scholarly journals A Comparison of Three Regions of Puppis A

1990 ◽  
Vol 115 ◽  
pp. 172-175
Author(s):  
K.F. Fischbach ◽  
L.M. Bateman ◽  
C.R. Canizares ◽  
T.H. Markert ◽  
P.J. Saez
Keyword(s):  
High Resolution ◽  
Shock Front ◽  
Electron Temperature ◽  
Plasma Diagnostics ◽  
Column Density ◽  
Equilibrium Analysis ◽  
Ionization Equilibrium ◽  
X Ray ◽  
Hydrogen Column Density ◽  
Non Equilibrium

AbstractHigh resolution X-ray spectral observations of Puppis A were performed with the FPCS on the Einstein Observatory at three regions of the remnant: the shock front, the bright eastern knot, and the interior. Plasma diagnostics of lines from OVII and OVIII constrain the values of electron temperature, ionization timescale, and hydrogen column density. We compare results of the diagnostics for these three regions. A non-equilibrium analysis of previously published fluxes of oxygen lines shows that the interior has not yet reached ionization equilibrium.

scholarly journals Plasma Diagnostics with X-ray Lines of Oxygen in Puppis A

1988 ◽  
Vol 101 ◽  
pp. 153-156 ◽  
Author(s):  
Kathryn F. Fischbach ◽  
Claude R. Canizares ◽  
Thomas H. Markert ◽  
Joan M. Coyne
Keyword(s):  
High Resolution ◽  
Plasma Diagnostics ◽  
Column Density ◽  
X Ray ◽  
Hydrogen Column Density

AbstractHigh resolution X-ray spectral observations of Puppis A were performed with the FPCS on Einstein. We use plasma diagnostics of lines from OVII and OVIII to constrain the values of temperature, ionization timescale, and hydrogen column density.

scholarly journals Non-Equilibrium Ionization in Puppis A

1983 ◽  
Vol 101 ◽  
pp. 245-252
Author(s):  
P. F. Winkler ◽  
C. R. Canizares ◽  
B. C. Bromley
Keyword(s):  
High Resolution ◽  
Spectroscopic Data ◽  
Supernova Remnant ◽  
Optical Data ◽  
Equilibrium Conditions ◽  
X Ray ◽  
Flux Measurements ◽  
Far From Equilibrium ◽  
Einstein Observatory ◽  
Non Equilibrium

High resolution X-ray spectroscopy of the brightest knot of emission in the Puppis A supernova remnant shows that it is made up of ionizing plasma, far from equilibrium. Flux measurements in several X-ray lines enable us to determine the non-equilibrium conditions: electron temperature, ion populations, and time since the knot was heated by the supernova shock. Imaging and spectroscopic data from the Einstein Observatory together suggest that this knot is a cloud of density about 10 cm−3 which has recently been shocked to a temperature 7 × 106 K. Radio and optical data on the region appear consistent with this picture.

Tracing Small-Scale Fluctuations in the Soft X-ray Background

1997 ◽  
Vol 166 ◽  
pp. 321-324
Author(s):  
R. Warwick ◽  
I. Hutchinson ◽  
R. Willingale ◽  
K. Kuntz ◽  
S. Snowden
Keyword(s):  
Column Density ◽  
Galactic Halo ◽  
Inverse Correlation ◽  
Line Of Sight ◽  
Small Scale ◽  
X Ray ◽  
Hydrogen Column Density ◽  
X Ray Background ◽  
Counting Statistics ◽  
Made In

AbstractAn overlapping set of ROSAT PSPC observations made in a region of very low Galactic foreground column density, has been used to investigate variations in the soft X-ray background on angular scales of 15′ – 5°. In the ¼ keV band there is a clear inverse correlation of the count-rate with the line-of-sight hydrogen column density. However, after correcting for this absorption effect, strong residual fluctuations remain in the data, with an amplitude which is significantly larger than that due to the counting statistics or the confusion of unresolved discrete sources. In contrast a similar analysis for the ¾ and 1.5 keV ROSAT bands shows no evidence for an excess signal. The most likely origin of the ¼ keV fluctuations would seem to be in a patchy distribution of ~ 106 K gas in the Galactic halo.

scholarly journals The Zone of Avoidance as an X-ray absorber - the role of the galactic foreground modelling Swift XRT spectra

2017 ◽  
Vol 12 (S333) ◽  
pp. 170-171
Author(s):  
I. I. Racz ◽  
Z. Bagoly ◽  
L. V. Tóth ◽  
L. G. Balázs ◽  
I. Horvath ◽  
...  
Keyword(s):  
Column Density ◽  
Large Scale ◽  
Gamma Ray ◽  
Small Scale ◽  
Prompt Gamma ◽  
Gamma Emission ◽  
Essential Information ◽  
X Ray ◽  
Hydrogen Column Density ◽  
Zone Of Avoidance

