395 citations · 5.4k across the 130 of their papers we have counts for
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On the origin of radio emission in radio quiet quasars
Ari Laor, Ehud Behar
The radio emission in radio loud quasars originates in a jet carrying relativistic electrons. In radio quiet quasars (RQQs) the relative radio emission is ~10^3 times weaker, and i…
The X-Ray Spectrum of a Planetary Nebula at High Resolution: Chandra Gratings Spectroscopy of BD+30 3639
Young Sam Yu, Raanan Nordon, Joel H. Kastner +3
We present the results of the first X-ray gratings spectroscopy observations of a planetary nebula (PN), the X-ray-bright, young BD+30 3639. We observed BD+30 3639 for a total of 3…
A high-velocity transient outflow in Eta Carinae
Ehud Behar, Raanan Nordon, Noam Soker
We analyze velocity profiles of the X-ray spectral lines emitted by the Eta Carinae stellar binary at four epochs, just before the X-ray minimum (associated with periastron) and mo…
Absorption Measure Distribution of the Outflow in IRAS 13349+2438: Direct Observation of Thermal Instability?
Tomer Holczer, Ehud Behar, Shai Kaspi
We analyze the Chandra X-ray spectrum obtained with the HETGS grating spectrometer of IRAS 13349+2438, which has one of the richest absorption spectra of a quasar outflow. Absorpti…
Chemical Abundances in AGN Environment: X-Ray/UV Campaign on the MRK 279 Outflow
Nahum Arav, Jack R. Gabel, Kirk T. Korista +11
We present the first reliable determination of chemical abundances in an AGN outflow. The abundances are extracted from the deep and simultaneous FUSE and HST/STIS observations of…
X-Ray Emission from Planetary Nebulae Calculated by 1D Spherical Numerical Simulations
Muhammad Akashi, Noam Soker, Ehud Behar +1
We calculate the X-ray emission from both constant and time evolving shocked fast winds blown by the central stars of planetary nebulae (PNs) and compare with observations. Using s…
Hubble Space Telescope Ultraviolet Spectroscopy of Fourteen Low-Redshift Quasars
Rajib Ganguly, Michael S. Brotherton, Nahum Arav +35
We present low-resolution ultraviolet spectra of 14 low redshift (z<0.8) quasars observed with HST/STIS as part of a Snap project to understand the relationship between quasar outf…
High-resolution X-ray Spectroscopy of BD +30 3639
Joel H. Kastner, Young Sam Yu, John Houck +3
We present preliminary results from the first X-ray gratings spectrometer observations of a planetary nebula (PN). We have used the Chandra X-ray Observatory Low Energy Transmissio…
A hot transient outflow from eta Carinae
Ehud Behar, Raanan Nordon, Eyal Ben-Bassat +1
eta Carinae is a stellar binary system with a period of 5.54 years. It harbors one of the brightest and most massive stars in our galaxy. This paper presents spectroscopic evidence…
Accretion onto the Companion of Eta Carinae During the Spectroscopic Event: III. the He II 4686 Line
Noam Soker, Ehud Behar
We continue to explore the accretion model of the massive binary system eta Carinae by studying the anomalously high He II 4686 line. The line appears just before periastron and di…
Inner-shell Absorption Lines of Fe~VI-- Fe~XVI: A Many-body Perturbation Theory Approach
Ming F. Gu, Tomer Holczer, Ehud Behar +1
We provide improved atomic calculation of wavelengths, oscillator strengths, and autoionization rates relevant to the inner-shell transitions of Fe~VI--XVI, the so-called…
The High-Velocity Outflow of PG 1211+143: An Unbiased View Based on Several Observations
Shai Kaspi, Ehud Behar
We present and discuss high-resolution grating spectra of the quasar PG1211+143 obtained over three years. Based on an early observation from 2001, we find an outflow component of…
