1723+5553. We detect J1723+5553 (3\\sigma) in the observed 3-10 keV band, and constrain its intrinsic NH column density to NH > 7e23 cm^-2, by modeling its X-ray hardness ratio. This is only the second detection in the ...

We present an analysis of 60 spectra of 27 Seyfert galaxies observed with the Ginga Large Area proportional Counter (LAC). The 2-10 keV continuum is found to be compatible with previous spectral surveys, but a spectral flattening, or `hard tail', is evident above 10 keV. Excess absorption over the Galactic column density is found in around half of the ...

We perform a series of cosmological simulations using Enzo, an Eulerian adaptive-mesh refinement, N-body + hydrodynamical code, applied to study the warm/hot intergalactic medium (WHIM). The WHIM may be an important component of the baryons missing observationally at low redshift. We investigate the dependence of the global star formation rate and mass fraction in various baryonic phases on ...

We perform a series of cosmological simulations using Enzo, an Eulerian adaptive-mesh refinement, N-body + hydrodynamical code, applied to study the warm/hot intergalactic medium. The WHIM may be an important component of the baryons missing observationally at low redshift. We investigate the dependence of the global star formation rate and mass fraction in various baryonic phases on spatial ...

We present the 0.1-200 keV BeppoSAX spectrum of MR 2251-178observed at two epochs in 1998 separated by 5 months. Both epochs show identical spectral shape and X-ray flux. Analysis of the combined spectra allow us to confirm the presence of the ionized Fe Kalpha line detected by ASCA and to test the presence of reflection from ionized material. The best self-consistent spectral fit is obtained when ...

A previous four-year study of fatal automobile accidents has shown that the steering assembly-the column and steering wheel rim--ranked high as one of the major causes of fatzal and serious injuries to drivers in automobile crashes. These studies indicate...

A procedure is proposed for the prediction of concentration profiles for a countercurrent ion-exchange absorption column, use being made of equilibrium and kinetic data derived from small-scale batch tests. A comparison is presented between the prediction...

The ion cyclotron wave is generated in a plasma by an induction coil (Stix-type coil) wrapped around the plasma column. The absorbed rf power spectrum is estimated on the basis of the linearized VlasovMaxwell equations by taking into account of the variat...

... provide refuge for water column grazers (i.e., regenerators, Klarer and Millie 1994) and absorb NH4+ mineralized ... ...

Values for the maximum frequency up to which cyclotron radiation in the accretion columns of magnetic degenerate stars is self-absorbed are presented and the results applied to the Am Herculis binaries and Hercules X-1.

Over the last years, ground-based multi-axis differential absorption spectroscopy (MAXDOAS) has been proved to be a very promising tool for the automated retrieval of tropospheric pollutants. The MAXDOAS instruments are designed to allow for the quasi simultaneous observation of the scattered sun light in a range of different line-of-sight (LOS) directions from the horizon to the zenith, resulting ...

This paper reports dual-epoch, Very Long Baseline Array observations of H I absorption toward 3C 147. One of these epochs (2005) represents new observations, while one (1998) represents the reprocessing of previous observations to obtain higher signal-to-noise results. Significant H I opacity and column density variations, both spatially and temporally, ...

. After passing through the absorption column, the transmitted light impinged on a sodium salycilate

The Ozone Monitoring Instrument (OMI), which is on the EOS AURA satellite, retrieves vertical column

... Title : Analysis of Water Column Stability Using Shipboard and Submarine Density and Shear Measurements. Descriptive Note : Master's thesis,. ...

density of structural defects. These defects lie along the [0001] direction delineating the boundaries of the individual columns. The AIN columns have a ...

... used. 2. Columns with density less than NTHRSH are considered sparse and are packed in a conventional column list. For ...

Bright soil and sand surfaces of the arid environments in the UAE have much ...... absorbing aerosol (Mexico City, Beijing and the Maldives) the slope as a ...

Mar 2, 2010 ... Explanation: An eerie blue glow and ominous columns of dark dust ... The dark filamentary dust not only absorbs light, but also reflects the light ...

... methods of soil application of termiticides to prevent structural infestation. The breakthrough of bromide and fluorescein in column eluates were measured. The absorbance of fluorescein at ... ...

We use a new approach to obtain limits on the absorbing columns towards an initial sample of 10 long

Jun 25, 2009... intensity of light filtering through a given column of atmosphere. Aerosol particles scatter or absorb portions of the incoming light, ...

A device incorporating a crushable honeycomb column as the energy dissipating mechanism was designed

... coluui to remove any nonspecifically absorbed proteins. ... SWAM0 silica- supported hydrophilic polymer column ... A single major protein Peak detected ...

... joule/kilogram (J/kg) (radiation dose absorbed) 1.000000 Gray (Gy) ... The Kumer and James model relies on parametric descriptions of column ...

... inch 0. D. aluminum columns packed with 60-80 mesh Chromosorb P (acid washed) on which was absorbed 20% (by weight) Carbowax ZOM were ...

The X-ray spectra of two intermediate-type Seyfert galaxies are investigated using ASCA observations separated by more than 1 yr. Both NGC 4388 and ESO 103-G35 exhibit strong, narrow Fe Kalpha line emission and absorption by cold neutral gas with a column density ~10^23 cm^-2, characteristic of the X-ray spectra of type 2 Seyfert galaxies. The power-law ...

We conducted a systematic search for signatures of the Intergalactic Medium (IGM) 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. We present a search algorithm, and criteria for distinguishing candidates from spurious Lyman a forest lines. In addition, we compare our ...

The critical masses, the fast and slow neutron flux distributions, and the fast and slow adjoint functions are calculated for Pool Test Reactor having D/ sub 2/O thermal columns of 7 different diameters, 3 with a central H/sub 2/O column. The sensitivities of PTR to fissionable samples, and absorbers as well as the mean ...

With the goal of investigating the nature of OVI absorbers at high redshifts, we study the effects of proximity to the background quasar. In a sample of 16 quasars at zQSO between 2.14 and 2.87 observed at high signal-to-noise ratio and 6.6 kms-1 resolution with the Very Large Telescope/Ultraviolet and Visual Echelle Spectrograph (VLT/UVES), we detect 35 OVI absorption-line ...

Using the state-of-the-art cosmological hydrodynamic simulations of the standard cold dark matter model with star formation feedback strength normalized to match the observed star formation history of the universe at z= 0-6, we compute the metal-enrichment history of the intergalactic medium (IGM). Overall we show that galactic superwind (GSW) feedback from star formation can transport metals to ...

O VI absorption is observed in a wide range of astrophysical environments, including the local interstellar medium, the disk and halo of the Milky Way, high-velocity clouds, the Magellanic Clouds, starburst galaxies, the intergalactic medium (IGM), damped Ly? systems, and gamma-ray-burst host galaxies. Here, a new compilation of 775 O VI absorbers drawn from the literature is ...

GRB 070125 is among the most energetic bursts detected and the most extensively observed so far. Nevertheless, unresolved issues are still open in the literature on the physics of the afterglow and on the gamma-ray burst (GRB) environment. In particular, GRB 070125 was claimed to have exploded in a galactic halo environment, based on the uniqueness of the optical spectrum and the non-detection of ...