AbstractGamma-ray bursts (GRBs) are the most powerful explosive events in the Universe. The prompt gamma emission is followed by an X-ray afterglow that is also detected for over nine hundred GRBs by the Swift BAT and XRT detectors. The X-ray afterglow spectrum bears essential information about the burst, and the surrounding interstellar medium (ISM). Since the radiation travels through the line of sight intergalactic medium and the ISM in the Milky Way, the observed emission is influenced by extragalactic and galactic components. The column density of the Galactic foreground ranges several orders of magnitudes, due to both the large scale distribution of ISM and its small scale structures. We examined the effect of local HI column density on the penetrating X-ray emission, as the first step towards a precise modeling of the measured X-ray spectra. We fitted the X-ray spectra using the Xspec software, and checked how the shape of the initially power low spectrum changes with varying input Galactic HI column density. The total absorbing HI column is a sum of the intrinsic and Galactic component. We also investigated the model results for the intrinsic component varying the Galactic foreground. We found that such variations may alter the intrinsic hydrogen column density up to twenty-five percent. We will briefly discuss its consequences.

High resolution wavelength dispersive X-ray spectroscopy for ECR plasma diagnostics

1996 ◽  
Vol 99 (1) ◽  
pp. 235-241 ◽  
Author(s):  
U. Lehnert ◽  
C. Zippe ◽  
G. Zschornack
Keyword(s):  
High Resolution ◽  
Plasma Diagnostics ◽  
X Ray ◽  
Ecr Plasma

High‐resolution duo‐multichannel soft x‐ray spectrometer for tokamak plasma diagnostics

1987 ◽  
Vol 58 (9) ◽  
pp. 1601-1615 ◽  
Author(s):  
J. L. Schwob ◽  
A. W. Wouters ◽  
S. Suckewer ◽  
M. Finkenthal
Keyword(s):  
High Resolution ◽  
Plasma Diagnostics ◽  
Tokamak Plasma ◽  
X Ray

scholarly journals New Chandra/HST-STIS Results on Seyfert I AGN: Photoionized Outflows

2003 ◽  
Vol 214 ◽  
pp. 259-264
Author(s):  
Barry McKernan ◽  
Tahir Yaqoob
Keyword(s):  
High Resolution ◽  
Column Density ◽  
Emission Lines ◽  
High Resolution Spectroscopy ◽  
Type I ◽  
Ionization State ◽  
X Ray ◽  
Spectral Signatures

We present soft X-ray results from observations with Chandra (HETGS) of the Seyfert I AGN NGC 4593 and Mrk 509. We discuss the photoionized outflows associated with Seyfert I AGN in terms of their absorption spectral signatures and discuss their kinematics, column density and ionization state. We discuss the link between UV and X-ray absorbers in Mrk 509 (which was simultaneously observed with Chandra and HST-STIS). We also briefly discuss the possibility of absorption due to neutral Fe embedded in the warm absorber of NGC 4593 versus an interpretation of the data in terms of soft X-ray relativistic emission lines. We conclude with a summary of what is being learnt about warm absorbers in type I AGN from high resolution spectroscopy.

scholarly journals The X-shooter GRB afterglow legacy sample (XS-GRB)

2019 ◽  
Vol 623 ◽  
pp. A92 ◽  
Author(s):  
J. Selsing ◽  
D. Malesani ◽  
P. Goldoni ◽  
J. P. U. Fynbo ◽  
T. Krühler ◽  
...  
Keyword(s):  
Selection Criteria ◽  
Column Density ◽  
Neutral Hydrogen ◽  
Cosmic Time ◽  
Late Time ◽  
Host Galaxies ◽  
X Ray ◽  
Hydrogen Column Density ◽  
X Ray Absorption

In this work we present spectra of all γ-ray burst (GRB) afterglows that have been promptly observed with the X-shooter spectrograph until 31/03/2017. In total, we have obtained spectroscopic observations of 103 individual GRBs observed within 48 hours of the GRB trigger. Redshifts have been measured for 97 per cent of these, covering a redshift range from 0.059 to 7.84. Based on a set of observational selection criteria that minimise biases with regards to intrinsic properties of the GRBs, the follow-up effort has been focused on producing a homogeneously selected sample of 93 afterglow spectra for GRBs discovered by the Swift satellite. We here provide a public release of all the reduced spectra, including continuum estimates and telluric absorption corrections. For completeness, we also provide reductions for the 18 late-time observations of the underlying host galaxies. We provide an assessment of the degree of completeness with respect to the parent GRB population, in terms of the X-ray properties of the bursts in the sample and find that the sample presented here is representative of the full Swift sample. We have constrained the fraction of dark bursts to be <28 per cent and confirm previous results that higher optical darkness is correlated with increased X-ray absorption. For the 42 bursts for which it is possible, we have provided a measurement of the neutral hydrogen column density, increasing the total number of published HI column density measurements by ∼33 per cent. This dataset provides a unique resource to study the ISM across cosmic time, from the local progenitor surroundings to the intervening Universe.

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