Principal component analysis of the X-ray variability in NGC 7469
A. J. Blustin, S. V. Fuerst, G. Branduardi-Raymont +3
We apply Principal Component Analysis (PCA) to study the variability of the X-ray continuum in the Seyfert 1 galaxy NGC 7469. The PCA technique is used to separate out linear compo…
The High-Velocity Outflow of PG1211+143 May Not be That Fast
Shai Kaspi, Ehud Behar
We analyze the X-ray spectrum of the quasar PG1211+143 observed with the CCD and grating spectrometers on board XMM-Newton. Using an ion by ion fitting model we find an outflow com…
Accretion onto the Companion of Eta Carinae During the Spectroscopic Event: II. X-Ray Emission Cycle
Muhammad Akashi, Noam Soker, Ehud Behar
We calculate the X-ray luminosity and light curve for the stellar binary system Eta Carinae for the entire orbital period of 5.54 years. By using a new approach we find, as suggest…
X-Ray Emission by A Shocked Fast Wind from the Central Stars of Planetary Nebulae
Muhammad Akashi, Noam Soker, Ehud Behar
We calculate the X-ray emission from the shocked fast wind blown by the central stars of planetary nebulae (PNs) and compare with observations. Using spherically symmetric self sim…
Simultaneous Ultraviolet and X-ray Observations of the Seyfert Galaxy NGC 4151. I. Physical Conditions in the X-ray Absorbers
S. B. Kraemer, I. M. George, D. M. Crenshaw +9
We present a detailed analysis of the intrinsic X-ray absorption in the Seyfert 1 galaxy NGC 4151 using Chandra/HETGS data obtained 2002 May, as part of a program which included si…
Is The Fe M-shell Absorber Part of The Outflow in Active Galactic Nuclei?
Tomer Holczer, Ehud Behar, Shai Kaspi
The X-ray emission of many active galactic nuclei (AGNs) is absorbed between 15 and 17 Angstrom by means of unresolved (inner-shell) transition arrays (UTAs) of Fe M-shell ions. Th…
Laboratory Measurement and Theoretical Modeling of K-shell X-ray Lines from Inner-shell Excited and Ionized Ions of Oxygen
Ming Feng Gu, Mike Schmidt, Peter Beiersdorfer +5
We present high resolution laboratory spectra of K-shell X-ray lines from inner-shell excited and ionized ions of oxygen, obtained with a reflection grating spectrometer on the ele…
X-ray/UV Observing Campaign on the Mrk 279 AGN Outflow: A Global Fitting Analysis of the UV Absorption
Jack R. Gabel, Nahum Arav, Jelle S. Kaastra +12
We present an analysis of the intrinsic UV absorption in the Seyfert 1 galaxy Mrk 279 based on simultaneous long observations with the Hubble Space Telescope (41 ks) and the Far Ul…
Resolving X-ray sources from B-stars spectroscopically: The example of mu Lep
Ehud Behar, Maurice Leutenegger, Rami Doron +4
We present high-resolution X-ray observations of the chemically peculiar late-type B-star: mu Lep. However, we find spectroscopic and astrometric evidence, which show that the X-ra…
The Ionized Gas and Nuclear Environment in NGC 3783. IV. Variability and Modeling of the 900 ks CHANDRA Spectrum
H. Netzer, S. Kaspi, E. Behar +12
We present a detailed spectral analysis of the data obtained from NGC 3783 during the period 2000-2001 using Chandra. This analysis leads us to the following results. 1) NGC 3783 f…
A Long Look at NGC 3783 with the XMM-Newton Reflection Grating Spectrometers
Ehud Behar, Andrew P. Rasmussen, Alexander J. Blustin +5
A long 280 ks observation of the Seyfert 1 galaxy NGC 3783 with XMM-Newton is reported. We focus on the oxygen line complex between 17 and 24 A as measured with the RGS spectromete…
Chandra LETGS and XMM-Newton observations of NGC 4593
K. C. Steenbrugge, J. S. Kaastra, A. J. Blustin +6
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 Spectromet…